In this paper, fouling mechanisms of mullite ceramic membranes for treatment of oily wastewaters in hybrid coagulation-microfiltration(MF) process presented. Hermia's models for cross flow filtration were used to ...In this paper, fouling mechanisms of mullite ceramic membranes for treatment of oily wastewaters in hybrid coagulation-microfiltration(MF) process presented. Hermia's models for cross flow filtration were used to investigate the fouling mechanisms of membranes with various coagulating chemicals concentrations. Four coagulating chemicals(FeCl2 ·4H2 O, FeSO4 ·7H2 O, AlCl3 ·6H2 O and Al2(SO4)3 ·18H2 O) plus Ca(OH)2 of the same concentration were evaluated in the coagulation-MF hybrid process with different concentrations(0, 50 mg·L 1, 100 mg·L 1and 200 mg·L 1). To determine whether the data agree with models under consideration, the coefficients of determination(R2) of all models were compared with one another. In addition, average prediction errors of models were calculated. The results showed that cake filtration model can be applied for prediction of permeation flux decline for MF and coagulation-(MF) hybrid process with the best average error equal to 0.09%. Results indicated that pore blocking behavior changes as time of filtration increases, and one model cannot predict pore blocking behavior in all filtration time with very good precision.展开更多
Oily wastewater poses significant threats to the soil, water, air and human beings because of the hazardous nature of its oil contents. The objective of this review paper is to highlight the current and recently devel...Oily wastewater poses significant threats to the soil, water, air and human beings because of the hazardous nature of its oil contents. The objective of this review paper is to highlight the current and recently developed methods for oily wastewater treatment through which contaminants such as oil, fats, grease, and inorganics can be removed for safe applications.These include electrochemical treatment, membrane filtration, biological treatment,hybrid technologies, use of biosurfactants, treatment via vacuum ultraviolet radiation,and destabilization of emulsions through the use of zeolites and other natural minerals.This review encompasses innovative and novel approaches to oily wastewater treatment and provides scientific background for future work that will be aimed at reducing the adverse impact of the discharge of oily wastewater into the environment. The current challenges affecting the optimal performance of oily wastewater treatment methods and opportunities for future research development in this field are also discussed.展开更多
Using microalgae to treat wastewater has received growing attention in the world because it is regarded as a novel means for wastewater treatment.It is commonly recognized that large-scale cultivation and commercial a...Using microalgae to treat wastewater has received growing attention in the world because it is regarded as a novel means for wastewater treatment.It is commonly recognized that large-scale cultivation and commercial application of microalgae are limited by the development of photobioreactor(PBR).Although there are a lot of PBRs for microalgae pure cultivation which used culture medium,specialized PBRs designed for wastewater treatment are rare.The composition of wastewater is quite complicated;this might cause a very different photosynthetic effect of microalgae compared to those grown in a pure cultivation medium.Therefore,PBRs for wastewater treatment need to be redesigned and improved based on the existing PBRs that are used for microalgae pure cultivation.In this review,different PBRs for microalgae cultivation and wastewater treatment are summarized.PBR configurations,PBR design parameters and types of wastewater are presented.In addition,the wastewater treatment efficiency and biomass productivity were also compared among each type of PBRs.Moreover,some other promising PBRs are introduced in this review,and a two-stage cultivation mode which combines both closed and open system is discussed as well.Ultimately,this article focuses on current problems and gives an outlook for this field,aiming at providing a primary reference for microalgae cultivation by using wastewater.展开更多
Due to the frequent occurrence of oil spills and the large-scale production of oily wastewater, the treatment of oily sewage has become an important issue for sustainable development. Recently, materials prepared from...Due to the frequent occurrence of oil spills and the large-scale production of oily wastewater, the treatment of oily sewage has become an important issue for sustainable development. Recently, materials prepared from lignocellulosic biomass(LCB) for oil-water separation have been found to be effective due to their high separation efficiency, good recyclability, and superior sustainability. However, few reviews have focused on the advantages and limitations of LCB for sewage treatment. This review summarizes the performance of modified LCB in oily wastewater treatment, in terms of the advanced modification methods applied and the structural dimensions of LCB materials according to the principle of superwetting oil-water separation. Research on the preparation technologies, separation mechanisms, and treatment efficiency of different LCB materials are briefly summarized, along with the characteristics of different LCB material types for oily wastewater treatment. Finally, the future prospects and challenges faced in the development of LCB materials are discussed.展开更多
China has been the forerunner of large-scale membrane bioreactor （MBR） application. Since the first large-scale MBR （≥ 10 000 m^3·d^-1） was put into operation in 2006, the engineering implementation of MBR i...China has been the forerunner of large-scale membrane bioreactor （MBR） application. Since the first large-scale MBR （≥ 10 000 m^3·d^-1） was put into operation in 2006, the engineering implementation of MBR in China has attained tremendous development. This paper outlines the commercial application of MBR since 2006 and provides a variety of engineering statistical data, covering the fields of municipal wastewater, industrial wastewater, and polluted surface water treatment. The total treatment capacity of MBRs reached 1× 10^6 m^3·d^-1 in 2010, and has currently exceeded 4.5 × 10^6 m^3·d^-1 with -75% of which pertaining to municipal wastewater treatment. The anaerobic/anoxic/aerobie-MBR and its derivative processes have been the most popular in the large-scale municipal application, with the process features and typical ranges of parameters also presented in this paper. For the treatment of various types of industrial wastewater, the configurations of the MBR-based processes are delineated with representative engineering cases. In view of the significance of the cost issue, statistics of capital and operating costs are also provided, including cost structure and energy composition. With continuous stimulation from the environmental stress, political propulsion, and market demand in China, the total treatment capacity is expected to reach 7.5 × 10^6 m^3·d^-1 by 2015 and a further expansion of the market is foreseeable in the next five years. However, MBR application is facing several challenges, such as the relatively high energy consumption. Judging MBR features and seeking suitable application areas should be of importance for the long-term development of this technology.展开更多
文摘In this paper, fouling mechanisms of mullite ceramic membranes for treatment of oily wastewaters in hybrid coagulation-microfiltration(MF) process presented. Hermia's models for cross flow filtration were used to investigate the fouling mechanisms of membranes with various coagulating chemicals concentrations. Four coagulating chemicals(FeCl2 ·4H2 O, FeSO4 ·7H2 O, AlCl3 ·6H2 O and Al2(SO4)3 ·18H2 O) plus Ca(OH)2 of the same concentration were evaluated in the coagulation-MF hybrid process with different concentrations(0, 50 mg·L 1, 100 mg·L 1and 200 mg·L 1). To determine whether the data agree with models under consideration, the coefficients of determination(R2) of all models were compared with one another. In addition, average prediction errors of models were calculated. The results showed that cake filtration model can be applied for prediction of permeation flux decline for MF and coagulation-(MF) hybrid process with the best average error equal to 0.09%. Results indicated that pore blocking behavior changes as time of filtration increases, and one model cannot predict pore blocking behavior in all filtration time with very good precision.
文摘Oily wastewater poses significant threats to the soil, water, air and human beings because of the hazardous nature of its oil contents. The objective of this review paper is to highlight the current and recently developed methods for oily wastewater treatment through which contaminants such as oil, fats, grease, and inorganics can be removed for safe applications.These include electrochemical treatment, membrane filtration, biological treatment,hybrid technologies, use of biosurfactants, treatment via vacuum ultraviolet radiation,and destabilization of emulsions through the use of zeolites and other natural minerals.This review encompasses innovative and novel approaches to oily wastewater treatment and provides scientific background for future work that will be aimed at reducing the adverse impact of the discharge of oily wastewater into the environment. The current challenges affecting the optimal performance of oily wastewater treatment methods and opportunities for future research development in this field are also discussed.
基金the financial support by the National Natural Science Foundation of China(51576206,51308535)Beijing Science and Technology Program(Z161100001316009).
文摘Using microalgae to treat wastewater has received growing attention in the world because it is regarded as a novel means for wastewater treatment.It is commonly recognized that large-scale cultivation and commercial application of microalgae are limited by the development of photobioreactor(PBR).Although there are a lot of PBRs for microalgae pure cultivation which used culture medium,specialized PBRs designed for wastewater treatment are rare.The composition of wastewater is quite complicated;this might cause a very different photosynthetic effect of microalgae compared to those grown in a pure cultivation medium.Therefore,PBRs for wastewater treatment need to be redesigned and improved based on the existing PBRs that are used for microalgae pure cultivation.In this review,different PBRs for microalgae cultivation and wastewater treatment are summarized.PBR configurations,PBR design parameters and types of wastewater are presented.In addition,the wastewater treatment efficiency and biomass productivity were also compared among each type of PBRs.Moreover,some other promising PBRs are introduced in this review,and a two-stage cultivation mode which combines both closed and open system is discussed as well.Ultimately,this article focuses on current problems and gives an outlook for this field,aiming at providing a primary reference for microalgae cultivation by using wastewater.
基金the National Natural Science Foundation of China (No. 51961165104)the Project of Thousand Youth Talents。
文摘Due to the frequent occurrence of oil spills and the large-scale production of oily wastewater, the treatment of oily sewage has become an important issue for sustainable development. Recently, materials prepared from lignocellulosic biomass(LCB) for oil-water separation have been found to be effective due to their high separation efficiency, good recyclability, and superior sustainability. However, few reviews have focused on the advantages and limitations of LCB for sewage treatment. This review summarizes the performance of modified LCB in oily wastewater treatment, in terms of the advanced modification methods applied and the structural dimensions of LCB materials according to the principle of superwetting oil-water separation. Research on the preparation technologies, separation mechanisms, and treatment efficiency of different LCB materials are briefly summarized, along with the characteristics of different LCB material types for oily wastewater treatment. Finally, the future prospects and challenges faced in the development of LCB materials are discussed.
文摘China has been the forerunner of large-scale membrane bioreactor （MBR） application. Since the first large-scale MBR （≥ 10 000 m^3·d^-1） was put into operation in 2006, the engineering implementation of MBR in China has attained tremendous development. This paper outlines the commercial application of MBR since 2006 and provides a variety of engineering statistical data, covering the fields of municipal wastewater, industrial wastewater, and polluted surface water treatment. The total treatment capacity of MBRs reached 1× 10^6 m^3·d^-1 in 2010, and has currently exceeded 4.5 × 10^6 m^3·d^-1 with -75% of which pertaining to municipal wastewater treatment. The anaerobic/anoxic/aerobie-MBR and its derivative processes have been the most popular in the large-scale municipal application, with the process features and typical ranges of parameters also presented in this paper. For the treatment of various types of industrial wastewater, the configurations of the MBR-based processes are delineated with representative engineering cases. In view of the significance of the cost issue, statistics of capital and operating costs are also provided, including cost structure and energy composition. With continuous stimulation from the environmental stress, political propulsion, and market demand in China, the total treatment capacity is expected to reach 7.5 × 10^6 m^3·d^-1 by 2015 and a further expansion of the market is foreseeable in the next five years. However, MBR application is facing several challenges, such as the relatively high energy consumption. Judging MBR features and seeking suitable application areas should be of importance for the long-term development of this technology.
