Yukio Osada, Megumu Fujibayashi, C. Maruo, Shinji Takahashi, Nobuyuki Tanaka, O. Nishimura
Essential fatty acids (EFAs) are used as an indicator of food source quality for animals. However, it is not clear whether the EFA composition of food sources is a good indicator of the abundance and richness of animals in ecosystems. In this study, field surveys of paddy fields were conducted to clarify the relationship between benthic animals and the EFA composition of sediment as a potential food source for those animals. We investigated sediment and benthic animals in several paddy fields in Miyagi prefecture from 2009 to 2011. We analyzed the EFA composition and Chl-a in sediment and identified the benthic animals present. We found a positive relationship (p < 0.05) between the concentration of 20:5ω3 in sediment and the number of families of benthic animals. It was considered that diatoms, widely known to be a producer of 20:5ω3, are diversity marker of benthic animals in paddy fields.
{"title":"Relationship between Essential Fatty Acid Composition of Sediments and Species Richness of Benthic Animals in Paddy Field Ecosystems","authors":"Yukio Osada, Megumu Fujibayashi, C. Maruo, Shinji Takahashi, Nobuyuki Tanaka, O. Nishimura","doi":"10.2965/jswe.43.17","DOIUrl":"https://doi.org/10.2965/jswe.43.17","url":null,"abstract":"Essential fatty acids (EFAs) are used as an indicator of food source quality for animals. However, it is not clear whether the EFA composition of food sources is a good indicator of the abundance and richness of animals in ecosystems. In this study, field surveys of paddy fields were conducted to clarify the relationship between benthic animals and the EFA composition of sediment as a potential food source for those animals. We investigated sediment and benthic animals in several paddy fields in Miyagi prefecture from 2009 to 2011. We analyzed the EFA composition and Chl-a in sediment and identified the benthic animals present. We found a positive relationship (p < 0.05) between the concentration of 20:5ω3 in sediment and the number of families of benthic animals. It was considered that diatoms, widely known to be a producer of 20:5ω3, are diversity marker of benthic animals in paddy fields.","PeriodicalId":16300,"journal":{"name":"Journal of Japan Society on Water Environment","volume":"55 1","pages":"17-23"},"PeriodicalIF":0.0,"publicationDate":"2020-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82110449","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}
Sewer stormwater overflow, one of the causes of water pollution in Higashi-Yokobori River–Dotonbori River that flow through central Osaka, has been stored in a rainwater storage pipe called “ Heisei no Taiko Gesui ” since April 2015, but the number of coliform bacteria in both rivers did not decrease significantly. If the pipe is working, the number of coliform bacteria at a downstream point should depend on the number at the upstream point, flowing time, and water temperature. Thus, the decay rates of coliform bacteria were determined experimentally, and the predicted numbers of coliform bacteria at the downstream point were compared with the expected values obtained by the Monte Carlo method. The predicted values tended to be underestimated because the obtained decay rates did not reflect the effects of sunlight and other factors. However, the differences between the expected and predicted values after completion become close regardless of the weather, indicating that the pipe is functioning. It was considered that the number of coliform bacteria has not declined in both rivers because the increased load from the upstream cancelled the reduction effect of the pipe.
{"title":"A Study of Why the Number of Coliform Bacteria Did Not Decrease in Higashi-Yokobori River—Dotonbori River Despite the Completion of the New Stormwater Storage Pipe “Heisei no Taiko Gesui”","authors":"Akira Oshima, M. Kitano","doi":"10.2965/jswe.43.189","DOIUrl":"https://doi.org/10.2965/jswe.43.189","url":null,"abstract":"Sewer stormwater overflow, one of the causes of water pollution in Higashi-Yokobori River–Dotonbori River that flow through central Osaka, has been stored in a rainwater storage pipe called “ Heisei no Taiko Gesui ” since April 2015, but the number of coliform bacteria in both rivers did not decrease significantly. If the pipe is working, the number of coliform bacteria at a downstream point should depend on the number at the upstream point, flowing time, and water temperature. Thus, the decay rates of coliform bacteria were determined experimentally, and the predicted numbers of coliform bacteria at the downstream point were compared with the expected values obtained by the Monte Carlo method. The predicted values tended to be underestimated because the obtained decay rates did not reflect the effects of sunlight and other factors. However, the differences between the expected and predicted values after completion become close regardless of the weather, indicating that the pipe is functioning. It was considered that the number of coliform bacteria has not declined in both rivers because the increased load from the upstream cancelled the reduction effect of the pipe.","PeriodicalId":16300,"journal":{"name":"Journal of Japan Society on Water Environment","volume":"34 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2020-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"88159791","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}
Y. Shibata, Y. Iwasaki, Shion Takemura, T. Yasutaka, Toru Takahashi, H. Matsuda
A local association, “Wagagawa no seiryu wo mamoru kai” (The Association for Protection of Clean Water of the Waga River), was established by diverse stakeholders to protect the “clean” Waga River in 1972. As a major activity, the association has been monitoring the water quality (pH and concentrations of Cu, Zn, Cd, Pb, and As) of discharges from closed mines and downstream river sites, and reporting the results in their annual newsletter. To understand how information should be disclosed, it is worth noting that all the monitoring results, including the exceedance of mine discharge standards of the above-mentioned metals, have been made public and discussed in the newsletters. The analysis of the text of the annual newsletters published in 1972-2019 showed long-term primary changes in topics, that is, from (1) initial concern about general environmental pollution to (2) water quality monitoring and measures for preventing environmental pollution by closed mines to (3) the protection of natural environments including aquatic organisms. Our results would contribute to further analysis and discussion of the activities of this association to consider purpose-driven flexible environmental management in abandoned and closed mines in Japan.
{"title":"Analyzing Annual Newsletters of Local Association for Protection of Waga River: Water Quality Monitoring for Closed Mines and Long-term Changes in Related Topics in Newsletters","authors":"Y. Shibata, Y. Iwasaki, Shion Takemura, T. Yasutaka, Toru Takahashi, H. Matsuda","doi":"10.2965/jswe.43.183","DOIUrl":"https://doi.org/10.2965/jswe.43.183","url":null,"abstract":"A local association, “Wagagawa no seiryu wo mamoru kai” (The Association for Protection of Clean Water of the Waga River), was established by diverse stakeholders to protect the “clean” Waga River in 1972. As a major activity, the association has been monitoring the water quality (pH and concentrations of Cu, Zn, Cd, Pb, and As) of discharges from closed mines and downstream river sites, and reporting the results in their annual newsletter. To understand how information should be disclosed, it is worth noting that all the monitoring results, including the exceedance of mine discharge standards of the above-mentioned metals, have been made public and discussed in the newsletters. The analysis of the text of the annual newsletters published in 1972-2019 showed long-term primary changes in topics, that is, from (1) initial concern about general environmental pollution to (2) water quality monitoring and measures for preventing environmental pollution by closed mines to (3) the protection of natural environments including aquatic organisms. Our results would contribute to further analysis and discussion of the activities of this association to consider purpose-driven flexible environmental management in abandoned and closed mines in Japan.","PeriodicalId":16300,"journal":{"name":"Journal of Japan Society on Water Environment","volume":"33 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2020-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"87162513","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}
Assuming application in areas with difficulties in installing, maintaining and operating large-scale water supply systems, the effectiveness of decentralized systems was examined by a one-year field test of disinfection apparatuses equipped with ultraviolet light-emitting diodes (UV-LED) at a faucet supplying untreated water from a mountain stream. The untreated water was sporadically positive with Escherichia coli and had a high heterotrophic plate count (HPC) of bacteria exceeding the target value of drinking water, indicating the need of disinfection process for potable use. In UV-LED treated water, both the concentration and the positive ratio of bacteria decreased, and the maximum concentration of positive samples for E. coli, total coliforms, standard plate count and HPC were 0.5, 1.0, 6.0 and 485 CFU mL, respectively. One model of the UV-LED apparatus achieved all-negative detection of E. coli throughout the one-year test period. No apparatus showed any notable trend of performance deterioration for HPC inactivation with operation time, and scale formation was not apparent inside the body of the apparatuses after the test. This study shows the potential of UV-LED apparatuses as an option of decentralized water treatment technologies.
{"title":"Field Test of Ultraviolet Light-Emitting Diode (UV-LED) Apparatuses as an Option of Decentralized Water Treatment Technologies","authors":"K. Oguma, S. Watanabe","doi":"10.2965/jswe.43.119","DOIUrl":"https://doi.org/10.2965/jswe.43.119","url":null,"abstract":"Assuming application in areas with difficulties in installing, maintaining and operating large-scale water supply systems, the effectiveness of decentralized systems was examined by a one-year field test of disinfection apparatuses equipped with ultraviolet light-emitting diodes (UV-LED) at a faucet supplying untreated water from a mountain stream. The untreated water was sporadically positive with Escherichia coli and had a high heterotrophic plate count (HPC) of bacteria exceeding the target value of drinking water, indicating the need of disinfection process for potable use. In UV-LED treated water, both the concentration and the positive ratio of bacteria decreased, and the maximum concentration of positive samples for E. coli, total coliforms, standard plate count and HPC were 0.5, 1.0, 6.0 and 485 CFU mL, respectively. One model of the UV-LED apparatus achieved all-negative detection of E. coli throughout the one-year test period. No apparatus showed any notable trend of performance deterioration for HPC inactivation with operation time, and scale formation was not apparent inside the body of the apparatuses after the test. This study shows the potential of UV-LED apparatuses as an option of decentralized water treatment technologies.","PeriodicalId":16300,"journal":{"name":"Journal of Japan Society on Water Environment","volume":"1 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2020-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"85220168","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}
Kaho Watanabe, S. Kobayashi, Masaki Fuchi, S. Asaoka, M. Hayashi
The inner part of Osaka Bay in Japan is affected by eutrophication, and the western part of the bay is affected by oligotrophic conditions. In this study, the distribution, sources, and decomposition rate of organic nitrogen （ Org-N ） in the estuarine region of Osaka Bay, defined as the region from the mouth of the Yodo River to the bay head, were studied to elucidate the cause of this uneven distribution of nutrients in the bay. Concentrations of Org-N are much higher in the estuary region than in freshwater areas or in the bay itself. Particulate organic nitrogen, which potentially sinks toward the bottom, accounted for 74 ± 11% of Org-N. The decomposition rate of dissolved organic nitrogen over 100 days, which is potentially supplied to the sea with low-salinity water, was 29 ± 4%. These results regarding the decomposition rate of organic matter in the estuarine region of Osaka Bay may improve the accuracy of models of the impact of land-sourced nutrient load on nutrient conditions in the bay.
{"title":"Source and Decomposition of Organic Matter in the Estuary of Yodo River","authors":"Kaho Watanabe, S. Kobayashi, Masaki Fuchi, S. Asaoka, M. Hayashi","doi":"10.2965/jswe.43.87","DOIUrl":"https://doi.org/10.2965/jswe.43.87","url":null,"abstract":"The inner part of Osaka Bay in Japan is affected by eutrophication, and the western part of the bay is affected by oligotrophic conditions. In this study, the distribution, sources, and decomposition rate of organic nitrogen （ Org-N ） in the estuarine region of Osaka Bay, defined as the region from the mouth of the Yodo River to the bay head, were studied to elucidate the cause of this uneven distribution of nutrients in the bay. Concentrations of Org-N are much higher in the estuary region than in freshwater areas or in the bay itself. Particulate organic nitrogen, which potentially sinks toward the bottom, accounted for 74 ± 11% of Org-N. The decomposition rate of dissolved organic nitrogen over 100 days, which is potentially supplied to the sea with low-salinity water, was 29 ± 4%. These results regarding the decomposition rate of organic matter in the estuarine region of Osaka Bay may improve the accuracy of models of the impact of land-sourced nutrient load on nutrient conditions in the bay.","PeriodicalId":16300,"journal":{"name":"Journal of Japan Society on Water Environment","volume":"27 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2020-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84074912","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 objective of this study is to develop a toilet independent of infrastructure, that is, electricity, water and sewerage. The treatment performance of the water purification unit to reclaime wastewater for toilet usage with minimum running energy for the circulation of water was tested. The chromaticity of reclaimed wastewater was maintained at less than 30 degrees after the total number of times of toilet use reached 897 (218 excremental and 679 urinal uses). Since the complete elimination of Escherichia coli using only the water purification unit was difficult, it was found that some disinfection countermeasure would be necessary to maintain hygienic safety. The removal efficiencies for CODMn, total nitrogen and total phosphorus estimated from the total number of times of toilet use and the final water quality of reclaimed wastewater were approximately 99%, 83% and 98%, respectively, despite the frequency of toilet usage. These results confirmed that the water purification unit consisting of a multistage filtration bed could stably reclaim wastewater for reuse in the toilet.
{"title":"Treatment Performance of Water Purification Unit for Reclaimed Wastewater of Independent Toilet","authors":"R. Yokote, T. Taniguchi, A. Hashimoto, K. Nakano","doi":"10.2965/jswe.43.69","DOIUrl":"https://doi.org/10.2965/jswe.43.69","url":null,"abstract":"The objective of this study is to develop a toilet independent of infrastructure, that is, electricity, water and sewerage. The treatment performance of the water purification unit to reclaime wastewater for toilet usage with minimum running energy for the circulation of water was tested. The chromaticity of reclaimed wastewater was maintained at less than 30 degrees after the total number of times of toilet use reached 897 (218 excremental and 679 urinal uses). Since the complete elimination of Escherichia coli using only the water purification unit was difficult, it was found that some disinfection countermeasure would be necessary to maintain hygienic safety. The removal efficiencies for CODMn, total nitrogen and total phosphorus estimated from the total number of times of toilet use and the final water quality of reclaimed wastewater were approximately 99%, 83% and 98%, respectively, despite the frequency of toilet usage. These results confirmed that the water purification unit consisting of a multistage filtration bed could stably reclaim wastewater for reuse in the toilet.","PeriodicalId":16300,"journal":{"name":"Journal of Japan Society on Water Environment","volume":"22 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2020-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"72961980","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}
Satoko Yokoyama, Takahiro Tannzawa, T. Hoshino, M. Mayuzumi, Katsumasa Hanno
{"title":"Effluent Load at an Irrigation and Drainage Pump Station, Originating from Paddy Fields in the Inbanuma Basin","authors":"Satoko Yokoyama, Takahiro Tannzawa, T. Hoshino, M. Mayuzumi, Katsumasa Hanno","doi":"10.2965/jswe.43.133","DOIUrl":"https://doi.org/10.2965/jswe.43.133","url":null,"abstract":"","PeriodicalId":16300,"journal":{"name":"Journal of Japan Society on Water Environment","volume":"40 1","pages":"133-139"},"PeriodicalIF":0.0,"publicationDate":"2020-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"74989884","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}
K. Wada, Masahisa Nakamura, Keisuke Sato, H. Tsuno, Shinya Fukuju
Making use of relevant Geographic Information System (GIS) data, an attempt was made to analyze the changes in the magnitude and spatial distribution of the land-based sources of nonpoint pollution loads for the entire Lake Biwa– Yodo River Basin over the 18-year period between 1991 and 2009. Specifically, the magnitudes per unit area of the runoff coefficient and of the COD, T-N and T-P pollutant loads, respectively, were computed and displayed as GIS visual images. The resulting GIS outputs indicate that the runoff coefficient increased along the riparian zones of rivers and around the lakeshore in the middle and lower basin regions, except for the mountainous regions. This implies that the pollutants flow directly into the immediately adjacent receiving waterbodies. Also, the trends of water pollutants were found to be affected by the unit load. The runoff coefficient and the COD loads were related with the progress of urbanization, indicating that the increase and decrease in T-N and T-P pollutant loads were caused by the conversion of land mainly from paddy agriculture to other agricultural purposes. In conclusion, it was confirmed that the results displayed in the form of GIS outputs are useful not only for numerical assessment but also for the assessment of spatial distributions.
{"title":"GIS Analysis of Eighteen-year Trend in Land Use, Runoff, and Nonpoint Load Characteristics in the Lake Biwa–Yodo River Basin","authors":"K. Wada, Masahisa Nakamura, Keisuke Sato, H. Tsuno, Shinya Fukuju","doi":"10.2965/jswe.43.141","DOIUrl":"https://doi.org/10.2965/jswe.43.141","url":null,"abstract":"Making use of relevant Geographic Information System (GIS) data, an attempt was made to analyze the changes in the magnitude and spatial distribution of the land-based sources of nonpoint pollution loads for the entire Lake Biwa– Yodo River Basin over the 18-year period between 1991 and 2009. Specifically, the magnitudes per unit area of the runoff coefficient and of the COD, T-N and T-P pollutant loads, respectively, were computed and displayed as GIS visual images. The resulting GIS outputs indicate that the runoff coefficient increased along the riparian zones of rivers and around the lakeshore in the middle and lower basin regions, except for the mountainous regions. This implies that the pollutants flow directly into the immediately adjacent receiving waterbodies. Also, the trends of water pollutants were found to be affected by the unit load. The runoff coefficient and the COD loads were related with the progress of urbanization, indicating that the increase and decrease in T-N and T-P pollutant loads were caused by the conversion of land mainly from paddy agriculture to other agricultural purposes. In conclusion, it was confirmed that the results displayed in the form of GIS outputs are useful not only for numerical assessment but also for the assessment of spatial distributions.","PeriodicalId":16300,"journal":{"name":"Journal of Japan Society on Water Environment","volume":"25 1","pages":"141-152"},"PeriodicalIF":0.0,"publicationDate":"2020-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83030836","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 relationship between seawater nutrient concentrations and ecosystem production was studied by in situ growth experiments, which have been conducted along the nutrient concentration gradient from the eutrophic Osaka Bay head to the oligotrophic adjoining Harima Sea. Bivalves (asari clam Ruditapes philippinarum) were cultured in suspended cargo, and sessile organisms were collected on a suspended plate at each station. The distribution of the primary production was also calculated within the study area. The wet weight of the molluscous part and the condition index of asari clam are strongly correlated with the annual mean total nitrogen (TN). The primary production (PP) is significantly correlated with TN in the area of TN > 0.2 mg L. In contrast, PP is small and of a pelagic nature in the area of TN ≦ 0.2 mg L. The annual mean TN is strongly correlated with TP, and TN = 0.2 mg L is equivalent to TP = 0.029 mg L.
{"title":"Minimum Nutrient Concentrations for Sustaining Marine Ecosystem Productivity: Measurement during in situ Growth Experiments of Bivalve and Sessile Organisms","authors":"T. Fujiwara, K. Higuchi, T. Fujii","doi":"10.2965/jswe.43.175","DOIUrl":"https://doi.org/10.2965/jswe.43.175","url":null,"abstract":"The relationship between seawater nutrient concentrations and ecosystem production was studied by in situ growth experiments, which have been conducted along the nutrient concentration gradient from the eutrophic Osaka Bay head to the oligotrophic adjoining Harima Sea. Bivalves (asari clam Ruditapes philippinarum) were cultured in suspended cargo, and sessile organisms were collected on a suspended plate at each station. The distribution of the primary production was also calculated within the study area. The wet weight of the molluscous part and the condition index of asari clam are strongly correlated with the annual mean total nitrogen (TN). The primary production (PP) is significantly correlated with TN in the area of TN > 0.2 mg L. In contrast, PP is small and of a pelagic nature in the area of TN ≦ 0.2 mg L. The annual mean TN is strongly correlated with TP, and TN = 0.2 mg L is equivalent to TP = 0.029 mg L.","PeriodicalId":16300,"journal":{"name":"Journal of Japan Society on Water Environment","volume":"10 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2020-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"88239809","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}
Manabu Kashiwabara, K. Hata, Masaya Matsuki, Takaoki Koga, Toyokazu Koga, Shusaku Hirakawa, Y. Kurokawa, T. Miyawaki, N. Shimizu, Gensei Matsumoto, Yuko Ishibashi, H. Yamanishi
The total nitrogen concentration in chlorinated wastewater from a sewage treatment plant included a large amount of ammonium nitrogen as determined by a measurement method established by the Water Pollution Prevention Act, but it was less than the concentration of dissolved inorganic nitrogen. The total nitrogen concentration may have been underestimated because some of the chloramines in the sample changed to nitrogen gas or nitrous oxide gas under alkaline conditions. Therefore, we evaluated a novel pretreatment method for total nitrogen analysis. The recovery rate of total nitrogen in a sample including 1 mg L -1 ammonium nitrogen and 1 mg L -1 available chlorine from sodium hypochlorite was enhanced to 98% by the addition of 50 mmol L -1 sodium sulfite solution, which accounted for at least 0.4 vol% of the sample. Additionally, a recovery test was carried out with some real samples. The recovery rates of total nitrogen in wastewater from the sewage treatment plant and in water from the environment around the plant were 100-104% after the addition of 50 mmol L -1 sodium sulfite solution.
根据《水污染防治法》规定的测量方法，某污水处理厂氯化废水中总氮浓度含有大量铵态氮，但低于溶解态无机氮浓度。总氮浓度可能被低估了，因为样品中的一些氯胺在碱性条件下变成了氮气或氧化亚氮气体。因此，我们评估了一种新的总氮分析前处理方法。对含有1 mg L -1铵态氮和1 mg L -1有效氯的次氯酸钠样品，添加50 mmol L -1亚硫酸钠溶液可使总氮的回收率提高到98%，至少占样品的0.4 vol%。并对一些实际样品进行了回收试验。添加50 mmol L -1亚硫酸钠溶液后，污水处理厂废水及周围环境水中总氮的回收率为100-104%。
{"title":"Analysis Method for Total Nitrogen in Chlorinated Wastewater Containing Ammonium Nitrogen from Sewage Treatment Plant","authors":"Manabu Kashiwabara, K. Hata, Masaya Matsuki, Takaoki Koga, Toyokazu Koga, Shusaku Hirakawa, Y. Kurokawa, T. Miyawaki, N. Shimizu, Gensei Matsumoto, Yuko Ishibashi, H. Yamanishi","doi":"10.2965/jswe.43.35","DOIUrl":"https://doi.org/10.2965/jswe.43.35","url":null,"abstract":"The total nitrogen concentration in chlorinated wastewater from a sewage treatment plant included a large amount of ammonium nitrogen as determined by a measurement method established by the Water Pollution Prevention Act, but it was less than the concentration of dissolved inorganic nitrogen. The total nitrogen concentration may have been underestimated because some of the chloramines in the sample changed to nitrogen gas or nitrous oxide gas under alkaline conditions. Therefore, we evaluated a novel pretreatment method for total nitrogen analysis. The recovery rate of total nitrogen in a sample including 1 mg L -1 ammonium nitrogen and 1 mg L -1 available chlorine from sodium hypochlorite was enhanced to 98% by the addition of 50 mmol L -1 sodium sulfite solution, which accounted for at least 0.4 vol% of the sample. Additionally, a recovery test was carried out with some real samples. The recovery rates of total nitrogen in wastewater from the sewage treatment plant and in water from the environment around the plant were 100-104% after the addition of 50 mmol L -1 sodium sulfite solution.","PeriodicalId":16300,"journal":{"name":"Journal of Japan Society on Water Environment","volume":"18 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2020-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"73352889","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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