The study aimed to evaluate the ability of some terrestrial and aquatic plants for wastewater purification.Aquatic plants can remove pollutants from wastewater by consuming and accumulating various contaminants in diff...The study aimed to evaluate the ability of some terrestrial and aquatic plants for wastewater purification.Aquatic plants can remove pollutants from wastewater by consuming and accumulating various contaminants in different parts of plants.Different aquatic and terrestrial plants(Rosa sinensis,Typha latifolia,Ocimm bacilicum,Azolla pinnata,and Salvinia molesta)which have the ability to decrease water pollution were utilized in this study.The capability offive different species of plants was investigated by measuring chemical oxygen demand(COD),biological oxygen demand(BOD),electrical conductivity(EC),total dissolved solids(TDS),and pH of the medium.In this research,some aquatic and terrestrial plants were transplanted in wastewater plastic pots containing domestic wastewater with different ratios of 50%and 100%.Then,after 30 days,the physiological and biochemical parameters of plants were calculated to observe the effect of wastewater on plants.Results revealed higher chlorophyll and carotenoids in typha plants treated with 100%wastewater.The highest percentage of elimination in BOD(65%),COD(27%),TDS(72%),EC(83%),and pH(6.8%)was noted with the use of typha and azolla.Intriguingly,total soluble sugars,total free amino acids,and total proteins were found maximum in the hibiscus plant as compared to the other plants under 100%and 50%domestic wastewater treatment,while typha and ocimum showed lower values of these parameters irrespective of wastewater treatments.Moreover,the COD,BOD,TDS,EC,and pH trend was higher in 100%wastewater as compared to 50%wastewater.Taking into account the accumulation capacity of the tested plants especially typha can be efficiently used for the treatment of domestic wastewater.展开更多
A laboratory-scale anaerobic-anoxic-aerobic process(A^(2)O)with a small aerobic zone and a bigger anoxic zone and biologic aerated filter(A^(2)O-BAF)system was operated to treat low carbon-to-nitrogen ratio domestic w...A laboratory-scale anaerobic-anoxic-aerobic process(A^(2)O)with a small aerobic zone and a bigger anoxic zone and biologic aerated filter(A^(2)O-BAF)system was operated to treat low carbon-to-nitrogen ratio domestic wastewater.The A^(2)O process was employed mainly for organic matter and phosphorus removal,and for denitrification.The BAF was only used for nitrification which coupled with a settling tank Compared with a conventional A^(2)O process,the suspended activated sludge in this A^(2)OBAF process contained small quantities of nitrifier,but nitrification overwhelmingly conducted in BAF.So the system successfully avoided the contradiction in sludge retention time(SRT)between nitrifying bacteria and phosphorus accumulating organisms(PAOs).Denitrifying phosphorus accumulating organisms(DPAOs)played an important role in removing up to 91%of phosphorus along with nitrogen,which indicated that the suspended activated sludge process presented a good denitrifying phosphorus removal performance.The average removal efficiency of chemical oxygen demand(COD),total nitrogen(TN),total phosphorus(TP),and NH_(4)^(+)-N were 85.56%,92.07%,81.24%and 98.7%respectively.The effluent quality consistently satisfied the national first level A effluent discharge standard of China.The average sludge volume index(SVI)was 85.4 mL·g^(-1)additionally,the volume ratio of anaerobic,anoxic and aerobic zone in A^(2)O process was also investigated,and the results demonstrated that the optimum value was 1:6:2.展开更多
Reclamation of domestic wastewater for agricultural irrigation is viewed as a sustainable option to create an alternative water source and address water scarcity. Free-living amoebae(FLA), which are amphizoic protozoa...Reclamation of domestic wastewater for agricultural irrigation is viewed as a sustainable option to create an alternative water source and address water scarcity. Free-living amoebae(FLA), which are amphizoic protozoa, are widely distributed in various environmental sources. The FLA could cause considerable environmental and health risks. However, little information is available on the risk of these protozoa. In this study, we evaluated the feasibility using rural domestic wastewater for agricultural irrigation, and analyzed dynamic changes of the microbial community structure and FLA populations in raw and treated wastewater, as well as the phyllosphere and rhizosphere of lettuce production sites that were irrigated with different water sources. The bacterial community dynamics were analyzed by terminal restriction fragment length polymorphism(T-RFLP). The bacterial community structures in the influent were similar to that in the effluent, while in some cases relative abundances varied significantly. The populations of Acanthamoeba spp. and Hartmannella vermiformis in the anaerobically treated wastewater were significantly higher than in the raw wastewater. The vegetables could harbor diverse amoebae, and the abundances of Acanthamoeba spp. and H. vermiformis in the rhizosphere were significantly higher than in the phyllosphere. Accordingly, our studies show insight into the distribution and dissemination of amoebae in wastewater treatment and irrigation practices.展开更多
The slow initiation of anammox for treating typical domestic wastewater and the relatively high footprint of wastewater treatment infrastructures are major concerns for practical wastewater treatment systems.Herein,a ...The slow initiation of anammox for treating typical domestic wastewater and the relatively high footprint of wastewater treatment infrastructures are major concerns for practical wastewater treatment systems.Herein,a 300 m^(3)/d hybrid biofilm reactor(HBR)process was developed and operated with a short hydraulic retention time(HRT)of 8 h.The analysis of the bacterial community demonstrated that anammox were enriched in the anoxic zone of the HBR process.The percentage abundance of Candidatus Brocadia in the total bacterial community of the anoxic zone increased from 0 at Day 1 to 0.33%at Day 130 and then to 2.89%at Day 213.Based upon the activity of anammox bacteria,the removal of ammonia nitrogen(NH_(4)^(+)-N)in the anoxic zone was approximately 15%.This showed that the nitrogen transformation pathway was enhanced in the HBR system through partial anammox process in the anoxic zone.The final effluent contained 12 mg/L chemical oxygen demand(COD),0.662 mg/L NH_(4)^(+)-N,7.2 mg/L total nitrogen(TN),and 6 mg/L SS,indicating the effectiveness of the HBR process for treating real domestic wastewater.展开更多
The characteristic of phosphorus removal andappropriate change of the traditional operation modes wereinvestigated in UniFed sequencing batch reactor (SBR)laboratory-scale apparatus (40 L), treating actual domesticwas...The characteristic of phosphorus removal andappropriate change of the traditional operation modes wereinvestigated in UniFed sequencing batch reactor (SBR)laboratory-scale apparatus (40 L), treating actual domesticwastewater with low ratios of C/N (2.57) and C/P (30.18),providing theoretical basis for actual application ofwastewater treatment plant. UniFed SBR system with itsunique operation mode had the distinct superiority ofphosphorus removal. On this occasion, the effect ofvolumetric exchange ratio (VER) and the method ofinfluent introduction for phosphorus removal were studied.When the carbon source became the limiting factor tophosphorus release, the higher the VER, the lower thephosphorus concentration in the effluent. Three differentinfluent patterns, including one-time filling, four-timefilling, and continuous filling with the same quantity ofwastewater could increase the release rate of anaerobicphosphorus from 0.082 to 0.143 mg·P·(L·min)-1. Appropriatechange of the traditional operation modes couldoptimize the efficiency of phosphorus removal. When thefeed/ decant time was extended from 2 h to 4 h, thephosphorous removal efficiency increased from 59.93% to88.45% without any external carbon source. In the mode ofalternation of anoxic-aerobic (A/O) condition, phosphorousremoval efficiency increased from 55.07% to 72.27%clearly. The carbon source in the influent can be usedadequately, and denitrifying phosphorus removal wascarried out in anoxic stage 2 (A2). This mode was optimalfor the treatment of actual domestic wastewater with lowC/N and C/P ratios.展开更多
Long-term sampling and analysis were conducted in a domestic wastewater treatment plant for the investigation on the characteristics of the representative contaminants in raw sewage such as SS,COD,BOD5,TP,and TN.All t...Long-term sampling and analysis were conducted in a domestic wastewater treatment plant for the investigation on the characteristics of the representative contaminants in raw sewage such as SS,COD,BOD5,TP,and TN.All these constituents were classified into dissolved and suspended groups by using a 0.45-μm membrane filter,and the concen-tration of each constituent in each group was analyzed.As a result,almost 100%of the SS was found to be suspended matter,as well as about 65% of COD,60% of BOD_(5),50% of P,and 20%of N.All these could be easily removed by sedimentation or coagulation/sedimentation.A treatability evaluation diagram was proposed for a rational selection of wastewater treatment process in accordance with raw water quality.展开更多
In this study,a microbial consortium isolated from an activated sludge tank of a conventional wastewater treatment plant was immobilized using sodium alginate(SA)as a support material for contaminant biodegradation in...In this study,a microbial consortium isolated from an activated sludge tank of a conventional wastewater treatment plant was immobilized using sodium alginate(SA)as a support material for contaminant biodegradation in wastewater.A volume of 500 mL of activated sludge was immobilized in the SA beads(with a mass concentration of 25 g/L).The resulting SA beads were characterized,introduced into a fluidized bed reactor,fed with 1000 mL of the sample,and characterized again after the treatment process.The SA-immobilized microorganisms were tested first for degradation of organic matter(expressed as chemical oxygen demand)and total phosphorous in domestic wastewater,achieving removal efficiencies of 71%and 93%,respectively,after 12 h.Subsequently,the SA-immobilized microorganisms were tested for degradation of a basic blue 9(BB9)textile dye in a condition that simulated textile wastewater.The efficiency of the BB9 degradation was found to be as high as 99.5%after 2 h.According to these results,SA-immobilized microorganisms were found to be an environmentally friendly and cost-effective alternative for treatment of municipal and industrial wastewater effluents.展开更多
By combining with the actual situation in the rural area,the practical technology of domestic wastewater treatment which had the wide popularization value was developed in the rural area of Taihu Basin.Moreover,the mu...By combining with the actual situation in the rural area,the practical technology of domestic wastewater treatment which had the wide popularization value was developed in the rural area of Taihu Basin.Moreover,the multi-soil-layering system was used to treat the concentrated rural domestic wastewater,and the demonstration project was established in Fenshui Village,Yixing,Jiangsu.The result showed that the infrastructure and operating cost of system was low,and the treatment effect was good.The average removal ratios of COD,NH+4-N,TN,TP and SS were respectively 70%,83%,59%,76% and 94%.The quality of yielding water could reach Grade A standard of Pollutant Emission Standards in Urban Wastewater Treatment Plant.展开更多
文摘The study aimed to evaluate the ability of some terrestrial and aquatic plants for wastewater purification.Aquatic plants can remove pollutants from wastewater by consuming and accumulating various contaminants in different parts of plants.Different aquatic and terrestrial plants(Rosa sinensis,Typha latifolia,Ocimm bacilicum,Azolla pinnata,and Salvinia molesta)which have the ability to decrease water pollution were utilized in this study.The capability offive different species of plants was investigated by measuring chemical oxygen demand(COD),biological oxygen demand(BOD),electrical conductivity(EC),total dissolved solids(TDS),and pH of the medium.In this research,some aquatic and terrestrial plants were transplanted in wastewater plastic pots containing domestic wastewater with different ratios of 50%and 100%.Then,after 30 days,the physiological and biochemical parameters of plants were calculated to observe the effect of wastewater on plants.Results revealed higher chlorophyll and carotenoids in typha plants treated with 100%wastewater.The highest percentage of elimination in BOD(65%),COD(27%),TDS(72%),EC(83%),and pH(6.8%)was noted with the use of typha and azolla.Intriguingly,total soluble sugars,total free amino acids,and total proteins were found maximum in the hibiscus plant as compared to the other plants under 100%and 50%domestic wastewater treatment,while typha and ocimum showed lower values of these parameters irrespective of wastewater treatments.Moreover,the COD,BOD,TDS,EC,and pH trend was higher in 100%wastewater as compared to 50%wastewater.Taking into account the accumulation capacity of the tested plants especially typha can be efficiently used for the treatment of domestic wastewater.
基金This work was supported by the project of Scientific Research Base And Scientific Innovation Platform of Beijing Municipal Education Commission(No.PXM2008_014204_050843)Supported by State Key Laboratory of Urban Water Resource and Environment(HIT)(No.QAK200802).
文摘A laboratory-scale anaerobic-anoxic-aerobic process(A^(2)O)with a small aerobic zone and a bigger anoxic zone and biologic aerated filter(A^(2)O-BAF)system was operated to treat low carbon-to-nitrogen ratio domestic wastewater.The A^(2)O process was employed mainly for organic matter and phosphorus removal,and for denitrification.The BAF was only used for nitrification which coupled with a settling tank Compared with a conventional A^(2)O process,the suspended activated sludge in this A^(2)OBAF process contained small quantities of nitrifier,but nitrification overwhelmingly conducted in BAF.So the system successfully avoided the contradiction in sludge retention time(SRT)between nitrifying bacteria and phosphorus accumulating organisms(PAOs).Denitrifying phosphorus accumulating organisms(DPAOs)played an important role in removing up to 91%of phosphorus along with nitrogen,which indicated that the suspended activated sludge process presented a good denitrifying phosphorus removal performance.The average removal efficiency of chemical oxygen demand(COD),total nitrogen(TN),total phosphorus(TP),and NH_(4)^(+)-N were 85.56%,92.07%,81.24%and 98.7%respectively.The effluent quality consistently satisfied the national first level A effluent discharge standard of China.The average sludge volume index(SVI)was 85.4 mL·g^(-1)additionally,the volume ratio of anaerobic,anoxic and aerobic zone in A^(2)O process was also investigated,and the results demonstrated that the optimum value was 1:6:2.
基金supported by the National Science and Technology Major Project of China (Nos. 2014ZX07204-005, 2015ZX07206-006)the National Key Technology R&D Program of China (No. 2014BAC01B03)the National Natural Science Foundation of China (No. 31570494)
文摘Reclamation of domestic wastewater for agricultural irrigation is viewed as a sustainable option to create an alternative water source and address water scarcity. Free-living amoebae(FLA), which are amphizoic protozoa, are widely distributed in various environmental sources. The FLA could cause considerable environmental and health risks. However, little information is available on the risk of these protozoa. In this study, we evaluated the feasibility using rural domestic wastewater for agricultural irrigation, and analyzed dynamic changes of the microbial community structure and FLA populations in raw and treated wastewater, as well as the phyllosphere and rhizosphere of lettuce production sites that were irrigated with different water sources. The bacterial community dynamics were analyzed by terminal restriction fragment length polymorphism(T-RFLP). The bacterial community structures in the influent were similar to that in the effluent, while in some cases relative abundances varied significantly. The populations of Acanthamoeba spp. and Hartmannella vermiformis in the anaerobically treated wastewater were significantly higher than in the raw wastewater. The vegetables could harbor diverse amoebae, and the abundances of Acanthamoeba spp. and H. vermiformis in the rhizosphere were significantly higher than in the phyllosphere. Accordingly, our studies show insight into the distribution and dissemination of amoebae in wastewater treatment and irrigation practices.
基金supported by The Major Science and Technology Program for Water Pollution Control and Treatment(Ministry of Ecology and Environment,China)(No.2017ZX07103-003)and seed fund for Beijing Young Engineering,China.
文摘The slow initiation of anammox for treating typical domestic wastewater and the relatively high footprint of wastewater treatment infrastructures are major concerns for practical wastewater treatment systems.Herein,a 300 m^(3)/d hybrid biofilm reactor(HBR)process was developed and operated with a short hydraulic retention time(HRT)of 8 h.The analysis of the bacterial community demonstrated that anammox were enriched in the anoxic zone of the HBR process.The percentage abundance of Candidatus Brocadia in the total bacterial community of the anoxic zone increased from 0 at Day 1 to 0.33%at Day 130 and then to 2.89%at Day 213.Based upon the activity of anammox bacteria,the removal of ammonia nitrogen(NH_(4)^(+)-N)in the anoxic zone was approximately 15%.This showed that the nitrogen transformation pathway was enhanced in the HBR system through partial anammox process in the anoxic zone.The final effluent contained 12 mg/L chemical oxygen demand(COD),0.662 mg/L NH_(4)^(+)-N,7.2 mg/L total nitrogen(TN),and 6 mg/L SS,indicating the effectiveness of the HBR process for treating real domestic wastewater.
基金This work was supported by the Joint Research Fund for Overseas Natural Science Foundation of China(Grant No.50628808)State Key Laboratory of Urban Water Resource and Environment(HIT)(No.QAK200802)Academic Human Resources Development in Institutions of Higher Learning Under the Jurisdiction of Beijing Municipality(No.PHR20090502)。
文摘The characteristic of phosphorus removal andappropriate change of the traditional operation modes wereinvestigated in UniFed sequencing batch reactor (SBR)laboratory-scale apparatus (40 L), treating actual domesticwastewater with low ratios of C/N (2.57) and C/P (30.18),providing theoretical basis for actual application ofwastewater treatment plant. UniFed SBR system with itsunique operation mode had the distinct superiority ofphosphorus removal. On this occasion, the effect ofvolumetric exchange ratio (VER) and the method ofinfluent introduction for phosphorus removal were studied.When the carbon source became the limiting factor tophosphorus release, the higher the VER, the lower thephosphorus concentration in the effluent. Three differentinfluent patterns, including one-time filling, four-timefilling, and continuous filling with the same quantity ofwastewater could increase the release rate of anaerobicphosphorus from 0.082 to 0.143 mg·P·(L·min)-1. Appropriatechange of the traditional operation modes couldoptimize the efficiency of phosphorus removal. When thefeed/ decant time was extended from 2 h to 4 h, thephosphorous removal efficiency increased from 59.93% to88.45% without any external carbon source. In the mode ofalternation of anoxic-aerobic (A/O) condition, phosphorousremoval efficiency increased from 55.07% to 72.27%clearly. The carbon source in the influent can be usedadequately, and denitrifying phosphorus removal wascarried out in anoxic stage 2 (A2). This mode was optimalfor the treatment of actual domestic wastewater with lowC/N and C/P ratios.
基金This study was supported by the National Natural Science Foundation of China(Grant No.50138020).
文摘Long-term sampling and analysis were conducted in a domestic wastewater treatment plant for the investigation on the characteristics of the representative contaminants in raw sewage such as SS,COD,BOD5,TP,and TN.All these constituents were classified into dissolved and suspended groups by using a 0.45-μm membrane filter,and the concen-tration of each constituent in each group was analyzed.As a result,almost 100%of the SS was found to be suspended matter,as well as about 65% of COD,60% of BOD_(5),50% of P,and 20%of N.All these could be easily removed by sedimentation or coagulation/sedimentation.A treatability evaluation diagram was proposed for a rational selection of wastewater treatment process in accordance with raw water quality.
文摘In this study,a microbial consortium isolated from an activated sludge tank of a conventional wastewater treatment plant was immobilized using sodium alginate(SA)as a support material for contaminant biodegradation in wastewater.A volume of 500 mL of activated sludge was immobilized in the SA beads(with a mass concentration of 25 g/L).The resulting SA beads were characterized,introduced into a fluidized bed reactor,fed with 1000 mL of the sample,and characterized again after the treatment process.The SA-immobilized microorganisms were tested first for degradation of organic matter(expressed as chemical oxygen demand)and total phosphorous in domestic wastewater,achieving removal efficiencies of 71%and 93%,respectively,after 12 h.Subsequently,the SA-immobilized microorganisms were tested for degradation of a basic blue 9(BB9)textile dye in a condition that simulated textile wastewater.The efficiency of the BB9 degradation was found to be as high as 99.5%after 2 h.According to these results,SA-immobilized microorganisms were found to be an environmentally friendly and cost-effective alternative for treatment of municipal and industrial wastewater effluents.
基金Supported by The Important Special Item of National Water Body Pollution Control and Treatment Science Technology(2009ZX07528005)~~
文摘By combining with the actual situation in the rural area,the practical technology of domestic wastewater treatment which had the wide popularization value was developed in the rural area of Taihu Basin.Moreover,the multi-soil-layering system was used to treat the concentrated rural domestic wastewater,and the demonstration project was established in Fenshui Village,Yixing,Jiangsu.The result showed that the infrastructure and operating cost of system was low,and the treatment effect was good.The average removal ratios of COD,NH+4-N,TN,TP and SS were respectively 70%,83%,59%,76% and 94%.The quality of yielding water could reach Grade A standard of Pollutant Emission Standards in Urban Wastewater Treatment Plant.
