The overarching goal of this study is to offer an effective and sustainable solution to the challenges of sanitation in rural and school settings in the northern region of Senegal. The study explores a wastewater trea...The overarching goal of this study is to offer an effective and sustainable solution to the challenges of sanitation in rural and school settings in the northern region of Senegal. The study explores a wastewater treatment approach based on phytoremediation, with a particular focus on the use of horizontally-flowing reed bed filters. Furthermore, it aims to adapt and optimize these systems for the specific needs of Senegal, focusing on wastewater in school environments. Thus, we constructed a horizontally-flowing reed bed filter, planted with Typha, at the Ndiébène Gandiol school in Senegal. We will investigate the efficiency of wastewater treatment by this horizontally-flowing reed bed filter, emphasizing the role of the plant used: Typha. The filter is described in detail, specifying its dimensions, its composition of flint gravel, and the choice of plants, namely Typha. The experimental protocol is detailed, describing the sampling at the entrance and exit of the filter to evaluate water quality. The parameters analyzed include Chemical Oxygen Demand (COD), Biochemical Oxygen Demand over 5 days (BOD5), suspended solids, ammonium, nitrates, phosphates, pH, conductivity, and fecal coliforms. The results indicate a significant improvement in water quality after treatment. COD, BOD5, suspended solids, and fecal coliforms are greatly reduced, thus demonstrating the efficacy of the Typha filter. However, nitrate concentrations remain relatively stable, suggesting room for improvement in their elimination. A perspective of reuse of the treated water is considered, showing that the effluents from the planted filter meet Senegalese and international standards for irrigation. The findings suggest that these waters could be used for a variety of crops, thereby reducing the pressure on freshwater resources. In conclusion, the Typha-based filtration system shows promising results for improving water quality in this region of Senegal. However, adjustments are necessary for more effective nitrate removal. This study paves the way for sustainable use of treated wastewater for irrigation, thus contributing to food security and the preservation of water resources.展开更多
Confronted with the challenge of wastewater management, particularly in the school environment of Senegal, our study set out to achieve multiple objectives. Following field surveys, laboratory analyses of wastewater s...Confronted with the challenge of wastewater management, particularly in the school environment of Senegal, our study set out to achieve multiple objectives. Following field surveys, laboratory analyses of wastewater samples were carried out, revealing a significant pollutant load. In the community of Gandiol, near Saint-Louis (Senegal), the school of Ndiebene Gandiol 1 faces significant sanitation challenges. Our study aimed to address this issue by using a constructed filter composed of two filtering bed cells measuring 12 × 8.5 m, preceded by a septic tank. We particularly focused on the influence of Vetiver;a plant chosen for its purification potential. Our analyses showed remarkable efficiency of the filter. Elimination rates reached 95% for 5-Day Biochemical Oxygen Demand (BOD5), 91% for Chemical Oxygen Demand (COD), and 92% for SS, far exceeding the Senegalese standards set at 50 mg/L, 200 mg/L, and 40 mg/L, respectively. Furthermore, the concentration of fecal coliforms was reduced to 176 FCU/100mL, well below the Senegalese threshold of 2000 FCU/100mL and close to the World Health Organization’s (WHO) recommendation of 1000 FCU/100mL. However, despite these promising results, some parameters, particularly the concentration of certain pollutants, approached the thresholds defined by European legislation. For example, for Suspended Solids (SS), the post-treatment level of 3 mg/L was well below the Senegalese standard but edged close to the European minimum of 10 mg/L. In conclusion, the Vetiver filter demonstrated a remarkable ability to treat school wastewater, offering high pollutant elimination percentages. These results suggest significant opportunities for the reuse of treated water, potentially in areas such as irrigation, though some adjustments may be necessary to meet the strictest standards such as those of the European union (EU).展开更多
In Saint-Louis, Senegal, a constructed wetland with horizontal flow reed beds (FHa and FHb) has demonstrated significant efficacy in treating municipal wastewater. Analyzing various treatment stages, the system showed...In Saint-Louis, Senegal, a constructed wetland with horizontal flow reed beds (FHa and FHb) has demonstrated significant efficacy in treating municipal wastewater. Analyzing various treatment stages, the system showed only a slight temperature variation, from an influent average of 26.3°C to an effluent of 24.7°C. Electrical conductivity decreased from 1331 mS/cm to 974.5 mS/cm post-primary treatment, with suspended solids (SS) dramatically reduced from 718.9 mg/L to 5.7 mg/L in the final effluent. Biochemical oxygen demand (BOD5) and chemical oxygen demand (COD) saw a notable decrease, from initial levels of 655.6 mg/L and 1240 mg/L to 2.3 mg/L and 71.3 mg/L, respectively. Nitrogenous compounds (N-TN) and phosphates () also decreased significantly, indicating the system’s nutrient removal capacity. Microbiological analysis revealed a reduction in fecal coliforms from 7.5 Ulog/100ml to 1.8 Ulog/100ml and a complete elimination of helminth eggs. The presence of Phragmites and Typha was instrumental in enhancing these reductions. The system’s compliance with the Senegalese standards for disposal into natural environments, WHO recommendations for unrestricted water reuse in irrigation, and the European legislation for water reuse was established. The effluent quality met the stringent criteria for various classes of agricultural reuse, illustrating the system’s potential for sustainable water management. This wetland model presents a robust solution for water-stressed regions, ensuring environmental protection while supporting agricultural needs. The study calls for ongoing research to further refine the system for optimal, reliable wastewater treatment and water resource sustainability.展开更多
Glucocorticoids(GCs) are a group of endocrine-disrupting compounds(EDCs) frequently prescribed against various medical conditions.Recently,GCs have been shown to be effective in managing septic shock in patients infec...Glucocorticoids(GCs) are a group of endocrine-disrupting compounds(EDCs) frequently prescribed against various medical conditions.Recently,GCs have been shown to be effective in managing septic shock in patients infected with the 2019 novel coronavirus(COVID-19).Due to colossal consumption and potential risks to aquatic organisms,GCs have immensely attracted the focus of the scientific research community as a water pollutant.Therefore,the aim of this paper is to review the current knowledge on the occurrence of various GCs in the aquatic environment and their removal during wastewater treatment.A variety of GCs are ubiquitous in surface water,hospital wastewater,and sewage water worldwide.And the minimum concentration in volume is below 0.01 ng/L,and the maximum one is 10 000 ng/L,and enter the environment through hospital and urban wastewater discharging.Compared with natural GCs,higher risks to aquatic environments could be induced by synthetic GCs.The current activated sludge processes used in wastewater treatment plants(WWTPs) are not fully effective in eliminating GCs,some of which may further increase the risk of GC in the environment.In comparison with the aerobic process in WWTPs,the anaerobic and anoxic processes were found to be more efficient for GC degradation.Of the studied GCs,fluticasone propionate,clobetasol propionate,fluocinolone acetonide,and triamcinolone acetonide need more attention due to their low removal efficiencies and strong toxicity.Among the advanced treatment processes,reverse osmosis,ultraviolet irradiation,CaO_(2),and plasma could achieve significant GC activity removal while micro/ultra-filtration,chlorination,and ozonation were less efficient.展开更多
Water pollution is an increasingly serious environmental problem because many pollutants have carcinogenic effects on humans and aquatic organisms.Metal organic framework(MOF),made up of metal ions and multifunctional...Water pollution is an increasingly serious environmental problem because many pollutants have carcinogenic effects on humans and aquatic organisms.Metal organic framework(MOF),made up of metal ions and multifunctional organic ligands,has been one of the most concerned materials because of its adjustable and regular pore structure.MOFs have always shown attractive advantages in membrane separation and adsorption technologies,among which water-stable MOFs are particularly prominent in wastewater treatment(WWT)applications.This review systematically summarizes the application of MOF membranes in membrane filtration,membrane pervaporation and membrane distillation.Also,the adsorption mechanisms of heavy metals,dyes and antibacterials in wastewater have been concluded.In order to tap the full application potential of pristine MOFs in sustainable wastewater treatment,current challenges are discussed in detail and future research directions are proposed.展开更多
There have been many studies on life cycle assessment in sewage treatment,but there are scarce few studies on the treatment of industrial wastewater in combination with advanced oxidation technology,especially in cata...There have been many studies on life cycle assessment in sewage treatment,but there are scarce few studies on the treatment of industrial wastewater in combination with advanced oxidation technology,especially in catalytic wet air oxidation(CWAO).There are no cases of using actual industrialized data onto life cycle assessment.This paper uses Simapro 9.0 software to establish a life cycle assessment model for the treatment of high-concentration organic wastewater by CWAO,and comprehensively explains the impact on the environment from three aspects:the construction phase,the operation phase and the demolition phase.In addition,sensitivity analysis and uncertainty analysis were performed.The results showed that the key factors affecting the environment were marine ecotoxicity,mineral resource consumption and global warming,the operation stage had the greatest impact on the environment,which was related to high power consumption during operation and emissions from the treatment process.Sensitivity analysis showed that electricity consumption has the greatest impact on abiotic depletion and freshwater aquatic ecotoxicity,and it also proved that global warming is mainly caused by pollutant emissions during operation phase.Monte Carlo simulations found slightly higher uncertainty for abiotic depletion and toxicity-related impact categories.展开更多
Electrocoagulation is progressively becoming an ecologically friendly water treatment method owing to its lack of secondary pollution,high active ingredient concentration,high treatment effectiveness,simple equipment,...Electrocoagulation is progressively becoming an ecologically friendly water treatment method owing to its lack of secondary pollution,high active ingredient concentration,high treatment effectiveness,simple equipment,and simplicity of automated control implementation.Herein,electrocoagulation is offered as a method for treating wastewater containing azo dyes using a revolutionary flexible electronic fabric that can be mass-producible at a reasonable price.A computer-controlled machine embroiders 316L stainless steel fiber(316L SSF)onto an insulating fabric to manufacture a flexible electronic device of cathode and anode with a monopolar arrangement on the fabric surface.Using methyl orange(MO)solution to simulate azo dye wastewater,the decolorization rate of 500 ml MO reached 99.25% under the conditions of 50 mg·L^(-1)initial mass concentration,120 min electrolysis time,15 mA·g^(-1)current density,1 cm electrode spacing,0.1 mol·L^(-1)NaCl,pH 7.6,200 r·min^(-1)rotational speed of the stirrer,and 22-25℃ room temperature.In addition,it is feasible to embroider flexible electronic fabrics with varied sizes and numbers of electrodes based on the amount of treated sewage to increase the degradation rate,which has significant practical application value.展开更多
This study examined the application of co-benefit-type wastewater treatment technology in the fish-processing industry. Given that there was a dearth of information on fish-processing industrial wastewater in Indonesi...This study examined the application of co-benefit-type wastewater treatment technology in the fish-processing industry. Given that there was a dearth of information on fish-processing industrial wastewater in Indonesia, site surveys were conducted. For the entire fish-processing industry throughout the country, the dissemination rate of wastewater treatment facilities was less than 50%. Using a co-benefit approach, a real-scale swim-bed technology (SBT) and a system combining an anaerobic baffled reactor (ABR) with SBT (ABR–SBT) were installed in a fishmeal processing factory in Bali, Indonesia, and the wastewater system process performance was evaluated. In a business-as-usual scenario, the estimated chemical oxygen demand load and greenhouse gas (GHG) emissions from wastewater from the Indonesian fish-processing industry were 33 000 tons per year and 220 000 tons of equivalent CO_(2) per year, respectively. On the other hand, the GHG emissions in the co-benefit scenarios of the SBT system and ABR–SBT system were 98 149 and 26 720 tons per year, respectively. Therefore, introducing co-benefit-type wastewater treatment to Indonesia’s fish-processing industry would significantly reduce pollution loads and GHG emissions.展开更多
In this research, the quality of the wastewater discharged into the environment has been investigated. The effluent from solar desalination pond contains large amounts of TDS (3.68 grams per liter) and TH (6.50 grams ...In this research, the quality of the wastewater discharged into the environment has been investigated. The effluent from solar desalination pond contains large amounts of TDS (3.68 grams per liter) and TH (6.50 grams per liter). Since the use of filter is not economical in this case, three types of commercial coagulants such as aluminum sulfate, ferric chloride and ferric sulfide have been used in this study. The main parameters such as effectiveness of three inorganic coagulants, ammonium sulfate, ferric sulfate, and ferric chloride, which separately help to remove hardness, have been studied. According to the results, using laboratory test, 25/g of ferric sulfate as coagulant is best coagulant mass and the ratio of 4 to 3 for auxiliary coagulant (sodium carbonate and sodium hydroxide) to coagulant will be best ratio. Also, the mixing rate of 120 rpm in the first reactor will give the best mixing speed. These conditions will lead to 0.348 grams per liter of TDS, 0.345 grams per liter of TH and 0.195 grams per liter of calcium hardness and 300 micro Siemens electrical conductivity of the purified sample.展开更多
The aim of this work is the purification of wastewater by double filtration on granular activated carbon prepared from peanut shells. The samples of carbonized peanut shells were activated with 35% sulfuric acid and f...The aim of this work is the purification of wastewater by double filtration on granular activated carbon prepared from peanut shells. The samples of carbonized peanut shells were activated with 35% sulfuric acid and finally, we proceeded to the purification tests on double filtration of wastewater. Granular activated carbons (GAC) were very effective for the treatment of turbidity, dissolved oxygen, suspended solids, iron, COD and BOD5 but the best results were observed with nitrite, nitrate and phosphate. However, the second filtration was the most efficient while the lowest rates were observed for pH (17.91% on average), and conductivity (29.71% on average). In addition, this work has allowed increasing the dissolved oxygen by more than 50.16% at the exit of the first filter and more than 105.36% at the exit of the second filter. This study shows that granular activated carbon prepared from peanut shells could be a credible alternative for developing countries in the control of pollution and environmental protection.展开更多
Waste water treatment process(WWTP)control has been attracting more and more attention.However,various undesired factors,such as disturbance,uncertainties,and strong nonlinear couplings,propose big challenges to the c...Waste water treatment process(WWTP)control has been attracting more and more attention.However,various undesired factors,such as disturbance,uncertainties,and strong nonlinear couplings,propose big challenges to the control of a WWTP.In order to improve the control performance of the closed-loop system and guarantee the discharge requirements of the effluent quality,rather than take the model dependent control approaches,an active disturbance rejection control(ADRC)is utilized.Based on the control signal and system output,a phase optimized ADRC(POADRC)is designed to control the dissolved oxygen and nitrate concentration in a WWTP.The phase advantage of the phase optimized extended state observer(POESO),convergence of the POESO,and stability of the closed-loop system are analyzed from the theoretical point of view.Finally,a commonly accepted benchmark simulation model no.1.(BSM1)is utilized to test the POESO and POADRC.Linear active disturbance rejection control(LADRC)and the suggested proportion-integration(PI)control are taken to make a comparative research.Both system responses and performance index values confirm the advantage of the POADRC over the LADRC and the suggested PI control.Numerical results show that,as a result of the leading phase of the total disturbance estimation,the POESO based POADRC is an effective and promising way to control the dissolved oxygen and nitrate concentration so as to ensure the effluent quality of a WWTP.展开更多
The most abundant natural biopolymer on earth, cellulose fiber, may offer a highly efficient, low-cost, and chemical-free option for wastewater treatment. Cellulose is widely distributed in plants and several marine a...The most abundant natural biopolymer on earth, cellulose fiber, may offer a highly efficient, low-cost, and chemical-free option for wastewater treatment. Cellulose is widely distributed in plants and several marine animals. It is a carbohydrate polymer consisting of β-1,4-linked anhydro-D-glucose units with three hydroxyl groups per anhydroglucose unit(AGU). Cellulose-based materials have been used in food, industrial, pharmaceutical, paper, textile production, and in wastewater treatment applications due to their low cost, renewability,biodegradability, and non-toxicity. For water treatment in the oil and gas industry, cellulose-based materials can be used as adsorbents, flocculants, and oil/water separation membranes. In this review, the uses of cellulose-based materials for wastewater treatment in the oil & gas industry are summarized, and recent research progress in the following aspects are highlighted: crude oil spill cleaning, flocculation of solid suspended matter in drilling or oil recovery in the upstream oil industry, adsorption of heavy metal or chemicals, and separation of oil/water by cellulosic membrane in the downstream water treatment.展开更多
Microplastics, plastic pieces of ≤5 mm in size, are ubiquitous in ther environment and can be found in both terrestrial and aquatic ecosystems. This manuscript reviews the literature on the fate of microplastics in w...Microplastics, plastic pieces of ≤5 mm in size, are ubiquitous in ther environment and can be found in both terrestrial and aquatic ecosystems. This manuscript reviews the literature on the fate of microplastics in wastewater treatment and briefly highlights novel developments in the removal of microplastics from aqueous systems.展开更多
Despite the number of studies focusing on the financial analysis of production activities, conducting on technical solutions, and improving water quality, no study has been conducted on the application of economic ins...Despite the number of studies focusing on the financial analysis of production activities, conducting on technical solutions, and improving water quality, no study has been conducted on the application of economic instruments that apply to water quality management in craft villages, and several studies of WTP also. This study aimed to estimate the households’ willingness-to-pay for wastewater treatment in selected traditional agro-food processing villages in Nhue-Day River Basin, Vietnam. A pilot Choice Experiment (CE) technique in Choice Modelling (CM) approach was applied for this study with 267 selected agro-food processing households by using the conditional logit (CL) and random parameter logit (RPL) models. The results showed that total annual environmental fee for wastewater treatment from agro-food processing households is estimated as 1089 million VND (equal to US$47,868 per year) for the total of 902 agro-food processing households in three research sites in Nhue-Day River Basin. This estimated budget for wastewater treatment accounted for 55.85% of total annual operation and maintenance costs only. In addition, the technology is improved to enable 90% of treated wastewater. Overall, the results of this study suggest the new wastewater treatment plant construction and improved wastewater collection system by increasing the investment in order to improve the water quality in Nhue-Day River Basin that brings about the reducing environmental degradation, biodiversity loss and human health risks.展开更多
Adsorption is a unit operation widely used for the tertiary treatment of the most diverse effluents,whose mechanism is based on removing recalcitrant compounds from the organic and inorganic origin.In this process,cho...Adsorption is a unit operation widely used for the tertiary treatment of the most diverse effluents,whose mechanism is based on removing recalcitrant compounds from the organic and inorganic origin.In this process,choosing a suitable adsorbent is a fundamental point.This review article focuses on the adsorbents with natural geological origin:minerals,clays,geopolymers,and even wastes resulted from mining activity.Therefore,over 450 articles and research papers were explored.These materials’main sources are described,and their characteristics,composition,and intrinsic properties are related to adsorption.Herein,we discuss the effects of several process parameters,such as p H,temperature,pollutant,and adsorbent concentration.Furthermore,equilibrium,kinetics,and thermodynamic aspects are also addressed,and relevant regeneration prospects and final disposal.Finally,some suggestions and perspectives on applying these adsorbents in wastewater treatment are presented as future trends.展开更多
Nitrogen removal is a critical process in water treatment plants(WIPs)and wastewater treatment plants(WWTPs).The recent discovery of a novel bacterial process,complete ammonia oxidation(comammox,CMX),has refuted a cen...Nitrogen removal is a critical process in water treatment plants(WIPs)and wastewater treatment plants(WWTPs).The recent discovery of a novel bacterial process,complete ammonia oxidation(comammox,CMX),has refuted a century-long perception of the two-step conversion of NH3to NO3-.Compared with canonical nitrifiers,CMX bacteria offer undeniable advantages,such as a high growth yield propensity and adaptability to nutrient-and growth-limiting conditions,which collectively draw attention to validate the aptness of CMX bacteria to wastewater treatment.As there has been no comprehensive review on the relevance of CMX bacteria for sustainable water and wastewater treatment,this review is intended to discuss the roles and applications of CMX in the removal of nitrogen and pollutants from water and wastewater.We took into account insights into the metabolic versatilities of CMX bacteria at the clade and subclade levels.We focused on the distribution of CMX bacteria in engineered systems,niche differentiation,co-occurrence and interactions with cano nical nitrifiers for a better understanding of CMX bacteria in terms of their ecophysiology.Conceptualized details on the reactor adaptability and stress response of CMX bacteria are provided.The potential of CMX bacteria to degrade micropollutants either directly or co-metabolically was evaluated,and these insights would be an indispensable advantage in opening the doors for wider applications of CMX bacteria in WWTPs.Finally,we summarized future directions of research that are imperative in improving the understanding of CMX biology.展开更多
A bacterium strain HS-03 was isolated from the activated sludge plant in a suburb of Wuhan city, China which has been found to be capable of aerobic denitrification. The effect of different inoculated amounts of pre-c...A bacterium strain HS-03 was isolated from the activated sludge plant in a suburb of Wuhan city, China which has been found to be capable of aerobic denitrification. The effect of different inoculated amounts of pre-cultured media was analyzed. The denitrifying rates of this strain under aerobic and micro-anaerobic conditions were compared. The result indicated that the rate was almost not affected by the presence of oxygen. 10m M nitrate was removed more than 90% in 36 hours by this bacterium in the specific medium. During the denitrifying process, nitrite was always kept at very low level. The denitrification potential of this bacterium was evaluated to treat artificial wastewater under fully aerobic conditions. Main biochemical and physiological features of this strain were characterized. The 16S rDNA sequence was compared with the published data in GenBank by using BLAST. The BLAST level of similarity to Pseudomonas stutzeri was 99.1%. These results of phenotype and genotype proved that the strain HS-03 was a new strain belonging to the species of P. stutzeri.展开更多
Small wastewater treatment plants (WWTP) are frequently located, by necessity, in remote and isolated sites, which increases the difficulty of its energy supply. Some of them are located near the seaside, in environme...Small wastewater treatment plants (WWTP) are frequently located, by necessity, in remote and isolated sites, which increases the difficulty of its energy supply. Some of them are located near the seaside, in environmental sensible zones, and due to tourism activity of these sites, seasonal effects related with population size fluctuation can occur, which can originate certain inefficiencies concerning WWTP design and energy supply. The objective of this paper is to describe a step by step procedure for evaluation of the wind potential of sites that are dependent of in-situ energy generation, as well as, a case study on the utilization of the potential wind energy in Magoito WWTP (5000 p.e.). The employed methodology comprised the collection of one year of in-situ wind data and its validation by comparison with historical data of about 10 years of a nearby anemometric station. The data provided by the two anemometric stations was statistically treated. It allowed the analysis of the results from the two stations are promissory in terms of wind availability and velocity. Finally, it comprised the simulation of the local wind conditions for a considerable larger area in order to find the best site for locating a wind turbine.展开更多
Before the construction of the Kuching Centralized Wastewater Treatment System Package 1 (KCWTSP1), partially treated blackwater and greywater were discharged directly into natural waterways. The accumulated wastewate...Before the construction of the Kuching Centralized Wastewater Treatment System Package 1 (KCWTSP1), partially treated blackwater and greywater were discharged directly into natural waterways. The accumulated wastewater had polluted Sarawak river, which is regulated and cannot discharge freely into the South China Sea. The polluted Sarawak river has endangered human health, river water quality, and aquatic ecosystems. Hence, the KCWTSP1 commissioned in 2015 serves the purpose of removing pollutants from wastewater before it is discharged into natural waterways. However, the effectiveness of KCWTPP1 is unknown. This paper is aimed to discuss and review the effectiveness of KCWTPP1 in treating wastewater since its inception in 2015. From 2017 to 2020, KCWTPP1 has treated an average of 4,200,000 m<sup>3</sup> of wastewater per year. Generally, most of the discharge effluent met Environmental Quality Act (1974) Standard A criteria, except for the oil and grease parameter. Initially, the plant could not treat suspended solids and total phosphorus, but this was greatly improved in subsequent years. Therefore, some improvements are required to treat oil and grease parameters effectively and efficiently to ensure that only Standard A effluent is discharged into the Sarawak River in the future.展开更多
The question of wastewater treatment and control is reflected from a very specific viewpoint: the low priority given to accurate and useful measurements within wastewater treatment. The matter is discussed from four v...The question of wastewater treatment and control is reflected from a very specific viewpoint: the low priority given to accurate and useful measurements within wastewater treatment. The matter is discussed from four various perspectives, that may be labelled “Legal understanding”;“Needs for accurate measurement results already in the planning and design stage”;“The measurement problem and human behaviour”;“The understanding of the short term and long term dynamics and changes in pollution and flow loads on a wastewater treatment plant (WWTP)”. All these aspects bring about much improved needs for an accurate and frequent measurement scheme both for pollutants and flows entering a WWTP. The conclusion is stated as follows: A far more and well elaborated on-line measurement system at the plants would become a needed tool for improved water environment protection at lower costs.展开更多
文摘The overarching goal of this study is to offer an effective and sustainable solution to the challenges of sanitation in rural and school settings in the northern region of Senegal. The study explores a wastewater treatment approach based on phytoremediation, with a particular focus on the use of horizontally-flowing reed bed filters. Furthermore, it aims to adapt and optimize these systems for the specific needs of Senegal, focusing on wastewater in school environments. Thus, we constructed a horizontally-flowing reed bed filter, planted with Typha, at the Ndiébène Gandiol school in Senegal. We will investigate the efficiency of wastewater treatment by this horizontally-flowing reed bed filter, emphasizing the role of the plant used: Typha. The filter is described in detail, specifying its dimensions, its composition of flint gravel, and the choice of plants, namely Typha. The experimental protocol is detailed, describing the sampling at the entrance and exit of the filter to evaluate water quality. The parameters analyzed include Chemical Oxygen Demand (COD), Biochemical Oxygen Demand over 5 days (BOD5), suspended solids, ammonium, nitrates, phosphates, pH, conductivity, and fecal coliforms. The results indicate a significant improvement in water quality after treatment. COD, BOD5, suspended solids, and fecal coliforms are greatly reduced, thus demonstrating the efficacy of the Typha filter. However, nitrate concentrations remain relatively stable, suggesting room for improvement in their elimination. A perspective of reuse of the treated water is considered, showing that the effluents from the planted filter meet Senegalese and international standards for irrigation. The findings suggest that these waters could be used for a variety of crops, thereby reducing the pressure on freshwater resources. In conclusion, the Typha-based filtration system shows promising results for improving water quality in this region of Senegal. However, adjustments are necessary for more effective nitrate removal. This study paves the way for sustainable use of treated wastewater for irrigation, thus contributing to food security and the preservation of water resources.
文摘Confronted with the challenge of wastewater management, particularly in the school environment of Senegal, our study set out to achieve multiple objectives. Following field surveys, laboratory analyses of wastewater samples were carried out, revealing a significant pollutant load. In the community of Gandiol, near Saint-Louis (Senegal), the school of Ndiebene Gandiol 1 faces significant sanitation challenges. Our study aimed to address this issue by using a constructed filter composed of two filtering bed cells measuring 12 × 8.5 m, preceded by a septic tank. We particularly focused on the influence of Vetiver;a plant chosen for its purification potential. Our analyses showed remarkable efficiency of the filter. Elimination rates reached 95% for 5-Day Biochemical Oxygen Demand (BOD5), 91% for Chemical Oxygen Demand (COD), and 92% for SS, far exceeding the Senegalese standards set at 50 mg/L, 200 mg/L, and 40 mg/L, respectively. Furthermore, the concentration of fecal coliforms was reduced to 176 FCU/100mL, well below the Senegalese threshold of 2000 FCU/100mL and close to the World Health Organization’s (WHO) recommendation of 1000 FCU/100mL. However, despite these promising results, some parameters, particularly the concentration of certain pollutants, approached the thresholds defined by European legislation. For example, for Suspended Solids (SS), the post-treatment level of 3 mg/L was well below the Senegalese standard but edged close to the European minimum of 10 mg/L. In conclusion, the Vetiver filter demonstrated a remarkable ability to treat school wastewater, offering high pollutant elimination percentages. These results suggest significant opportunities for the reuse of treated water, potentially in areas such as irrigation, though some adjustments may be necessary to meet the strictest standards such as those of the European union (EU).
文摘In Saint-Louis, Senegal, a constructed wetland with horizontal flow reed beds (FHa and FHb) has demonstrated significant efficacy in treating municipal wastewater. Analyzing various treatment stages, the system showed only a slight temperature variation, from an influent average of 26.3°C to an effluent of 24.7°C. Electrical conductivity decreased from 1331 mS/cm to 974.5 mS/cm post-primary treatment, with suspended solids (SS) dramatically reduced from 718.9 mg/L to 5.7 mg/L in the final effluent. Biochemical oxygen demand (BOD5) and chemical oxygen demand (COD) saw a notable decrease, from initial levels of 655.6 mg/L and 1240 mg/L to 2.3 mg/L and 71.3 mg/L, respectively. Nitrogenous compounds (N-TN) and phosphates () also decreased significantly, indicating the system’s nutrient removal capacity. Microbiological analysis revealed a reduction in fecal coliforms from 7.5 Ulog/100ml to 1.8 Ulog/100ml and a complete elimination of helminth eggs. The presence of Phragmites and Typha was instrumental in enhancing these reductions. The system’s compliance with the Senegalese standards for disposal into natural environments, WHO recommendations for unrestricted water reuse in irrigation, and the European legislation for water reuse was established. The effluent quality met the stringent criteria for various classes of agricultural reuse, illustrating the system’s potential for sustainable water management. This wetland model presents a robust solution for water-stressed regions, ensuring environmental protection while supporting agricultural needs. The study calls for ongoing research to further refine the system for optimal, reliable wastewater treatment and water resource sustainability.
基金National Natural Science Foundation of China (No. 52270062)Natural Science Foundation of Shanghai,China (No. 22ZR1402800)+1 种基金Shanghai Rising-Star Program,China (No. 23QC1400800)Shenzhen Science and Technology Program,China (No. JSGG20220606141402005)。
文摘Glucocorticoids(GCs) are a group of endocrine-disrupting compounds(EDCs) frequently prescribed against various medical conditions.Recently,GCs have been shown to be effective in managing septic shock in patients infected with the 2019 novel coronavirus(COVID-19).Due to colossal consumption and potential risks to aquatic organisms,GCs have immensely attracted the focus of the scientific research community as a water pollutant.Therefore,the aim of this paper is to review the current knowledge on the occurrence of various GCs in the aquatic environment and their removal during wastewater treatment.A variety of GCs are ubiquitous in surface water,hospital wastewater,and sewage water worldwide.And the minimum concentration in volume is below 0.01 ng/L,and the maximum one is 10 000 ng/L,and enter the environment through hospital and urban wastewater discharging.Compared with natural GCs,higher risks to aquatic environments could be induced by synthetic GCs.The current activated sludge processes used in wastewater treatment plants(WWTPs) are not fully effective in eliminating GCs,some of which may further increase the risk of GC in the environment.In comparison with the aerobic process in WWTPs,the anaerobic and anoxic processes were found to be more efficient for GC degradation.Of the studied GCs,fluticasone propionate,clobetasol propionate,fluocinolone acetonide,and triamcinolone acetonide need more attention due to their low removal efficiencies and strong toxicity.Among the advanced treatment processes,reverse osmosis,ultraviolet irradiation,CaO_(2),and plasma could achieve significant GC activity removal while micro/ultra-filtration,chlorination,and ozonation were less efficient.
基金supported by the National Natural Science Foundation of China (NSFC-U1904215)Natural Science Foundation of Jiangsu Province (BK20200044)Changjiang scholars program of the Ministry of Education (Q2018270).
文摘Water pollution is an increasingly serious environmental problem because many pollutants have carcinogenic effects on humans and aquatic organisms.Metal organic framework(MOF),made up of metal ions and multifunctional organic ligands,has been one of the most concerned materials because of its adjustable and regular pore structure.MOFs have always shown attractive advantages in membrane separation and adsorption technologies,among which water-stable MOFs are particularly prominent in wastewater treatment(WWT)applications.This review systematically summarizes the application of MOF membranes in membrane filtration,membrane pervaporation and membrane distillation.Also,the adsorption mechanisms of heavy metals,dyes and antibacterials in wastewater have been concluded.In order to tap the full application potential of pristine MOFs in sustainable wastewater treatment,current challenges are discussed in detail and future research directions are proposed.
基金supported by National Natural Science Foundation of China(52100072,52100213)the Fundamental Research FundsfortheCentralUniversities(JZ2021HGTA0159,JZ2021HGQA0212)+2 种基金the Strategic Priority Research Program of the Chinese Academy of Sciences(XDA21021101)the Scientific Research Common Program of Beijing Municipal Commission of Education(KM202010017006)the Beijing Natural Science Foundation(8214056)。
文摘There have been many studies on life cycle assessment in sewage treatment,but there are scarce few studies on the treatment of industrial wastewater in combination with advanced oxidation technology,especially in catalytic wet air oxidation(CWAO).There are no cases of using actual industrialized data onto life cycle assessment.This paper uses Simapro 9.0 software to establish a life cycle assessment model for the treatment of high-concentration organic wastewater by CWAO,and comprehensively explains the impact on the environment from three aspects:the construction phase,the operation phase and the demolition phase.In addition,sensitivity analysis and uncertainty analysis were performed.The results showed that the key factors affecting the environment were marine ecotoxicity,mineral resource consumption and global warming,the operation stage had the greatest impact on the environment,which was related to high power consumption during operation and emissions from the treatment process.Sensitivity analysis showed that electricity consumption has the greatest impact on abiotic depletion and freshwater aquatic ecotoxicity,and it also proved that global warming is mainly caused by pollutant emissions during operation phase.Monte Carlo simulations found slightly higher uncertainty for abiotic depletion and toxicity-related impact categories.
基金financial support from the National Natural Science Foundation of China(31872901)Major State Basic Research Development Program of China(2016YFA0501602)。
文摘Electrocoagulation is progressively becoming an ecologically friendly water treatment method owing to its lack of secondary pollution,high active ingredient concentration,high treatment effectiveness,simple equipment,and simplicity of automated control implementation.Herein,electrocoagulation is offered as a method for treating wastewater containing azo dyes using a revolutionary flexible electronic fabric that can be mass-producible at a reasonable price.A computer-controlled machine embroiders 316L stainless steel fiber(316L SSF)onto an insulating fabric to manufacture a flexible electronic device of cathode and anode with a monopolar arrangement on the fabric surface.Using methyl orange(MO)solution to simulate azo dye wastewater,the decolorization rate of 500 ml MO reached 99.25% under the conditions of 50 mg·L^(-1)initial mass concentration,120 min electrolysis time,15 mA·g^(-1)current density,1 cm electrode spacing,0.1 mol·L^(-1)NaCl,pH 7.6,200 r·min^(-1)rotational speed of the stirrer,and 22-25℃ room temperature.In addition,it is feasible to embroider flexible electronic fabrics with varied sizes and numbers of electrodes based on the amount of treated sewage to increase the degradation rate,which has significant practical application value.
文摘This study examined the application of co-benefit-type wastewater treatment technology in the fish-processing industry. Given that there was a dearth of information on fish-processing industrial wastewater in Indonesia, site surveys were conducted. For the entire fish-processing industry throughout the country, the dissemination rate of wastewater treatment facilities was less than 50%. Using a co-benefit approach, a real-scale swim-bed technology (SBT) and a system combining an anaerobic baffled reactor (ABR) with SBT (ABR–SBT) were installed in a fishmeal processing factory in Bali, Indonesia, and the wastewater system process performance was evaluated. In a business-as-usual scenario, the estimated chemical oxygen demand load and greenhouse gas (GHG) emissions from wastewater from the Indonesian fish-processing industry were 33 000 tons per year and 220 000 tons of equivalent CO_(2) per year, respectively. On the other hand, the GHG emissions in the co-benefit scenarios of the SBT system and ABR–SBT system were 98 149 and 26 720 tons per year, respectively. Therefore, introducing co-benefit-type wastewater treatment to Indonesia’s fish-processing industry would significantly reduce pollution loads and GHG emissions.
文摘In this research, the quality of the wastewater discharged into the environment has been investigated. The effluent from solar desalination pond contains large amounts of TDS (3.68 grams per liter) and TH (6.50 grams per liter). Since the use of filter is not economical in this case, three types of commercial coagulants such as aluminum sulfate, ferric chloride and ferric sulfide have been used in this study. The main parameters such as effectiveness of three inorganic coagulants, ammonium sulfate, ferric sulfate, and ferric chloride, which separately help to remove hardness, have been studied. According to the results, using laboratory test, 25/g of ferric sulfate as coagulant is best coagulant mass and the ratio of 4 to 3 for auxiliary coagulant (sodium carbonate and sodium hydroxide) to coagulant will be best ratio. Also, the mixing rate of 120 rpm in the first reactor will give the best mixing speed. These conditions will lead to 0.348 grams per liter of TDS, 0.345 grams per liter of TH and 0.195 grams per liter of calcium hardness and 300 micro Siemens electrical conductivity of the purified sample.
文摘The aim of this work is the purification of wastewater by double filtration on granular activated carbon prepared from peanut shells. The samples of carbonized peanut shells were activated with 35% sulfuric acid and finally, we proceeded to the purification tests on double filtration of wastewater. Granular activated carbons (GAC) were very effective for the treatment of turbidity, dissolved oxygen, suspended solids, iron, COD and BOD5 but the best results were observed with nitrite, nitrate and phosphate. However, the second filtration was the most efficient while the lowest rates were observed for pH (17.91% on average), and conductivity (29.71% on average). In addition, this work has allowed increasing the dissolved oxygen by more than 50.16% at the exit of the first filter and more than 105.36% at the exit of the second filter. This study shows that granular activated carbon prepared from peanut shells could be a credible alternative for developing countries in the control of pollution and environmental protection.
基金supported by the Key program of Beijing Municipal Education Commission(KZ201810011012)National Natural Science Foundation of China(61873005)Support Project of High-level Teachers in Beijing Municipal Universities in the Period of 13th Fiveyear Plan(CIT&TCD201704044)。
文摘Waste water treatment process(WWTP)control has been attracting more and more attention.However,various undesired factors,such as disturbance,uncertainties,and strong nonlinear couplings,propose big challenges to the control of a WWTP.In order to improve the control performance of the closed-loop system and guarantee the discharge requirements of the effluent quality,rather than take the model dependent control approaches,an active disturbance rejection control(ADRC)is utilized.Based on the control signal and system output,a phase optimized ADRC(POADRC)is designed to control the dissolved oxygen and nitrate concentration in a WWTP.The phase advantage of the phase optimized extended state observer(POESO),convergence of the POESO,and stability of the closed-loop system are analyzed from the theoretical point of view.Finally,a commonly accepted benchmark simulation model no.1.(BSM1)is utilized to test the POESO and POADRC.Linear active disturbance rejection control(LADRC)and the suggested proportion-integration(PI)control are taken to make a comparative research.Both system responses and performance index values confirm the advantage of the POADRC over the LADRC and the suggested PI control.Numerical results show that,as a result of the leading phase of the total disturbance estimation,the POESO based POADRC is an effective and promising way to control the dissolved oxygen and nitrate concentration so as to ensure the effluent quality of a WWTP.
基金financially supported by PetroChina Scientific Research and Technology Development Project, China (2018A-0907, YGJ2019-11-01)the support from CFI and NSERC, Canada
文摘The most abundant natural biopolymer on earth, cellulose fiber, may offer a highly efficient, low-cost, and chemical-free option for wastewater treatment. Cellulose is widely distributed in plants and several marine animals. It is a carbohydrate polymer consisting of β-1,4-linked anhydro-D-glucose units with three hydroxyl groups per anhydroglucose unit(AGU). Cellulose-based materials have been used in food, industrial, pharmaceutical, paper, textile production, and in wastewater treatment applications due to their low cost, renewability,biodegradability, and non-toxicity. For water treatment in the oil and gas industry, cellulose-based materials can be used as adsorbents, flocculants, and oil/water separation membranes. In this review, the uses of cellulose-based materials for wastewater treatment in the oil & gas industry are summarized, and recent research progress in the following aspects are highlighted: crude oil spill cleaning, flocculation of solid suspended matter in drilling or oil recovery in the upstream oil industry, adsorption of heavy metal or chemicals, and separation of oil/water by cellulosic membrane in the downstream water treatment.
文摘Microplastics, plastic pieces of ≤5 mm in size, are ubiquitous in ther environment and can be found in both terrestrial and aquatic ecosystems. This manuscript reviews the literature on the fate of microplastics in wastewater treatment and briefly highlights novel developments in the removal of microplastics from aqueous systems.
基金Southeast Asia Regional Center for Graduate Study and Research Agriculture(SEARCA)provide me the financial support to conduct this research.
文摘Despite the number of studies focusing on the financial analysis of production activities, conducting on technical solutions, and improving water quality, no study has been conducted on the application of economic instruments that apply to water quality management in craft villages, and several studies of WTP also. This study aimed to estimate the households’ willingness-to-pay for wastewater treatment in selected traditional agro-food processing villages in Nhue-Day River Basin, Vietnam. A pilot Choice Experiment (CE) technique in Choice Modelling (CM) approach was applied for this study with 267 selected agro-food processing households by using the conditional logit (CL) and random parameter logit (RPL) models. The results showed that total annual environmental fee for wastewater treatment from agro-food processing households is estimated as 1089 million VND (equal to US$47,868 per year) for the total of 902 agro-food processing households in three research sites in Nhue-Day River Basin. This estimated budget for wastewater treatment accounted for 55.85% of total annual operation and maintenance costs only. In addition, the technology is improved to enable 90% of treated wastewater. Overall, the results of this study suggest the new wastewater treatment plant construction and improved wastewater collection system by increasing the investment in order to improve the water quality in Nhue-Day River Basin that brings about the reducing environmental degradation, biodiversity loss and human health risks.
基金the funding agencies CAPES,CNPq,and FAPERGS for financial support。
文摘Adsorption is a unit operation widely used for the tertiary treatment of the most diverse effluents,whose mechanism is based on removing recalcitrant compounds from the organic and inorganic origin.In this process,choosing a suitable adsorbent is a fundamental point.This review article focuses on the adsorbents with natural geological origin:minerals,clays,geopolymers,and even wastes resulted from mining activity.Therefore,over 450 articles and research papers were explored.These materials’main sources are described,and their characteristics,composition,and intrinsic properties are related to adsorption.Herein,we discuss the effects of several process parameters,such as p H,temperature,pollutant,and adsorbent concentration.Furthermore,equilibrium,kinetics,and thermodynamic aspects are also addressed,and relevant regeneration prospects and final disposal.Finally,some suggestions and perspectives on applying these adsorbents in wastewater treatment are presented as future trends.
基金supported by the National Natural Science Foundation of China(52000185 and 51878675)Key Research and Development Program of Shandong Province(2019JZZY020308)China Postdoctoral Science Foundation,China(2017M612807)。
文摘Nitrogen removal is a critical process in water treatment plants(WIPs)and wastewater treatment plants(WWTPs).The recent discovery of a novel bacterial process,complete ammonia oxidation(comammox,CMX),has refuted a century-long perception of the two-step conversion of NH3to NO3-.Compared with canonical nitrifiers,CMX bacteria offer undeniable advantages,such as a high growth yield propensity and adaptability to nutrient-and growth-limiting conditions,which collectively draw attention to validate the aptness of CMX bacteria to wastewater treatment.As there has been no comprehensive review on the relevance of CMX bacteria for sustainable water and wastewater treatment,this review is intended to discuss the roles and applications of CMX in the removal of nitrogen and pollutants from water and wastewater.We took into account insights into the metabolic versatilities of CMX bacteria at the clade and subclade levels.We focused on the distribution of CMX bacteria in engineered systems,niche differentiation,co-occurrence and interactions with cano nical nitrifiers for a better understanding of CMX bacteria in terms of their ecophysiology.Conceptualized details on the reactor adaptability and stress response of CMX bacteria are provided.The potential of CMX bacteria to degrade micropollutants either directly or co-metabolically was evaluated,and these insights would be an indispensable advantage in opening the doors for wider applications of CMX bacteria in WWTPs.Finally,we summarized future directions of research that are imperative in improving the understanding of CMX biology.
基金National Natural Science Foundation of China No.3017001
文摘A bacterium strain HS-03 was isolated from the activated sludge plant in a suburb of Wuhan city, China which has been found to be capable of aerobic denitrification. The effect of different inoculated amounts of pre-cultured media was analyzed. The denitrifying rates of this strain under aerobic and micro-anaerobic conditions were compared. The result indicated that the rate was almost not affected by the presence of oxygen. 10m M nitrate was removed more than 90% in 36 hours by this bacterium in the specific medium. During the denitrifying process, nitrite was always kept at very low level. The denitrification potential of this bacterium was evaluated to treat artificial wastewater under fully aerobic conditions. Main biochemical and physiological features of this strain were characterized. The 16S rDNA sequence was compared with the published data in GenBank by using BLAST. The BLAST level of similarity to Pseudomonas stutzeri was 99.1%. These results of phenotype and genotype proved that the strain HS-03 was a new strain belonging to the species of P. stutzeri.
文摘Small wastewater treatment plants (WWTP) are frequently located, by necessity, in remote and isolated sites, which increases the difficulty of its energy supply. Some of them are located near the seaside, in environmental sensible zones, and due to tourism activity of these sites, seasonal effects related with population size fluctuation can occur, which can originate certain inefficiencies concerning WWTP design and energy supply. The objective of this paper is to describe a step by step procedure for evaluation of the wind potential of sites that are dependent of in-situ energy generation, as well as, a case study on the utilization of the potential wind energy in Magoito WWTP (5000 p.e.). The employed methodology comprised the collection of one year of in-situ wind data and its validation by comparison with historical data of about 10 years of a nearby anemometric station. The data provided by the two anemometric stations was statistically treated. It allowed the analysis of the results from the two stations are promissory in terms of wind availability and velocity. Finally, it comprised the simulation of the local wind conditions for a considerable larger area in order to find the best site for locating a wind turbine.
文摘Before the construction of the Kuching Centralized Wastewater Treatment System Package 1 (KCWTSP1), partially treated blackwater and greywater were discharged directly into natural waterways. The accumulated wastewater had polluted Sarawak river, which is regulated and cannot discharge freely into the South China Sea. The polluted Sarawak river has endangered human health, river water quality, and aquatic ecosystems. Hence, the KCWTSP1 commissioned in 2015 serves the purpose of removing pollutants from wastewater before it is discharged into natural waterways. However, the effectiveness of KCWTPP1 is unknown. This paper is aimed to discuss and review the effectiveness of KCWTPP1 in treating wastewater since its inception in 2015. From 2017 to 2020, KCWTPP1 has treated an average of 4,200,000 m<sup>3</sup> of wastewater per year. Generally, most of the discharge effluent met Environmental Quality Act (1974) Standard A criteria, except for the oil and grease parameter. Initially, the plant could not treat suspended solids and total phosphorus, but this was greatly improved in subsequent years. Therefore, some improvements are required to treat oil and grease parameters effectively and efficiently to ensure that only Standard A effluent is discharged into the Sarawak River in the future.
文摘The question of wastewater treatment and control is reflected from a very specific viewpoint: the low priority given to accurate and useful measurements within wastewater treatment. The matter is discussed from four various perspectives, that may be labelled “Legal understanding”;“Needs for accurate measurement results already in the planning and design stage”;“The measurement problem and human behaviour”;“The understanding of the short term and long term dynamics and changes in pollution and flow loads on a wastewater treatment plant (WWTP)”. All these aspects bring about much improved needs for an accurate and frequent measurement scheme both for pollutants and flows entering a WWTP. The conclusion is stated as follows: A far more and well elaborated on-line measurement system at the plants would become a needed tool for improved water environment protection at lower costs.
