The objective of this study is to investigate the mesophilic, anaerobic, co-digestion of scum with thickened waste activated sludge (TWAS) and primary sludge (PS). Observations of the reactor waste show that higher pretreatment temperatures assist in scum integration and appear to limit coagulation and separation effects associated with digesting fats, oils and greases. The 0.40 kg VS/m3 · d scum loaded reactor with scum pretreated at 70 °C achieved the greatest improvement in biogas production over PS and TWAS co-digestion without scum addition. Based on cell viability analysis of the reactor waste, scum-containing reactors were shown to produce 48 and 39% more biogas per m3 of live cells; signifying that scum addition increased the activity of the microbial population embedded in the waste or caused a microbial shift in the waste towards more active communities.
本研究的目的是研究中温、厌氧、浮渣与浓缩废物活性污泥(TWAS)和初级污泥(PS)的共消化。对反应器废物的观察表明，较高的预处理温度有助于浮渣的整合，并似乎限制了与消化脂肪、油和油脂有关的混凝和分离效果。与不添加浮渣的PS和TWAS共消化相比，在70°C下对浮渣进行预处理的0.40 kg VS/m3·d浮渣负载反应器的沼气产量提高最大。根据反应器废物的细胞活力分析，含浮渣反应器显示每立方米活细胞多产生48%和39%的沼气;表明添加浮渣增加了嵌入在废物中的微生物种群的活性或导致废物中的微生物向更活跃的群落转移。
{"title":"Semi-continuous mesophilic anaerobic co-digestion of thermally pretreated scum","authors":"B. Young, K. Kennedy, R. Delatolla, R. Sherif","doi":"10.2166/WQRJC.2016.024","DOIUrl":"https://doi.org/10.2166/WQRJC.2016.024","url":null,"abstract":"The objective of this study is to investigate the mesophilic, anaerobic, co-digestion of scum with thickened waste activated sludge (TWAS) and primary sludge (PS). Observations of the reactor waste show that higher pretreatment temperatures assist in scum integration and appear to limit coagulation and separation effects associated with digesting fats, oils and greases. The 0.40 kg VS/m3 · d scum loaded reactor with scum pretreated at 70 °C achieved the greatest improvement in biogas production over PS and TWAS co-digestion without scum addition. Based on cell viability analysis of the reactor waste, scum-containing reactors were shown to produce 48 and 39% more biogas per m3 of live cells; signifying that scum addition increased the activity of the microbial population embedded in the waste or caused a microbial shift in the waste towards more active communities.","PeriodicalId":54407,"journal":{"name":"Water Quality Research Journal of Canada","volume":null,"pages":null},"PeriodicalIF":2.0,"publicationDate":"2016-05-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.2166/WQRJC.2016.024","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"67982413","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}
We have studied the pH and the temperature effects on copper ions' adsorption on natural and treated clays from Algeria. The clay was also treated to improve the adsorption capacity. X-ray diffraction identified montmorillonite and kaolinite as major clay minerals. The Langmuir adsorption model was used for the mathematical description of the adsorption equilibrium and the equilibrium data adhered very well to this model. The treated and natural clay had a monolayer adsorption capacity equal to 15.40 and 12.22 mg/g, respectively, at pH value of 6.5 and temperature 20 °C, the adsorption isotherms could be fitted with Langmuir isotherms, and the coefficients indicated favorable adsorption of Cu(II) on the clays. Determination of the thermodynamic parameters, H, S , and G showed that the adsorption process was spontaneous and exothermic accompanied by a decrease in entropy and Gibbs energy. Results of this study will be useful for future scale-up for using this material as a low-cost adsorbent for the removal of Cu(II) from wastewater.
{"title":"Adsorption of Cu(II) on natural and treated clays","authors":"M. Djebbar, F. Djafri","doi":"10.2166/WQRJC.2015.051","DOIUrl":"https://doi.org/10.2166/WQRJC.2015.051","url":null,"abstract":"We have studied the pH and the temperature effects on copper ions' adsorption on natural and treated clays from Algeria. The clay was also treated to improve the adsorption capacity. X-ray diffraction identified montmorillonite and kaolinite as major clay minerals. The Langmuir adsorption model was used for the mathematical description of the adsorption equilibrium and the equilibrium data adhered very well to this model. The treated and natural clay had a monolayer adsorption capacity equal to 15.40 and 12.22 mg/g, respectively, at pH value of 6.5 and temperature 20 °C, the adsorption isotherms could be fitted with Langmuir isotherms, and the coefficients indicated favorable adsorption of Cu(II) on the clays. Determination of the thermodynamic parameters, H, S , and G showed that the adsorption process was spontaneous and exothermic accompanied by a decrease in entropy and Gibbs energy. Results of this study will be useful for future scale-up for using this material as a low-cost adsorbent for the removal of Cu(II) from wastewater.","PeriodicalId":54407,"journal":{"name":"Water Quality Research Journal of Canada","volume":null,"pages":null},"PeriodicalIF":2.0,"publicationDate":"2016-02-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.2166/WQRJC.2015.051","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"67981935","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}
It is my distinct pleasure to communicate to you that my co-chief editor, Professor Peter Vanrolleghem, has received the President's Award from the House of Delegates at this year's WEFTEC (http://www.weftec.org/). He was one of two recipients of this prestigious award. From its policies and procedures document the House of Delegates is the deliberative and representational body of the Water Environment Federation (WEF). It advises the Board on matters of strategic direction and public policy development. There are currently 115 members of the House, comprised of representatives from provincial, state/regional WEF daughter organizations from Canada, the USA, and elsewhere in the world. For those of us in …
{"title":"Peter Vanrolleghem is awarded 2015 Water Environment Federation President's Award","authors":"R. Droste","doi":"10.2166/WQRJC.2015.101","DOIUrl":"https://doi.org/10.2166/WQRJC.2015.101","url":null,"abstract":"It is my distinct pleasure to communicate to you that my co-chief editor, Professor Peter Vanrolleghem, has received the President's Award from the House of Delegates at this year's WEFTEC (http://www.weftec.org/). He was one of two recipients of this prestigious award.\u0000\u0000From its policies and procedures document the House of Delegates is the deliberative and representational body of the Water Environment Federation (WEF). It advises the Board on matters of strategic direction and public policy development. There are currently 115 members of the House, comprised of representatives from provincial, state/regional WEF daughter organizations from Canada, the USA, and elsewhere in the world. \u0000\u0000\u0000\u0000For those of us in …","PeriodicalId":54407,"journal":{"name":"Water Quality Research Journal of Canada","volume":null,"pages":null},"PeriodicalIF":2.0,"publicationDate":"2016-02-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.2166/WQRJC.2015.101","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"67982001","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 detailed investigation of photocatalytic degradation of m -cresol purple ( m CP) dye has been carried out in aqueous heterogeneous medium containing zinc oxide (ZnO) as the photocatalyst in a batch reactor. The effects of some parameters such as amount of photocatalyst, dye concentration, initial pH of solution, ethanol concentration and temperature were examined. The most efficient pH in removal of the dye with photocatalytic degradation and dark surface adsorption processes was observed to be 8. The adsorption constant calculated from the linear transform of the Langmuir isotherm model, was similar to that obtained in photocatalytic degradation at pH = 8; hence, the Langmuir–Hinshelwood model was found to be accurate for photocatalytic degradation at this pH. Dark surface adsorption and degradation efficiency were increased by enhancement in the temperature at the optimum pH of 8 and the apparent activation energy (E a ) for the photocatalytic degradation of m CP was determined as 14.09 kJ/mol at this pH. The electrical energy consumption per order of magnitude ( E EO ) for photocatalytic degradation of m CP was also determined.
{"title":"Effect of operational parameters and kinetic study on the photocatalytic degradation of m-cresol purple using irradiated ZnO in aqueous medium","authors":"S. Khezrianjoo, H. D. Revanasiddappa","doi":"10.2166/WQRJC.2015.028","DOIUrl":"https://doi.org/10.2166/WQRJC.2015.028","url":null,"abstract":"A detailed investigation of photocatalytic degradation of m -cresol purple ( m CP) dye has been carried out in aqueous heterogeneous medium containing zinc oxide (ZnO) as the photocatalyst in a batch reactor. The effects of some parameters such as amount of photocatalyst, dye concentration, initial pH of solution, ethanol concentration and temperature were examined. The most efficient pH in removal of the dye with photocatalytic degradation and dark surface adsorption processes was observed to be 8. The adsorption constant calculated from the linear transform of the Langmuir isotherm model, was similar to that obtained in photocatalytic degradation at pH = 8; hence, the Langmuir–Hinshelwood model was found to be accurate for photocatalytic degradation at this pH. Dark surface adsorption and degradation efficiency were increased by enhancement in the temperature at the optimum pH of 8 and the apparent activation energy (E a ) for the photocatalytic degradation of m CP was determined as 14.09 kJ/mol at this pH. The electrical energy consumption per order of magnitude ( E EO ) for photocatalytic degradation of m CP was also determined.","PeriodicalId":54407,"journal":{"name":"Water Quality Research Journal of Canada","volume":null,"pages":null},"PeriodicalIF":2.0,"publicationDate":"2016-02-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.2166/WQRJC.2015.028","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"67982172","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 paper comparatively assessed the effectiveness of potable water filtration methods, commonly used in the hinterlands in some Ghanaian communities. Physico-chemical and microbiological analysis were carried out on pond, dam and river water samples, using spectrophotometric, pour plate count and the most probable number (MPN) methods. For the unfiltered water samples the total dissolved solids (TDS) and colour were the only parameters with values within recommended standards. The other parameters, total suspended solids (TSS), turbidity, total coliforms and bacterial counts levels were above their standard recommended values. All the filtration methods showed reduction in the levels or better accepted values of the physico-chemical and microbiological parameters. The ceramic filters and the household sand filters showed outstanding results, with all analysed parameters being within the acceptable standards levels. These two methods could be promoted for use to treat untreated drinking water. It is envisaged that a combination of a number of these methods would produce even better results, especially when agents such as alum and activated carbon are included. Follow-up research in this regard is therefore recommended.
{"title":"Comparative analysis on the effectiveness of various filtration methods on the potability of water","authors":"S. Achio, F. Kutsanedzie, E. Ameko","doi":"10.2166/WQRJC.2015.014","DOIUrl":"https://doi.org/10.2166/WQRJC.2015.014","url":null,"abstract":"This paper comparatively assessed the effectiveness of potable water filtration methods, commonly used in the hinterlands in some Ghanaian communities. Physico-chemical and microbiological analysis were carried out on pond, dam and river water samples, using spectrophotometric, pour plate count and the most probable number (MPN) methods. For the unfiltered water samples the total dissolved solids (TDS) and colour were the only parameters with values within recommended standards. The other parameters, total suspended solids (TSS), turbidity, total coliforms and bacterial counts levels were above their standard recommended values. All the filtration methods showed reduction in the levels or better accepted values of the physico-chemical and microbiological parameters. The ceramic filters and the household sand filters showed outstanding results, with all analysed parameters being within the acceptable standards levels. These two methods could be promoted for use to treat untreated drinking water. It is envisaged that a combination of a number of these methods would produce even better results, especially when agents such as alum and activated carbon are included. Follow-up research in this regard is therefore recommended.","PeriodicalId":54407,"journal":{"name":"Water Quality Research Journal of Canada","volume":null,"pages":null},"PeriodicalIF":2.0,"publicationDate":"2016-02-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.2166/WQRJC.2015.014","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"67981975","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 infiltration of water and its influencing factors in disturbed or reclaimed land are not well understood. A better understanding would provide essential information for assessing the hydrological processes in disturbed ecosystems. We measured the infiltration of water in soils from loamy and sandy reclaimed land. The relationships between infiltration and soil properties were analyzed based on three models: the Kostiakov, Philip, and Green–Ampt equations. Our objectives were to understand water infiltration in reclaimed land with a variety of soil textures and to establish the dependence of water infiltration on soil properties. Both the rate of infiltration and the cumulative infiltration were higher in sandy than in loamy soils. The rate of infiltration and the cumulative infiltration decreased with soil depth in undisturbed land. The sorptivity rate ( S ) from the Philip equation, empirical coefficient ( K ) from the Kostiakov equation, and the satiated hydraulic conductivity ( Ksl ) from the Green–Ampt equation were 22%, 16%, and 7.1% higher, respectively, in sandy than in loamy soils. The Ksl increased significantly with Ks (saturated hydraulic conductivity) in both sandy and loamy soils. These indicated that the Green–Ampt equation can be used to describe Ks and the characteristics of infiltration for soils on disturbed land.
{"title":"Effect of soil texture on water infiltration in semiarid reclaimed land","authors":"Wenmei Ma, Xingchang Zhang, Qing Zhen, Yanjiang Zhang","doi":"10.2166/WQRJC.2015.025","DOIUrl":"https://doi.org/10.2166/WQRJC.2015.025","url":null,"abstract":"The infiltration of water and its influencing factors in disturbed or reclaimed land are not well understood. A better understanding would provide essential information for assessing the hydrological processes in disturbed ecosystems. We measured the infiltration of water in soils from loamy and sandy reclaimed land. The relationships between infiltration and soil properties were analyzed based on three models: the Kostiakov, Philip, and Green–Ampt equations. Our objectives were to understand water infiltration in reclaimed land with a variety of soil textures and to establish the dependence of water infiltration on soil properties. Both the rate of infiltration and the cumulative infiltration were higher in sandy than in loamy soils. The rate of infiltration and the cumulative infiltration decreased with soil depth in undisturbed land. The sorptivity rate ( S ) from the Philip equation, empirical coefficient ( K ) from the Kostiakov equation, and the satiated hydraulic conductivity ( Ksl ) from the Green–Ampt equation were 22%, 16%, and 7.1% higher, respectively, in sandy than in loamy soils. The Ksl increased significantly with Ks (saturated hydraulic conductivity) in both sandy and loamy soils. These indicated that the Green–Ampt equation can be used to describe Ks and the characteristics of infiltration for soils on disturbed land.","PeriodicalId":54407,"journal":{"name":"Water Quality Research Journal of Canada","volume":null,"pages":null},"PeriodicalIF":2.0,"publicationDate":"2016-02-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.2166/WQRJC.2015.025","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"67982158","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}
Colin Dring, J. Devlin, G. Boag, M. Sunohara, J. FitzGibbon, E. Topp, D. Lapen
This study investigates incentives and disincentives regarding adoption of controlled tile drainage (CTD) in a region of eastern Ontario, Canada, where CTD could be used prolifically from a biophysical standpoint, but is not. Irrespective of documented environmental and agronomic benefits of CTD, adoption remains low. Surveys and semi-structured interviews with producers and drainage contractors/experts were used to evaluate awareness of CTD and identify producer adoption impediments. Surveys indicated nearly 70% of producer respondents had heard about CTD. Top ranked incentives identified by producers (who adopted) and drainage contractors/experts combined were: soil water retention benefits, increased crop yields, and gratification improving the environment. Top ranked disincentives combined by target groups were: increased farm labor, perceived lack of extension services, and costs. Many producer adopters emphasized motivators grounded in personal or community bearing, such as peer interaction and doing the right thing for the environment. Drainage contractors emphasized adoption impediments tied to a perceived lack of extension support for CTD. Drainage contractors themselves desired more extension support and firm data/research foundations with respect to advocating CTD to clients. With respect to motivation for producers to adopt CTD, this latter point may be critical given that producers highly valued drainage contractors as an information source on drainage practices.
{"title":"Incentives and disincentives identified by producers and drainage contractors/experts on the adoption of controlled tile drainage in eastern Ontario, Canada","authors":"Colin Dring, J. Devlin, G. Boag, M. Sunohara, J. FitzGibbon, E. Topp, D. Lapen","doi":"10.2166/WQRJC.2015.047","DOIUrl":"https://doi.org/10.2166/WQRJC.2015.047","url":null,"abstract":"This study investigates incentives and disincentives regarding adoption of controlled tile drainage (CTD) in a region of eastern Ontario, Canada, where CTD could be used prolifically from a biophysical standpoint, but is not. Irrespective of documented environmental and agronomic benefits of CTD, adoption remains low. Surveys and semi-structured interviews with producers and drainage contractors/experts were used to evaluate awareness of CTD and identify producer adoption impediments. Surveys indicated nearly 70% of producer respondents had heard about CTD. Top ranked incentives identified by producers (who adopted) and drainage contractors/experts combined were: soil water retention benefits, increased crop yields, and gratification improving the environment. Top ranked disincentives combined by target groups were: increased farm labor, perceived lack of extension services, and costs. Many producer adopters emphasized motivators grounded in personal or community bearing, such as peer interaction and doing the right thing for the environment. Drainage contractors emphasized adoption impediments tied to a perceived lack of extension support for CTD. Drainage contractors themselves desired more extension support and firm data/research foundations with respect to advocating CTD to clients. With respect to motivation for producers to adopt CTD, this latter point may be critical given that producers highly valued drainage contractors as an information source on drainage practices.","PeriodicalId":54407,"journal":{"name":"Water Quality Research Journal of Canada","volume":null,"pages":null},"PeriodicalIF":2.0,"publicationDate":"2016-02-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.2166/WQRJC.2015.047","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"67982484","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}
Islem Louati, F. Guesmi, A. Chaabouni, Chiraz Hannachi, B. Hamrouni
The effect of ionic strength variation on the ion exchange equilibrium between AMX anion exchange membrane and electrolyte solutions containing the most dominant anions on natural waters (Cl−, NO3−, and SO42−) was studied. All experiments were carried out at a constant temperature of 25 °C. Ion exchange isotherms were established, at different ionic strengths from 0.1 to 0.5 M, for the systems (Cl−/NO3−), (Cl−/SO42−) and (NO3−/SO42−). Obtained results showed that for I = 0.1 M the affinity order is SO42 −>NO3−>Cl−. For I = 0.2 M this order is NO3−>SO42−>Cl−. For 0.3 and 0.5 M the AMX membrane becomes more selective for chloride than for nitrate or sulfate. Selectivity coefficients KNO3−Cl−, K2Cl−SO42− and K2NO3−SO42−, thermodynamic constants, and separation factors were calculated and decreased with the increase of ionic strength.
{"title":"Effect of ionic strength on the ion exchange equilibrium between AMX membrane and electrolyte solutions","authors":"Islem Louati, F. Guesmi, A. Chaabouni, Chiraz Hannachi, B. Hamrouni","doi":"10.2166/WQRJC.2015.006","DOIUrl":"https://doi.org/10.2166/WQRJC.2015.006","url":null,"abstract":"The effect of ionic strength variation on the ion exchange equilibrium between AMX anion exchange membrane and electrolyte solutions containing the most dominant anions on natural waters (Cl−, NO3−, and SO42−) was studied. All experiments were carried out at a constant temperature of 25 °C. Ion exchange isotherms were established, at different ionic strengths from 0.1 to 0.5 M, for the systems (Cl−/NO3−), (Cl−/SO42−) and (NO3−/SO42−). Obtained results showed that for I = 0.1 M the affinity order is SO42 −>NO3−>Cl−. For I = 0.2 M this order is NO3−>SO42−>Cl−. For 0.3 and 0.5 M the AMX membrane becomes more selective for chloride than for nitrate or sulfate. Selectivity coefficients KNO3−Cl−, K2Cl−SO42− and K2NO3−SO42−, thermodynamic constants, and separation factors were calculated and decreased with the increase of ionic strength.","PeriodicalId":54407,"journal":{"name":"Water Quality Research Journal of Canada","volume":null,"pages":null},"PeriodicalIF":2.0,"publicationDate":"2016-02-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.2166/WQRJC.2015.006","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"67981906","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}
J. Kohn, D. X. Soto, M. Iwanyshyn, B. Olson, A. Kalischuk, K. Lorenz, M. Hendry
The potential effect of manure management from livestock production on groundwater quality is an issue of concern. Groundwater sampling from a regional transect in southern Alberta, Canada, was conducted to determine changes in groundwater quality with time. The study area has extensive irrigation and a high density of confined feeding operations. Nitrate-N (NO3−-N) and chloride (Cl−) concentration data from 23 groundwater-study wells were evaluated from 1994 to 2014. Twelve of these wells were water-table wells and 11 were piezometers. Of the 23 wells, 14 had significant temporal trends (increasing or decreasing) for NO3−-N and/or Cl− concentrations. On a regional basis, NO3−-N increased slightly with time while Cl− changed very little, suggesting that the effects of agricultural activities on regional groundwater quality have generally remained constant. However, concentration changes occurred on a smaller scale. Shallow groundwater in coarse-textured soils is at a relatively higher risk to contamination than groundwater with fine-textured soils, especially in locations where intensive agricultural activities occur.
{"title":"Groundwater nitrate and chloride trends in an agriculture-intensive area in southern Alberta, Canada","authors":"J. Kohn, D. X. Soto, M. Iwanyshyn, B. Olson, A. Kalischuk, K. Lorenz, M. Hendry","doi":"10.2166/WQRJC.2015.132","DOIUrl":"https://doi.org/10.2166/WQRJC.2015.132","url":null,"abstract":"The potential effect of manure management from livestock production on groundwater quality is an issue of concern. Groundwater sampling from a regional transect in southern Alberta, Canada, was conducted to determine changes in groundwater quality with time. The study area has extensive irrigation and a high density of confined feeding operations. Nitrate-N (NO3−-N) and chloride (Cl−) concentration data from 23 groundwater-study wells were evaluated from 1994 to 2014. Twelve of these wells were water-table wells and 11 were piezometers. Of the 23 wells, 14 had significant temporal trends (increasing or decreasing) for NO3−-N and/or Cl− concentrations. On a regional basis, NO3−-N increased slightly with time while Cl− changed very little, suggesting that the effects of agricultural activities on regional groundwater quality have generally remained constant. However, concentration changes occurred on a smaller scale. Shallow groundwater in coarse-textured soils is at a relatively higher risk to contamination than groundwater with fine-textured soils, especially in locations where intensive agricultural activities occur.","PeriodicalId":54407,"journal":{"name":"Water Quality Research Journal of Canada","volume":null,"pages":null},"PeriodicalIF":2.0,"publicationDate":"2016-02-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.2166/WQRJC.2015.132","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"67982044","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}
Dilute manure is classified as wastewater due to the large quantity of water used in livestock production in Korea. Livestock wastewater treatment is required in order to reduce high moisture content and treat fluids discharged from the digestion process. In livestock wastewater treatment plants, large quantities of CO2 gas are produced at combined heat and power facilities as well as in the anaerobic digestion (AD) process. This gas produced during livestock wastewater treatment can be used as a separator of solids from liquid in wastewater. In this study, a flotation system using recycled CO2 gas was used for sludge thickening. An anaerobic toxicity assay (ATA) and a biochemical methane potential assay were used to assess the toxicity impact of recycling CO2 on the methane production potential. ATA experiments confirmed that CO2 toxicity did not impair the AD process. The tests indicated that the cumulative methane yield from influent livestock manure enriched with CO2 was approximately 190 mL-CH4/g-VSadded. The data demonstrated the potential of using dissolved CO2 flotation in the AD of diluted livestock wastewater.
{"title":"Solid thickening and methane production of livestock wastewater using dissolved carbon dioxide flotation","authors":"D. Kwak, S. Chae","doi":"10.2166/WQRJC.2015.033","DOIUrl":"https://doi.org/10.2166/WQRJC.2015.033","url":null,"abstract":"Dilute manure is classified as wastewater due to the large quantity of water used in livestock production in Korea. Livestock wastewater treatment is required in order to reduce high moisture content and treat fluids discharged from the digestion process. In livestock wastewater treatment plants, large quantities of CO2 gas are produced at combined heat and power facilities as well as in the anaerobic digestion (AD) process. This gas produced during livestock wastewater treatment can be used as a separator of solids from liquid in wastewater. In this study, a flotation system using recycled CO2 gas was used for sludge thickening. An anaerobic toxicity assay (ATA) and a biochemical methane potential assay were used to assess the toxicity impact of recycling CO2 on the methane production potential. ATA experiments confirmed that CO2 toxicity did not impair the AD process. The tests indicated that the cumulative methane yield from influent livestock manure enriched with CO2 was approximately 190 mL-CH4/g-VSadded. The data demonstrated the potential of using dissolved CO2 flotation in the AD of diluted livestock wastewater.","PeriodicalId":54407,"journal":{"name":"Water Quality Research Journal of Canada","volume":null,"pages":null},"PeriodicalIF":2.0,"publicationDate":"2016-02-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.2166/WQRJC.2015.033","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"67982351","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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