{"title":"Markov Chain Monte Carlo (MCMC) simulation of geostatistical variogram parameters of spatial soil test phosphorus using a Gibbs sampler","authors":"A. Boluwade, C. Madramootoo","doi":"10.2166/WQRJC.2014.048","DOIUrl":"https://doi.org/10.2166/WQRJC.2014.048","url":null,"abstract":"","PeriodicalId":54407,"journal":{"name":"Water Quality Research Journal of Canada","volume":null,"pages":null},"PeriodicalIF":2.0,"publicationDate":"2014-09-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"67981056","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Time series data such as monthly stream flows can be modelled using time series methods and then used to simulate or forecast flows for short term planning. Two methods of time series modelling were reviewed and compared: the well-known auto regressive moving average (ARMA) method and the state-space time-series (SSTS) method. ARMA has been used in hydrology to model and simulate flows with good results and is widely accepted for this purpose. SSTS modelling is a more recently developed method that is relatively unused for hydrologic modelling. This paper focuses on modelling the stream flows from basins of different sizes using these two time series modelling methods and comparing the results. Three rivers in Labrador and South-East Quebec were modelled: the Romaine, Ugjoktok and Alexis Rivers. Both models were compared for accuracy of prediction, ease of software use and simplicity of model to determine the preferred time series methodology approach for modelling these rivers. The SSTS was considered very easy to use but model diagnostics were found to require a high level of statistical understanding. Ultimately, the ARMA method was determined to be the better method for the typical engineer to use, considering the diagnostics were simple and the monthly flows could be easily simulated to verify results.
{"title":"Comparison of autoregressive moving average and state space methods for monthly time series modelling of Labrador and South-East Quebec river flows","authors":"Carissa Sparkes, L. Lye, S. Richter","doi":"10.2166/WQRJC.2015.021","DOIUrl":"https://doi.org/10.2166/WQRJC.2015.021","url":null,"abstract":"Time series data such as monthly stream flows can be modelled using time series methods and then used to simulate or forecast flows for short term planning. Two methods of time series modelling were reviewed and compared: the well-known auto regressive moving average (ARMA) method and the state-space time-series (SSTS) method. ARMA has been used in hydrology to model and simulate flows with good results and is widely accepted for this purpose. SSTS modelling is a more recently developed method that is relatively unused for hydrologic modelling. This paper focuses on modelling the stream flows from basins of different sizes using these two time series modelling methods and comparing the results. Three rivers in Labrador and South-East Quebec were modelled: the Romaine, Ugjoktok and Alexis Rivers. Both models were compared for accuracy of prediction, ease of software use and simplicity of model to determine the preferred time series methodology approach for modelling these rivers. The SSTS was considered very easy to use but model diagnostics were found to require a high level of statistical understanding. Ultimately, the ARMA method was determined to be the better method for the typical engineer to use, considering the diagnostics were simple and the monthly flows could be easily simulated to verify results.","PeriodicalId":54407,"journal":{"name":"Water Quality Research Journal of Canada","volume":null,"pages":null},"PeriodicalIF":2.0,"publicationDate":"2014-08-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.2166/WQRJC.2015.021","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"67982112","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Woodwaste produces large volumes of leachate, which often contains high concentrations of phenolic compounds. These compounds are environmental contaminants whose proper management and treatment are mandated to reduce associated environmental impacts. Quality diagnostic and treatment efficiency assessments necessitate the development of rapid, accurate, and reproducible methods of detection and analysis to accurately quantify phenolic compounds. Liquid chromatography (LC) analysis with ultraviolet (UV) detection and solid-phase extraction (SPE) sample preparation on Oasis HLB cartridges were performed and adapted to quantify eight priority phenolic compounds in woodwaste leachate. The method was validated on a synthetic solution simulating the woodwaste leachate, on spiked real woodwaste leachate to 1 μg mL −1 , and applied to quantify phenolic compounds in the real woodwaste leachate. Calibration curves were linear for all compounds in the range of 1–30 μg mL −1 , and high recoveries varying between 93.5% for 2-chlorophenol and 112.8% for 4-nitrophenol were obtained. Detection limits ranged from 0.06 μg L −1 for 2-chlorophenol to 0.129 μg L −1 for phenol. The proposed method reduced interference, background noise, analysis time, amount of organic solvents and is less costly when compared with other methods.
{"title":"Application of a solid phase extraction-liquid chromatography method to quantify phenolic compounds in woodwaste leachate","authors":"N. Kamal, Rosa Galvez, G. Buelna","doi":"10.2166/WQRJC.2014.002","DOIUrl":"https://doi.org/10.2166/WQRJC.2014.002","url":null,"abstract":"Woodwaste produces large volumes of leachate, which often contains high concentrations of phenolic compounds. These compounds are environmental contaminants whose proper management and treatment are mandated to reduce associated environmental impacts. Quality diagnostic and treatment efficiency assessments necessitate the development of rapid, accurate, and reproducible methods of detection and analysis to accurately quantify phenolic compounds. Liquid chromatography (LC) analysis with ultraviolet (UV) detection and solid-phase extraction (SPE) sample preparation on Oasis HLB cartridges were performed and adapted to quantify eight priority phenolic compounds in woodwaste leachate. The method was validated on a synthetic solution simulating the woodwaste leachate, on spiked real woodwaste leachate to 1 μg mL −1 , and applied to quantify phenolic compounds in the real woodwaste leachate. Calibration curves were linear for all compounds in the range of 1–30 μg mL −1 , and high recoveries varying between 93.5% for 2-chlorophenol and 112.8% for 4-nitrophenol were obtained. Detection limits ranged from 0.06 μg L −1 for 2-chlorophenol to 0.129 μg L −1 for phenol. The proposed method reduced interference, background noise, analysis time, amount of organic solvents and is less costly when compared with other methods.","PeriodicalId":54407,"journal":{"name":"Water Quality Research Journal of Canada","volume":null,"pages":null},"PeriodicalIF":2.0,"publicationDate":"2014-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.2166/WQRJC.2014.002","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"67980272","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
A wastewater biofiltration model is used to assess the potential of modelling plant-sized secondary carbon removal biofilter units. Two distinct datasets collected at the Seine-Centre biofiltration plant (Colombes, France) are used. The model is first calibrated on multiple grab samples taken at different heights inside the filter media. Data from 24 hour composite samples at the unit influent and effluent over a 2 year period are then simulated. Additional data are used to estimate hourly concentration profiles from composite samples in order to correctly use both composite and grab samples during modelling. The calibrated model is in most cases able to correctly predict the general nutrient behaviour for both datasets. The results of statistical scores such as the mean error and the mean absolute error are low for soluble components and remain correct for particles during years 2008–2009. Only one parameter set containing few heavily modified values is used to obtain these results. Modelling plant-sized biofilters appears to be practical and can be useful for easily evaluating plant optimization scenarios.
{"title":"Modelling of a carbon removal biological aerated filter doing partial nitrification during large-scale secondary treatment","authors":"Jean Bernier, V. Rocher, S. Guérin, P. Lessard","doi":"10.2166/WQRJC.2014.045","DOIUrl":"https://doi.org/10.2166/WQRJC.2014.045","url":null,"abstract":"A wastewater biofiltration model is used to assess the potential of modelling plant-sized secondary carbon removal biofilter units. Two distinct datasets collected at the Seine-Centre biofiltration plant (Colombes, France) are used. The model is first calibrated on multiple grab samples taken at different heights inside the filter media. Data from 24 hour composite samples at the unit influent and effluent over a 2 year period are then simulated. Additional data are used to estimate hourly concentration profiles from composite samples in order to correctly use both composite and grab samples during modelling. The calibrated model is in most cases able to correctly predict the general nutrient behaviour for both datasets. The results of statistical scores such as the mean error and the mean absolute error are low for soluble components and remain correct for particles during years 2008–2009. Only one parameter set containing few heavily modified values is used to obtain these results. Modelling plant-sized biofilters appears to be practical and can be useful for easily evaluating plant optimization scenarios.","PeriodicalId":54407,"journal":{"name":"Water Quality Research Journal of Canada","volume":null,"pages":null},"PeriodicalIF":2.0,"publicationDate":"2014-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.2166/WQRJC.2014.045","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"67981034","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
S. A. Kumar, G. Lekshmi, Rajesh Banu Jeyakumar, I. Yeom
Combined heterogeneous and homogenous photo-catalytic degradation of hospital wastewater was investigated. Three processes – solar/TiO 2 /H 2 O 2 , solar/Fe 2+ /H 2 O 2 and solar/TiO 2 /Fe 2+ /H 2 O 2 – were evaluated. The solar/TiO 2 /Fe 2+ /H 2 O 2 process displayed increased efficiency due to the synergetic effect of homogeneous and heterogeneous photo-catalytic reaction. The combination increased the photo process efficiency by decreasing the reaction time of the separate operations and decreased the cost of treatment. The optimal conditions enabling over 99% reduction of chemical oxygen demand (COD) were pH 7, 0.5 g/L Fe 2+ , 0.2 g/L TiO 2 and 1.35 g/L H 2 O 2 . The effluent COD and total suspended solids concentrations were 20 and 30 mg/L, respectively, which met the discharge standard requirements.
{"title":"Synergistic degradation of hospital wastewater by solar/TiO2/Fe2+/H2O2 process","authors":"S. A. Kumar, G. Lekshmi, Rajesh Banu Jeyakumar, I. Yeom","doi":"10.2166/WQRJC.2014.026","DOIUrl":"https://doi.org/10.2166/WQRJC.2014.026","url":null,"abstract":"Combined heterogeneous and homogenous photo-catalytic degradation of hospital wastewater was investigated. Three processes – solar/TiO 2 /H 2 O 2 , solar/Fe 2+ /H 2 O 2 and solar/TiO 2 /Fe 2+ /H 2 O 2 – were evaluated. The solar/TiO 2 /Fe 2+ /H 2 O 2 process displayed increased efficiency due to the synergetic effect of homogeneous and heterogeneous photo-catalytic reaction. The combination increased the photo process efficiency by decreasing the reaction time of the separate operations and decreased the cost of treatment. The optimal conditions enabling over 99% reduction of chemical oxygen demand (COD) were pH 7, 0.5 g/L Fe 2+ , 0.2 g/L TiO 2 and 1.35 g/L H 2 O 2 . The effluent COD and total suspended solids concentrations were 20 and 30 mg/L, respectively, which met the discharge standard requirements.","PeriodicalId":54407,"journal":{"name":"Water Quality Research Journal of Canada","volume":null,"pages":null},"PeriodicalIF":2.0,"publicationDate":"2014-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.2166/WQRJC.2014.026","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"67980796","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The use of mathematical models to study the transport of suspended sediments and heavy metals (HM) in water and riverbeds is of growing interest among the scientific community. A model of three partial differential equations solved by a numerical scheme of a third order was applied. The aim was to verify a numerical one-dimensional (1D) model for sediment and heavy metal concentrations in the water and bed applying analytical solutions, for three sedimentological conditions with a continuous source. The importance of the magnitude and sense of the diffusive process in the active bed sediment layer was studied. Differences between numerical and analytical results were quantified for: sediment concentration in the water column, total HM concentration in the water column and HM concentration in bed sediments. All these differences were less than 0.4% in all cases. Numerical results for two more complex scenarios were included. For the first scenario, water without HM flowing over a contaminated bed was assumed, whereas for the second one, the opposite – contaminated water with HM flowing over a clean bed − was adopted. A brief analysis of the initial conditions of HM concentration showed the importance of determining such initial conditions in actual environmental studies.
{"title":"Analytical and numerical solutions for sediment and heavy metal transport: a 1D simplified case","authors":"A. Álvarez, A. Trento","doi":"10.2166/WQRJC.2014.028","DOIUrl":"https://doi.org/10.2166/WQRJC.2014.028","url":null,"abstract":"The use of mathematical models to study the transport of suspended sediments and heavy metals (HM) in water and riverbeds is of growing interest among the scientific community. A model of three partial differential equations solved by a numerical scheme of a third order was applied. The aim was to verify a numerical one-dimensional (1D) model for sediment and heavy metal concentrations in the water and bed applying analytical solutions, for three sedimentological conditions with a continuous source. The importance of the magnitude and sense of the diffusive process in the active bed sediment layer was studied. Differences between numerical and analytical results were quantified for: sediment concentration in the water column, total HM concentration in the water column and HM concentration in bed sediments. All these differences were less than 0.4% in all cases. Numerical results for two more complex scenarios were included. For the first scenario, water without HM flowing over a contaminated bed was assumed, whereas for the second one, the opposite – contaminated water with HM flowing over a clean bed − was adopted. A brief analysis of the initial conditions of HM concentration showed the importance of determining such initial conditions in actual environmental studies.","PeriodicalId":54407,"journal":{"name":"Water Quality Research Journal of Canada","volume":null,"pages":null},"PeriodicalIF":2.0,"publicationDate":"2014-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.2166/WQRJC.2014.028","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"67980817","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
A. Hossain, H. Ngo, Wenshan Guo, Jian Zhang, S. Liang
This study tested the ability of maple leaf powder (MLP) to reduce the level of Pb(II) ions in aqueous solutions. As a biosorbent, MLP has a larger specific surface area (10.94 m 2 /g) and contains Pb(II) binding functional groups. The highest Pb(II) removals were achieved at pH of 6.2, particle size of less than 75 μm, dose of 0.5 g, initial concentration of 10 mg/l and equilibrium time of >15 minutes. Thermodynamic results indicated that the Pb(II) adsorption process was spontaneous and exothermic. MLP biosorbent could be reused for five cycles after successfully recovery by 0.1N H 2 SO 4 . Both adsorption and desorption data fit well with Langmuir and Sips isotherm models ( R 2 ≈ 0.961–1.00). The Pb(II) adsorption and desorption capacities ( q m ) of MLP were up to 50.27 mg/g and 40.06 mg/g, respectively, for a 1 g dose at room temperature. Kinetics processes were rate controlling step and showed good fitness with the pseudo-second order and intraparticle diffusion models. Results suggest that multiple mechanisms (chelating bond, physisorption and chemisorption) are involved to adsorb the Pb(II) ions on to MLP. Higher Pb(II) removal revealed the practical applicability of MLP in water and wastewater treatment systems.
本研究考察了枫叶粉(MLP)对水溶液中铅(II)离子的降低能力。作为生物吸附剂，MLP具有较大的比表面积(10.94 m2 /g)，并含有Pb(II)结合官能团。当pH = 6.2、粒径< 75 μm、投加量为0.5 g、初始浓度为10 mg/l、平衡时间为> ~ 15 min时，对Pb(II)的去除率最高。热力学结果表明，Pb(II)的吸附过程是自发的、放热的。MLP生物吸附剂经0.1N H 2 SO 4回收成功后，可重复使用5次。吸附和解吸数据均符合Langmuir和Sips等温模型(r2≈0.961-1.00)。在室温条件下，当用量为1 g时，MLP对Pb(II)的吸附量和解吸量(q m)分别达到50.27 mg/g和40.06 mg/g。动力学过程为速率控制步骤，与拟二级扩散模型和颗粒内扩散模型具有良好的拟合性。结果表明，铅离子在MLP上的吸附涉及多种机制(螯合键、物理吸附和化学吸附)。较高的Pb(II)去除率揭示了MLP在水和废水处理系统中的实际适用性。
{"title":"A laboratory study using maple leaves as a biosorbent for lead removal from aqueous solutions","authors":"A. Hossain, H. Ngo, Wenshan Guo, Jian Zhang, S. Liang","doi":"10.2166/WQRJC.2014.027","DOIUrl":"https://doi.org/10.2166/WQRJC.2014.027","url":null,"abstract":"This study tested the ability of maple leaf powder (MLP) to reduce the level of Pb(II) ions in aqueous solutions. As a biosorbent, MLP has a larger specific surface area (10.94 m 2 /g) and contains Pb(II) binding functional groups. The highest Pb(II) removals were achieved at pH of 6.2, particle size of less than 75 μm, dose of 0.5 g, initial concentration of 10 mg/l and equilibrium time of >15 minutes. Thermodynamic results indicated that the Pb(II) adsorption process was spontaneous and exothermic. MLP biosorbent could be reused for five cycles after successfully recovery by 0.1N H 2 SO 4 . Both adsorption and desorption data fit well with Langmuir and Sips isotherm models ( R 2 ≈ 0.961–1.00). The Pb(II) adsorption and desorption capacities ( q m ) of MLP were up to 50.27 mg/g and 40.06 mg/g, respectively, for a 1 g dose at room temperature. Kinetics processes were rate controlling step and showed good fitness with the pseudo-second order and intraparticle diffusion models. Results suggest that multiple mechanisms (chelating bond, physisorption and chemisorption) are involved to adsorb the Pb(II) ions on to MLP. Higher Pb(II) removal revealed the practical applicability of MLP in water and wastewater treatment systems.","PeriodicalId":54407,"journal":{"name":"Water Quality Research Journal of Canada","volume":null,"pages":null},"PeriodicalIF":2.0,"publicationDate":"2014-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.2166/WQRJC.2014.027","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"67980807","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Fang He, Fusheng Li, Hai-hong Zhou, Lingling Niu, Liguo Wang
In this research, biocompounds designed out of two polymers having different degradability was investigated for use as the sole carbon source and biofilm carrier to remove perchlorate in particle-fixed biofilm reactors. Both laboratory batch and column experiments were conducted with perchlorate contaminated groundwater. Batch experiments demonstrated clearly that ClO4– was removed from the aqueous phase readily and the degradation rate constants ( k ) changed in the range of 0.23–0.37 mg/L h as ClO4– concentration increased from 2 to 8 mg/L. Simultaneous perchlorate and nitrate degradation occurred in the polymer bioreactor. Effluent concentrations of perchlorate varied positively with temperature and fitted the Arrhenius equation expression as k = k 20•100.0316( t –20) over the range of 13–30 °C. No perchlorate was detected in the effluent of polymer columns after 20 days’ startup. Complete perchlorate removal was observed at a hydraulic loading rate doubled to 1.8 mL/min. Images prove the concept of the pore and filament structure within the biocompounds, which provide both a heterotrophic biofilm and carbon source. Denaturing gradient gel electrophoresis analysis and partial sequencing of 16S rRNA genes indicated that formerly reported perchlorate-reducing bacteria were present in the polymer particle-fixed biofilm reactors.
{"title":"Perchlorate removal using two component biodegradable carriers in particle-fixed biofilm reactor","authors":"Fang He, Fusheng Li, Hai-hong Zhou, Lingling Niu, Liguo Wang","doi":"10.2166/WQRJC.2014.047","DOIUrl":"https://doi.org/10.2166/WQRJC.2014.047","url":null,"abstract":"In this research, biocompounds designed out of two polymers having different degradability was investigated for use as the sole carbon source and biofilm carrier to remove perchlorate in particle-fixed biofilm reactors. Both laboratory batch and column experiments were conducted with perchlorate contaminated groundwater. Batch experiments demonstrated clearly that ClO4– was removed from the aqueous phase readily and the degradation rate constants ( k ) changed in the range of 0.23–0.37 mg/L h as ClO4– concentration increased from 2 to 8 mg/L. Simultaneous perchlorate and nitrate degradation occurred in the polymer bioreactor. Effluent concentrations of perchlorate varied positively with temperature and fitted the Arrhenius equation expression as k = k 20•100.0316( t –20) over the range of 13–30 °C. No perchlorate was detected in the effluent of polymer columns after 20 days’ startup. Complete perchlorate removal was observed at a hydraulic loading rate doubled to 1.8 mL/min. Images prove the concept of the pore and filament structure within the biocompounds, which provide both a heterotrophic biofilm and carbon source. Denaturing gradient gel electrophoresis analysis and partial sequencing of 16S rRNA genes indicated that formerly reported perchlorate-reducing bacteria were present in the polymer particle-fixed biofilm reactors.","PeriodicalId":54407,"journal":{"name":"Water Quality Research Journal of Canada","volume":null,"pages":null},"PeriodicalIF":2.0,"publicationDate":"2014-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.2166/WQRJC.2014.047","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"67981045","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
This study aims at estimating nanoparticle typed zero-valent iron (nZVI) process as an advanced nitrogen removal technique. To focus on investigating characteristics and effects of nZVI on nitrogen removal for sewage treatment, batch reactor experiments were conducted to reduce excessive nitrate nitrogen (NO3-N). To improve NO3-N removal efficiency and to find a supporter or alternative of nZVI, silica sand, synthetic zeolite, and a mixture of silica sand, synthetic zeolite, and nZVI were used in the experiments. As a result of this study, the chemical denitrification by nZVI attracted on the magnet surface may be useful for total nitrogen removal in conventional sewage and wastewater treatment plants under the optimal conditions, and application of silica sand also is an excellent adsorbent or media for N-component removal and a supporter as well. This study concludes the end product in this study may be nitrogen gas (N2) through Fe reaction with O2 and NO3− in aerobic nZVI (Fe)–H2O system. Future study is required to examine the competition of nZVI between nitrate and many other compounds depending upon various experimental conditions for improving the nitrate removal efficiency and impeding the ammonium generation.
{"title":"Treatment characteristics and effects of nanoparticle zero-valent iron (nZVI) powder on nitrogen removal efficiency for sewage treatment","authors":"Mi-Sug Kim, D. Kwak","doi":"10.2166/WQRJC.2014.102","DOIUrl":"https://doi.org/10.2166/WQRJC.2014.102","url":null,"abstract":"This study aims at estimating nanoparticle typed zero-valent iron (nZVI) process as an advanced nitrogen removal technique. To focus on investigating characteristics and effects of nZVI on nitrogen removal for sewage treatment, batch reactor experiments were conducted to reduce excessive nitrate nitrogen (NO3-N). To improve NO3-N removal efficiency and to find a supporter or alternative of nZVI, silica sand, synthetic zeolite, and a mixture of silica sand, synthetic zeolite, and nZVI were used in the experiments. As a result of this study, the chemical denitrification by nZVI attracted on the magnet surface may be useful for total nitrogen removal in conventional sewage and wastewater treatment plants under the optimal conditions, and application of silica sand also is an excellent adsorbent or media for N-component removal and a supporter as well. This study concludes the end product in this study may be nitrogen gas (N2) through Fe reaction with O2 and NO3− in aerobic nZVI (Fe)–H2O system. Future study is required to examine the competition of nZVI between nitrate and many other compounds depending upon various experimental conditions for improving the nitrate removal efficiency and impeding the ammonium generation.","PeriodicalId":54407,"journal":{"name":"Water Quality Research Journal of Canada","volume":null,"pages":null},"PeriodicalIF":2.0,"publicationDate":"2014-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.2166/WQRJC.2014.102","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"67980824","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
A. Huo, Jia Zhang, C. Qiao, Chen Li, Juan Xie, Jucui Wang, Xu Zhang
Eutrophication has become the primary water quality issue for many urban landscape waters in the world. It is a focus in this paper which analyzes Enhanced Thematic Mapper images and quality observation data for 12 consecutive years in 20 parts of the urban landscape water in Xi9an City, China. A water quality model for urban landscape water based on Support Vector Machine (SVM) was established. Based on in situ monitoring data, the model is compared with water quality retrieving methods of multiple regression and back propagation neural network. Results show that the Genetic Algorithm-SVM (GA-SVM) method has better prediction accuracy than the inversion results of the neural network and the traditional statistical regression method. In short, GA-SVM provides a new method for remote sensing monitoring of urban water eutrophication and has more accurate predictions in inversion results [such as chlorophyll a (Chl-a)] in the Xi9an area. Additionally, remote sensing results highly agreed with in situ monitoring data, indicating that the technology is effective and less costly than in situ monitoring. The technology also can be used to evaluate large lake eutrophication.
{"title":"Multispectral remote sensing inversion for city landscape water eutrophication based on Genetic Algorithm-Support Vector Machine","authors":"A. Huo, Jia Zhang, C. Qiao, Chen Li, Juan Xie, Jucui Wang, Xu Zhang","doi":"10.2166/WQRJC.2014.040","DOIUrl":"https://doi.org/10.2166/WQRJC.2014.040","url":null,"abstract":"Eutrophication has become the primary water quality issue for many urban landscape waters in the world. It is a focus in this paper which analyzes Enhanced Thematic Mapper images and quality observation data for 12 consecutive years in 20 parts of the urban landscape water in Xi9an City, China. A water quality model for urban landscape water based on Support Vector Machine (SVM) was established. Based on in situ monitoring data, the model is compared with water quality retrieving methods of multiple regression and back propagation neural network. Results show that the Genetic Algorithm-SVM (GA-SVM) method has better prediction accuracy than the inversion results of the neural network and the traditional statistical regression method. In short, GA-SVM provides a new method for remote sensing monitoring of urban water eutrophication and has more accurate predictions in inversion results [such as chlorophyll a (Chl-a)] in the Xi9an area. Additionally, remote sensing results highly agreed with in situ monitoring data, indicating that the technology is effective and less costly than in situ monitoring. The technology also can be used to evaluate large lake eutrophication.","PeriodicalId":54407,"journal":{"name":"Water Quality Research Journal of Canada","volume":null,"pages":null},"PeriodicalIF":2.0,"publicationDate":"2014-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.2166/WQRJC.2014.040","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"67980991","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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