Background: Cosmetic formulations, and particularly solar products which contain mineral and chemical UV-filters, are often suspected of causing harmful effects on marine fauna and flora. After the publication of our ...Background: Cosmetic formulations, and particularly solar products which contain mineral and chemical UV-filters, are often suspected of causing harmful effects on marine fauna and flora. After the publication of our work in 2019 concerning the ecotoxicological effects of such formulations on corals (Seriatopora hystrix), we here provide some new information about the biodegradability and the ecotoxicological effects of these products on marine zoo- and phytoplankton. Therefore, we choose to realize in silico and in vitro studies of the biodegradability of several solar products but also to evaluate the ecotoxicological effects of these products on one phytoplankton, i.e. Phaeodactylum tricornutum, and one zooplankton, i.e. Acartia tonsa, of a great importance for sea species survival (notably as sources of food). Materials and methods: Two different approaches were used to study the biodegradability of the tested products: One in silico method and an in vitro one. 2 solar products were involved in the in silico study which consisted in the determination of the degradation factor (DF) of each ingredient of the tested formulas in order to finally obtain their estimated biodegradability percentage. Already available data concerning each ingredient coupled to a computer model developed with one of our partners were used to achieve this study. The in vitro study involved 8 formulas containing UV-filters and was led by following the OECD 301 F guidelines. Ecotoxicological studies of 7 of the formulas containing UV-filters were for their part realized by following the ISO 10253 guidelines for the experiments led with Phaeodactylum tricornutum, and the ISO 14669 guidelines for the experiments led with Acartia tonsa. In these studies, the effect of each tested product on crustaceans’ mortality and algal growth inhibition was assessed. Results: The in silico study predicted that formulas containing chemical UV-filters display a high biodegradability (superior to the threshold value of 60% given by the OECD 301 F guidelines). In the in vitro part of our work, the 8 tested formulas showed a biodegradability slightly inferior to the one predicted in the in silico experiments. Therefore, in order to evaluate if these calculated biodegradability value could have significant harmful effects on zoo- or phytoplankton, we studied the effect of our products regarding the growth inhibition on Phaeodactylum tricornutum and the mortality on Acartia tonsa. In this last part of the study, all the tested products were classified as “non ecotoxic” following an internal classification based on Part 4 entitled “Environmental Hazards” of Globally Harmonized System of Classification and Labelling of Chemicals (GHS), 9<sup>th</sup> edition (2021). Conclusions: These results are notably in line with those published by our teams in 2019 on the effects of solar cosmetic products on corals and seem to confirm that formulas containing mineral and chemical UV-filters can be daily used without displaying significant noxious effects on marine fauna and flora. .展开更多
In this paper, the influence of inorganic salt on aerobic biodegradability of dyestuffs was studied by means of semi continuous activated sludge method. It was found that: biodegradability of dyestuffs would decrease ...In this paper, the influence of inorganic salt on aerobic biodegradability of dyestuffs was studied by means of semi continuous activated sludge method. It was found that: biodegradability of dyestuffs would decrease with the increase of the concentration of NaCl; however, biodegradability in the condition of NaCl=30 g/L was better than that in the condition of NaCl=15 g/L; in the three NaCl conditions, biodegradability of tested dyestuffs followed the following order: NaCl=0 g/L > NaCl=30 g/L>NaCl=15 g/L.展开更多
The influence of synthetic caprylic methyl diethanolamine phosphate ester (abbreviated as MDEACP) on biodegradability and tribological properties of 400SN mineral base oil was studied. The biodegradability of the neat...The influence of synthetic caprylic methyl diethanolamine phosphate ester (abbreviated as MDEACP) on biodegradability and tribological properties of 400SN mineral base oil was studied. The biodegradability of the neat base oil and the oil doped with MDEACP was determined on a biodegradation tester. The tribological properties of the neat base oil and the oil doped with MDEACP were evaluated on a four-ball tester. Moreover, the worn surfaces were investigated by scanning electron microscopy (SEM) and X-ray photoelectron spectroscopy (XPS). The results revealed that MDEACP significantly promoted the biodegradation of the mineral base oil. The improvement in biodegradability was attributed to the enhanced growth and quantity of microbes by MDEACP. Furthermore, MDEACP enhanced the anti-wear properties, the friction-reducing properties, and the extreme pressure properties of the base oil. It was mainly attributed to the formation of the complex boundary lubrication film resulted from the adsorption and tribochemical reactions of MDEACP on the friction surface.展开更多
Waterborne polyurethane(WBPU)with controlled biodegradability and biocompatibility was synthesized by using poly(ε-caprolactone)(PCL)as the polyglycol,isophorone diisocyanate(IPDI)as the isocyanate,2,2-bishydroxymeth...Waterborne polyurethane(WBPU)with controlled biodegradability and biocompatibility was synthesized by using poly(ε-caprolactone)(PCL)as the polyglycol,isophorone diisocyanate(IPDI)as the isocyanate,2,2-bishydroxymethylbutyric acid(DMPA)as the chain extender and 1,4-butanediol(BDO)as the hard-segment regulating agent.We found that BDO content significantlyinfluencedmechanicalproperties,degradable performances and cyto-biocompatibility of PCL-WBPUs.Increasing the BDO content in PCL-WBPU enhanced its tensile strength and decreases strain.Enzymolysis and hydrolysis properties were also regulated by BDO content,but with different mechanisms.Cytobiocompatibility was evaluated with ATDC5 cells.The results show that the biodegradability of PCL-WBPU is significantly determined by BDO content,which exerts a serious influence on its polymer structure,leading to resultant degradable properties.展开更多
In this paper, a rational test method for determining biodegradability of organic substanceunder aerobic conditions was established. Index of biodegradation was elaborated through analysis forbiodegradability of organ...In this paper, a rational test method for determining biodegradability of organic substanceunder aerobic conditions was established. Index of biodegradation was elaborated through analysis forbiodegradability of organic substances. 23 organic substance we展开更多
Solid waste and air pollution are never ending environmental problems that can be partially solved by turning waste into useful bio-products. In this study, enzymatic solutions were developed by formulating enzymatic ...Solid waste and air pollution are never ending environmental problems that can be partially solved by turning waste into useful bio-products. In this study, enzymatic solutions were developed by formulating enzymatic solutions from fish intestines and fruit peels. This aimed to help in biodegradation of organic solid wastes. Organic waste samples were treated with formulated enzymatic solutions for 7 days in aerated set-up for aerobic degradation. Biodegradability and odor of the waste samples were compared with commercial enzymatic solution. Determination of evolved carbon dioxide (CO2) using gravimetric analysis (GA) was used to determine the percent biodegradability, Dt, of organic solid waste and odor-ranking method was used to determine the odor intensity of the organic waste samples. The result showed that the weight loss and percentage biodegradability of organic waste sample treated with formulated enzymatic solution is comparable with that of the commercial enzymatic solution. In terms of odor intensity, waste treated with the product, formulated enzymatic solution (FES) is also comparable to the waste treated with commercial enzymatic solution. Thus, implying that the developed FES is as efficient as that of the commercial enzymatic solution. These significant results will be helpful to future researchers in providing ways on improving the degradation of organic solid waste and mitigating the increasing glitches on our environment. Enzyme kinetics, physical and chemical properties studies of the solution were recommended for future researchers to accurately determine the effectiveness of the formulated enzymatic solution in the degradation of organic solid waste.展开更多
This work deals with the effect of combined microwave-ultrasonic pretreatment on the anaerobic biodegradability of primary, excess activated and mixed sludge. The characteristics, biodegradability and anaerobic digest...This work deals with the effect of combined microwave-ultrasonic pretreatment on the anaerobic biodegradability of primary, excess activated and mixed sludge. The characteristics, biodegradability and anaerobic digester performance for untreated primary, excess activated and mixed sludge were compared to combined microwave-ultrasonic pretreated primary, excess activated and mixed sludge. All sludge samples were subjected to Microwave treatment at 2450 MHz, 800 W and 3 min followed by ultrasonic treatment at a density of 0.4 W/mL, amplitude of 90%, Intensity of 150 W, pulse of 55/5 for 6min. Methane production in pretreated primary sludge was significantly greater (11.9 ml/g TCOD) than the methane yield of the untreated primary sludge (7.9 ml/g TCOD). Cumulative methane production of pretreated Excess Activated Sludge (EAS) was higher (66.5 ml/g TCOD) than the methane yield from pretreated mixed sludge (44.1 ml/g TCOD). Furthermore, digested EAS showed significantly higher dewaterability (201 s) than digested primary sludge (305 s) or mixed sludge (522 s). The average Methane: Carbondioxide ratio from EAS (1.85) was higher than that for mixed untreated sludge (1.24). VS reduction was also higher for EAS than the other two sludge types. However, pretreatment of EAS resulted in significant reduction in dewaterability due to higher percentage of fine floc particles in the pretreated EAS.展开更多
Natural fiber reinforced composites have gained considerable attention particularly in the manufacturing industry owing to their light weight, corrosion resistance, abundance, and biodegradability. In this work, alkal...Natural fiber reinforced composites have gained considerable attention particularly in the manufacturing industry owing to their light weight, corrosion resistance, abundance, and biodegradability. In this work, alkaline treated and untreated groundnut shell powder (GSP) was used to reinforce recycled polyethylene to produce GSP-recycled polyethylene composites with improved mechanical properties and biodegradability. GSP with particle sizes of 0 - 300 μm and 300 - 600 μm was used in different proportions: 5%, 10%, 15%, 20%, 25%, and 30% wt. The fiber was immersed for 5 hours in a 10 wt% NaOH solution. Tensile and hardness test data showed an improvement in mechanical properties of the treated fiber composites. Results of water absorption test also showed that treated GSP-recycled polyethylene composites had a lower rate of water absorption than the untreated GSP-recycled polyethylene composites. Through Fourier transform infrared spectroscopy, disappearance of characteristics peaks of hemicellulose and lignin was observed. Growth of fungi on the fiber-reinforced composites was observed, which was evidence that GSP-recycled polyethylene composite was biodegradable. Finally, SEM micrographs showed uniform distribution of treated fibers in the polymer matrix;this explained the observed improvement in the mechanical properties of treated GSP-recycled polyethylene composites.展开更多
Methyl diethanolamine fatty acid esters, viz. methyl diethanolamine octanoate and methyl diethanolamine oleate,were prepared. Their impacts on the biodegradability and tribological properties of mineral base oil 400 S...Methyl diethanolamine fatty acid esters, viz. methyl diethanolamine octanoate and methyl diethanolamine oleate,were prepared. Their impacts on the biodegradability and tribological properties of mineral base oil 400 SN were evaluated by a tester for fast evaluating the biodegradability of lubricants and by a four-ball tester, respectively. The results showed that methyl diethanolamine octanoate and methyl diethanolamine oleate both could markedly promote the biodegradation of the oil and improved its tribological properties. The improvement of biodegradability was attributed to the enhanced growth and quantity of microbes by methyl diethanolamine fatty acid esters. The worn surfaces were analyzed by a scanning electron microscope(SEM) equipped with an energy dispersive spectrometer(EDS) and an X-ray photoelectron spectroscope(XPS). The results indicated that the enhancement of friction-reducing and anti-wear properties of the mineral oil was attributed to the formation of complicated boundary lubrication films composed of species such as Fe_2O_3, Fe_3O_4 and organic nitrogen-containing compounds with a structure of –C-N-or R-NH_2.展开更多
Lignin is the most abundant heteropolymer based on aromatic subunits in nature.Large quantities of lignin are annually produced from pulping processes and biorefinery industries.Its unclearly defined structure and dif...Lignin is the most abundant heteropolymer based on aromatic subunits in nature.Large quantities of lignin are annually produced from pulping processes and biorefinery industries.Its unclearly defined structure and difficult biodegradation mainly limit its utilization.This work focused on the effect of hydroxylation of lignin on its microbial degradation.Butyloxy carbonyl-modified lignin,and hydroxylated-lignin were synthesized with di-tert-butyl dicarbonate and hydrogen peroxide,respectively,using lignin as raw material.The degradation of the modifiedlignins both by P.chrysosporium and B.subtilis were analyzed using UV-vis spectroscopy.Results revealed that the lignin degradation velocity raises with the increase hydroxylation level of lignin.Moreover,FTIR and 1H NMR analysis of the biodegradation products of lignin further indicated that higher content of hydroxyl groups in lignin facilitated the demethylation combined with the aromatic ring cracking in the presence of fungus and bacteria.展开更多
Blends of biodegradable copolymer based on starch, poly lactic acid (PLA), poly vinyl alcohol (PVA) and natural rubber (NR) have been prepared. Gamma radiation induced synthesis and modification of polymer hydrogel wa...Blends of biodegradable copolymer based on starch, poly lactic acid (PLA), poly vinyl alcohol (PVA) and natural rubber (NR) have been prepared. Gamma radiation induced synthesis and modification of polymer hydrogel was studied. The polymer blends have been chemically surface modified by glycerol. The modified polymer blends have been investigated for swelling ratio, tensile strength and 9 scanning electron microscopy. The swelling ratio of polymer blends increased significantly after surface modification with glycerol. The swelling of polymer was decreased as a function of (NR) content in polymer blends. The gel fraction (PVA-starch-PLA) and (PVA-starch-NR) blends increased by increasing the radiation doses (kGy) to reach the maximum amount of (~99%) and (~88.2%), respectively. Addition of 2.5% (PLA) led to greater increase of the swelling ratio than 10% (NR) to blends and the maximum swelling was found at dose (5 kGy). At concentration of glycerol (5.0% w/w), tensile strength decreased and elongation at break % increased. The polymers degrading microorganisms were isolated from soil samples. The degradation ability of the microbial isolates for each polymeric material was tested on agar plates. Among these isolates, the most efficient degrader isolates for prepared blends in MSM shaking flasks were selected and the degradation was confirmed by scanning electron microscopy.展开更多
Material efficiency is nowadays an essential topic to promote the sustainable use of natural resources, waste materials and industrial by-products, in agreement with the principle of sustainable development and LCA (l...Material efficiency is nowadays an essential topic to promote the sustainable use of natural resources, waste materials and industrial by-products, in agreement with the principle of sustainable development and LCA (life cycle assessment). In this research it was determined the biodegradation of used vegetable oil based products and their important physico- chemical properties for their suitability in different applications such as chain oil in the forestry equipment and mold oil in concrete casting etc. Biodegradability is a measure of the ecological nature of products, and thus from an environ- mental point of view, is the most important evaluated property in this research. As a result, all measured properties of the studied recycled vegetable oils show that the products are environmentally friendly. Two types of vegetable oil were studied;three chain oils and two mold oils. The degree of biodegradation (BOD28) of the mold oils, was about 77 % and the biodegradation of chain oils was about 60% - 62%. In addition, this paper also presents a process outline for manu- facturing recycling vegetable oils.展开更多
Injectable materials show their special merits in regeneration of damaged/degenerated bones in minimally-invasive approach.Injectable calcium phosphate bone cement(CPC)has attracted broad attention for its bioactivity...Injectable materials show their special merits in regeneration of damaged/degenerated bones in minimally-invasive approach.Injectable calcium phosphate bone cement(CPC)has attracted broad attention for its bioactivity,as compared to non-degradable polymethyl methacrylate cement.However,its brittleness,poor anti-washout property and uncontrollable biodegradability are the main challenges to limit its further clinical application mainly because of its stone-like dense structure and fragile inorganic-salt weakness.Herein,we developed a kind of injectable CPC bone cement with porous structure and improved robustness by incorporating poly(lactide-co-glycolic acid)(PLGA)nanofiber into CPC,with carboxymethyl cellulose(CMC)to offer good injectability as well as anti-wash-out capacity.Furthermore,the introduction of PLGA and CMC also enabled a formation of initial porous structure in the cements,where PLGA nanofiber endowed the cement with a dynamically controllable biodegradability which provided room for cell movement and bone ingrowth.Inter-estingly,the reinforced biodegradable cement afforded a sustainable provision of Ca^(2+)bioactive components,together with its porous structure,to improve synergistically new bone formation and osteo-integration in vivo by using a rat model of femur condyle defect.Further study on regenerative mechanisms indicated that the good minimally-invasive bone regeneration may come from the synergistic enhanced osteogenic effect of calcium ion enrichment and the improved revascularization capacity contributed from the porosity as well as the lactic acid released from PLGA nanofiber.These results indicate the injectable bone cement with high strength,anti-washout property and controllable biodegradability is a promising candidate for bone regeneration in a minimally-invasive approach.展开更多
Biodegradable implants from magnesium(Mg)alloys have emerged in the biomedical field especially in the orthopedic and cardiovascular stent applications owing to their low density,high specific strength,excellent machi...Biodegradable implants from magnesium(Mg)alloys have emerged in the biomedical field especially in the orthopedic and cardiovascular stent applications owing to their low density,high specific strength,excellent machinability,good biocompatibility,and biodegradability.The primary shortcoming of Mg-based implants is their low corrosion resistance in the physiological environment,which results in premature mechanical integrity loss before adequate healing and the production of excessive hydrogen gas,which is harmful to the body tissues and negatively affects the biocompatibility of the implant.Laser surface modification has recently received attention because it can improve the surface properties such as surface chemistry,roughness,topography,corrosion resistance,wear resistance,hydrophilicity,and thus cell response to the surface of the material.The composition and microstructures including textures and phases of laser-treated surfaces depend largely on the laser processing parameters(input laser power,laser scan velocity,frequency,pulse duration,pressure,gas circulation,working time,spot size,beam focal position,and laser track overlap)and the thermophysical properties of the substrate(solubility,melting point,and boiling point).This review investigates the impacts of various laser surface modification techniques including laser surface melting,laser surface alloying,laser cladding,laser surface texturing,and laser shock peening,and highlights their significance in improving the surface properties of biodegradable Mg alloys for implant applications.Additionally,we explore how different laser process parameters affect its composition,microstructure,and surface properties in each laser surface modification technique.展开更多
Actual pharmaceutical wastewater was treatedusing a combined ultrasonic irradiation (US) and iron/cokeinternal electrolysis (Fe/C) technology. A significantsynergetic effect was observed, showing that ultrasonicirradi...Actual pharmaceutical wastewater was treatedusing a combined ultrasonic irradiation (US) and iron/cokeinternal electrolysis (Fe/C) technology. A significantsynergetic effect was observed, showing that ultrasonicirradiation dramatically enhanced the chemical oxygendemand (COD) removal efficiencies by internal electrolysis.The effects of primary operating factors on CODremoval were evaluated systematically. Higher ultrasonicfrequency and lower pH values as well as longer reactiontime were favorable to COD removal. The ratio ofbiochemical oxygen demand (BOD) and COD (B/C) ofthe wastewater increased from 0.21 to 0.32 after US-Fe/Ctreatment. An acute biotoxicity assay measuring theinhibition of bioluminescence indicated that the wastewaterwith overall toxicity of 4.3 mg-Zn^(2+)·L^(-1) wasreduced to 0.5 mg-Zn^(2+)·L^(-1) after treatment. Both the rawand the treated wastewater samples were separated andidentified. The types of compounds suggested that theincreased biodegradability and reduced biotoxicityresulted mainly from the destruction of N,N-2 dimethylformamide and aromatic compounds in the pharmaceuticalwastewater.展开更多
This study aims to investigate the addition of Zn on the corrosion property and cytocompatibility of Mg- 2Gd-xZn (x = 0, 3, 4 and 5;wt%) alloys, which were prepared by gravity permanent mold casting and solution treat...This study aims to investigate the addition of Zn on the corrosion property and cytocompatibility of Mg- 2Gd-xZn (x = 0, 3, 4 and 5;wt%) alloys, which were prepared by gravity permanent mold casting and solution treatment, respectively. The results show that the intermetallic phases of these ternary alloys are mainly composed of Mg12GdZn and Mg3GdZn3. The content of secondary phases as well as the grain size is greatly dependent on the Zn addition. Compared to the binary Mg- 2Gd alloy, the corrosion resistance of the most ternary alloys is significantly improved. Furthermore, the in vitro cell culture study demonstrates the potential cytocompatibility of the developed ternary alloys. It indicates that a series of Mg-2Gd-xZn (x = 0, 3, 4 and 5;wt%) with medically acceptable corrosion rate are developed and show great potential use as a new type of biodegradable implants.展开更多
The present work reports the inclusion of different proportions of Mango/Sheesham/Mahogany/Babool dust to polypropylene for improving mechanical,wear behavior and biodegradability of wood-plastic composite(WPC).The wo...The present work reports the inclusion of different proportions of Mango/Sheesham/Mahogany/Babool dust to polypropylene for improving mechanical,wear behavior and biodegradability of wood-plastic composite(WPC).The wood dust(10%,15%,20%by weight)was mixed with polypropylene granules and WPCs were prepared using an injection molding technique.The mechanical,wear,and morphological characterizations of fabricated WPCs were carried out using standard ASTM methods,pin on disk apparatus,and scanning electron microscopy(SEM),respectively.Further,the biodegradability and resistance to natural weathering of WPCs were evaluated following ASTM D5338-11 and ASTM D1435-99,respectively.The WPCs consisting ofBabool and Sheesham dust were having superior mechanical properties whereas the WPCs consisting of Mango and Mahogany were more wear resistant.It was found that increasing wood powder proportion results in higher Young's modulus,lesser wear rate,and decreased stress at break.The WPCs made of Sheesham dust were least biodegradable.It was noticed that the biodegradability corresponds with resistance to natural weathering;more biodegradable WPCs were having the lesser resistance to natural weathering.展开更多
Evaluating anaerobic biodegradability of sludge and then identifying the stabilization of digestate is necessary in sludge treatment and disposal.48 sludge samples from 24 typical waste water treatment plants(WWTPs)in...Evaluating anaerobic biodegradability of sludge and then identifying the stabilization of digestate is necessary in sludge treatment and disposal.48 sludge samples from 24 typical waste water treatment plants(WWTPs)in 11 provinces in China were selected to investigate the relationship between Biochemical Acidogenic Potential(BAP)test and Biochemical Methane Potential(BMP)test.The volatile fatty acid(VFA)production obtained from BAP tests was found linearly related to the ultimate methane production from corresponding BMP tests.Satisfying results were obtained with Pearson correlation coefficient as 0.929 and R^2 value as 0.76.Furthermore,the physio-chemical characteristics(FCI,SUVA254,E 4/E 6)of supernatant,which were associated with humic-like substances(HS),were investigated before and after BMP tests.Through which a new criterion(FCI>1.50,SUVA 254>1.10,E 4/E 6<4.0)was proposed to evaluate the stabilization level of anaerobic digested sludge.展开更多
Synthetic micromotor has gained substantial attention in biomedicine and environmental remediation.Metal-based degradable micromotor composed of magnesium(Mg),zinc(Zn),and iron(Fe)have promise due to their nontoxic fu...Synthetic micromotor has gained substantial attention in biomedicine and environmental remediation.Metal-based degradable micromotor composed of magnesium(Mg),zinc(Zn),and iron(Fe)have promise due to their nontoxic fuel-free propulsion,favorable biocompatibility,and safe excretion of degradation products Recent advances in degradable metallic micromotor have shown their fast movement in complex biological media,efficient cargo delivery and favorable biocompatibility.A noteworthy number of degradable metal-based micromotors employ bubble propulsion,utilizing water as fuel to generate hydrogen bubbles.This novel feature has projected degradable metallic micromotors for active in vivo drug delivery applications.In addition,understanding the degradation mechanism of these micromotors is also a key parameter for their design and performance.Its propulsion efficiency and life span govern the overall performance of a degradable metallic micromotor.Here we review the design and recent advancements of metallic degradable micromotors.Furthermore,we describe the controlled degradation,efficient in vivo drug delivery,and built-in acid neutralization capabilities of degradable micromotors with versatile biomedical applications.Moreover,we discuss micromotors’efficacy in detecting and destroying environmental pollutants.Finally,we address the limitations and future research directions of degradable metallic micromotors.展开更多
文摘Background: Cosmetic formulations, and particularly solar products which contain mineral and chemical UV-filters, are often suspected of causing harmful effects on marine fauna and flora. After the publication of our work in 2019 concerning the ecotoxicological effects of such formulations on corals (Seriatopora hystrix), we here provide some new information about the biodegradability and the ecotoxicological effects of these products on marine zoo- and phytoplankton. Therefore, we choose to realize in silico and in vitro studies of the biodegradability of several solar products but also to evaluate the ecotoxicological effects of these products on one phytoplankton, i.e. Phaeodactylum tricornutum, and one zooplankton, i.e. Acartia tonsa, of a great importance for sea species survival (notably as sources of food). Materials and methods: Two different approaches were used to study the biodegradability of the tested products: One in silico method and an in vitro one. 2 solar products were involved in the in silico study which consisted in the determination of the degradation factor (DF) of each ingredient of the tested formulas in order to finally obtain their estimated biodegradability percentage. Already available data concerning each ingredient coupled to a computer model developed with one of our partners were used to achieve this study. The in vitro study involved 8 formulas containing UV-filters and was led by following the OECD 301 F guidelines. Ecotoxicological studies of 7 of the formulas containing UV-filters were for their part realized by following the ISO 10253 guidelines for the experiments led with Phaeodactylum tricornutum, and the ISO 14669 guidelines for the experiments led with Acartia tonsa. In these studies, the effect of each tested product on crustaceans’ mortality and algal growth inhibition was assessed. Results: The in silico study predicted that formulas containing chemical UV-filters display a high biodegradability (superior to the threshold value of 60% given by the OECD 301 F guidelines). In the in vitro part of our work, the 8 tested formulas showed a biodegradability slightly inferior to the one predicted in the in silico experiments. Therefore, in order to evaluate if these calculated biodegradability value could have significant harmful effects on zoo- or phytoplankton, we studied the effect of our products regarding the growth inhibition on Phaeodactylum tricornutum and the mortality on Acartia tonsa. In this last part of the study, all the tested products were classified as “non ecotoxic” following an internal classification based on Part 4 entitled “Environmental Hazards” of Globally Harmonized System of Classification and Labelling of Chemicals (GHS), 9<sup>th</sup> edition (2021). Conclusions: These results are notably in line with those published by our teams in 2019 on the effects of solar cosmetic products on corals and seem to confirm that formulas containing mineral and chemical UV-filters can be daily used without displaying significant noxious effects on marine fauna and flora. .
文摘In this paper, the influence of inorganic salt on aerobic biodegradability of dyestuffs was studied by means of semi continuous activated sludge method. It was found that: biodegradability of dyestuffs would decrease with the increase of the concentration of NaCl; however, biodegradability in the condition of NaCl=30 g/L was better than that in the condition of NaCl=15 g/L; in the three NaCl conditions, biodegradability of tested dyestuffs followed the following order: NaCl=0 g/L > NaCl=30 g/L>NaCl=15 g/L.
基金financial support from the National Defense Science Technology Foundation (Project No.3604003)the National Natural Science Foundation of China (Project No.51375491)+2 种基金the Natural Science Foundation of Chongqing (Project No. CSTC, 2014JCYJAA50021)the Postgraduate Research and the Innovation Project of Chongqing (No. CYB 18128)the Natural Science Foundation of Chongqing (Project No. CSTC, 2017JCYJAX0058)
文摘The influence of synthetic caprylic methyl diethanolamine phosphate ester (abbreviated as MDEACP) on biodegradability and tribological properties of 400SN mineral base oil was studied. The biodegradability of the neat base oil and the oil doped with MDEACP was determined on a biodegradation tester. The tribological properties of the neat base oil and the oil doped with MDEACP were evaluated on a four-ball tester. Moreover, the worn surfaces were investigated by scanning electron microscopy (SEM) and X-ray photoelectron spectroscopy (XPS). The results revealed that MDEACP significantly promoted the biodegradation of the mineral base oil. The improvement in biodegradability was attributed to the enhanced growth and quantity of microbes by MDEACP. Furthermore, MDEACP enhanced the anti-wear properties, the friction-reducing properties, and the extreme pressure properties of the base oil. It was mainly attributed to the formation of the complex boundary lubrication film resulted from the adsorption and tribochemical reactions of MDEACP on the friction surface.
基金National Natural Science Foundation of China(No.51173144)International Science&Technology Cooperation Program Supported by Ministry of Science and Technology of China and Shaanxi Province,China(No.2013KW14-02)+3 种基金Program for the Key Science and Technology Innovative Team of Shaanxi Province,China(No.2013KCT-05)China Postdoctoral Science Foundation(No.2014M562405)Natural Science Foundation of Shaanxi Province,China(No.2015JQ5137)Collaborative Innovation Center of Suzhou Nano Science and Technology,Suzhou Research Institute,China(No.BY2013036)
文摘Waterborne polyurethane(WBPU)with controlled biodegradability and biocompatibility was synthesized by using poly(ε-caprolactone)(PCL)as the polyglycol,isophorone diisocyanate(IPDI)as the isocyanate,2,2-bishydroxymethylbutyric acid(DMPA)as the chain extender and 1,4-butanediol(BDO)as the hard-segment regulating agent.We found that BDO content significantlyinfluencedmechanicalproperties,degradable performances and cyto-biocompatibility of PCL-WBPUs.Increasing the BDO content in PCL-WBPU enhanced its tensile strength and decreases strain.Enzymolysis and hydrolysis properties were also regulated by BDO content,but with different mechanisms.Cytobiocompatibility was evaluated with ATDC5 cells.The results show that the biodegradability of PCL-WBPU is significantly determined by BDO content,which exerts a serious influence on its polymer structure,leading to resultant degradable properties.
文摘In this paper, a rational test method for determining biodegradability of organic substanceunder aerobic conditions was established. Index of biodegradation was elaborated through analysis forbiodegradability of organic substances. 23 organic substance we
文摘Solid waste and air pollution are never ending environmental problems that can be partially solved by turning waste into useful bio-products. In this study, enzymatic solutions were developed by formulating enzymatic solutions from fish intestines and fruit peels. This aimed to help in biodegradation of organic solid wastes. Organic waste samples were treated with formulated enzymatic solutions for 7 days in aerated set-up for aerobic degradation. Biodegradability and odor of the waste samples were compared with commercial enzymatic solution. Determination of evolved carbon dioxide (CO2) using gravimetric analysis (GA) was used to determine the percent biodegradability, Dt, of organic solid waste and odor-ranking method was used to determine the odor intensity of the organic waste samples. The result showed that the weight loss and percentage biodegradability of organic waste sample treated with formulated enzymatic solution is comparable with that of the commercial enzymatic solution. In terms of odor intensity, waste treated with the product, formulated enzymatic solution (FES) is also comparable to the waste treated with commercial enzymatic solution. Thus, implying that the developed FES is as efficient as that of the commercial enzymatic solution. These significant results will be helpful to future researchers in providing ways on improving the degradation of organic solid waste and mitigating the increasing glitches on our environment. Enzyme kinetics, physical and chemical properties studies of the solution were recommended for future researchers to accurately determine the effectiveness of the formulated enzymatic solution in the degradation of organic solid waste.
文摘This work deals with the effect of combined microwave-ultrasonic pretreatment on the anaerobic biodegradability of primary, excess activated and mixed sludge. The characteristics, biodegradability and anaerobic digester performance for untreated primary, excess activated and mixed sludge were compared to combined microwave-ultrasonic pretreated primary, excess activated and mixed sludge. All sludge samples were subjected to Microwave treatment at 2450 MHz, 800 W and 3 min followed by ultrasonic treatment at a density of 0.4 W/mL, amplitude of 90%, Intensity of 150 W, pulse of 55/5 for 6min. Methane production in pretreated primary sludge was significantly greater (11.9 ml/g TCOD) than the methane yield of the untreated primary sludge (7.9 ml/g TCOD). Cumulative methane production of pretreated Excess Activated Sludge (EAS) was higher (66.5 ml/g TCOD) than the methane yield from pretreated mixed sludge (44.1 ml/g TCOD). Furthermore, digested EAS showed significantly higher dewaterability (201 s) than digested primary sludge (305 s) or mixed sludge (522 s). The average Methane: Carbondioxide ratio from EAS (1.85) was higher than that for mixed untreated sludge (1.24). VS reduction was also higher for EAS than the other two sludge types. However, pretreatment of EAS resulted in significant reduction in dewaterability due to higher percentage of fine floc particles in the pretreated EAS.
文摘Natural fiber reinforced composites have gained considerable attention particularly in the manufacturing industry owing to their light weight, corrosion resistance, abundance, and biodegradability. In this work, alkaline treated and untreated groundnut shell powder (GSP) was used to reinforce recycled polyethylene to produce GSP-recycled polyethylene composites with improved mechanical properties and biodegradability. GSP with particle sizes of 0 - 300 μm and 300 - 600 μm was used in different proportions: 5%, 10%, 15%, 20%, 25%, and 30% wt. The fiber was immersed for 5 hours in a 10 wt% NaOH solution. Tensile and hardness test data showed an improvement in mechanical properties of the treated fiber composites. Results of water absorption test also showed that treated GSP-recycled polyethylene composites had a lower rate of water absorption than the untreated GSP-recycled polyethylene composites. Through Fourier transform infrared spectroscopy, disappearance of characteristics peaks of hemicellulose and lignin was observed. Growth of fungi on the fiber-reinforced composites was observed, which was evidence that GSP-recycled polyethylene composite was biodegradable. Finally, SEM micrographs showed uniform distribution of treated fibers in the polymer matrix;this explained the observed improvement in the mechanical properties of treated GSP-recycled polyethylene composites.
基金financial supports from National Defense Science Technology Foundation (Project No.3604003)National Natural Science Foundation of China (Project No.51375491)+1 种基金Natural Science Foundation of Chongqing (Project No. CSTC 2014JCYJAA50021)Natural Science Foundation of Chongqing (Project No. cstc2017jcyjAX0058)
文摘Methyl diethanolamine fatty acid esters, viz. methyl diethanolamine octanoate and methyl diethanolamine oleate,were prepared. Their impacts on the biodegradability and tribological properties of mineral base oil 400 SN were evaluated by a tester for fast evaluating the biodegradability of lubricants and by a four-ball tester, respectively. The results showed that methyl diethanolamine octanoate and methyl diethanolamine oleate both could markedly promote the biodegradation of the oil and improved its tribological properties. The improvement of biodegradability was attributed to the enhanced growth and quantity of microbes by methyl diethanolamine fatty acid esters. The worn surfaces were analyzed by a scanning electron microscope(SEM) equipped with an energy dispersive spectrometer(EDS) and an X-ray photoelectron spectroscope(XPS). The results indicated that the enhancement of friction-reducing and anti-wear properties of the mineral oil was attributed to the formation of complicated boundary lubrication films composed of species such as Fe_2O_3, Fe_3O_4 and organic nitrogen-containing compounds with a structure of –C-N-or R-NH_2.
基金This work was financially supported by the Science and Technology Innovation Program of Hunan Province(Contract Grant No.2018RS3101).
文摘Lignin is the most abundant heteropolymer based on aromatic subunits in nature.Large quantities of lignin are annually produced from pulping processes and biorefinery industries.Its unclearly defined structure and difficult biodegradation mainly limit its utilization.This work focused on the effect of hydroxylation of lignin on its microbial degradation.Butyloxy carbonyl-modified lignin,and hydroxylated-lignin were synthesized with di-tert-butyl dicarbonate and hydrogen peroxide,respectively,using lignin as raw material.The degradation of the modifiedlignins both by P.chrysosporium and B.subtilis were analyzed using UV-vis spectroscopy.Results revealed that the lignin degradation velocity raises with the increase hydroxylation level of lignin.Moreover,FTIR and 1H NMR analysis of the biodegradation products of lignin further indicated that higher content of hydroxyl groups in lignin facilitated the demethylation combined with the aromatic ring cracking in the presence of fungus and bacteria.
文摘Blends of biodegradable copolymer based on starch, poly lactic acid (PLA), poly vinyl alcohol (PVA) and natural rubber (NR) have been prepared. Gamma radiation induced synthesis and modification of polymer hydrogel was studied. The polymer blends have been chemically surface modified by glycerol. The modified polymer blends have been investigated for swelling ratio, tensile strength and 9 scanning electron microscopy. The swelling ratio of polymer blends increased significantly after surface modification with glycerol. The swelling of polymer was decreased as a function of (NR) content in polymer blends. The gel fraction (PVA-starch-PLA) and (PVA-starch-NR) blends increased by increasing the radiation doses (kGy) to reach the maximum amount of (~99%) and (~88.2%), respectively. Addition of 2.5% (PLA) led to greater increase of the swelling ratio than 10% (NR) to blends and the maximum swelling was found at dose (5 kGy). At concentration of glycerol (5.0% w/w), tensile strength decreased and elongation at break % increased. The polymers degrading microorganisms were isolated from soil samples. The degradation ability of the microbial isolates for each polymeric material was tested on agar plates. Among these isolates, the most efficient degrader isolates for prepared blends in MSM shaking flasks were selected and the degradation was confirmed by scanning electron microscopy.
文摘Material efficiency is nowadays an essential topic to promote the sustainable use of natural resources, waste materials and industrial by-products, in agreement with the principle of sustainable development and LCA (life cycle assessment). In this research it was determined the biodegradation of used vegetable oil based products and their important physico- chemical properties for their suitability in different applications such as chain oil in the forestry equipment and mold oil in concrete casting etc. Biodegradability is a measure of the ecological nature of products, and thus from an environ- mental point of view, is the most important evaluated property in this research. As a result, all measured properties of the studied recycled vegetable oils show that the products are environmentally friendly. Two types of vegetable oil were studied;three chain oils and two mold oils. The degree of biodegradation (BOD28) of the mold oils, was about 77 % and the biodegradation of chain oils was about 60% - 62%. In addition, this paper also presents a process outline for manu- facturing recycling vegetable oils.
基金National Key R&D Program of China(2018YFE0201500)National Natural Science Foundation of China(81772317,82272457 and 51973060)+4 种基金National Natural Science Foundation of China for Innovative Research Groups(51621002)“Technology Innovation Action Plan”of Shanghai Science and Technology Commission(21S11902700)Natural Science Foundation of Shanghai(21ZR1412300)Shanghai Talent Development Fund(2020067)Shanghai“Rising Stars of Medical Talent”Youth Development Program(Youth Medical Talents–Specialist Program,[2020]087).
文摘Injectable materials show their special merits in regeneration of damaged/degenerated bones in minimally-invasive approach.Injectable calcium phosphate bone cement(CPC)has attracted broad attention for its bioactivity,as compared to non-degradable polymethyl methacrylate cement.However,its brittleness,poor anti-washout property and uncontrollable biodegradability are the main challenges to limit its further clinical application mainly because of its stone-like dense structure and fragile inorganic-salt weakness.Herein,we developed a kind of injectable CPC bone cement with porous structure and improved robustness by incorporating poly(lactide-co-glycolic acid)(PLGA)nanofiber into CPC,with carboxymethyl cellulose(CMC)to offer good injectability as well as anti-wash-out capacity.Furthermore,the introduction of PLGA and CMC also enabled a formation of initial porous structure in the cements,where PLGA nanofiber endowed the cement with a dynamically controllable biodegradability which provided room for cell movement and bone ingrowth.Inter-estingly,the reinforced biodegradable cement afforded a sustainable provision of Ca^(2+)bioactive components,together with its porous structure,to improve synergistically new bone formation and osteo-integration in vivo by using a rat model of femur condyle defect.Further study on regenerative mechanisms indicated that the good minimally-invasive bone regeneration may come from the synergistic enhanced osteogenic effect of calcium ion enrichment and the improved revascularization capacity contributed from the porosity as well as the lactic acid released from PLGA nanofiber.These results indicate the injectable bone cement with high strength,anti-washout property and controllable biodegradability is a promising candidate for bone regeneration in a minimally-invasive approach.
基金the Australian Research Council(ARC)through the discovery grant DP210101862。
文摘Biodegradable implants from magnesium(Mg)alloys have emerged in the biomedical field especially in the orthopedic and cardiovascular stent applications owing to their low density,high specific strength,excellent machinability,good biocompatibility,and biodegradability.The primary shortcoming of Mg-based implants is their low corrosion resistance in the physiological environment,which results in premature mechanical integrity loss before adequate healing and the production of excessive hydrogen gas,which is harmful to the body tissues and negatively affects the biocompatibility of the implant.Laser surface modification has recently received attention because it can improve the surface properties such as surface chemistry,roughness,topography,corrosion resistance,wear resistance,hydrophilicity,and thus cell response to the surface of the material.The composition and microstructures including textures and phases of laser-treated surfaces depend largely on the laser processing parameters(input laser power,laser scan velocity,frequency,pulse duration,pressure,gas circulation,working time,spot size,beam focal position,and laser track overlap)and the thermophysical properties of the substrate(solubility,melting point,and boiling point).This review investigates the impacts of various laser surface modification techniques including laser surface melting,laser surface alloying,laser cladding,laser surface texturing,and laser shock peening,and highlights their significance in improving the surface properties of biodegradable Mg alloys for implant applications.Additionally,we explore how different laser process parameters affect its composition,microstructure,and surface properties in each laser surface modification technique.
基金This study was supported by the Nation Water Pollution Control and Management of Major Special Science and Technology of China(No.2008ZX07314-001-02)the Key Projects in the National Science&Technology Pillar Program during the“Eleventh Five Year Plan”period(No.2009BAC60B02)the State Key Laboratory of Pollution Control and Resource Reuse Foundation(No.PCRRF10013).
文摘Actual pharmaceutical wastewater was treatedusing a combined ultrasonic irradiation (US) and iron/cokeinternal electrolysis (Fe/C) technology. A significantsynergetic effect was observed, showing that ultrasonicirradiation dramatically enhanced the chemical oxygendemand (COD) removal efficiencies by internal electrolysis.The effects of primary operating factors on CODremoval were evaluated systematically. Higher ultrasonicfrequency and lower pH values as well as longer reactiontime were favorable to COD removal. The ratio ofbiochemical oxygen demand (BOD) and COD (B/C) ofthe wastewater increased from 0.21 to 0.32 after US-Fe/Ctreatment. An acute biotoxicity assay measuring theinhibition of bioluminescence indicated that the wastewaterwith overall toxicity of 4.3 mg-Zn^(2+)·L^(-1) wasreduced to 0.5 mg-Zn^(2+)·L^(-1) after treatment. Both the rawand the treated wastewater samples were separated andidentified. The types of compounds suggested that theincreased biodegradability and reduced biotoxicityresulted mainly from the destruction of N,N-2 dimethylformamide and aromatic compounds in the pharmaceuticalwastewater.
基金financially supported by the National Natural Science Foundation of China (Nos. 31300808 and 31400815)the Scientific and Technological Innovation Programs of Higher Education Institutions in Shanxi (No. 201417)the Natural Science Foundation of Shanxi Province (No. 2013021011-1)
文摘This study aims to investigate the addition of Zn on the corrosion property and cytocompatibility of Mg- 2Gd-xZn (x = 0, 3, 4 and 5;wt%) alloys, which were prepared by gravity permanent mold casting and solution treatment, respectively. The results show that the intermetallic phases of these ternary alloys are mainly composed of Mg12GdZn and Mg3GdZn3. The content of secondary phases as well as the grain size is greatly dependent on the Zn addition. Compared to the binary Mg- 2Gd alloy, the corrosion resistance of the most ternary alloys is significantly improved. Furthermore, the in vitro cell culture study demonstrates the potential cytocompatibility of the developed ternary alloys. It indicates that a series of Mg-2Gd-xZn (x = 0, 3, 4 and 5;wt%) with medically acceptable corrosion rate are developed and show great potential use as a new type of biodegradable implants.
文摘The present work reports the inclusion of different proportions of Mango/Sheesham/Mahogany/Babool dust to polypropylene for improving mechanical,wear behavior and biodegradability of wood-plastic composite(WPC).The wood dust(10%,15%,20%by weight)was mixed with polypropylene granules and WPCs were prepared using an injection molding technique.The mechanical,wear,and morphological characterizations of fabricated WPCs were carried out using standard ASTM methods,pin on disk apparatus,and scanning electron microscopy(SEM),respectively.Further,the biodegradability and resistance to natural weathering of WPCs were evaluated following ASTM D5338-11 and ASTM D1435-99,respectively.The WPCs consisting ofBabool and Sheesham dust were having superior mechanical properties whereas the WPCs consisting of Mango and Mahogany were more wear resistant.It was found that increasing wood powder proportion results in higher Young's modulus,lesser wear rate,and decreased stress at break.The WPCs made of Sheesham dust were least biodegradable.It was noticed that the biodegradability corresponds with resistance to natural weathering;more biodegradable WPCs were having the lesser resistance to natural weathering.
基金Shanghai Technology Leader Program(No.17XD1420500)National Key R&D Program of China(No.2018YFC1900905)。
文摘Evaluating anaerobic biodegradability of sludge and then identifying the stabilization of digestate is necessary in sludge treatment and disposal.48 sludge samples from 24 typical waste water treatment plants(WWTPs)in 11 provinces in China were selected to investigate the relationship between Biochemical Acidogenic Potential(BAP)test and Biochemical Methane Potential(BMP)test.The volatile fatty acid(VFA)production obtained from BAP tests was found linearly related to the ultimate methane production from corresponding BMP tests.Satisfying results were obtained with Pearson correlation coefficient as 0.929 and R^2 value as 0.76.Furthermore,the physio-chemical characteristics(FCI,SUVA254,E 4/E 6)of supernatant,which were associated with humic-like substances(HS),were investigated before and after BMP tests.Through which a new criterion(FCI>1.50,SUVA 254>1.10,E 4/E 6<4.0)was proposed to evaluate the stabilization level of anaerobic digested sludge.
基金the National Convergence Research of Scientific Challenges through the National Research Foundation of Korea(NRF)the DGIST R&D Program(No.2021M3F7A1082275 and 23-CoE-BT-02)funded by the Ministry of Science and ICT.
文摘Synthetic micromotor has gained substantial attention in biomedicine and environmental remediation.Metal-based degradable micromotor composed of magnesium(Mg),zinc(Zn),and iron(Fe)have promise due to their nontoxic fuel-free propulsion,favorable biocompatibility,and safe excretion of degradation products Recent advances in degradable metallic micromotor have shown their fast movement in complex biological media,efficient cargo delivery and favorable biocompatibility.A noteworthy number of degradable metal-based micromotors employ bubble propulsion,utilizing water as fuel to generate hydrogen bubbles.This novel feature has projected degradable metallic micromotors for active in vivo drug delivery applications.In addition,understanding the degradation mechanism of these micromotors is also a key parameter for their design and performance.Its propulsion efficiency and life span govern the overall performance of a degradable metallic micromotor.Here we review the design and recent advancements of metallic degradable micromotors.Furthermore,we describe the controlled degradation,efficient in vivo drug delivery,and built-in acid neutralization capabilities of degradable micromotors with versatile biomedical applications.Moreover,we discuss micromotors’efficacy in detecting and destroying environmental pollutants.Finally,we address the limitations and future research directions of degradable metallic micromotors.
