This study examined the application of co-benefit-type wastewater treatment technology in the fish-processing industry. Given that there was a dearth of information on fish-processing industrial wastewater in Indonesi...This study examined the application of co-benefit-type wastewater treatment technology in the fish-processing industry. Given that there was a dearth of information on fish-processing industrial wastewater in Indonesia, site surveys were conducted. For the entire fish-processing industry throughout the country, the dissemination rate of wastewater treatment facilities was less than 50%. Using a co-benefit approach, a real-scale swim-bed technology (SBT) and a system combining an anaerobic baffled reactor (ABR) with SBT (ABR–SBT) were installed in a fishmeal processing factory in Bali, Indonesia, and the wastewater system process performance was evaluated. In a business-as-usual scenario, the estimated chemical oxygen demand load and greenhouse gas (GHG) emissions from wastewater from the Indonesian fish-processing industry were 33 000 tons per year and 220 000 tons of equivalent CO_(2) per year, respectively. On the other hand, the GHG emissions in the co-benefit scenarios of the SBT system and ABR–SBT system were 98 149 and 26 720 tons per year, respectively. Therefore, introducing co-benefit-type wastewater treatment to Indonesia’s fish-processing industry would significantly reduce pollution loads and GHG emissions.展开更多
The most abundant natural biopolymer on earth, cellulose fiber, may offer a highly efficient, low-cost, and chemical-free option for wastewater treatment. Cellulose is widely distributed in plants and several marine a...The most abundant natural biopolymer on earth, cellulose fiber, may offer a highly efficient, low-cost, and chemical-free option for wastewater treatment. Cellulose is widely distributed in plants and several marine animals. It is a carbohydrate polymer consisting of β-1,4-linked anhydro-D-glucose units with three hydroxyl groups per anhydroglucose unit(AGU). Cellulose-based materials have been used in food, industrial, pharmaceutical, paper, textile production, and in wastewater treatment applications due to their low cost, renewability,biodegradability, and non-toxicity. For water treatment in the oil and gas industry, cellulose-based materials can be used as adsorbents, flocculants, and oil/water separation membranes. In this review, the uses of cellulose-based materials for wastewater treatment in the oil & gas industry are summarized, and recent research progress in the following aspects are highlighted: crude oil spill cleaning, flocculation of solid suspended matter in drilling or oil recovery in the upstream oil industry, adsorption of heavy metal or chemicals, and separation of oil/water by cellulosic membrane in the downstream water treatment.展开更多
Water pollution has become one of the most pressing health crises in the world. Water pollution control began as early as the late 1800s. In 2008, there were 14,780 municipal wastewater treatment plants operating in t...Water pollution has become one of the most pressing health crises in the world. Water pollution control began as early as the late 1800s. In 2008, there were 14,780 municipal wastewater treatment plants operating in the United States. These plants range in size from a few hundred gallons per day (GPD) to over 1.445 billion gallons (MGD) per day. Wastewater treatment facilities are designed and constructed or upgraded to reduce the amount and diversity of pollutants. This article gives a review of the current industrial wastewater treatment technology in recent years, including treatment principles, advantages and disadvantages of each method, and the corresponding applications. Also, this article reviewed two common biological technologies Anaerobic Ammonium Oxidation (ANAMMOX) and Anaerobic Membrane Bioreactor (ANMBR) technology, by assessing their advantages, disadvantages, and costs, and provides resources for further technical research. This article can serve as a guide for anyone seeking information on innovative and emerging industry wastewater treatment technologies.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
The powdered activated carbon treatment(PACT) process has been widely used in many industrial fields, however,very few PACT processes are built for petrochemical wastewater treatment in China. An industrial PACT unit ...The powdered activated carbon treatment(PACT) process has been widely used in many industrial fields, however,very few PACT processes are built for petrochemical wastewater treatment in China. An industrial PACT unit launched in a petrochemical plant was introduced and evaluated from both the practice and mechanism study. Practically, the PACT process showed excellent capability in pollutants removal, shock resistance, toxicity tolerance, and the COD and ammoniumN in effluent of PACT unit assisted by PAC was equal to 15.5 mg/L and 0.7 mg/L lower than that without PAC addition,respectively. The wet oxidation regeneration unit was quite efficient in supplying regenerated PAC, and, however, the hard calcium sulphate scale and the high pollutant concentration solution needed to be carefully controlled. Moreover, although the carbon balance showed that the adsorption capability of regenerated PAC was negligible, the biological tests proved that the regenerated PAC increased microbe activity up to 17% more than pure activated sludge system, which was almost compatible with the fresh activated carbon.展开更多
Since the introduction of the membrane bioreactor(MBR)in China in the early 1990s,remarkable progress has been achieved on the research and application of this technology.China has now become one of the most active fi...Since the introduction of the membrane bioreactor(MBR)in China in the early 1990s,remarkable progress has been achieved on the research and application of this technology.China has now become one of the most active fields in the world in this regard.This review outlines the development of MBR-based processes in China and their performance of treating municipal and industrial wastewaters.Since membrane fouling is a critical operational problem with MBR processes,this paper also proposes updated understanding of fouling mechanisms and strategies of fouling control,which are mainly compiled from publications of Chinese researchers.As for the commercial application of MBR in the country,the latest statistics of large-scale MBR plants(>10000 m^(3)·d^(–1))are provided,and the growth trend of total treatment capacity as well as its driving force is analyzed.展开更多
This paper presents an evaluation of the suitability of a mixed absorbent based on peat and carbon-containing ash for treatment of wastewaters, such as wastewater from professional car washes, landfill leachate and st...This paper presents an evaluation of the suitability of a mixed absorbent based on peat and carbon-containing ash for treatment of wastewaters, such as wastewater from professional car washes, landfill leachate and stormwater. This mixture is very attractive, since it is a low-cost material which has a capability to simultaneously remove inorganic as well as organic pollutants. Since any filter material eventually needs to be replaced either due to saturation of pollutants or reduced infiltration capacity, it is important that the residual can be handled at low cost and that the environment will be not impaired. The tested mixture, used in filter beds, showed low leaching values and high simultaneous removal efficiency of metals as Cu, Cd and Pb, non-polar organic compounds such as PCBs. Polar organic compounds as phenols were also efficiently removed by microbial and/or chemical degradation in the studied treatment plants with the filter bed acted as a biofilter. Filter material used for three years in a full-scale plant for leachate treatment and four years in treatment plants for wastewater from car washes, had sufficiently high energy content indicating that energy recovery is a good alternative for handling after its usage. Results show that the presented filter material is excellent for both small scale applications (e.g. treatment systems for car wash wastewater with capacity between 250 - 3000 m3 per year) as well as large-scale applications (e.g. filter systems for landfill leachates with capacity above 30,000 m3 per year).展开更多
In this study,we have determined the main important physical and chemical properties as well as the heavy metal concentrations of the primary and secondary wastewater treatment sludge from a pulp and board mill comple...In this study,we have determined the main important physical and chemical properties as well as the heavy metal concentrations of the primary and secondary wastewater treatment sludge from a pulp and board mill complex located in Finland in order to evaluate the utilization of these by-products as a soil amendment agent or a fertilizer product.Easily soluble Ca,Mg,K,Na,P and S concentrations in the sludges were extracted by ammonium acetate(CH3COONH4)and easily soluble Cu,Mn and Zn concentrations by CH3COONH4+Na2EDTA.For the determination of total nutrient and total heavy metal concentrations in sludges,they were digested using aqua regia(3 mL HCl+9 mL HNO3).The total heavy concentrations in the primary sludge were lower than the Finnish heavy metal limit values for fertilizer products.In the secondary sludge,all other total heavy metals than the total Cd concentration(4.8 mg/kg;d.w.)were lower than the heavy metal limit values for fertilizer products.Due to the low total heavy metal concentrations,which were lower than the Finnish limit values for fertilizer products,the primary sludge is a potential fertilizer.Although the total Cd concentration(4.8 mg/kg;d.w.)in the secondary sludge exceed the limit value of 1.5 mg/kg(d.w.)for fertilizer products,this residue may be used as a soil improver,a growing media or as a fertilizer product in landfill sites or in other closed industrial areas,because the Finnish limit values for fertilizer products are not applied at these sites.展开更多
A full-scale plant using anaerobic, anoxic and oxic processes (A1/A2/O), along with a pilot-scale membrane bioreactor (MBR), nanofiltration (NF) and reverse osmosis (RO) integrated system developed by Shanghai...A full-scale plant using anaerobic, anoxic and oxic processes (A1/A2/O), along with a pilot-scale membrane bioreactor (MBR), nanofiltration (NF) and reverse osmosis (RO) integrated system developed by Shanghai Baosteel Chemical Co. Ltd., was investigated to treat coking wastewater for industrial reuse over a period of one year. The removals reached 82.5% (COD), 89.6% (BOD), 99.8% (ammonium nitrogen), 99.9% (phenol), 44.6% (total cyanide (T-CN)), 99.7% (thiocyanide (SCN-)) and 8.9% (fluoride), during the A1/A2/O biological treatment stage, and all parameters were further reduced by over 96.0%, except for fluoride (86.4%), in the final discharge effluent from the currently operating plant. The pilot-scale MBR process reduced the turbidity to less than 0.65 NTU, and most of the toxic organic compounds were degraded or intercepted by the A1/A2/O followed MBR processes. In addition, parameters including COD, T-CN, total nitrogen, fluoride, chloride ion, hardness and conductivity were significantly reduced by the NF-RO system to a level suitable for industrial reuse, with a total water production ratio of 70.7%. However, the concentrates from the NF and RO units were highly polluted and should be disposed of properly or further treated before being discharged.展开更多
The characteristics and harm of high concentrations of organic wastewater were introducecl firstly, and then several treatment processes and effects of high concentrations of organic wastewater were summarized, which ...The characteristics and harm of high concentrations of organic wastewater were introducecl firstly, and then several treatment processes and effects of high concentrations of organic wastewater were summarized, which can provide theoretical references for the choice of wastewater treatment process.展开更多
Whereas the pulp and paper industrial sector—considered the second highest consumer of freshwater in Europe—has already been provided with sufficient wastewater characterization and treatment technologies, other woo...Whereas the pulp and paper industrial sector—considered the second highest consumer of freshwater in Europe—has already been provided with sufficient wastewater characterization and treatment technologies, other wood-based industries (e.g. furniture, floor production), which do not use water for manufacturing processes, generate different wastewater streams after: 1) cleaning/washing of machinery that applies adhesives and coatings onto wood surfaces;2) cleaning/washing of machinery that applies specific products for the curing phase of adhesives;3) cleaning/washing of sharp planar blades used for the sawn process and to prepare wood surfaces for the adhesive application;4) cleaning/washing of the floor;5) cleaning/washing of trucks and vehicles. The dilution of low-volumes of highly polluted wastewater is not acceptable any longer since conventional treatment plants are not designed for these types of industrial wastewater. There is a need for proper characterization, treatability studies, designing and testing alternative small size and cost-effective treatment systems for on-site implementation. Treatment systems based on sorption mechanisms are flexible, easy to operate and generate less sludge and several low-cost sorbents generated by forestry activities have advantageous physico-chemical characteristics. The current paper presents the preliminary results from a pilot treatment system consisting of an equalization tank, settling/sedimentation and two sorption reactors in parallel using Pinus sylvestris sawdust as sorbent implemented as part of an integrated water management plan in a wood-floor industry. The simple to operate and cost-effective pilot treatment system performs satisfactorily during an initial period of operation. The study shows an average 39% - 54% reduction of TPH;17% - 38% reduction of oil;2% - 15% of reduction of COD and;11% - 74% reduction of most toxic metals but for Co, Ni and Zn in the system B. Based on these results, Pinus sylvestris sawdust is a potential low-cost and abundant material to be considered for industrial wastewater treatment plants.展开更多
The aim of this work was to investigate the aerobic degradation of high-strength industrial (refinery) wastewaters in the inverse fluidized bed biological reactor, in which polypropylene particles of density 910 kg/m3...The aim of this work was to investigate the aerobic degradation of high-strength industrial (refinery) wastewaters in the inverse fluidized bed biological reactor, in which polypropylene particles of density 910 kg/m3 were fluidized by an upward flow of gas through a bed. Measurements of chemical oxygen demand (COD) versus residence time t were performed for various ratios of settled bed volume to reactor volume (Vb/VR) and air velocities u. The largest COD reduction, namely, from 54,840 to 2,190 mg/l, i.e. a 96% COD decrease, was achieved when the reactor was operated at the ratio (Vb/VR) = 0.55, air velocity u = 0.046 m/s and t = 65 h. Thus, these values of (Vb/VR), u and t can be considered as the optimal operating parameters for a reactor when used in treatment of high-strength refinery wastewaters. In the treatment operation conducted in a reactor optimally controlled at (Vb/VR) = 0.55, u = 0.046 m/s and t = 65 h, the conversions obtained for all phenolic constituents of the wastewater were larger than 95%. The conversions of about 90% were attained for other hydrocarbons.展开更多
The destruction of toxic organic wastewaters from munitions demilitarization and complex industrial chemical clearly becomes an overwhelming problem if left to conventional treatment processes. Two options, incinerati...The destruction of toxic organic wastewaters from munitions demilitarization and complex industrial chemical clearly becomes an overwhelming problem if left to conventional treatment processes. Two options, incineration and supercritical water oxidation (SCWO), exist for the complete destruction of toxic organic wastewaters. Incinerator has associated problems such as very high cost and public resentment; on the other hand, SCWO has proved to be a very promising method for the treatment of many different wastewaters with extremely efficient organic waste destruction 99.99% with none of the emissions associated with incineration. In this review, the concepts of SCWO, result and present perspectives of application, and industrial status of SCWO are critically examined and discussed.展开更多
文摘This study examined the application of co-benefit-type wastewater treatment technology in the fish-processing industry. Given that there was a dearth of information on fish-processing industrial wastewater in Indonesia, site surveys were conducted. For the entire fish-processing industry throughout the country, the dissemination rate of wastewater treatment facilities was less than 50%. Using a co-benefit approach, a real-scale swim-bed technology (SBT) and a system combining an anaerobic baffled reactor (ABR) with SBT (ABR–SBT) were installed in a fishmeal processing factory in Bali, Indonesia, and the wastewater system process performance was evaluated. In a business-as-usual scenario, the estimated chemical oxygen demand load and greenhouse gas (GHG) emissions from wastewater from the Indonesian fish-processing industry were 33 000 tons per year and 220 000 tons of equivalent CO_(2) per year, respectively. On the other hand, the GHG emissions in the co-benefit scenarios of the SBT system and ABR–SBT system were 98 149 and 26 720 tons per year, respectively. Therefore, introducing co-benefit-type wastewater treatment to Indonesia’s fish-processing industry would significantly reduce pollution loads and GHG emissions.
基金financially supported by PetroChina Scientific Research and Technology Development Project, China (2018A-0907, YGJ2019-11-01)the support from CFI and NSERC, Canada
文摘The most abundant natural biopolymer on earth, cellulose fiber, may offer a highly efficient, low-cost, and chemical-free option for wastewater treatment. Cellulose is widely distributed in plants and several marine animals. It is a carbohydrate polymer consisting of β-1,4-linked anhydro-D-glucose units with three hydroxyl groups per anhydroglucose unit(AGU). Cellulose-based materials have been used in food, industrial, pharmaceutical, paper, textile production, and in wastewater treatment applications due to their low cost, renewability,biodegradability, and non-toxicity. For water treatment in the oil and gas industry, cellulose-based materials can be used as adsorbents, flocculants, and oil/water separation membranes. In this review, the uses of cellulose-based materials for wastewater treatment in the oil & gas industry are summarized, and recent research progress in the following aspects are highlighted: crude oil spill cleaning, flocculation of solid suspended matter in drilling or oil recovery in the upstream oil industry, adsorption of heavy metal or chemicals, and separation of oil/water by cellulosic membrane in the downstream water treatment.
文摘Water pollution has become one of the most pressing health crises in the world. Water pollution control began as early as the late 1800s. In 2008, there were 14,780 municipal wastewater treatment plants operating in the United States. These plants range in size from a few hundred gallons per day (GPD) to over 1.445 billion gallons (MGD) per day. Wastewater treatment facilities are designed and constructed or upgraded to reduce the amount and diversity of pollutants. This article gives a review of the current industrial wastewater treatment technology in recent years, including treatment principles, advantages and disadvantages of each method, and the corresponding applications. Also, this article reviewed two common biological technologies Anaerobic Ammonium Oxidation (ANAMMOX) and Anaerobic Membrane Bioreactor (ANMBR) technology, by assessing their advantages, disadvantages, and costs, and provides resources for further technical research. This article can serve as a guide for anyone seeking information on innovative and emerging industry wastewater treatment technologies.
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.
基金financially supported by SINOPEC (CLY15043)CRICC of ChemChina (2017-KZY03 and 2018-KZ-Y04)
文摘The powdered activated carbon treatment(PACT) process has been widely used in many industrial fields, however,very few PACT processes are built for petrochemical wastewater treatment in China. An industrial PACT unit launched in a petrochemical plant was introduced and evaluated from both the practice and mechanism study. Practically, the PACT process showed excellent capability in pollutants removal, shock resistance, toxicity tolerance, and the COD and ammoniumN in effluent of PACT unit assisted by PAC was equal to 15.5 mg/L and 0.7 mg/L lower than that without PAC addition,respectively. The wet oxidation regeneration unit was quite efficient in supplying regenerated PAC, and, however, the hard calcium sulphate scale and the high pollutant concentration solution needed to be carefully controlled. Moreover, although the carbon balance showed that the adsorption capability of regenerated PAC was negligible, the biological tests proved that the regenerated PAC increased microbe activity up to 17% more than pure activated sludge system, which was almost compatible with the fresh activated carbon.
基金the National Science Fund for Distinguished Young Scholars(Grant No.50725827)the National High Technology Research and Development Program(863 program)of China(Grant No.2009AA062901).
文摘Since the introduction of the membrane bioreactor(MBR)in China in the early 1990s,remarkable progress has been achieved on the research and application of this technology.China has now become one of the most active fields in the world in this regard.This review outlines the development of MBR-based processes in China and their performance of treating municipal and industrial wastewaters.Since membrane fouling is a critical operational problem with MBR processes,this paper also proposes updated understanding of fouling mechanisms and strategies of fouling control,which are mainly compiled from publications of Chinese researchers.As for the commercial application of MBR in the country,the latest statistics of large-scale MBR plants(>10000 m^(3)·d^(–1))are provided,and the growth trend of total treatment capacity as well as its driving force is analyzed.
基金the financial support of Stena Recycling AB(Sweden)and the Knowledge Foundation(Sweden).
文摘This paper presents an evaluation of the suitability of a mixed absorbent based on peat and carbon-containing ash for treatment of wastewaters, such as wastewater from professional car washes, landfill leachate and stormwater. This mixture is very attractive, since it is a low-cost material which has a capability to simultaneously remove inorganic as well as organic pollutants. Since any filter material eventually needs to be replaced either due to saturation of pollutants or reduced infiltration capacity, it is important that the residual can be handled at low cost and that the environment will be not impaired. The tested mixture, used in filter beds, showed low leaching values and high simultaneous removal efficiency of metals as Cu, Cd and Pb, non-polar organic compounds such as PCBs. Polar organic compounds as phenols were also efficiently removed by microbial and/or chemical degradation in the studied treatment plants with the filter bed acted as a biofilter. Filter material used for three years in a full-scale plant for leachate treatment and four years in treatment plants for wastewater from car washes, had sufficiently high energy content indicating that energy recovery is a good alternative for handling after its usage. Results show that the presented filter material is excellent for both small scale applications (e.g. treatment systems for car wash wastewater with capacity between 250 - 3000 m3 per year) as well as large-scale applications (e.g. filter systems for landfill leachates with capacity above 30,000 m3 per year).
文摘In this study,we have determined the main important physical and chemical properties as well as the heavy metal concentrations of the primary and secondary wastewater treatment sludge from a pulp and board mill complex located in Finland in order to evaluate the utilization of these by-products as a soil amendment agent or a fertilizer product.Easily soluble Ca,Mg,K,Na,P and S concentrations in the sludges were extracted by ammonium acetate(CH3COONH4)and easily soluble Cu,Mn and Zn concentrations by CH3COONH4+Na2EDTA.For the determination of total nutrient and total heavy metal concentrations in sludges,they were digested using aqua regia(3 mL HCl+9 mL HNO3).The total heavy concentrations in the primary sludge were lower than the Finnish heavy metal limit values for fertilizer products.In the secondary sludge,all other total heavy metals than the total Cd concentration(4.8 mg/kg;d.w.)were lower than the heavy metal limit values for fertilizer products.Due to the low total heavy metal concentrations,which were lower than the Finnish limit values for fertilizer products,the primary sludge is a potential fertilizer.Although the total Cd concentration(4.8 mg/kg;d.w.)in the secondary sludge exceed the limit value of 1.5 mg/kg(d.w.)for fertilizer products,this residue may be used as a soil improver,a growing media or as a fertilizer product in landfill sites or in other closed industrial areas,because the Finnish limit values for fertilizer products are not applied at these sites.
文摘A full-scale plant using anaerobic, anoxic and oxic processes (A1/A2/O), along with a pilot-scale membrane bioreactor (MBR), nanofiltration (NF) and reverse osmosis (RO) integrated system developed by Shanghai Baosteel Chemical Co. Ltd., was investigated to treat coking wastewater for industrial reuse over a period of one year. The removals reached 82.5% (COD), 89.6% (BOD), 99.8% (ammonium nitrogen), 99.9% (phenol), 44.6% (total cyanide (T-CN)), 99.7% (thiocyanide (SCN-)) and 8.9% (fluoride), during the A1/A2/O biological treatment stage, and all parameters were further reduced by over 96.0%, except for fluoride (86.4%), in the final discharge effluent from the currently operating plant. The pilot-scale MBR process reduced the turbidity to less than 0.65 NTU, and most of the toxic organic compounds were degraded or intercepted by the A1/A2/O followed MBR processes. In addition, parameters including COD, T-CN, total nitrogen, fluoride, chloride ion, hardness and conductivity were significantly reduced by the NF-RO system to a level suitable for industrial reuse, with a total water production ratio of 70.7%. However, the concentrates from the NF and RO units were highly polluted and should be disposed of properly or further treated before being discharged.
文摘The characteristics and harm of high concentrations of organic wastewater were introducecl firstly, and then several treatment processes and effects of high concentrations of organic wastewater were summarized, which can provide theoretical references for the choice of wastewater treatment process.
文摘Whereas the pulp and paper industrial sector—considered the second highest consumer of freshwater in Europe—has already been provided with sufficient wastewater characterization and treatment technologies, other wood-based industries (e.g. furniture, floor production), which do not use water for manufacturing processes, generate different wastewater streams after: 1) cleaning/washing of machinery that applies adhesives and coatings onto wood surfaces;2) cleaning/washing of machinery that applies specific products for the curing phase of adhesives;3) cleaning/washing of sharp planar blades used for the sawn process and to prepare wood surfaces for the adhesive application;4) cleaning/washing of the floor;5) cleaning/washing of trucks and vehicles. The dilution of low-volumes of highly polluted wastewater is not acceptable any longer since conventional treatment plants are not designed for these types of industrial wastewater. There is a need for proper characterization, treatability studies, designing and testing alternative small size and cost-effective treatment systems for on-site implementation. Treatment systems based on sorption mechanisms are flexible, easy to operate and generate less sludge and several low-cost sorbents generated by forestry activities have advantageous physico-chemical characteristics. The current paper presents the preliminary results from a pilot treatment system consisting of an equalization tank, settling/sedimentation and two sorption reactors in parallel using Pinus sylvestris sawdust as sorbent implemented as part of an integrated water management plan in a wood-floor industry. The simple to operate and cost-effective pilot treatment system performs satisfactorily during an initial period of operation. The study shows an average 39% - 54% reduction of TPH;17% - 38% reduction of oil;2% - 15% of reduction of COD and;11% - 74% reduction of most toxic metals but for Co, Ni and Zn in the system B. Based on these results, Pinus sylvestris sawdust is a potential low-cost and abundant material to be considered for industrial wastewater treatment plants.
文摘The aim of this work was to investigate the aerobic degradation of high-strength industrial (refinery) wastewaters in the inverse fluidized bed biological reactor, in which polypropylene particles of density 910 kg/m3 were fluidized by an upward flow of gas through a bed. Measurements of chemical oxygen demand (COD) versus residence time t were performed for various ratios of settled bed volume to reactor volume (Vb/VR) and air velocities u. The largest COD reduction, namely, from 54,840 to 2,190 mg/l, i.e. a 96% COD decrease, was achieved when the reactor was operated at the ratio (Vb/VR) = 0.55, air velocity u = 0.046 m/s and t = 65 h. Thus, these values of (Vb/VR), u and t can be considered as the optimal operating parameters for a reactor when used in treatment of high-strength refinery wastewaters. In the treatment operation conducted in a reactor optimally controlled at (Vb/VR) = 0.55, u = 0.046 m/s and t = 65 h, the conversions obtained for all phenolic constituents of the wastewater were larger than 95%. The conversions of about 90% were attained for other hydrocarbons.
基金Project supported by the Korea Institute of Science and Technology (KIST).
文摘The destruction of toxic organic wastewaters from munitions demilitarization and complex industrial chemical clearly becomes an overwhelming problem if left to conventional treatment processes. Two options, incineration and supercritical water oxidation (SCWO), exist for the complete destruction of toxic organic wastewaters. Incinerator has associated problems such as very high cost and public resentment; on the other hand, SCWO has proved to be a very promising method for the treatment of many different wastewaters with extremely efficient organic waste destruction 99.99% with none of the emissions associated with incineration. In this review, the concepts of SCWO, result and present perspectives of application, and industrial status of SCWO are critically examined and discussed.