Urban water supply is the lifeblood of people's production, life and economic development. For a long time, as a state-owned public welfare enterprise, on the one hand, water supply company undertakes the importan...Urban water supply is the lifeblood of people's production, life and economic development. For a long time, as a state-owned public welfare enterprise, on the one hand, water supply company undertakes the important task of safe water supply in urban development and its service targets are urban residents and water users of all walks of life. Its service is a social hot issue affecting thousands of households and involving the vital interests of every citizen. On the other hand, in order to serve the urban construction and attract investment, the investment in water supply infrastructure construction is increasing and the water supply enterprises must constantly improve their own strength to meet the requirements of local social and economic development, but the existing water supply projects can not meet the current situation. Therefore, it is urgent to explore a healthy and stable management mode and development road.展开更多
Water is one of the most important elements on which our daily lives depend,because of its many uses in various fields.To ensure that people have the right of access to water,the authorities must provide them with tre...Water is one of the most important elements on which our daily lives depend,because of its many uses in various fields.To ensure that people have the right of access to water,the authorities must provide them with treated water that complies with the regulations and standards in force,particularly from a physico-chemical point of view,for all possible uses to avoid any health problems for consumers.The aim of this research is to study the water in the Mamouwol River by measuring physico-chemical parameters:(1)pH,it varies from 5.2“Mam3”to 7.8“Mam4”in August 2021 then from 5.5“Mam3”to 7.7“Mam4”in March 2022,i.e.an average of 6.9 for all sampling points;(2)Turbidity varies from 0.3 NTU“Mam1”to 26.3 NTU“Mam4”in August 2021,then from 0.3 NTU“Mam1”to 30.6 NTU“Mam4”in March 2022,i.e.an average of 9.0 NTU for all sampling points;(3)Suspended matter,varying from 0.6 mg/L“Mam1”to 17.6 mg/L“Mam4”in August 2021,then from 0.6 mg/L“Mam1”to 30.0 mg/L“Mam4”in March 2022,i.e.an average of 8.8 mg/L for all the sampling points“Mam1”,“Mam2”,“Mam3”and“Mam4”;(4)Dissolved oxygen,varying from 2.07 mg/L“Mam3”to 6.12 mg/L“Mam1”in August 2021,then from 1.05 mg/L“Mam3”to 5.05 mg/L“Mam1”in March 2022,i.e.an average of 2.77 mg/L for all sampling points;(5)Nitrates vary from 1.32 mg/L“Mam1”to 3.96 mg/L“Mam4”in August 2021,then from 1.49 mg/L“Mam1”to 5.27 mg/L“Mam3”in March 2022,i.e.an average of 5.53 mg/L for all sampling points;(6)Nitrites,varying from 0 mg/L“Mam1”and“Mam2”to 0.06 mg/L“Mam3”in August 2021,then from 0 mg/L“Mam1”and“Mam2”to 0.13 mg/L“Mam3”in March 2022,i.e.an average of 0.03 mg/L for all sampling points.The results show the presence of organic pollution.展开更多
This study utilizes multiple regression analysis and the technique for computing economies of scale to evaluate the dynamics of NRW in the AER of GWCL. Data on monthly total production, billed consumption, total reven...This study utilizes multiple regression analysis and the technique for computing economies of scale to evaluate the dynamics of NRW in the AER of GWCL. Data on monthly total production, billed consumption, total revenue, total production cost and the volume of NRW spanning the period January 2015 to June 2019, was obtained from the headquarters of AER and used for the analysis. The study showed that NRW averaged 59.3% for the period under consideration, which far exceeds the 25% threshold set by the World Bank for developing economies. It was also established that a fairly inelastic relationship exists between NRW and total revenue. Results further show that resources are not optimally used in the AER as proof of diseconomies of scale was observed.展开更多
A GAC-sand dual media filter （GSF） was devised as an alternative solution for drinking water treatment plant to tackle the raw water polluted by ammonium in place of expensive ozone-GAC processes or bio-pretreatment...A GAC-sand dual media filter （GSF） was devised as an alternative solution for drinking water treatment plant to tackle the raw water polluted by ammonium in place of expensive ozone-GAC processes or bio-pretreatments. The ammonium removal pathways and microbial community in the GSFs were investigated. The concentrations of ammonium, nitrite and nitrate nitrogen were monitored along the filter. Total inorganic nitrogen （TIN） loss occurred during the filtration. For 1 mg ammonium removal, the TIN loss was as high as 0.35 mg, DO consumption was 3.06 mg, and alkalinity consumption was 5.55 rag. It was assumed that both nitrification and denitrification processes occur in the filters to fit the TIN loss and low DO consumption. During the filtration, nitritation, nitrification and nitritation-anaerobic ammonium oxidation processes probably occur, while traditional nitrification and denitrification and simultaneous nitrification and denitrification processes may occur. In the GSFs, Nitrosomonas and Nitrospira are likely to be involved in nitrification processes, while Novosphingobium, Comamonadaceae and Oxalobacteraceae may be involved in denitrification processes.展开更多
The hollow fiber supported liquid membrane extraction was introduced to treat coal gasification wastewater to recover phenolic compounds,with tributyl phosphate (TBP) as carrier,kerosene as the membrane solvent,sodium...The hollow fiber supported liquid membrane extraction was introduced to treat coal gasification wastewater to recover phenolic compounds,with tributyl phosphate (TBP) as carrier,kerosene as the membrane solvent,sodium hydroxide solution as the stripping agent and PVDF as the membrane material. Factors having strong impact on the extraction efficiency were studied in detail,including the mass transfer mode,twophase flow rate,stripping phase concentration. As extraction system with 20% TBP-kerosene,parallel flow mass transfer,stripping phase concentration 0.1 mol/L,the optimal operating conditions could be obtained. Under the optimum operating conditions,the time required to reach equilibrium for the extraction is 50 min, and extraction efficiency of phenol is 86. 2% and the phenol concentration of effluent is 98.64 mg/L.展开更多
Stainless steels generally have extremely good corrosion resistance, but are still susceptible to pitting corrosion. As a result, corrosion scales can form on the surface of stainless steel after extended exposure to ...Stainless steels generally have extremely good corrosion resistance, but are still susceptible to pitting corrosion. As a result, corrosion scales can form on the surface of stainless steel after extended exposure to aggressive aqueous environments. Corrosion scales play an important role in affecting water quality. These research results showed that interior regions of stainless steel corrosion scales have a high percentage of chromium phases. We reveal the morphology, micro-structure and physicochemical characteristics of stainless steel corrosion scales. Stainless steel corrosion scale is identified as a podiforrn chromite deposit according to these characteristics, which is unlike deposit formed during iron corrosion. A conceptual model to explain the formation and growth of stainless steel corrosion scale is proposed based on its composition and structure. The scale growth process involves pitting corrosion on the stainless steel surface and the consecutive generation and homogeneous deposition of corrosion products, which is governed by a series of chemical and electrochemical reactions. This model shows the role of corrosion scales in the mechanism of iron and chromium release from pitting corroded stainless steel materials. The formation of corrosion scale is strongly related to water quality parameters. The presence of HCIO results in higher ferric content inside the scales. Cl- and SO2- ions in reclaimed water play an important role in corrosion pitting of stainless steel and promote the formation of scales.展开更多
A combined process of biological aerated filter,fiber ball filter and chlorine dioxide disinfection was used to treat effluent of primary hospital wastewater in Jinan.Its treatment capacity was designed as 400m^3/d ba...A combined process of biological aerated filter,fiber ball filter and chlorine dioxide disinfection was used to treat effluent of primary hospital wastewater in Jinan.Its treatment capacity was designed as 400m^3/d based on the reclaimed water demand of the large general hospital.The quality of the effluent can meet the requirements of the Reuse of Urban Recycling Water——Water Quality Standard for Urban Miscellaneous Water Consumption(GB/T18920-2002).The project has less site area,low investment and operation cost and high automatic control level,so it can provide scientific references for design and operation of similar projects.展开更多
The adsorption of aluminium(III) and iron(III) ions from their single and binary systems, by RHAC was investigated in a batch system. The activated carbon prepared from rice hulls was characterized by scanning electro...The adsorption of aluminium(III) and iron(III) ions from their single and binary systems, by RHAC was investigated in a batch system. The activated carbon prepared from rice hulls was characterized by scanning electron microscopy and Fourier transformation infrared techniques. Batch adsorption experiments were performed under different operating conditions including pH (2 - 5), adsorbent dosage (0.5 - 2.0 g/l), initial ion concentration (5 - 100 mg/l), and contact time (30 - 240 min). The equilibrium time for maximum ions removal was found to be 180 min in single and binary ions systems. The kinetics of adsorption was evaluated using the pseudo-first order, pseudo-second order and Elovich kinetic models. The Langmuir, Freundlich and Temkin equilibrium models were applied to the adsorption experimental data. Real wastewater samples were collected from different locations to investigate the efficiency of rice hull activated carbon in treating real samples. The real wastewater samples were treated with the activated carbon prepared from rice hulls and a commercial activated carbon. The results showed that the activated carbon prepared in the present work was more efficient in the removal of aluminium and iron from real wastewater as compared to the commercial activated carbon which is more advantageous considering both economics and environmental parameters.展开更多
This paper developed a sensitive and efficient analytical method for triclocarban (TCC), triclosan (TCS) and Methyl-triclosan (MTCS) determination in environmental water, which involves enrichment by using silicon dio...This paper developed a sensitive and efficient analytical method for triclocarban (TCC), triclosan (TCS) and Methyl-triclosan (MTCS) determination in environmental water, which involves enrichment by using silicon dioxide/polystyrene composite microspheres solid-phase extraction and detection with HPLC-ESI-MS. The influence of several operational parameters, including the eluant and its volume, the flow rate and acidity of water sample were investigated and optimized. Under the optimum conditions, the limits of detection were 1.0 ng/L, 2.5 and 4.5 ng/L for TCC, TCS, and MTCS, respectively. The linearity of the method was observed in the range of 5-2000 ng/L, with correlation coefficients (r2) >.99. The spiked recoveries of TCC, TCS and MTCS in water sampleswereachieved in the range of 89.5% -96.8% with RSD below 5.7%. The proposed method has been successfully applied to analyze real water samples and satisfactory results were achieved.展开更多
The Koekemoerspruit is a possible pollution source of the Middle Vaal River, an important drinking water source in South Africa. This case study aimed to establish the water quality of the Koekemoerspruit, to evaluate...The Koekemoerspruit is a possible pollution source of the Middle Vaal River, an important drinking water source in South Africa. This case study aimed to establish the water quality of the Koekemoerspruit, to evaluate the impact of the Koekemoerspruit on the Vaal River, and to use this information to identify shortcomings in the monitoring program. Monthly and weekly samples from both the Vaal River and the Koekemoerspruit were analyzed at an accredited testing laboratory based on ISO 17025 for 20 chemical methods. A dataset from 2002 to 2015 was statistically analyzed by means of Statistica software, the Mann-Kendall test and the Sens’s slope to determine descriptive statistics and significant trends respectively. The sites’ water quality was evaluated by comparison with both national drinking water standards and environmental target water quality objectives. Results indicated that the target water quality objectives for orthophosphate, nitrate and nitrite, and ammonia concentrations were considerably exceeded in the Koekemoerspruit. The drinking water quality of the Koekemoerspruit and the Middle Vaal was noncompliant with South African standards. Color, electrical conductivity, turbidity, sulfate, recoverable cyanide and arsenic at one site posed aesthetic, operational, acute and chronic health risks. Color, mean ammonia and total chlorophyll concentrations displayed significant trends of increase over time and increased drastically after 2012 at the site where water enters the Middle Vaal River. However, the Koekemoerspruit did not seem to have a significant impact on the overall water quality of the Middle Vaal River, except for total chlorophyll concentrations. Moreover, the review and recommendations for optimizing the water quality monitoring program proved that original monitoring objectives have been achieved. The reviewed monitoring program has consequently been adopted in the water safety plan to address the shortcomings that were identified during this case study.展开更多
In the experiment,PDMS membrane with NaY molecular sieve filling were chosen as the experimental objects and the flux of phenol and removal efficiency of phenol as evaluation index,the effect of the system operating t...In the experiment,PDMS membrane with NaY molecular sieve filling were chosen as the experimental objects and the flux of phenol and removal efficiency of phenol as evaluation index,the effect of the system operating temperature,the flow rate,liquid membrane downstream pressure,operation time,and filling proportion of NaY molecular sieve on pervaporation treatment efficiency for wastewater from coal gasification were investigated. With the increase of temperature and feed flow rate,pervaporation flux and phenol removal efficiency increases. The decrease of the membrane downstream pressure and elevating NaY molecular sieve filling proportion may result in the increase of flux and then phenol removal efficiency improves. When NaY molecular sieve filling proportion is 45% ,treatment efficiency is the best for coal gasification wastewater containing 1850 mg/L phenol as the flux of phenol was 12948. 23 mg/(h·m2) .展开更多
Drinking water quality deteriorates from treatment plant to customer taps, especially in the plumbing system. There is no direct evidence about what the differences are contributed by plumbing system. This study compa...Drinking water quality deteriorates from treatment plant to customer taps, especially in the plumbing system. There is no direct evidence about what the differences are contributed by plumbing system. This study compared the water quality in the water main and at customer tap by preparing a sampling tap on the water main. The biomass was quantified by adenosine triphosphate(ATP) and the microbial community was profiled by 454 pyrosequencing.The results showed that in distribution pipes, biofilm contributed >94% of the total biomass,while loose deposits showed little contribution(< 2%) because of the low amount of loose deposits. The distribution of biological stable water had minor effects on the microbiocidal water quality regarding both quantity(ATP 1 ng/L vs. 1.7 ng/L) and community of the bacteria. Whereas the plumbing system has significant contribution to the increase of active biomass(1.7 ng/L vs. 2.9 ng/L) and the changes of bacterial community. The relative abundance of Sphingomonas spp. at tap(22%) was higher than that at water main(2%), while the relative abundance of Pseudomonas spp. in tap water(15%) was lower than that in the water from street water main(29%). Though only one location was prepared and studied, the present study showed that the protocol of making sampling tap on water main offered directly evidences about the impacts of plumbing system on tap water quality, which makes it possible to distinguish and study the processes in distribution system and plumbing system separately.展开更多
Water pollution affects plants and organisms living in these bodies of water; and, in almost all cases the effect is damaging not only to individual species and populations, but also to the natural biological communit...Water pollution affects plants and organisms living in these bodies of water; and, in almost all cases the effect is damaging not only to individual species and populations, but also to the natural biological communities. Genetic algorithm and kernel partial least square （GA-KPLS） and Levenberg- Marquardt artificial neural network （L-M ANN） techniques were used to investigate the correlation between retention time （tR） and descriptors for 150 organic contaminants in natural water and wastewater, which are obtained by gas chromatography coupled to high-resolution time-of-flight mass spectrometry （GC-TOF MS）. The L-M ANN model gave a significantly better performance than the GA-KPLS model. This indicates that L-M ANN can be used as an alternative modeling toot for quantitative structure-retention relationship （QSRR） studies.展开更多
We evaluated several different pre-oxidation treatments, namely the introduction of either potassium permanganate (KMnO4), chlorine (Cl2), or both to remove manganese (Mn) from the Qiantang River source water. Our res...We evaluated several different pre-oxidation treatments, namely the introduction of either potassium permanganate (KMnO4), chlorine (Cl2), or both to remove manganese (Mn) from the Qiantang River source water. Our results showed that Mn removal percentages were 12.7%, 71.0%, 17.4% and 58.7% when none of the oxidants, KMnO4 only, Cl2 only, or both oxidants were added, respectively. Furthermore, a field study showed that when the available Mn concentration in the source water was 0.14 mg/L, it could be reduced to less than 0.05 mg/L when a solution of KMnO4 (0.47 mg/L) was added as the oxidant.展开更多
This study compares numerical models with analytical solutions in computing travel times and radius of protection zones for a pumping well located in an unconfined aquifer with uniform recharge and in a semi-confined ...This study compares numerical models with analytical solutions in computing travel times and radius of protection zones for a pumping well located in an unconfined aquifer with uniform recharge and in a semi-confined aquifer. Numerical models were capable of delineating protection zones using particle tracking method in both cases. However, protection zones defined by travel time criterion can only protect small percent of source water to the well; large percent of source water is not protected which may pose a risk of pollution of source water to the well. The case study of Leggeloo well field in the Netherlands indicates that although a well field protection area was enforced in 1980 s, elevated nitrate concentration has been monitored in the abstracted water since 1990 s. The analysis of protection areas shows that the current protection area only protects 37.4% of recharge water to the well field. A large protection area must be adopted in order to safeguard the sustainable water supply for the local community.展开更多
The article addresses the results of effective water losses prevention in public water supply systems, focusing on procedures for monitoring hidden leaks as the main part of losses and as the first step to control and...The article addresses the results of effective water losses prevention in public water supply systems, focusing on procedures for monitoring hidden leaks as the main part of losses and as the first step to control and prevent them. The described methodology has been applied based on a cross-border cooperation between twin capital cities Vienna and Bratislava in the Central Europe Region within the project deWaloP （Developing Water Loss Prevention） and adopted in Bratislava Water Company （BVS） in the Slovak Republic. The paper provides a complex of simple and easily available practices for analyses of water distribution measurements bringing essential information as to the necessity to use advanced procedures to actively reduce leakage. These practices involve minimum night flows analyses, hydrodynamic pressures analyses, pinpointing of water leakages by working with valves in the water network, the methodology of setting alarm limits for measured data, as well as use of advanced practices to obtain missing topologic data. As the water infrastructure in former socialistic countries are in bad technical condition and the lack of pertinent operational data is a significant obstacle to the application of a more sophisticated methodology based on GIS and other information systems, the procedures focus on using the most simple way to evaluate and control water losses. Finally, the introduction of described methodology in Bratislava Water Company after many years of unsuccessful effort even with expensive sophisticated leakage equipment brought positive outputs and the graph line of water losses level is finally going down. The use of expensive multi-correlating equipment together with human resources on the basis of implementing the above described leakage monitoring will subsequently become more effective, as it shall pinpoint major leakages, disclosure and removal of that shall significantly contribute to the effective reduction of water losses.展开更多
In this study we estimate agricultural water footprint and its components from consumption perspective in arid and semi-arid region like Iran. This study is based on blue water consumption in irrigated land. Iran has ...In this study we estimate agricultural water footprint and its components from consumption perspective in arid and semi-arid region like Iran. This study is based on blue water consumption in irrigated land. Iran has imported net virtual water about 11.64 billion cubic meters (bcm) as international crop trade in 2005-2006. Therefore, Iran has depended on virtual water imports. By conserving about 60% irrigation efficiency, the total water requirement to produce imported crops in Iran is nearly 20.78 billion cubic meters. It is nearly 9 percent of renewable water resources and 12.65% agricultural appropriated water which has added to internal water resources. Agricultural virtual water budget is about 112.78 Gm3/yr. Agricultural water footprint is 110.2 Gm3/yr. About 12.83% of agricultural water footprint of Iran is related to external water resources on the country boundaries. It means external water footprint. Water dependency, water self-sufficiency and water scarcity indexes in agricultural sector of Iran, are estimated 10.1%, 89.9% and 70.8%, respectively.展开更多
The purpose of this research is to investigate a biofilm system with trickling filter as a biological alternative process during low cost treatment connection with the possibility of reducing nutrients such as phospho...The purpose of this research is to investigate a biofilm system with trickling filter as a biological alternative process during low cost treatment connection with the possibility of reducing nutrients such as phosphorus. Given that nitrogen with phosphorus that are leading causes of algal bloom resulting in increased eutrophication or chemical nutrients are the basis of this document analysis. This increase in organisms results in less oxygen in water bodies and at times, slow decay leads many fresh water ponds, lakes and rivers. The process of eutrophication unfortunately tends to favor pollution and algae, which reduce the quality of the water. Kosovo has not a long tradition in the treatment of wastewater, especially in removing phosphorus, since the country has only a plant for wastewater treatment. The present plant is intended to protect the Klina river from eutrophication from wastewater discharged after treatment. This plant currently reduced phosphorus efficiently, but the goal of this paper is to increase the percentage of removal of phosphorus to 40% through trickling filters, presenting options for optimizing work on plant Skenderaj.展开更多
The goal of this topic is a synthesis of the main characteristics of iron in groundwater and the oxidation process used to remove it. Indeed, the kinetics of chemical oxidation of iron (II) was examined with reconstit...The goal of this topic is a synthesis of the main characteristics of iron in groundwater and the oxidation process used to remove it. Indeed, the kinetics of chemical oxidation of iron (II) was examined with reconstituted water (distilled water + iron sulphate) and proceeded to the application in the groundwater samples taken from <em><strong>South Pout</strong></em> (Senegal) precisely in the drilling <strong>PS2</strong>. The sources of iron are natural or anthropogenic. In Senegalese waters, its content is variable and sometimes exceeds the standards of potability. Despite the diversification of iron removal process, chemical oxidation is the most used solution in drinking water treatment plants in Senegalese rural areas. Applied oxidation processes such as aeration and chlorination, however, are insufficient to produce drinking water with an iron concentration in accordance with standards of potability.展开更多
In order to ensure the production quality and sustainable development of water supply enterprises, optimizing the production cost control of water supply enterprises is an important subject to be studied urgently. Com...In order to ensure the production quality and sustainable development of water supply enterprises, optimizing the production cost control of water supply enterprises is an important subject to be studied urgently. Combined with the characteristics of water supply enterprises, from the perspective of production cost management, this paper studies how to strengthen the cost control of water supply enterprises in daily management, improve the production quality, operating benefits and social benefits of water supply enterprises, and promote the long-term steady development of water supply companies.展开更多
文摘Urban water supply is the lifeblood of people's production, life and economic development. For a long time, as a state-owned public welfare enterprise, on the one hand, water supply company undertakes the important task of safe water supply in urban development and its service targets are urban residents and water users of all walks of life. Its service is a social hot issue affecting thousands of households and involving the vital interests of every citizen. On the other hand, in order to serve the urban construction and attract investment, the investment in water supply infrastructure construction is increasing and the water supply enterprises must constantly improve their own strength to meet the requirements of local social and economic development, but the existing water supply projects can not meet the current situation. Therefore, it is urgent to explore a healthy and stable management mode and development road.
文摘Water is one of the most important elements on which our daily lives depend,because of its many uses in various fields.To ensure that people have the right of access to water,the authorities must provide them with treated water that complies with the regulations and standards in force,particularly from a physico-chemical point of view,for all possible uses to avoid any health problems for consumers.The aim of this research is to study the water in the Mamouwol River by measuring physico-chemical parameters:(1)pH,it varies from 5.2“Mam3”to 7.8“Mam4”in August 2021 then from 5.5“Mam3”to 7.7“Mam4”in March 2022,i.e.an average of 6.9 for all sampling points;(2)Turbidity varies from 0.3 NTU“Mam1”to 26.3 NTU“Mam4”in August 2021,then from 0.3 NTU“Mam1”to 30.6 NTU“Mam4”in March 2022,i.e.an average of 9.0 NTU for all sampling points;(3)Suspended matter,varying from 0.6 mg/L“Mam1”to 17.6 mg/L“Mam4”in August 2021,then from 0.6 mg/L“Mam1”to 30.0 mg/L“Mam4”in March 2022,i.e.an average of 8.8 mg/L for all the sampling points“Mam1”,“Mam2”,“Mam3”and“Mam4”;(4)Dissolved oxygen,varying from 2.07 mg/L“Mam3”to 6.12 mg/L“Mam1”in August 2021,then from 1.05 mg/L“Mam3”to 5.05 mg/L“Mam1”in March 2022,i.e.an average of 2.77 mg/L for all sampling points;(5)Nitrates vary from 1.32 mg/L“Mam1”to 3.96 mg/L“Mam4”in August 2021,then from 1.49 mg/L“Mam1”to 5.27 mg/L“Mam3”in March 2022,i.e.an average of 5.53 mg/L for all sampling points;(6)Nitrites,varying from 0 mg/L“Mam1”and“Mam2”to 0.06 mg/L“Mam3”in August 2021,then from 0 mg/L“Mam1”and“Mam2”to 0.13 mg/L“Mam3”in March 2022,i.e.an average of 0.03 mg/L for all sampling points.The results show the presence of organic pollution.
文摘This study utilizes multiple regression analysis and the technique for computing economies of scale to evaluate the dynamics of NRW in the AER of GWCL. Data on monthly total production, billed consumption, total revenue, total production cost and the volume of NRW spanning the period January 2015 to June 2019, was obtained from the headquarters of AER and used for the analysis. The study showed that NRW averaged 59.3% for the period under consideration, which far exceeds the 25% threshold set by the World Bank for developing economies. It was also established that a fairly inelastic relationship exists between NRW and total revenue. Results further show that resources are not optimally used in the AER as proof of diseconomies of scale was observed.
基金supported by the Major Science and Technology Program for Water Pollution Control and Treatment(No. 2009ZX07423-003)
文摘A GAC-sand dual media filter （GSF） was devised as an alternative solution for drinking water treatment plant to tackle the raw water polluted by ammonium in place of expensive ozone-GAC processes or bio-pretreatments. The ammonium removal pathways and microbial community in the GSFs were investigated. The concentrations of ammonium, nitrite and nitrate nitrogen were monitored along the filter. Total inorganic nitrogen （TIN） loss occurred during the filtration. For 1 mg ammonium removal, the TIN loss was as high as 0.35 mg, DO consumption was 3.06 mg, and alkalinity consumption was 5.55 rag. It was assumed that both nitrification and denitrification processes occur in the filters to fit the TIN loss and low DO consumption. During the filtration, nitritation, nitrification and nitritation-anaerobic ammonium oxidation processes probably occur, while traditional nitrification and denitrification and simultaneous nitrification and denitrification processes may occur. In the GSFs, Nitrosomonas and Nitrospira are likely to be involved in nitrification processes, while Novosphingobium, Comamonadaceae and Oxalobacteraceae may be involved in denitrification processes.
文摘The hollow fiber supported liquid membrane extraction was introduced to treat coal gasification wastewater to recover phenolic compounds,with tributyl phosphate (TBP) as carrier,kerosene as the membrane solvent,sodium hydroxide solution as the stripping agent and PVDF as the membrane material. Factors having strong impact on the extraction efficiency were studied in detail,including the mass transfer mode,twophase flow rate,stripping phase concentration. As extraction system with 20% TBP-kerosene,parallel flow mass transfer,stripping phase concentration 0.1 mol/L,the optimal operating conditions could be obtained. Under the optimum operating conditions,the time required to reach equilibrium for the extraction is 50 min, and extraction efficiency of phenol is 86. 2% and the phenol concentration of effluent is 98.64 mg/L.
基金supported by the National High-tech Research Plan of China (No. 2013AA065205)The Program for Changjiang Scholars and Innovative Research Team in University (IRT1261)The Beijing Science and Technology Program (No. Z141100006014048)
文摘Stainless steels generally have extremely good corrosion resistance, but are still susceptible to pitting corrosion. As a result, corrosion scales can form on the surface of stainless steel after extended exposure to aggressive aqueous environments. Corrosion scales play an important role in affecting water quality. These research results showed that interior regions of stainless steel corrosion scales have a high percentage of chromium phases. We reveal the morphology, micro-structure and physicochemical characteristics of stainless steel corrosion scales. Stainless steel corrosion scale is identified as a podiforrn chromite deposit according to these characteristics, which is unlike deposit formed during iron corrosion. A conceptual model to explain the formation and growth of stainless steel corrosion scale is proposed based on its composition and structure. The scale growth process involves pitting corrosion on the stainless steel surface and the consecutive generation and homogeneous deposition of corrosion products, which is governed by a series of chemical and electrochemical reactions. This model shows the role of corrosion scales in the mechanism of iron and chromium release from pitting corroded stainless steel materials. The formation of corrosion scale is strongly related to water quality parameters. The presence of HCIO results in higher ferric content inside the scales. Cl- and SO2- ions in reclaimed water play an important role in corrosion pitting of stainless steel and promote the formation of scales.
基金Supported by the Science and Technology Plan Project of Shandong Province(2014GSF116023)Science and Technology Development Plan Project of Ji’nan City(201218006)
文摘A combined process of biological aerated filter,fiber ball filter and chlorine dioxide disinfection was used to treat effluent of primary hospital wastewater in Jinan.Its treatment capacity was designed as 400m^3/d based on the reclaimed water demand of the large general hospital.The quality of the effluent can meet the requirements of the Reuse of Urban Recycling Water——Water Quality Standard for Urban Miscellaneous Water Consumption(GB/T18920-2002).The project has less site area,low investment and operation cost and high automatic control level,so it can provide scientific references for design and operation of similar projects.
文摘The adsorption of aluminium(III) and iron(III) ions from their single and binary systems, by RHAC was investigated in a batch system. The activated carbon prepared from rice hulls was characterized by scanning electron microscopy and Fourier transformation infrared techniques. Batch adsorption experiments were performed under different operating conditions including pH (2 - 5), adsorbent dosage (0.5 - 2.0 g/l), initial ion concentration (5 - 100 mg/l), and contact time (30 - 240 min). The equilibrium time for maximum ions removal was found to be 180 min in single and binary ions systems. The kinetics of adsorption was evaluated using the pseudo-first order, pseudo-second order and Elovich kinetic models. The Langmuir, Freundlich and Temkin equilibrium models were applied to the adsorption experimental data. Real wastewater samples were collected from different locations to investigate the efficiency of rice hull activated carbon in treating real samples. The real wastewater samples were treated with the activated carbon prepared from rice hulls and a commercial activated carbon. The results showed that the activated carbon prepared in the present work was more efficient in the removal of aluminium and iron from real wastewater as compared to the commercial activated carbon which is more advantageous considering both economics and environmental parameters.
文摘This paper developed a sensitive and efficient analytical method for triclocarban (TCC), triclosan (TCS) and Methyl-triclosan (MTCS) determination in environmental water, which involves enrichment by using silicon dioxide/polystyrene composite microspheres solid-phase extraction and detection with HPLC-ESI-MS. The influence of several operational parameters, including the eluant and its volume, the flow rate and acidity of water sample were investigated and optimized. Under the optimum conditions, the limits of detection were 1.0 ng/L, 2.5 and 4.5 ng/L for TCC, TCS, and MTCS, respectively. The linearity of the method was observed in the range of 5-2000 ng/L, with correlation coefficients (r2) >.99. The spiked recoveries of TCC, TCS and MTCS in water sampleswereachieved in the range of 89.5% -96.8% with RSD below 5.7%. The proposed method has been successfully applied to analyze real water samples and satisfactory results were achieved.
文摘The Koekemoerspruit is a possible pollution source of the Middle Vaal River, an important drinking water source in South Africa. This case study aimed to establish the water quality of the Koekemoerspruit, to evaluate the impact of the Koekemoerspruit on the Vaal River, and to use this information to identify shortcomings in the monitoring program. Monthly and weekly samples from both the Vaal River and the Koekemoerspruit were analyzed at an accredited testing laboratory based on ISO 17025 for 20 chemical methods. A dataset from 2002 to 2015 was statistically analyzed by means of Statistica software, the Mann-Kendall test and the Sens’s slope to determine descriptive statistics and significant trends respectively. The sites’ water quality was evaluated by comparison with both national drinking water standards and environmental target water quality objectives. Results indicated that the target water quality objectives for orthophosphate, nitrate and nitrite, and ammonia concentrations were considerably exceeded in the Koekemoerspruit. The drinking water quality of the Koekemoerspruit and the Middle Vaal was noncompliant with South African standards. Color, electrical conductivity, turbidity, sulfate, recoverable cyanide and arsenic at one site posed aesthetic, operational, acute and chronic health risks. Color, mean ammonia and total chlorophyll concentrations displayed significant trends of increase over time and increased drastically after 2012 at the site where water enters the Middle Vaal River. However, the Koekemoerspruit did not seem to have a significant impact on the overall water quality of the Middle Vaal River, except for total chlorophyll concentrations. Moreover, the review and recommendations for optimizing the water quality monitoring program proved that original monitoring objectives have been achieved. The reviewed monitoring program has consequently been adopted in the water safety plan to address the shortcomings that were identified during this case study.
文摘In the experiment,PDMS membrane with NaY molecular sieve filling were chosen as the experimental objects and the flux of phenol and removal efficiency of phenol as evaluation index,the effect of the system operating temperature,the flow rate,liquid membrane downstream pressure,operation time,and filling proportion of NaY molecular sieve on pervaporation treatment efficiency for wastewater from coal gasification were investigated. With the increase of temperature and feed flow rate,pervaporation flux and phenol removal efficiency increases. The decrease of the membrane downstream pressure and elevating NaY molecular sieve filling proportion may result in the increase of flux and then phenol removal efficiency improves. When NaY molecular sieve filling proportion is 45% ,treatment efficiency is the best for coal gasification wastewater containing 1850 mg/L phenol as the flux of phenol was 12948. 23 mg/(h·m2) .
基金the support from the National Key R&D program of China(No.2018YFE0204100)the National Natural Science Foundation of China(No.52022103)the National Natural Science Foundation of China for International Cooperation and Exchange(No.51820105011)。
文摘Drinking water quality deteriorates from treatment plant to customer taps, especially in the plumbing system. There is no direct evidence about what the differences are contributed by plumbing system. This study compared the water quality in the water main and at customer tap by preparing a sampling tap on the water main. The biomass was quantified by adenosine triphosphate(ATP) and the microbial community was profiled by 454 pyrosequencing.The results showed that in distribution pipes, biofilm contributed >94% of the total biomass,while loose deposits showed little contribution(< 2%) because of the low amount of loose deposits. The distribution of biological stable water had minor effects on the microbiocidal water quality regarding both quantity(ATP 1 ng/L vs. 1.7 ng/L) and community of the bacteria. Whereas the plumbing system has significant contribution to the increase of active biomass(1.7 ng/L vs. 2.9 ng/L) and the changes of bacterial community. The relative abundance of Sphingomonas spp. at tap(22%) was higher than that at water main(2%), while the relative abundance of Pseudomonas spp. in tap water(15%) was lower than that in the water from street water main(29%). Though only one location was prepared and studied, the present study showed that the protocol of making sampling tap on water main offered directly evidences about the impacts of plumbing system on tap water quality, which makes it possible to distinguish and study the processes in distribution system and plumbing system separately.
文摘Water pollution affects plants and organisms living in these bodies of water; and, in almost all cases the effect is damaging not only to individual species and populations, but also to the natural biological communities. Genetic algorithm and kernel partial least square （GA-KPLS） and Levenberg- Marquardt artificial neural network （L-M ANN） techniques were used to investigate the correlation between retention time （tR） and descriptors for 150 organic contaminants in natural water and wastewater, which are obtained by gas chromatography coupled to high-resolution time-of-flight mass spectrometry （GC-TOF MS）. The L-M ANN model gave a significantly better performance than the GA-KPLS model. This indicates that L-M ANN can be used as an alternative modeling toot for quantitative structure-retention relationship （QSRR） studies.
文摘We evaluated several different pre-oxidation treatments, namely the introduction of either potassium permanganate (KMnO4), chlorine (Cl2), or both to remove manganese (Mn) from the Qiantang River source water. Our results showed that Mn removal percentages were 12.7%, 71.0%, 17.4% and 58.7% when none of the oxidants, KMnO4 only, Cl2 only, or both oxidants were added, respectively. Furthermore, a field study showed that when the available Mn concentration in the source water was 0.14 mg/L, it could be reduced to less than 0.05 mg/L when a solution of KMnO4 (0.47 mg/L) was added as the oxidant.
文摘This study compares numerical models with analytical solutions in computing travel times and radius of protection zones for a pumping well located in an unconfined aquifer with uniform recharge and in a semi-confined aquifer. Numerical models were capable of delineating protection zones using particle tracking method in both cases. However, protection zones defined by travel time criterion can only protect small percent of source water to the well; large percent of source water is not protected which may pose a risk of pollution of source water to the well. The case study of Leggeloo well field in the Netherlands indicates that although a well field protection area was enforced in 1980 s, elevated nitrate concentration has been monitored in the abstracted water since 1990 s. The analysis of protection areas shows that the current protection area only protects 37.4% of recharge water to the well field. A large protection area must be adopted in order to safeguard the sustainable water supply for the local community.
文摘The article addresses the results of effective water losses prevention in public water supply systems, focusing on procedures for monitoring hidden leaks as the main part of losses and as the first step to control and prevent them. The described methodology has been applied based on a cross-border cooperation between twin capital cities Vienna and Bratislava in the Central Europe Region within the project deWaloP （Developing Water Loss Prevention） and adopted in Bratislava Water Company （BVS） in the Slovak Republic. The paper provides a complex of simple and easily available practices for analyses of water distribution measurements bringing essential information as to the necessity to use advanced procedures to actively reduce leakage. These practices involve minimum night flows analyses, hydrodynamic pressures analyses, pinpointing of water leakages by working with valves in the water network, the methodology of setting alarm limits for measured data, as well as use of advanced practices to obtain missing topologic data. As the water infrastructure in former socialistic countries are in bad technical condition and the lack of pertinent operational data is a significant obstacle to the application of a more sophisticated methodology based on GIS and other information systems, the procedures focus on using the most simple way to evaluate and control water losses. Finally, the introduction of described methodology in Bratislava Water Company after many years of unsuccessful effort even with expensive sophisticated leakage equipment brought positive outputs and the graph line of water losses level is finally going down. The use of expensive multi-correlating equipment together with human resources on the basis of implementing the above described leakage monitoring will subsequently become more effective, as it shall pinpoint major leakages, disclosure and removal of that shall significantly contribute to the effective reduction of water losses.
文摘In this study we estimate agricultural water footprint and its components from consumption perspective in arid and semi-arid region like Iran. This study is based on blue water consumption in irrigated land. Iran has imported net virtual water about 11.64 billion cubic meters (bcm) as international crop trade in 2005-2006. Therefore, Iran has depended on virtual water imports. By conserving about 60% irrigation efficiency, the total water requirement to produce imported crops in Iran is nearly 20.78 billion cubic meters. It is nearly 9 percent of renewable water resources and 12.65% agricultural appropriated water which has added to internal water resources. Agricultural virtual water budget is about 112.78 Gm3/yr. Agricultural water footprint is 110.2 Gm3/yr. About 12.83% of agricultural water footprint of Iran is related to external water resources on the country boundaries. It means external water footprint. Water dependency, water self-sufficiency and water scarcity indexes in agricultural sector of Iran, are estimated 10.1%, 89.9% and 70.8%, respectively.
文摘The purpose of this research is to investigate a biofilm system with trickling filter as a biological alternative process during low cost treatment connection with the possibility of reducing nutrients such as phosphorus. Given that nitrogen with phosphorus that are leading causes of algal bloom resulting in increased eutrophication or chemical nutrients are the basis of this document analysis. This increase in organisms results in less oxygen in water bodies and at times, slow decay leads many fresh water ponds, lakes and rivers. The process of eutrophication unfortunately tends to favor pollution and algae, which reduce the quality of the water. Kosovo has not a long tradition in the treatment of wastewater, especially in removing phosphorus, since the country has only a plant for wastewater treatment. The present plant is intended to protect the Klina river from eutrophication from wastewater discharged after treatment. This plant currently reduced phosphorus efficiently, but the goal of this paper is to increase the percentage of removal of phosphorus to 40% through trickling filters, presenting options for optimizing work on plant Skenderaj.
文摘The goal of this topic is a synthesis of the main characteristics of iron in groundwater and the oxidation process used to remove it. Indeed, the kinetics of chemical oxidation of iron (II) was examined with reconstituted water (distilled water + iron sulphate) and proceeded to the application in the groundwater samples taken from <em><strong>South Pout</strong></em> (Senegal) precisely in the drilling <strong>PS2</strong>. The sources of iron are natural or anthropogenic. In Senegalese waters, its content is variable and sometimes exceeds the standards of potability. Despite the diversification of iron removal process, chemical oxidation is the most used solution in drinking water treatment plants in Senegalese rural areas. Applied oxidation processes such as aeration and chlorination, however, are insufficient to produce drinking water with an iron concentration in accordance with standards of potability.
文摘In order to ensure the production quality and sustainable development of water supply enterprises, optimizing the production cost control of water supply enterprises is an important subject to be studied urgently. Combined with the characteristics of water supply enterprises, from the perspective of production cost management, this paper studies how to strengthen the cost control of water supply enterprises in daily management, improve the production quality, operating benefits and social benefits of water supply enterprises, and promote the long-term steady development of water supply companies.
