Nanoscale drug delivery systems(nDDS)have been employed widely in enhancing the therapeutic efficacy of drugs against diseases with reduced side effects.Although several nDDS have been successfully approved for clinic...Nanoscale drug delivery systems(nDDS)have been employed widely in enhancing the therapeutic efficacy of drugs against diseases with reduced side effects.Although several nDDS have been successfully approved for clinical use up to now,biological barriers between the administration site and the target site hinder the wider clinical adoption of nDDS in disease treatment.Polyethylene glycol(PEG)-modification(or PEGylation)has been regarded as the gold standard for stabilising nDDS in complex biological environment.However,the accelerated blood clearance(ABC)of PEGylated nDDS after repeated injections becomes great challenges for their clinical applications.Zwitterionic polymer,a novel family of antifouling materials,have evolved as an alternative to PEG due to their super-hydrophilicity and biocompatibility.Zwitterionic nDDS could avoid the generation of ABC phenomenon and exhibit longer blood circulation time than the PEGylated analogues.More impressively,zwitterionic nDDS have recently been shown to overcome multiple biological barriers such as nonspecific organ distribution,pressure gradients,impermeable cell membranes and lysosomal degradation without the need of any complex chemical modifications.The realization of overcoming multiple biological barriers by zwitterionic nDDS may simplify the current overly complex design of nDDS,which could facilitate their better clinical translation.Herein,we summarise the recent progress of zwitterionic nDDS at overcoming various biological barriers and analyse their underlyingmechanisms.Finally,prospects and challenges are introduced to guide the rational design of zwitterionic nDDS for disease treatment.展开更多
This article is a comprehensive study based on research on the connection between diabetes mellitus(DM)and prostate cancer(PCa).It investigates the potential role of DM as an independent risk factor for PCa,delving in...This article is a comprehensive study based on research on the connection between diabetes mellitus(DM)and prostate cancer(PCa).It investigates the potential role of DM as an independent risk factor for PCa,delving into the biological links,including insulin resistance and hormonal changes.The paper critically analyzes previous studies that have shown varying results and introduces mendelian randomization as a method for establishing causality.It emphasizes the importance of early DM screening and lifestyle modifications in preventing PCa,and proposes future research directions for further understanding the DM-PCa relationship.展开更多
Tumor necrosis factor-α(TNF-α)inhibitors are biological agents introduced in the late 1990s for the treatment of different immune-mediated diseases as inflammatory bowel disease,rheumatoid arthritis and psoriasis.Th...Tumor necrosis factor-α(TNF-α)inhibitors are biological agents introduced in the late 1990s for the treatment of different immune-mediated diseases as inflammatory bowel disease,rheumatoid arthritis and psoriasis.The most commonly used TNF-αantagonists are infliximab,adalimumab,and certolizumab pegol,and though highly effective in lowering inflammation,the efficacy must be weighed against the potential for adverse events.The treatment-induced immunosuppression is suspected to increase the risk of infections,including the risk of reactivation of latent tuberculosis,as the TNF-αcytokine plays an important role in the immune function.In this topic highlight a short overview of the infection risk associated with TNF-αinhibiter therapy is outlined with a focus on the overall risk of serious infections,mycobacterial infection and latent viral infections.展开更多
As a result of agriculture practices, million tons of agriculture are produced as a secondary or by-products; however, with low nutritive values. Many methods are applied to improve the nutritive value and increase it...As a result of agriculture practices, million tons of agriculture are produced as a secondary or by-products; however, with low nutritive values. Many methods are applied to improve the nutritive value and increase its utilization in ruminant's nutrition. The biological treatments are the most common with more safe-treated products. In most cases, the biological treatments are paralleled with decreased crude fiber and fiber fractions content with increased crude protein content. Direct-fed microbial and exogenous enzymes to animal are other ways of biological methods for improving nutritive value of feeds. Here in this review, we will try to cover the biological treatments of by-products from different sides view with different types of animals and different animal end-products.展开更多
The slightly polluted wastewater from oil refinery contains some COD, oil pollutants and suspended solids (SS). A small-scale fixed film biological aerated filter (BAF) process was used to treat the wastewater. Th...The slightly polluted wastewater from oil refinery contains some COD, oil pollutants and suspended solids (SS). A small-scale fixed film biological aerated filter (BAF) process was used to treat the wastewater. The influences of hydraulic retention time (HRT), air/water volume flow ratio and backwashing cycle on treatment efficiencies were investigated. The wastewater was treated by the BAF process under optimal conditions: the HRT of 1.0 h, the air/water volume flow ratio of about 5 : 1 and the backwashing cycle of every 4-7 days. The results showed that the average removal efficiency of COD, oil pollutants and SS was 84.5%, 94.0% and 83.4%, respectively. And the average effluent concentration of COD, oil pollutants and SS was 12.5, 0.27, 14.5 mg·L^-1, respectively. The experimental results demonstrated that the BAF process is a suitable and highly efficient method to treat the wastewater.展开更多
The treatment of patients with inflammatory bowel disease(IBD),especially those with severe or refractory disease,represents an important challenge for the clinical gastroenterologist.It seems to be no exaggeration to...The treatment of patients with inflammatory bowel disease(IBD),especially those with severe or refractory disease,represents an important challenge for the clinical gastroenterologist.It seems to be no exaggeration to say that in these patients,not only the scientific background of the gastroenterologist is tested,but also the abundance of“gifts”that he should possess(insight,intuition,determ-ination,ability to take initiative,etc.)for the successful outcome of the treatment.In daily clinical practice,depending on the severity of the attack,IBD is treated with one or a combination of two or more pharmaceutical agents.These combin-ations include not only the first-line drugs(e.g.,mesalazine,corticosteroids,antibiotics,etc)but also second-and third-line drugs(immunosuppressants and biologic agents).It is a fact that despite the significant therapeutic advances there is still a significant percentage of patients who do not satisfactorily respond to the treatment applied.Therefore,a part of these patients are going to surgery.In recent years,several small-size clinical studies,reviews,and case reports have been published combining not only biological agents with other drugs(e.g.,immunosuppressants or corticosteroids)but also the combination of two biologi-cal agents simultaneously,especially in severe cases.In our opinion,it is at least a strange(and largely unexplained)fact that we often use combinations of drugs in a given patient although studies comparing the simultaneous administration of two or more drugs with monotherapy are very few.As mentioned above,there is a timid tendency in the literature to combine two biological agents in severe cases unresponsive to the applied treatment or patients with severe extraintestinal manifestations.The appropriate dosage,the duration of the administration,the suitable timing for checking the clinical and laboratory outcome,as well as the treatment side-effects,should be the subject of intense clinical research shortly.In this editorial,we attempt to summarize the existing data regarding the already applied combination therapies and to humbly formulate thoughts and suggestions for the future application of the combination treatment of biological agents in a well-defined category of patients.We suggest that the application of biomarkers and artificial intelligence could help in establishing new forms of treatment using the available modern drugs in patients with IBD resistant to treatment.展开更多
The united membrane biological reactor(UMBR) was studied for the treatment of some simulate and municipal wastewater. The removal efficiency for COD and turbidity are greater than 80% and 99% respectively. Effluent CO...The united membrane biological reactor(UMBR) was studied for the treatment of some simulate and municipal wastewater. The removal efficiency for COD and turbidity are greater than 80% and 99% respectively. Effluent COD is less than 100 mg/L while turbidity less than 5 The removal of LAS in bath wastewater is greater than 70%. In treatment of dinning hall wastewater, removal of fatty oil is greater than 90%, and its concentration in effluent is less than 5 mg/L. The match of biological reactor and the membrane separation component were calculated. The stable performance of wastewater treatment can be maintained by the optimization of operation conditions and the cleanout of membranes.展开更多
Clean drinking water is one of the United Nations Sustainable Development Goals.Despite significant progress in the water purification technology,many regions still lack access to clean water.This paper provides a rev...Clean drinking water is one of the United Nations Sustainable Development Goals.Despite significant progress in the water purification technology,many regions still lack access to clean water.This paper provides a review of selected water contaminants and their impacts on human health.The World Health Organization(WHO)guidelines and regional standards for key contaminants were used to characterise water quality in the European Union and UK.The concept of safe drinking water was explained based on the non-observed adverse effect level,threshold concentrations for toxic chemicals,and their total daily intake.Various techniques for monitoring water contaminants and the drinking water standards from five different countries,including the UK,USA,Canada,Pakistan and India,were compared to WHO recommended guidelines.The literature on actual water quality in these regions and its potential health impacts was also discussed.Finally,the role of public water suppliers in identifying and monitoring drinking water contaminants in selected developed countries was presented as a potential guideline for developing countries.This review emphasised the need for a comprehensive understanding of water quality and its impacts on human health to ensure access to clean drinking water worldwide.展开更多
The biological aerated filter(BAF)was used to treat the oil-field produced water.The removal effi- ciency for oil,COD,BOD and suspended solids(SS)was 76.3%—80.3%,31.6%—57.9%,86.3%—96.3%and 76.4%—82.7%,respectively...The biological aerated filter(BAF)was used to treat the oil-field produced water.The removal effi- ciency for oil,COD,BOD and suspended solids(SS)was 76.3%—80.3%,31.6%—57.9%,86.3%—96.3%and 76.4%—82.7%,respectively when the hydraulic loading rates varied from 0.6m.h- 1to 1.4m.h -1.The greatest part of removal,for example more than 80%of COD removal,occurred on the top 100cm of the media in BAF.The ki- netic performance of BAF indicated that the relationship of BOD removal efficiency with the hydraulic loading rates in biological aerated filters could be described by cr/ci=1-exp(-2.44/L 0.59).This equation could be used to predict the BOD removal efficiency at different hydraulic loading rates.展开更多
Chitin and chitosan have been applied to biological wastewater treatment.From a number of parallel comparison experiments,it can be concluded that the application of chitin and chitosan can both enhance the biological...Chitin and chitosan have been applied to biological wastewater treatment.From a number of parallel comparison experiments,it can be concluded that the application of chitin and chitosan can both enhance the biological treatment,besides which chitosan is more efficient than chitin.The study on the enhancement mechanism reveals the difference between the two additives:chitosan improves the sludge structure and settlibility,while chitin acts as a kind of carrier for microorganism in the biological treatment system.展开更多
Accumulating operational experience in both aerobic and anaerobic mechanical biological waste treatment (MBT) makes it increasingly obvious that controlled water management would substantially reduce the cost of MBT...Accumulating operational experience in both aerobic and anaerobic mechanical biological waste treatment (MBT) makes it increasingly obvious that controlled water management would substantially reduce the cost of MBT and also enhance resource recovery of the organic and inorganic fraction. The MBT plant at Gescher, Germany, is used as an example in order to determine the quantity and composition of process water and leachates from intensive and subsequent rotting, pressing water from anaerobic digestion and scrubber water from acid exhaust air treatment, and hence prepare an MBT water balance. The potential of, requirements for and limits to internal process water reuse as well as the possibilities of resource recovery from scrubber water are also examined. Finally, an assimilated process water management concept with the purpose of an extensive reduction of wastewater quantity and freshwater demand is presented.展开更多
Landfill leachate is mainly the result of precipitation of water into the layers of buried waste, and biochemical reactions of waste that has dangerous substances and pollutants that lead to the contamination of surfa...Landfill leachate is mainly the result of precipitation of water into the layers of buried waste, and biochemical reactions of waste that has dangerous substances and pollutants that lead to the contamination of surface and groundwater resources. Therefore, it must be collected and treated properly. The investigation of various biological methods in leachate treatment, their advantages and disadvantages, and their effect on reduction of COD (chemical oxygen demand) are the objectives of this study. Reviewed processes include anaerobic and aerobic sequencing batch reactor, up-flow anaerobic sludge blanket, moving-bed biofilm reactor, membrane bioreactor, and aerated lagoons, lead to reduction of biodegradability pollutants in different circumstances. The present study has indicated that the most and the least reduction of COD has been through aerated lagoon (95%) and moving-bed biofilm reactor (8%), respectively.展开更多
Being familiar with characteristics of industrial town effluents from various wastewater treatment units, which have high qualitative and quantitative variations and more uncertainties compared to urban wastewaters, p...Being familiar with characteristics of industrial town effluents from various wastewater treatment units, which have high qualitative and quantitative variations and more uncertainties compared to urban wastewaters, plays very effective role in governing them. With regard to environmental issues, proper operation of wastewater treatment plants is of par- ticular importance that in the case of inappropriate utilization, they will cause serious problems. Processes that exist in environmental systems mostly have two major characteristics: they are dependent on many variables;and there are complex relationships between its components which make them very difficult to analyze. In order to achieve a better and efficient control over the operation of an industrial wastewater treatment plant (WWTP), powerful mathematical tool can be used that is based on recorded data from some basic parameters of wastewater during a period of treatment plant operation. In this study, the treatment plant was divided into two main subsystems including: Low TDS (Total Dissolved Solids) treatment unit and Biological unit (extended aeration). The multilayer perceptron feed forward neural network with a hidden layer and stop training method was used to predict quality parameters of the industrial effluent. Data of this study are related to the Fajr Industrial Wastewater Treatment Plant, located in Mahshahr—Iran that qualita- tive and quantitative characteristics of its units were used for training, calibration and validation of the neural model. Also, Principal Component Analysis (PCA) technique was applied to improve performance of generated models of neural networks. The results of L-TDS unit showed good accuracy of the models in estimating qualitative profile of wastewater but results of biological unit did not have sufficient accuracy to being used. This model facilitates evaluating the performance of each treatment plant units through comparing the results of prediction model with the standard amount of outputs.展开更多
Biological aerated filters have many advantages such as small volume and high treatment efficiency. This research focused on sewage treatment performance of integrated biological aerated filter (IBAF) under different ...Biological aerated filters have many advantages such as small volume and high treatment efficiency. This research focused on sewage treatment performance of integrated biological aerated filter (IBAF) under different conditions such as aeration, hydraulic retention time and the height of fillers layer, to identify the turn of marked affecting factor of removal performance through orthogonal experiments, optimize the function parameter of IBAF, reveal the regularity of sewage treatment of IBAF under different conditions, and adopt suitable measures to guarantee excess water quality of IBAF.展开更多
Nano-TiO2 photocatalytic oxidation was used to perform the advanced treatment of biologically treated chemical comprehensive wastewater. The effects of reaction time,nano-TiO2 dosage and initial p H of the wastewater ...Nano-TiO2 photocatalytic oxidation was used to perform the advanced treatment of biologically treated chemical comprehensive wastewater. The effects of reaction time,nano-TiO2 dosage and initial p H of the wastewater on the removal rate of COD were tested. The GC/MS and EEM techniques were used to qualitatively analyze organic compounds in the wastewater before and after treatment. The result showed that after the biologically treated chemical comprehensive wastewater was treated by nano-TiO2 photocatalytic oxidation under the conditions of reaction time 3 h,nano-TiO2 dosage 8 g/L,and pH 8. 0,the effluent COD was 61. 9 mg/L and its removal rate was 63. 8%. Additionally,the species of organic pollutants reduced from 12 to 6. Meanwhile,the content of humic-like and fulvic-like substances dropped dramatically.展开更多
Monocytes (MC), lymphocytes (LC) and Kupffer cells (KC) were isolated respectively from blood and surgical liver samples of patients suffering from he-patocellular carcinoma (HCC). 13 patients were given BCG, mixed ba...Monocytes (MC), lymphocytes (LC) and Kupffer cells (KC) were isolated respectively from blood and surgical liver samples of patients suffering from he-patocellular carcinoma (HCC). 13 patients were given BCG, mixed bacterium vaccine (MBV) and human white blood cell interferon (IFN), the other 3 patients were not treated with any biological immune stimulants (BIS) and served as controls. The cytosta-tic and cytotoxic effects of MC and KC on human hepatoma SMMC-7721 (TC) were assayed in vitro and the numbers of T total (Tt), T helper (Th) and T suppressor (Ts) cells were counted using CD monoclonal antibody immunofluorescence. The results were as follows: (1) On the 7th day after the first administration of BIS, the cytostatic and cytotoxic effects of MC on TC showed obvious increase over pre-administration. The activity of BIS was 1 ?5 times as high as that in the controls. (2) After 3 administrations, the cytostatic effect of MC on TC increased to the normal level (84%), while the controls remained as before (45%). (3) On the 7th day after first administration, cytostatic and cytotoxic effects of KC on TC were 0.5 and 1 times higher respectively than those of the controls. (4) The numbers of Tt and Th of patients given BIS increased continuously; on the contrary Ts decreased in number. These results indicate that combined use of BCG, MBV and IFN can actively enhance the immune anti-hepatoma function of patients suffering from HCC.展开更多
Chitosan of different molecular weight (M. W.) was added into SBR bioreactor to treat domestic wastewater. From comparison of treatment efficiency, sludge activity, sludge structure etc., we revealed the mechanism tha...Chitosan of different molecular weight (M. W.) was added into SBR bioreactor to treat domestic wastewater. From comparison of treatment efficiency, sludge activity, sludge structure etc., we revealed the mechanism that chitosan enhanced the biological treatment function of activated sludge. The results proved that, chitosan is certain to restrain the reaction of activated sludge, but it do improve the structure of sludge flocs and increase the treatment efficiency of activated sludge. The bigger the M. W. of chitosan is, the better the efficiency of enhancing biological treatment can be.展开更多
基金financially supported by the National Natural Science Foundation of China(grant no.8217070298)Guangdong Basic and Applied Basic Research Foundation(grant no.2020A1515110770,2021A1515220011,2022A1515010335).
文摘Nanoscale drug delivery systems(nDDS)have been employed widely in enhancing the therapeutic efficacy of drugs against diseases with reduced side effects.Although several nDDS have been successfully approved for clinical use up to now,biological barriers between the administration site and the target site hinder the wider clinical adoption of nDDS in disease treatment.Polyethylene glycol(PEG)-modification(or PEGylation)has been regarded as the gold standard for stabilising nDDS in complex biological environment.However,the accelerated blood clearance(ABC)of PEGylated nDDS after repeated injections becomes great challenges for their clinical applications.Zwitterionic polymer,a novel family of antifouling materials,have evolved as an alternative to PEG due to their super-hydrophilicity and biocompatibility.Zwitterionic nDDS could avoid the generation of ABC phenomenon and exhibit longer blood circulation time than the PEGylated analogues.More impressively,zwitterionic nDDS have recently been shown to overcome multiple biological barriers such as nonspecific organ distribution,pressure gradients,impermeable cell membranes and lysosomal degradation without the need of any complex chemical modifications.The realization of overcoming multiple biological barriers by zwitterionic nDDS may simplify the current overly complex design of nDDS,which could facilitate their better clinical translation.Herein,we summarise the recent progress of zwitterionic nDDS at overcoming various biological barriers and analyse their underlyingmechanisms.Finally,prospects and challenges are introduced to guide the rational design of zwitterionic nDDS for disease treatment.
文摘This article is a comprehensive study based on research on the connection between diabetes mellitus(DM)and prostate cancer(PCa).It investigates the potential role of DM as an independent risk factor for PCa,delving into the biological links,including insulin resistance and hormonal changes.The paper critically analyzes previous studies that have shown varying results and introduces mendelian randomization as a method for establishing causality.It emphasizes the importance of early DM screening and lifestyle modifications in preventing PCa,and proposes future research directions for further understanding the DM-PCa relationship.
文摘Tumor necrosis factor-α(TNF-α)inhibitors are biological agents introduced in the late 1990s for the treatment of different immune-mediated diseases as inflammatory bowel disease,rheumatoid arthritis and psoriasis.The most commonly used TNF-αantagonists are infliximab,adalimumab,and certolizumab pegol,and though highly effective in lowering inflammation,the efficacy must be weighed against the potential for adverse events.The treatment-induced immunosuppression is suspected to increase the risk of infections,including the risk of reactivation of latent tuberculosis,as the TNF-αcytokine plays an important role in the immune function.In this topic highlight a short overview of the infection risk associated with TNF-αinhibiter therapy is outlined with a focus on the overall risk of serious infections,mycobacterial infection and latent viral infections.
文摘As a result of agriculture practices, million tons of agriculture are produced as a secondary or by-products; however, with low nutritive values. Many methods are applied to improve the nutritive value and increase its utilization in ruminant's nutrition. The biological treatments are the most common with more safe-treated products. In most cases, the biological treatments are paralleled with decreased crude fiber and fiber fractions content with increased crude protein content. Direct-fed microbial and exogenous enzymes to animal are other ways of biological methods for improving nutritive value of feeds. Here in this review, we will try to cover the biological treatments of by-products from different sides view with different types of animals and different animal end-products.
基金Supported by the Foundation of Science and Technology Project of Guangdong Province (2004B33301001)
文摘The slightly polluted wastewater from oil refinery contains some COD, oil pollutants and suspended solids (SS). A small-scale fixed film biological aerated filter (BAF) process was used to treat the wastewater. The influences of hydraulic retention time (HRT), air/water volume flow ratio and backwashing cycle on treatment efficiencies were investigated. The wastewater was treated by the BAF process under optimal conditions: the HRT of 1.0 h, the air/water volume flow ratio of about 5 : 1 and the backwashing cycle of every 4-7 days. The results showed that the average removal efficiency of COD, oil pollutants and SS was 84.5%, 94.0% and 83.4%, respectively. And the average effluent concentration of COD, oil pollutants and SS was 12.5, 0.27, 14.5 mg·L^-1, respectively. The experimental results demonstrated that the BAF process is a suitable and highly efficient method to treat the wastewater.
文摘The treatment of patients with inflammatory bowel disease(IBD),especially those with severe or refractory disease,represents an important challenge for the clinical gastroenterologist.It seems to be no exaggeration to say that in these patients,not only the scientific background of the gastroenterologist is tested,but also the abundance of“gifts”that he should possess(insight,intuition,determ-ination,ability to take initiative,etc.)for the successful outcome of the treatment.In daily clinical practice,depending on the severity of the attack,IBD is treated with one or a combination of two or more pharmaceutical agents.These combin-ations include not only the first-line drugs(e.g.,mesalazine,corticosteroids,antibiotics,etc)but also second-and third-line drugs(immunosuppressants and biologic agents).It is a fact that despite the significant therapeutic advances there is still a significant percentage of patients who do not satisfactorily respond to the treatment applied.Therefore,a part of these patients are going to surgery.In recent years,several small-size clinical studies,reviews,and case reports have been published combining not only biological agents with other drugs(e.g.,immunosuppressants or corticosteroids)but also the combination of two biologi-cal agents simultaneously,especially in severe cases.In our opinion,it is at least a strange(and largely unexplained)fact that we often use combinations of drugs in a given patient although studies comparing the simultaneous administration of two or more drugs with monotherapy are very few.As mentioned above,there is a timid tendency in the literature to combine two biological agents in severe cases unresponsive to the applied treatment or patients with severe extraintestinal manifestations.The appropriate dosage,the duration of the administration,the suitable timing for checking the clinical and laboratory outcome,as well as the treatment side-effects,should be the subject of intense clinical research shortly.In this editorial,we attempt to summarize the existing data regarding the already applied combination therapies and to humbly formulate thoughts and suggestions for the future application of the combination treatment of biological agents in a well-defined category of patients.We suggest that the application of biomarkers and artificial intelligence could help in establishing new forms of treatment using the available modern drugs in patients with IBD resistant to treatment.
文摘The united membrane biological reactor(UMBR) was studied for the treatment of some simulate and municipal wastewater. The removal efficiency for COD and turbidity are greater than 80% and 99% respectively. Effluent COD is less than 100 mg/L while turbidity less than 5 The removal of LAS in bath wastewater is greater than 70%. In treatment of dinning hall wastewater, removal of fatty oil is greater than 90%, and its concentration in effluent is less than 5 mg/L. The match of biological reactor and the membrane separation component were calculated. The stable performance of wastewater treatment can be maintained by the optimization of operation conditions and the cleanout of membranes.
文摘Clean drinking water is one of the United Nations Sustainable Development Goals.Despite significant progress in the water purification technology,many regions still lack access to clean water.This paper provides a review of selected water contaminants and their impacts on human health.The World Health Organization(WHO)guidelines and regional standards for key contaminants were used to characterise water quality in the European Union and UK.The concept of safe drinking water was explained based on the non-observed adverse effect level,threshold concentrations for toxic chemicals,and their total daily intake.Various techniques for monitoring water contaminants and the drinking water standards from five different countries,including the UK,USA,Canada,Pakistan and India,were compared to WHO recommended guidelines.The literature on actual water quality in these regions and its potential health impacts was also discussed.Finally,the role of public water suppliers in identifying and monitoring drinking water contaminants in selected developed countries was presented as a potential guideline for developing countries.This review emphasised the need for a comprehensive understanding of water quality and its impacts on human health to ensure access to clean drinking water worldwide.
基金Supported by the National Natural Science Foundation of China (No.59978020).
文摘The biological aerated filter(BAF)was used to treat the oil-field produced water.The removal effi- ciency for oil,COD,BOD and suspended solids(SS)was 76.3%—80.3%,31.6%—57.9%,86.3%—96.3%and 76.4%—82.7%,respectively when the hydraulic loading rates varied from 0.6m.h- 1to 1.4m.h -1.The greatest part of removal,for example more than 80%of COD removal,occurred on the top 100cm of the media in BAF.The ki- netic performance of BAF indicated that the relationship of BOD removal efficiency with the hydraulic loading rates in biological aerated filters could be described by cr/ci=1-exp(-2.44/L 0.59).This equation could be used to predict the BOD removal efficiency at different hydraulic loading rates.
文摘Chitin and chitosan have been applied to biological wastewater treatment.From a number of parallel comparison experiments,it can be concluded that the application of chitin and chitosan can both enhance the biological treatment,besides which chitosan is more efficient than chitin.The study on the enhancement mechanism reveals the difference between the two additives:chitosan improves the sludge structure and settlibility,while chitin acts as a kind of carrier for microorganism in the biological treatment system.
文摘Accumulating operational experience in both aerobic and anaerobic mechanical biological waste treatment (MBT) makes it increasingly obvious that controlled water management would substantially reduce the cost of MBT and also enhance resource recovery of the organic and inorganic fraction. The MBT plant at Gescher, Germany, is used as an example in order to determine the quantity and composition of process water and leachates from intensive and subsequent rotting, pressing water from anaerobic digestion and scrubber water from acid exhaust air treatment, and hence prepare an MBT water balance. The potential of, requirements for and limits to internal process water reuse as well as the possibilities of resource recovery from scrubber water are also examined. Finally, an assimilated process water management concept with the purpose of an extensive reduction of wastewater quantity and freshwater demand is presented.
文摘Landfill leachate is mainly the result of precipitation of water into the layers of buried waste, and biochemical reactions of waste that has dangerous substances and pollutants that lead to the contamination of surface and groundwater resources. Therefore, it must be collected and treated properly. The investigation of various biological methods in leachate treatment, their advantages and disadvantages, and their effect on reduction of COD (chemical oxygen demand) are the objectives of this study. Reviewed processes include anaerobic and aerobic sequencing batch reactor, up-flow anaerobic sludge blanket, moving-bed biofilm reactor, membrane bioreactor, and aerated lagoons, lead to reduction of biodegradability pollutants in different circumstances. The present study has indicated that the most and the least reduction of COD has been through aerated lagoon (95%) and moving-bed biofilm reactor (8%), respectively.
文摘Being familiar with characteristics of industrial town effluents from various wastewater treatment units, which have high qualitative and quantitative variations and more uncertainties compared to urban wastewaters, plays very effective role in governing them. With regard to environmental issues, proper operation of wastewater treatment plants is of par- ticular importance that in the case of inappropriate utilization, they will cause serious problems. Processes that exist in environmental systems mostly have two major characteristics: they are dependent on many variables;and there are complex relationships between its components which make them very difficult to analyze. In order to achieve a better and efficient control over the operation of an industrial wastewater treatment plant (WWTP), powerful mathematical tool can be used that is based on recorded data from some basic parameters of wastewater during a period of treatment plant operation. In this study, the treatment plant was divided into two main subsystems including: Low TDS (Total Dissolved Solids) treatment unit and Biological unit (extended aeration). The multilayer perceptron feed forward neural network with a hidden layer and stop training method was used to predict quality parameters of the industrial effluent. Data of this study are related to the Fajr Industrial Wastewater Treatment Plant, located in Mahshahr—Iran that qualita- tive and quantitative characteristics of its units were used for training, calibration and validation of the neural model. Also, Principal Component Analysis (PCA) technique was applied to improve performance of generated models of neural networks. The results of L-TDS unit showed good accuracy of the models in estimating qualitative profile of wastewater but results of biological unit did not have sufficient accuracy to being used. This model facilitates evaluating the performance of each treatment plant units through comparing the results of prediction model with the standard amount of outputs.
文摘Biological aerated filters have many advantages such as small volume and high treatment efficiency. This research focused on sewage treatment performance of integrated biological aerated filter (IBAF) under different conditions such as aeration, hydraulic retention time and the height of fillers layer, to identify the turn of marked affecting factor of removal performance through orthogonal experiments, optimize the function parameter of IBAF, reveal the regularity of sewage treatment of IBAF under different conditions, and adopt suitable measures to guarantee excess water quality of IBAF.
文摘Nano-TiO2 photocatalytic oxidation was used to perform the advanced treatment of biologically treated chemical comprehensive wastewater. The effects of reaction time,nano-TiO2 dosage and initial p H of the wastewater on the removal rate of COD were tested. The GC/MS and EEM techniques were used to qualitatively analyze organic compounds in the wastewater before and after treatment. The result showed that after the biologically treated chemical comprehensive wastewater was treated by nano-TiO2 photocatalytic oxidation under the conditions of reaction time 3 h,nano-TiO2 dosage 8 g/L,and pH 8. 0,the effluent COD was 61. 9 mg/L and its removal rate was 63. 8%. Additionally,the species of organic pollutants reduced from 12 to 6. Meanwhile,the content of humic-like and fulvic-like substances dropped dramatically.
文摘Monocytes (MC), lymphocytes (LC) and Kupffer cells (KC) were isolated respectively from blood and surgical liver samples of patients suffering from he-patocellular carcinoma (HCC). 13 patients were given BCG, mixed bacterium vaccine (MBV) and human white blood cell interferon (IFN), the other 3 patients were not treated with any biological immune stimulants (BIS) and served as controls. The cytosta-tic and cytotoxic effects of MC and KC on human hepatoma SMMC-7721 (TC) were assayed in vitro and the numbers of T total (Tt), T helper (Th) and T suppressor (Ts) cells were counted using CD monoclonal antibody immunofluorescence. The results were as follows: (1) On the 7th day after the first administration of BIS, the cytostatic and cytotoxic effects of MC on TC showed obvious increase over pre-administration. The activity of BIS was 1 ?5 times as high as that in the controls. (2) After 3 administrations, the cytostatic effect of MC on TC increased to the normal level (84%), while the controls remained as before (45%). (3) On the 7th day after first administration, cytostatic and cytotoxic effects of KC on TC were 0.5 and 1 times higher respectively than those of the controls. (4) The numbers of Tt and Th of patients given BIS increased continuously; on the contrary Ts decreased in number. These results indicate that combined use of BCG, MBV and IFN can actively enhance the immune anti-hepatoma function of patients suffering from HCC.
文摘Chitosan of different molecular weight (M. W.) was added into SBR bioreactor to treat domestic wastewater. From comparison of treatment efficiency, sludge activity, sludge structure etc., we revealed the mechanism that chitosan enhanced the biological treatment function of activated sludge. The results proved that, chitosan is certain to restrain the reaction of activated sludge, but it do improve the structure of sludge flocs and increase the treatment efficiency of activated sludge. The bigger the M. W. of chitosan is, the better the efficiency of enhancing biological treatment can be.