Municipal wastewater treatment has long been known as a high-cost and energy-intensive process that destroys most of the energy-containing molecules by spending energy and that leaves little energy and few nutrients a...Municipal wastewater treatment has long been known as a high-cost and energy-intensive process that destroys most of the energy-containing molecules by spending energy and that leaves little energy and few nutrients available for reuse, Over the past few years, some wastewater treatment plants have tried to revamp themselves as "resource factories," enabled by new technologies and the upgrading of old technologies. In particular, there is an renewed interest in anaerobic biotechnologies, which can convert organic matter into usable energy and preserve nutrients for potential reuse. However, considerable technological and economic limitations still exist. Here, we provide an overview of recent advances in several cutting-edge anaerobic biotechnologies for wastewater treatment, including enhanced side- stream anaerobic sludge digestion, anaerobic membrane bioreactors, and microbial electrochemical systems, and discuss future challenges and opportunities for their applications. This review is intended to provide useful information to guide the future design and optimization of municipal wastewater treatment processes.展开更多
In this review paper, Anaerobic Membrane Bioreactor (AnMBR) is considering as highly efficient and reliable technology for organic material removal from wastewater with no additional energy requirement for aeration. A...In this review paper, Anaerobic Membrane Bioreactor (AnMBR) is considering as highly efficient and reliable technology for organic material removal from wastewater with no additional energy requirement for aeration. AnMBR is a combination of conventional anaerobic technology and modern membrane system. AnMBR is cost effective alternative technology with pros of anaerobic microbial activity because Methogenic microorganism can convert organic pollutant load of wastewater into renewable energy in the form of methane rich biogas, this conversion is mainly done by transformation of organic matter into energy by high chemical oxygen demand (COD), total suspended solid (TSS) and pathogens removal. Methane rich biogas can be used as a storable source of supplemental energy for the production of heat or power thus AnMBR technology provides improved effluent quality, reliability, and efficiency over the other traditional technologies. This review paper is included the overview of AnMBR, the advantages over other wastewater treatment technology, operational constraints and the concerned factors that has affected the performances of implemented systems, applications of AnMBR for various types of wastewaters, research and development summary and future perspective for further research.展开更多
This paper focuses on the recent research in the development of anaerobic membrane bioreactors in wastewater treatment. Anaerobic wastewater treatment technology is gaining increasing attention due to its capacity to ...This paper focuses on the recent research in the development of anaerobic membrane bioreactors in wastewater treatment. Anaerobic wastewater treatment technology is gaining increasing attention due to its capacity to convert wastewater BODs to usable biogas with relatively low energy consumption. The anaerobic membrane bioreactor (AnMBR), which is a combination of the anaerobic biological wastewater treatment process and membrane filtration, represents a recent development in the high-rate anaerobic bioreactors. This paper reviews applications and performances of AnMBR and the membrane filtration behaviour in AnMBRs.展开更多
The development of a process that could recover biofuel from industrial cellulose waste can not only reduce the negative environmental impacts by using fossil fuels, but also bring a green idea for the waste’s dispos...The development of a process that could recover biofuel from industrial cellulose waste can not only reduce the negative environmental impacts by using fossil fuels, but also bring a green idea for the waste’s disposing. In this study, hydrothermal pretreatment was optimized for cassava anaerobic residue, a cellulosic waste from cassava ethanol industry, to co-utilize xylose and glucose for producing bioethanol. The effect of the main pretreatment conditions, namely, temperature, solid content and time, was explored for the highest recovery of xylose in prehydrolysate and glucose in enzymatic hydrolysate. The single factor experiment results showed that the conditions for maximum xylose recovery in prehydrolysate and glucose recovery in enzymatic hydrolysate were 60℃, 75 min, 10% solids and 160℃, 75 min, 10% solids, respectively. Whereafter, response surface methodology(RSM) was applied to further optimize the pretreatment conditions for the maximum theoretical ethanol production through utilizing both xylose and glucose. A treatment at 163℃, for 59 min and with 9.5%solids was found optimal, with the highest ethanol production of 20.2 mg·g^-1 raw material. Furthermore, in order to assess the impacts of the pretreatment on cassava anaerobic residue, the changes in crystallinity and morphology for untreated and pretreated solids were investigated.展开更多
Waste disposal management and the energy crisis are important challenges facing most countries.The fruit-processing industry generates daily several tons of wastes,of which the major share comes from banana farms.Anae...Waste disposal management and the energy crisis are important challenges facing most countries.The fruit-processing industry generates daily several tons of wastes,of which the major share comes from banana farms.Anaerobic digestion(AD)technology has been applied to the treatment of wastewater,animal slurry,food waste,and agricultural residues,with the primary goals of energy production and waste elimination.This study examines the effect of organic loading(OL)and cow manure(CM)addition on AD performance when treating banana peel waste(BPW).The maximum daily biogas production rates of banana peels(BPs)with a CM content of 10%,20%,and 30%at 18 and 22 g of volatile solids(gvs)per liter were 50.20,48.66,and 62.78 mL (gvs.d)^-1 and 40.49,29.57,and 46.54 mL (gvs.d)^-1,respectively.However,the daily biogas yield showed no clear interdependence with OL or CM content.In addition,a kinetic analysis using first-order and cone models showed that the kinetic parameters can be influenced by the process parameters.展开更多
The paper provides a critical comparison between mesophilic and thermophilic anaerobic treatment of PTA wastewater through diagnosis of a case study. Aspects covered are bioavailability, biodegradability, microbial po...The paper provides a critical comparison between mesophilic and thermophilic anaerobic treatment of PTA wastewater through diagnosis of a case study. Aspects covered are bioavailability, biodegradability, microbial population, thermodynamics, kinetics involved and bio-reactor design for PTA wastewater treatment. The results of the case study suggests that one- stage thermophilic anaerobic reactor coupled with coagulation-flocculation pre-treatment unit and an aerobic post treatment unit could be techno-economically viable for PTA wastewater treatment to ensure that the final effluent quality conforms to the international standard. The in-formation emanated from this study could be useful and thought provoking to the professionals and academia in the area of PTA wastewater treatment and can serve as impetus toward the development of research lines in similar problems like the treatment of other petrochemical wastewater such as phenol-con- taining wastewater, benzene/benzoic acid-con- taining wastewater or wastewater from other similar industrial settings.展开更多
[Objectives]The research was to explore the antifungal effects of citronellal,wintergreen oil and their composite essence on Penicillium citrinum.[Methods]The inhibition zones of citronellal,wintergreen oil and their ...[Objectives]The research was to explore the antifungal effects of citronellal,wintergreen oil and their composite essence on Penicillium citrinum.[Methods]The inhibition zones of citronellal,wintergreen oil and their composite essence against P.citrinum were determined by disk diffusion method,and the growth of inhibition zone plate was observed.The fumigation fungicidal rate of fungi-bearing rice paper within 7 d was determined by plate counting method.[Results]Citronellal had strong antifungal effect,and wintergreen oil could slow down the growth rate of P.citrinum.The combination of citronellal and wintergreen oil had a synergistic effect.As fumigants,both citronellal and composite essence had fungicidal rates up to 100%within 7 d.Combined with anaerobic treatments,all the three essential oils could improve the fungicidal efficiency.The adsorbent in deoxidizing agent would adsorb the essential oils,so that their fumigation had a certain slow release effect.[Conclusions]This study can provide a more friendly and efficient method for the prevention and control of cultural relics mold.展开更多
Phosphorus is an irreplaceable and depletable element. Furthermore, it has an almost one-way circulation on earth, so it is necessary to close the phosphorus cycle loop. Phosphorus could be recovered as struvite, whic...Phosphorus is an irreplaceable and depletable element. Furthermore, it has an almost one-way circulation on earth, so it is necessary to close the phosphorus cycle loop. Phosphorus could be recovered as struvite, which is a good slow-released fertilizer for agriculture. The supernatant of anaerobic digestion used to treat sludge from wastewater treatment plant is one main source from which phosphorus can be recovered. Studies have proven that phosphorus recovery from digester supematant is a feasible choice to preserve phosphorus rock technically and economically. A modified "PHOSNIX" P-recovery process was applied under the operating conditions of a 9.0 pH value and a 1.8 mg: P ratio with the influent of the centrate coming from the sludge centrifuge of the Songjiang Wastewater Treatment Plant in Shanghai. More than 80% influent phosphorus was recovered as struvite. Crystal products with good purity and low heavy metal content were gained. The largest crystal had a length of up to 0.26 mm. It was found in our study that the reaction time did not play an important role in crystal growth. Therefore, the optimization of the reaction condition for crystal growth should be examined in future study.展开更多
Along with the development and progress of environmental protection management,it is necessary to pay full attention to the disposal of excess sludge in the process of urban sewage treatment plant management.It is nec...Along with the development and progress of environmental protection management,it is necessary to pay full attention to the disposal of excess sludge in the process of urban sewage treatment plant management.It is necessary to ensure effective integration of management mechanisms and management paths.To a certain extent,it can improve the actual efficiency of digestion and treatment work and lay a foundation for the optimal operation of environmental protection management.In this paper,the treatment of excess sludge in a sewage treatment plant is studied.The method and results of anaerobic digestion test of excess sludge in a sewage treatment plant are discussed for reference only.展开更多
Anaerobic digestion is a good method, which possesses the optimal combination of volume reduction, probability of success and potential for resource and energy recovery. However, relatively little research has been do...Anaerobic digestion is a good method, which possesses the optimal combination of volume reduction, probability of success and potential for resource and energy recovery. However, relatively little research has been done on the anaerobic digestion of organic solid wastes (OSW), especially in China. However, different substrates, start-up conditions, micro-organisms, processing technologies, pre-treatment methods could influence the result of anaerobic digestion. Anaerobic treatment of municipal OSW is less than that of wastewaters because some problems and obstructions need to be solved. Meanwhile, the application of anaerobic digestion of OSW is also discussed in the present paper.展开更多
Anaerobic treatment could effectively degrade organic chlorine. Reductive dechlorination mechanisms were confirmed through GC-MS analysis during anaerobic treatment of pulp bleachery effluents, the influence of sulfid...Anaerobic treatment could effectively degrade organic chlorine. Reductive dechlorination mechanisms were confirmed through GC-MS analysis during anaerobic treatment of pulp bleachery effluents, the influence of sulfide biologically produced and pH on the dechlorination revealed that nucleophilic substitution and alkaline hydrolysis were also nonbiological mechanisms.展开更多
This paper illustrates the general experiment principle of anaerobic biological cotton pulp black liquor microbial degradation, including the process and result of experiment. The result shows that the decrement of CO...This paper illustrates the general experiment principle of anaerobic biological cotton pulp black liquor microbial degradation, including the process and result of experiment. The result shows that the decrement of COD may arrive at 80% by the strengthen effect of Photosynthetic Bacteria. The biochemical methane Potential (BMP) and Chemical Oxygen Demand (COD) of cotton pulp black liquor are also measured during the experiment using improved measure method. The equivalent of COD and BMP is verified as a result. Finally analysis is done based on the experiment result.展开更多
To investigate the impact of anaerobic soil disinfestation(ASD)treatment with different processing duration on tomato continuous cropping soil,a total of eight treatments were designed,which included two treatment tem...To investigate the impact of anaerobic soil disinfestation(ASD)treatment with different processing duration on tomato continuous cropping soil,a total of eight treatments were designed,which included two treatment temperatures of 10℃ and 30℃,and four treatment times of 3,4,5 and 7 weeks(w).The results showed that whether the temperature was 10℃ or 30℃,the pH values,TOC and available K contents in the soil treated by the ASD method were significantly increased(P<0.05),while the EC values and NO_(3)^(-)contents in soils treated by ASD were significantly reduced compared with the untreated group(P<0.05).The Fusarium oxysporum population in soils treated by ASD decreased with the extension of the treatment time.When the treatment temperature was 30℃,the effect on the removal of the NO_(3)^(-)that had accumulated in soils treated by ASD was significantly better than the treatment temperature of 10℃(P<0.05).When soil was treated by ASD for more than 5 w at 30℃,the NH4+content in soil was significantly increased(P<0.05)compared with the untreated soil.In conclusion,NO_(3)^(-)accumulation in soils could not be completely eliminated with treatment by ASD,even when the treatment time at 10℃ was prolonged.Whether the treatment temperature was 10℃ or 30℃,the F.oxysporum population in soils treated by ASD decreased significantly with the extension of the treatment time to more than 5 w compared with treatment only for only 3 w.展开更多
Periodic anaerobic baffled reactor (PABR) is a novel reactor based on the design concept of anaerobic baffled reactor (ABR). Residence time distribution (RTD) studies on both clean and working reactors at the sa...Periodic anaerobic baffled reactor (PABR) is a novel reactor based on the design concept of anaerobic baffled reactor (ABR). Residence time distribution (RTD) studies on both clean and working reactors at the same hydraulic residence time (HRT) of 2 d were carded out to investigate the dead spaces and mixing patterns in PABRs at different organic loading rates (OLRs) in various switching manners and frequencies. The results showed that the fraction of dead space in PABR was similar to that in ABR, which was low in comparison with other reactor designs. Dead space may be divided into two categories, hydraulic and biological. In RTD studies without biomass, the hydraulic dead space in the PABR run in an "every second" switching manner with T = 2 d was the lowest whereas that in the PABR run in a T = ∞ (ABR) switching manner was the highest. The same trend was obtained with the total dead space in RTD studies with biomass no matter what the OLR was. Biological dead space was the major contributor to dead space but affected decreasingly at higher OLR whichever switching manner the PABR run in. The flow patterns within the PABRs were intermediate between plug-flow and perfectly mixed under all the conditions tested,展开更多
The high strength easily biodegradable pollutants (represented by COD E) are strong inhibitors of terephthalic acid (TA) anaerobic biodegradation. At the same time, TA can inhibit easily biodegradable pollutants remo...The high strength easily biodegradable pollutants (represented by COD E) are strong inhibitors of terephthalic acid (TA) anaerobic biodegradation. At the same time, TA can inhibit easily biodegradable pollutants removal under anaerobic conditions to a limited extent. This mutual inhibition could happen and cause a low removal efficiency of both TA and COD E, when the effluent from TA workshops containing TA and easily biodegradable pollutants are treated by a single anaerobic reactor system. Based upon the treatment kinetics analysis of both TA degradation and COD E removal, a two stage up flow anaerobic sludge blanket and up flow fixed film reactor(UASB UAFF) system for dealing with this kind of wastewater was developed and run successfully at laboratory scale. An UASB reactor with the methanogenic consortium as the first stage removes the easily biodegradable pollutants(COD E). An UAFF reactor as the second stage is mainly in charge of TA degradation. At a COD E loading of 15.3 g/(L\5d) and a TA loading of 1.4 g/(L\5d), HRT 18.5h, the COD E and TA removal rate of the system reached 89.2% and 71.6%, respectively.展开更多
A novel anaerobic reactor, jet biogas inter-loop anaerobic fluidized bed (JBILAFB), was designed and constructed. The start-up and performance of the reactor was investigated in the Process. of .artificial glucose w...A novel anaerobic reactor, jet biogas inter-loop anaerobic fluidized bed (JBILAFB), was designed and constructed. The start-up and performance of the reactor was investigated in the Process. of .artificial glucose wastewater treatment. With the wastewater recycle ratio of 2.5 : 1, the recycled wastewater with biogas could mix sludge and wastewater in the JBILAFB reactor completely. The start-up of the JBILAFB reactor could be completed in less than 70 d through maintenance of hydraulic retention time (HR^I") and stepwise increase of feed total organic carbon (TOC) concentration. After the start-up, with the volumetric TOC loadings of 14.3 kg·m ^-3·d^-1, the TOC removal ratio, the effluent pH, and the volatile fatty acids (VFA)/alkalinity of the JBILAFB reactor were more than 80%, close to 7.0 and less than 0.4, respectively. Moreover, CH4 was produced at more than 70% of the theoretical value, The reactor exhibited high stability under the condition of high volumetric TOC loading. Sludge granules in the JBILAFB reactor were developed during the start-up and their sizes were enlarged with the stepwise increase of volumetric TOC loadings from 0.8 kg.m^-3.d ^-1 to 14.3 kg.m^-3.d^-1. Granules, an offwhite color and a similar spherical shape, were mainly comprised of global-like bacteria. These had good methanogenic activity and settleability, which were formed probably through adhesion of the bacteria. Some inorganic metal compounds such as Fe, Ca, Mg, Al, etc. were advantageous to the formation of the granules.展开更多
Two runs of experiments were carried out to obtain an understanding of phosphorus release and uptake under the anaerobic condition and then the aerobic condition respectively. Under anaerobic condition, it was found t...Two runs of experiments were carried out to obtain an understanding of phosphorus release and uptake under the anaerobic condition and then the aerobic condition respectively. Under anaerobic condition, it was found that the extent of phosphorus release appeared to increase with the increase of the initial organic loading rate when the initial organic loading rate was up to 0.1 gSCOD/gMLSS. When the initial organic loading rate was higher than 0.1 gSCOD/gMLSS, the amount of phosphorus release per unit mass of MLSS reached nearly a same stationary value, and it seemed this is not affected by organic loading rate when there is external available substrate remained. In addition, the effect of NOx-N on the phosphorus release and uptake was also investigated, it was proved that the denitrifiers has an advantage over polyphosphate accumulating bacteria in competition for organic substrate under anoxic condition. Therefore, the existence of NOx-N is disadvantageous to the phosphorus release. Based upon the above investigations, the process configuration of membrane bioreactor(MBR) in combination with anaerobic phase was proposed to enhance the removal of phosphorus in treating domestic wastewater. During the experimental period of four months, average removals of 92.50%, 84.25%, 100%, 94.09% and 85.33% were achieved for COD, TP, SS, NH_3-N and TN respectively.展开更多
Taking the anaerobic digestion products of sludge as the object, through the analysis on the development of garden substrate market at home and abroad and the development status of horticultural products from the anae...Taking the anaerobic digestion products of sludge as the object, through the analysis on the development of garden substrate market at home and abroad and the development status of horticultural products from the anaerobic digestion products, the direction for the utilization of the anaerobic digestion products of sludge was pointed out. Based on the demand of Chongqing’s garden market, this paper analyzed the potential utilization of sludge anaerobic digestion products in Chongqing, and briefly introduced the research status of landscaping utilization of sludge anaerobic digestion products in Chongqing, in order to provide reference for the industry.展开更多
Anaerobic treatment model treats fish processing wastewater to be necessary for a small and medium factory that is very popular in Vietnam and other countries.Several techniques have been proposed.However,they are qui...Anaerobic treatment model treats fish processing wastewater to be necessary for a small and medium factory that is very popular in Vietnam and other countries.Several techniques have been proposed.However,they are quite expensive and hard to operate,especially in remote areas.In this study,the hydraulic retention times(HRT)including 3,5,and 7 hours with a various organic loading rate of 1.5 to 6.5 kg COD/m3/day were investigated.Biomass concentration as mix-liquor volatile suspended solid(MLVSS)in the model is at 6,000 to 9,000 mg/L.On the basis of the result the optimal HRT with a 4.0 kg COD/m3/day organic loading rate was 8 hours which BOD5,COD removal efficiency were 92.18,87.36 percent respectively.By the end of the optimal hydraulic retention times,the total methane gas volume as a by-product was collected with 2.6 liters.展开更多
Anaerobic digestion is often used as an approach to deal with high COD waste streams. Compared to the aeration systems it allows better energy management due to the biogas production but also has several limitations i...Anaerobic digestion is often used as an approach to deal with high COD waste streams. Compared to the aeration systems it allows better energy management due to the biogas production but also has several limitations including inlet waste streams quality and the additional equipment required for energy harvesting. In recent years, the bio-electrochemical systems (BES) and processes are intensively studied as a method for organic waste utilization, including wastewater. They potentially could bring several benefits to the wastewater treatment, mainly due to avoiding aeration (and aeration cost) and direct energy recovering in the form of electricity. Besides their anaerobic nature, the biological processes in BES are respiration-like contrary to the fermentative degradation typical for conventional anaerobic digestion which eventually will provide better mineralization and higher efficiency in terms of COD and BOD removal in such reactors. This study is a direct comparison between conventional anaerobic digestion and Microbial Fuel Cell (as a typical BES reactor) during utilization of wastewater from industrial production of ethanol by fermentation. COD removal rates and dynamics, energy recovery properties and parameters such as secondary sludge production are investigated in order to characterize the feasibility and technological readiness of BES as a step towards their commercialization.展开更多
基金Acknowledgements The authors wish to thank the National Natural Science Foundation of China (51522811 and 51278479), and the NSFC-RGC fund (21261160489) for the support of this work.
文摘Municipal wastewater treatment has long been known as a high-cost and energy-intensive process that destroys most of the energy-containing molecules by spending energy and that leaves little energy and few nutrients available for reuse, Over the past few years, some wastewater treatment plants have tried to revamp themselves as "resource factories," enabled by new technologies and the upgrading of old technologies. In particular, there is an renewed interest in anaerobic biotechnologies, which can convert organic matter into usable energy and preserve nutrients for potential reuse. However, considerable technological and economic limitations still exist. Here, we provide an overview of recent advances in several cutting-edge anaerobic biotechnologies for wastewater treatment, including enhanced side- stream anaerobic sludge digestion, anaerobic membrane bioreactors, and microbial electrochemical systems, and discuss future challenges and opportunities for their applications. This review is intended to provide useful information to guide the future design and optimization of municipal wastewater treatment processes.
文摘In this review paper, Anaerobic Membrane Bioreactor (AnMBR) is considering as highly efficient and reliable technology for organic material removal from wastewater with no additional energy requirement for aeration. AnMBR is a combination of conventional anaerobic technology and modern membrane system. AnMBR is cost effective alternative technology with pros of anaerobic microbial activity because Methogenic microorganism can convert organic pollutant load of wastewater into renewable energy in the form of methane rich biogas, this conversion is mainly done by transformation of organic matter into energy by high chemical oxygen demand (COD), total suspended solid (TSS) and pathogens removal. Methane rich biogas can be used as a storable source of supplemental energy for the production of heat or power thus AnMBR technology provides improved effluent quality, reliability, and efficiency over the other traditional technologies. This review paper is included the overview of AnMBR, the advantages over other wastewater treatment technology, operational constraints and the concerned factors that has affected the performances of implemented systems, applications of AnMBR for various types of wastewaters, research and development summary and future perspective for further research.
文摘This paper focuses on the recent research in the development of anaerobic membrane bioreactors in wastewater treatment. Anaerobic wastewater treatment technology is gaining increasing attention due to its capacity to convert wastewater BODs to usable biogas with relatively low energy consumption. The anaerobic membrane bioreactor (AnMBR), which is a combination of the anaerobic biological wastewater treatment process and membrane filtration, represents a recent development in the high-rate anaerobic bioreactors. This paper reviews applications and performances of AnMBR and the membrane filtration behaviour in AnMBRs.
基金financial support from Key Laboratory for Green Chemical Technology of Ministry of Education, R&D Center for Petrochemical Technology, Tianjin University
文摘The development of a process that could recover biofuel from industrial cellulose waste can not only reduce the negative environmental impacts by using fossil fuels, but also bring a green idea for the waste’s disposing. In this study, hydrothermal pretreatment was optimized for cassava anaerobic residue, a cellulosic waste from cassava ethanol industry, to co-utilize xylose and glucose for producing bioethanol. The effect of the main pretreatment conditions, namely, temperature, solid content and time, was explored for the highest recovery of xylose in prehydrolysate and glucose in enzymatic hydrolysate. The single factor experiment results showed that the conditions for maximum xylose recovery in prehydrolysate and glucose recovery in enzymatic hydrolysate were 60℃, 75 min, 10% solids and 160℃, 75 min, 10% solids, respectively. Whereafter, response surface methodology(RSM) was applied to further optimize the pretreatment conditions for the maximum theoretical ethanol production through utilizing both xylose and glucose. A treatment at 163℃, for 59 min and with 9.5%solids was found optimal, with the highest ethanol production of 20.2 mg·g^-1 raw material. Furthermore, in order to assess the impacts of the pretreatment on cassava anaerobic residue, the changes in crystallinity and morphology for untreated and pretreated solids were investigated.
文摘Waste disposal management and the energy crisis are important challenges facing most countries.The fruit-processing industry generates daily several tons of wastes,of which the major share comes from banana farms.Anaerobic digestion(AD)technology has been applied to the treatment of wastewater,animal slurry,food waste,and agricultural residues,with the primary goals of energy production and waste elimination.This study examines the effect of organic loading(OL)and cow manure(CM)addition on AD performance when treating banana peel waste(BPW).The maximum daily biogas production rates of banana peels(BPs)with a CM content of 10%,20%,and 30%at 18 and 22 g of volatile solids(gvs)per liter were 50.20,48.66,and 62.78 mL (gvs.d)^-1 and 40.49,29.57,and 46.54 mL (gvs.d)^-1,respectively.However,the daily biogas yield showed no clear interdependence with OL or CM content.In addition,a kinetic analysis using first-order and cone models showed that the kinetic parameters can be influenced by the process parameters.
文摘The paper provides a critical comparison between mesophilic and thermophilic anaerobic treatment of PTA wastewater through diagnosis of a case study. Aspects covered are bioavailability, biodegradability, microbial population, thermodynamics, kinetics involved and bio-reactor design for PTA wastewater treatment. The results of the case study suggests that one- stage thermophilic anaerobic reactor coupled with coagulation-flocculation pre-treatment unit and an aerobic post treatment unit could be techno-economically viable for PTA wastewater treatment to ensure that the final effluent quality conforms to the international standard. The in-formation emanated from this study could be useful and thought provoking to the professionals and academia in the area of PTA wastewater treatment and can serve as impetus toward the development of research lines in similar problems like the treatment of other petrochemical wastewater such as phenol-con- taining wastewater, benzene/benzoic acid-con- taining wastewater or wastewater from other similar industrial settings.
基金National Key Research and Development Program of China(2020YFC1522500)Special Project of Technical Innovation and Application Development of Chongqing City(cstc2020jscx-msxmX0097)。
文摘[Objectives]The research was to explore the antifungal effects of citronellal,wintergreen oil and their composite essence on Penicillium citrinum.[Methods]The inhibition zones of citronellal,wintergreen oil and their composite essence against P.citrinum were determined by disk diffusion method,and the growth of inhibition zone plate was observed.The fumigation fungicidal rate of fungi-bearing rice paper within 7 d was determined by plate counting method.[Results]Citronellal had strong antifungal effect,and wintergreen oil could slow down the growth rate of P.citrinum.The combination of citronellal and wintergreen oil had a synergistic effect.As fumigants,both citronellal and composite essence had fungicidal rates up to 100%within 7 d.Combined with anaerobic treatments,all the three essential oils could improve the fungicidal efficiency.The adsorbent in deoxidizing agent would adsorb the essential oils,so that their fumigation had a certain slow release effect.[Conclusions]This study can provide a more friendly and efficient method for the prevention and control of cultural relics mold.
文摘Phosphorus is an irreplaceable and depletable element. Furthermore, it has an almost one-way circulation on earth, so it is necessary to close the phosphorus cycle loop. Phosphorus could be recovered as struvite, which is a good slow-released fertilizer for agriculture. The supernatant of anaerobic digestion used to treat sludge from wastewater treatment plant is one main source from which phosphorus can be recovered. Studies have proven that phosphorus recovery from digester supematant is a feasible choice to preserve phosphorus rock technically and economically. A modified "PHOSNIX" P-recovery process was applied under the operating conditions of a 9.0 pH value and a 1.8 mg: P ratio with the influent of the centrate coming from the sludge centrifuge of the Songjiang Wastewater Treatment Plant in Shanghai. More than 80% influent phosphorus was recovered as struvite. Crystal products with good purity and low heavy metal content were gained. The largest crystal had a length of up to 0.26 mm. It was found in our study that the reaction time did not play an important role in crystal growth. Therefore, the optimization of the reaction condition for crystal growth should be examined in future study.
文摘Along with the development and progress of environmental protection management,it is necessary to pay full attention to the disposal of excess sludge in the process of urban sewage treatment plant management.It is necessary to ensure effective integration of management mechanisms and management paths.To a certain extent,it can improve the actual efficiency of digestion and treatment work and lay a foundation for the optimal operation of environmental protection management.In this paper,the treatment of excess sludge in a sewage treatment plant is studied.The method and results of anaerobic digestion test of excess sludge in a sewage treatment plant are discussed for reference only.
基金Granted by the Chongqing Municipal 2004’ Academician Funds(2004-8260).
文摘Anaerobic digestion is a good method, which possesses the optimal combination of volume reduction, probability of success and potential for resource and energy recovery. However, relatively little research has been done on the anaerobic digestion of organic solid wastes (OSW), especially in China. However, different substrates, start-up conditions, micro-organisms, processing technologies, pre-treatment methods could influence the result of anaerobic digestion. Anaerobic treatment of municipal OSW is less than that of wastewaters because some problems and obstructions need to be solved. Meanwhile, the application of anaerobic digestion of OSW is also discussed in the present paper.
文摘Anaerobic treatment could effectively degrade organic chlorine. Reductive dechlorination mechanisms were confirmed through GC-MS analysis during anaerobic treatment of pulp bleachery effluents, the influence of sulfide biologically produced and pH on the dechlorination revealed that nucleophilic substitution and alkaline hydrolysis were also nonbiological mechanisms.
文摘This paper illustrates the general experiment principle of anaerobic biological cotton pulp black liquor microbial degradation, including the process and result of experiment. The result shows that the decrement of COD may arrive at 80% by the strengthen effect of Photosynthetic Bacteria. The biochemical methane Potential (BMP) and Chemical Oxygen Demand (COD) of cotton pulp black liquor are also measured during the experiment using improved measure method. The equivalent of COD and BMP is verified as a result. Finally analysis is done based on the experiment result.
基金The Academic Support Project for Top Talents of Higher Education Subject(Major)in Anhui Province(gxbjZD2022077)The AgriculturalEcological Conservation and Pollution Control Key Laboratory of Anhui Province(FECPP201901)The High-level Talent Launch Foundationof the Applied Science Research Project of Bengbu University in 2024(2024YYX54QD).
文摘To investigate the impact of anaerobic soil disinfestation(ASD)treatment with different processing duration on tomato continuous cropping soil,a total of eight treatments were designed,which included two treatment temperatures of 10℃ and 30℃,and four treatment times of 3,4,5 and 7 weeks(w).The results showed that whether the temperature was 10℃ or 30℃,the pH values,TOC and available K contents in the soil treated by the ASD method were significantly increased(P<0.05),while the EC values and NO_(3)^(-)contents in soils treated by ASD were significantly reduced compared with the untreated group(P<0.05).The Fusarium oxysporum population in soils treated by ASD decreased with the extension of the treatment time.When the treatment temperature was 30℃,the effect on the removal of the NO_(3)^(-)that had accumulated in soils treated by ASD was significantly better than the treatment temperature of 10℃(P<0.05).When soil was treated by ASD for more than 5 w at 30℃,the NH4+content in soil was significantly increased(P<0.05)compared with the untreated soil.In conclusion,NO_(3)^(-)accumulation in soils could not be completely eliminated with treatment by ASD,even when the treatment time at 10℃ was prolonged.Whether the treatment temperature was 10℃ or 30℃,the F.oxysporum population in soils treated by ASD decreased significantly with the extension of the treatment time to more than 5 w compared with treatment only for only 3 w.
基金Project supported by the Hi-Tech Research and Development Program (863) of China (No.2002AA601310).
文摘Periodic anaerobic baffled reactor (PABR) is a novel reactor based on the design concept of anaerobic baffled reactor (ABR). Residence time distribution (RTD) studies on both clean and working reactors at the same hydraulic residence time (HRT) of 2 d were carded out to investigate the dead spaces and mixing patterns in PABRs at different organic loading rates (OLRs) in various switching manners and frequencies. The results showed that the fraction of dead space in PABR was similar to that in ABR, which was low in comparison with other reactor designs. Dead space may be divided into two categories, hydraulic and biological. In RTD studies without biomass, the hydraulic dead space in the PABR run in an "every second" switching manner with T = 2 d was the lowest whereas that in the PABR run in a T = ∞ (ABR) switching manner was the highest. The same trend was obtained with the total dead space in RTD studies with biomass no matter what the OLR was. Biological dead space was the major contributor to dead space but affected decreasingly at higher OLR whichever switching manner the PABR run in. The flow patterns within the PABRs were intermediate between plug-flow and perfectly mixed under all the conditions tested,
文摘The high strength easily biodegradable pollutants (represented by COD E) are strong inhibitors of terephthalic acid (TA) anaerobic biodegradation. At the same time, TA can inhibit easily biodegradable pollutants removal under anaerobic conditions to a limited extent. This mutual inhibition could happen and cause a low removal efficiency of both TA and COD E, when the effluent from TA workshops containing TA and easily biodegradable pollutants are treated by a single anaerobic reactor system. Based upon the treatment kinetics analysis of both TA degradation and COD E removal, a two stage up flow anaerobic sludge blanket and up flow fixed film reactor(UASB UAFF) system for dealing with this kind of wastewater was developed and run successfully at laboratory scale. An UASB reactor with the methanogenic consortium as the first stage removes the easily biodegradable pollutants(COD E). An UAFF reactor as the second stage is mainly in charge of TA degradation. At a COD E loading of 15.3 g/(L\5d) and a TA loading of 1.4 g/(L\5d), HRT 18.5h, the COD E and TA removal rate of the system reached 89.2% and 71.6%, respectively.
基金Supported by the National Natural Science Foundation of China (No.50278036), the Natural Science Foundation of Guangdong Province (No.04105951) and the National High Technology Research and Development Program of China (No.2006AA06Z378).
文摘A novel anaerobic reactor, jet biogas inter-loop anaerobic fluidized bed (JBILAFB), was designed and constructed. The start-up and performance of the reactor was investigated in the Process. of .artificial glucose wastewater treatment. With the wastewater recycle ratio of 2.5 : 1, the recycled wastewater with biogas could mix sludge and wastewater in the JBILAFB reactor completely. The start-up of the JBILAFB reactor could be completed in less than 70 d through maintenance of hydraulic retention time (HR^I") and stepwise increase of feed total organic carbon (TOC) concentration. After the start-up, with the volumetric TOC loadings of 14.3 kg·m ^-3·d^-1, the TOC removal ratio, the effluent pH, and the volatile fatty acids (VFA)/alkalinity of the JBILAFB reactor were more than 80%, close to 7.0 and less than 0.4, respectively. Moreover, CH4 was produced at more than 70% of the theoretical value, The reactor exhibited high stability under the condition of high volumetric TOC loading. Sludge granules in the JBILAFB reactor were developed during the start-up and their sizes were enlarged with the stepwise increase of volumetric TOC loadings from 0.8 kg.m^-3.d ^-1 to 14.3 kg.m^-3.d^-1. Granules, an offwhite color and a similar spherical shape, were mainly comprised of global-like bacteria. These had good methanogenic activity and settleability, which were formed probably through adhesion of the bacteria. Some inorganic metal compounds such as Fe, Ca, Mg, Al, etc. were advantageous to the formation of the granules.
文摘Two runs of experiments were carried out to obtain an understanding of phosphorus release and uptake under the anaerobic condition and then the aerobic condition respectively. Under anaerobic condition, it was found that the extent of phosphorus release appeared to increase with the increase of the initial organic loading rate when the initial organic loading rate was up to 0.1 gSCOD/gMLSS. When the initial organic loading rate was higher than 0.1 gSCOD/gMLSS, the amount of phosphorus release per unit mass of MLSS reached nearly a same stationary value, and it seemed this is not affected by organic loading rate when there is external available substrate remained. In addition, the effect of NOx-N on the phosphorus release and uptake was also investigated, it was proved that the denitrifiers has an advantage over polyphosphate accumulating bacteria in competition for organic substrate under anoxic condition. Therefore, the existence of NOx-N is disadvantageous to the phosphorus release. Based upon the above investigations, the process configuration of membrane bioreactor(MBR) in combination with anaerobic phase was proposed to enhance the removal of phosphorus in treating domestic wastewater. During the experimental period of four months, average removals of 92.50%, 84.25%, 100%, 94.09% and 85.33% were achieved for COD, TP, SS, NH_3-N and TN respectively.
基金Supported by Project "Synergistic Anaerobic Digestion Technology of Municipal Sewage Sludge and Incineration Plant Landfill Leachate and Its Productivity Test" of Chongqing Water Asset Management Co.Ltd
文摘Taking the anaerobic digestion products of sludge as the object, through the analysis on the development of garden substrate market at home and abroad and the development status of horticultural products from the anaerobic digestion products, the direction for the utilization of the anaerobic digestion products of sludge was pointed out. Based on the demand of Chongqing’s garden market, this paper analyzed the potential utilization of sludge anaerobic digestion products in Chongqing, and briefly introduced the research status of landscaping utilization of sludge anaerobic digestion products in Chongqing, in order to provide reference for the industry.
文摘Anaerobic treatment model treats fish processing wastewater to be necessary for a small and medium factory that is very popular in Vietnam and other countries.Several techniques have been proposed.However,they are quite expensive and hard to operate,especially in remote areas.In this study,the hydraulic retention times(HRT)including 3,5,and 7 hours with a various organic loading rate of 1.5 to 6.5 kg COD/m3/day were investigated.Biomass concentration as mix-liquor volatile suspended solid(MLVSS)in the model is at 6,000 to 9,000 mg/L.On the basis of the result the optimal HRT with a 4.0 kg COD/m3/day organic loading rate was 8 hours which BOD5,COD removal efficiency were 92.18,87.36 percent respectively.By the end of the optimal hydraulic retention times,the total methane gas volume as a by-product was collected with 2.6 liters.
文摘Anaerobic digestion is often used as an approach to deal with high COD waste streams. Compared to the aeration systems it allows better energy management due to the biogas production but also has several limitations including inlet waste streams quality and the additional equipment required for energy harvesting. In recent years, the bio-electrochemical systems (BES) and processes are intensively studied as a method for organic waste utilization, including wastewater. They potentially could bring several benefits to the wastewater treatment, mainly due to avoiding aeration (and aeration cost) and direct energy recovering in the form of electricity. Besides their anaerobic nature, the biological processes in BES are respiration-like contrary to the fermentative degradation typical for conventional anaerobic digestion which eventually will provide better mineralization and higher efficiency in terms of COD and BOD removal in such reactors. This study is a direct comparison between conventional anaerobic digestion and Microbial Fuel Cell (as a typical BES reactor) during utilization of wastewater from industrial production of ethanol by fermentation. COD removal rates and dynamics, energy recovery properties and parameters such as secondary sludge production are investigated in order to characterize the feasibility and technological readiness of BES as a step towards their commercialization.