G. Li, Chaoyi Wang, Yingying Zhang, Hongyou Wan, Ming Dou, Hongbin Xu
In this study, low-cost siderite was used to activate peroxydisulfate (PDS, S2O82-)-inactivated Enterococcus faecalis to study the inactivation characteristics and mechanism of siderite/PDS. The results showed that the siderite/PDS had a better inactivation effect on Enterococcus faecalis at pH 3. The sterilization effect increases with the increase of siderite dosage, PDS concentration and temperature. The inactivation rate is decreased with the increase of initial bacterial concentration. Inorganic ions and natural organic matter (NOM) can inhibit the inactivation effect of this technology, and the inhibition intensity is NOM > HCO3− > NO3−. The free radical quenching test shows that HO• is the main oxidizing substance in the sterilization process of siderite/PDS technology. In addition, the main disinfection mechanism is highly reactive oxygen species destroying the cell wall of bacteria and releasing organic compounds in cells. After siderite was reused for four times, simply washing siderite would recover almost 80% of the removal of Enterococcus faecalis in siderite/PDS, indicating that siderite has the potential of recycling.
{"title":"Characteristics and mechanism of persulfate activated by natural siderite for water disinfection","authors":"G. Li, Chaoyi Wang, Yingying Zhang, Hongyou Wan, Ming Dou, Hongbin Xu","doi":"10.2166/wrd.2022.030","DOIUrl":"https://doi.org/10.2166/wrd.2022.030","url":null,"abstract":"\u0000 In this study, low-cost siderite was used to activate peroxydisulfate (PDS, S2O82-)-inactivated Enterococcus faecalis to study the inactivation characteristics and mechanism of siderite/PDS. The results showed that the siderite/PDS had a better inactivation effect on Enterococcus faecalis at pH 3. The sterilization effect increases with the increase of siderite dosage, PDS concentration and temperature. The inactivation rate is decreased with the increase of initial bacterial concentration. Inorganic ions and natural organic matter (NOM) can inhibit the inactivation effect of this technology, and the inhibition intensity is NOM > HCO3− > NO3−. The free radical quenching test shows that HO• is the main oxidizing substance in the sterilization process of siderite/PDS technology. In addition, the main disinfection mechanism is highly reactive oxygen species destroying the cell wall of bacteria and releasing organic compounds in cells. After siderite was reused for four times, simply washing siderite would recover almost 80% of the removal of Enterococcus faecalis in siderite/PDS, indicating that siderite has the potential of recycling.","PeriodicalId":17556,"journal":{"name":"Journal of Water Reuse and Desalination","volume":"1 1","pages":""},"PeriodicalIF":2.3,"publicationDate":"2022-08-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41373925","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. Weidhaas, M. Olsen, J. McLean, N. Allen, L. Ahmadi, K. Duodu, R. Dupont
Arid and semi-arid locations are increasingly utilizing nontraditional irrigation water including reclaimed wastewater. Human health risk associated with reclaimed wastewater use was determined by testing reservoir, distribution line and home spigot water (n=190) and 14 types of vegetables and fruits (n=90) harvested from 5 home gardens for 7 waterborne pathogens, 47 antibiotic resistance genes and 12 pharmaceuticals and personal care products (PPCPs). Based on surveys of the residents’ use of the reclaimed wastewater, two exposure routes were modeled: irrigation of fruits and vegetables and drinking from irrigation hoses. Probabilistic quantitative microbial risk assessment indicated that consumption of raw vegetables and fruits exceeded a 0.015 benchmark illness rate due to adenovirus and enterococci. Chemical risk assessments indicated that consumption of tons of vegetables per day and hundreds to millions of gallons of water per day would be needed to reach an unacceptable risk among the 10 PPCPs detected in home spigot water, indicating de minimis risk from PPCPs. Eight different drug resistance gene families were detected in the water samples and crops indicating that antibiotic-resistant organisms are present on foods irrigated with reclaimed water containing pharmaceuticals. These results elucidate the combined risk from pathogens and PPCPs from reclaimed wastewater irrigation.
{"title":"Microbial and chemical risk from reclaimed water use for residential irrigation","authors":"J. Weidhaas, M. Olsen, J. McLean, N. Allen, L. Ahmadi, K. Duodu, R. Dupont","doi":"10.2166/wrd.2022.014","DOIUrl":"https://doi.org/10.2166/wrd.2022.014","url":null,"abstract":"\u0000 Arid and semi-arid locations are increasingly utilizing nontraditional irrigation water including reclaimed wastewater. Human health risk associated with reclaimed wastewater use was determined by testing reservoir, distribution line and home spigot water (n=190) and 14 types of vegetables and fruits (n=90) harvested from 5 home gardens for 7 waterborne pathogens, 47 antibiotic resistance genes and 12 pharmaceuticals and personal care products (PPCPs). Based on surveys of the residents’ use of the reclaimed wastewater, two exposure routes were modeled: irrigation of fruits and vegetables and drinking from irrigation hoses. Probabilistic quantitative microbial risk assessment indicated that consumption of raw vegetables and fruits exceeded a 0.015 benchmark illness rate due to adenovirus and enterococci. Chemical risk assessments indicated that consumption of tons of vegetables per day and hundreds to millions of gallons of water per day would be needed to reach an unacceptable risk among the 10 PPCPs detected in home spigot water, indicating de minimis risk from PPCPs. Eight different drug resistance gene families were detected in the water samples and crops indicating that antibiotic-resistant organisms are present on foods irrigated with reclaimed water containing pharmaceuticals. These results elucidate the combined risk from pathogens and PPCPs from reclaimed wastewater irrigation.","PeriodicalId":17556,"journal":{"name":"Journal of Water Reuse and Desalination","volume":" ","pages":""},"PeriodicalIF":2.3,"publicationDate":"2022-07-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48327879","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}
Safe water reuse usually means the provision of reclaimed water with its quality meeting the criteria for safeguarding human health and aquatic ecology. Regarding this, people often overstress the technological magic in terms of hazardous substances removal by engineered processes while ignoring the utilization of nature's power to provide an additional barrier for safety control. Based on an understanding of the function of the hydrological cycle to secure water quality and the fact that water reuse is through a water loop, the author presented his viewpoint on creating a quasi-natural water cycle for water reuse. Existing data showed the remarkable effects of emerging pollutants removal and associated reduction of biotoxicities from the reclaimed water during open-storage under a quasi-natural condition. Adsorption by soil particles, sunlight-induced photolysis and purification by aquatic life were thought to be the major actions contributing to effective water quality improvement in a quasi-natural manner. Safe water reuse through a quasi-natural water cycle can thus be a recommendable strategy for system design in accordance with the purposes of water use.
{"title":"Safe water reuse through a quasi-natural water cycle","authors":"Xiaochang C. Wang","doi":"10.2166/wrd.2022.039","DOIUrl":"https://doi.org/10.2166/wrd.2022.039","url":null,"abstract":"\u0000 Safe water reuse usually means the provision of reclaimed water with its quality meeting the criteria for safeguarding human health and aquatic ecology. Regarding this, people often overstress the technological magic in terms of hazardous substances removal by engineered processes while ignoring the utilization of nature's power to provide an additional barrier for safety control. Based on an understanding of the function of the hydrological cycle to secure water quality and the fact that water reuse is through a water loop, the author presented his viewpoint on creating a quasi-natural water cycle for water reuse. Existing data showed the remarkable effects of emerging pollutants removal and associated reduction of biotoxicities from the reclaimed water during open-storage under a quasi-natural condition. Adsorption by soil particles, sunlight-induced photolysis and purification by aquatic life were thought to be the major actions contributing to effective water quality improvement in a quasi-natural manner. Safe water reuse through a quasi-natural water cycle can thus be a recommendable strategy for system design in accordance with the purposes of water use.","PeriodicalId":17556,"journal":{"name":"Journal of Water Reuse and Desalination","volume":" ","pages":""},"PeriodicalIF":2.3,"publicationDate":"2022-07-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45011998","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}
Gerubin Liberath Msaki, K. Njau, A. Treydte, T. Lyimo
This study assessed the social knowledge, attitude, and perceptions (KAPs) on wastewater treatment, the technologies involved, and its reuse across different wastewater treatment areas in four regions of Tanzania. We used both quantitative and qualitative data collection methods in a household-level questionnaire (n=327) with structured and semi-structured questions, which involved face-to-face interviews and observation. Our results show that social KAPs surrounding wastewater treatment and reuse were sufficient based on KAP scores achieved from asked questions. However, the general knowledge on treatment technologies, processes, and reuse risks was still low. Of the respondents, over 50% approved using treated wastewater in various applications, while the majority (93%) were reluctant if the application involved direct contact with the water. Furthermore, over 90% of interviewees did not know the technologies used to treat wastewater and the potential health risks associated with its use (59%). Multivariate analysis of variance revealed significant differences (P<0.05) in the KAPs on treated wastewater across different studied demographic variables, i.e., age, sex, and education level. Therefore, we recommend that more effort be spent on providing public education about the potential of wastewater treatment and existing technologies in order to facilitate their adoption for the community's and environment's benefit.
{"title":"Social knowledge, attitudes, and perceptions on wastewater treatment, technologies, and reuse in Tanzania","authors":"Gerubin Liberath Msaki, K. Njau, A. Treydte, T. Lyimo","doi":"10.2166/wrd.2022.096","DOIUrl":"https://doi.org/10.2166/wrd.2022.096","url":null,"abstract":"\u0000 This study assessed the social knowledge, attitude, and perceptions (KAPs) on wastewater treatment, the technologies involved, and its reuse across different wastewater treatment areas in four regions of Tanzania. We used both quantitative and qualitative data collection methods in a household-level questionnaire (n=327) with structured and semi-structured questions, which involved face-to-face interviews and observation. Our results show that social KAPs surrounding wastewater treatment and reuse were sufficient based on KAP scores achieved from asked questions. However, the general knowledge on treatment technologies, processes, and reuse risks was still low. Of the respondents, over 50% approved using treated wastewater in various applications, while the majority (93%) were reluctant if the application involved direct contact with the water. Furthermore, over 90% of interviewees did not know the technologies used to treat wastewater and the potential health risks associated with its use (59%). Multivariate analysis of variance revealed significant differences (P<0.05) in the KAPs on treated wastewater across different studied demographic variables, i.e., age, sex, and education level. Therefore, we recommend that more effort be spent on providing public education about the potential of wastewater treatment and existing technologies in order to facilitate their adoption for the community's and environment's benefit.","PeriodicalId":17556,"journal":{"name":"Journal of Water Reuse and Desalination","volume":" ","pages":""},"PeriodicalIF":2.3,"publicationDate":"2022-06-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42863196","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}
Zhang Hongwei, Qi Junye, Che Yinglong, Man Shide, Liu Jianlin, Wei Bigui
To improve the separation efficiency of the oil/water mixture and simplify the separation process, a superhydrophilic/underwater superoleophobic quartz sand filter media (PR@QS) was prepared by coating potato residue onto the quartz sand surface, and an oil/water mixture separator containing two horizontally placed filter columns and one inlet chamber was proposed. One filter column was filled with the PR@QS, and the other column was filled with the superhydrophobic/superoleophilic quartz sand filter media. The experimental results showed that the separation efficiencies of five kinds of oil/water mixtures (petroleum ether, engine oil, diesel oil, cyclohexane, and methylene chloride) were up to 99.4%. Except for engine oil, the hydraulic conductivities of the other four oils and water are all greater than 3.5 m/h. When the filter layer is invaded by the lyophobic liquid, its filtration performance can be restored by backwashing. In summary, the separator can separate oil/water mixtures continuously and efficiently without filter contamination. Therefore, it has a broad prospect for practical application.
{"title":"Continuous and efficient oil/water separation by special wettability granular filter media","authors":"Zhang Hongwei, Qi Junye, Che Yinglong, Man Shide, Liu Jianlin, Wei Bigui","doi":"10.2166/wrd.2022.102","DOIUrl":"https://doi.org/10.2166/wrd.2022.102","url":null,"abstract":"<p>To improve the separation efficiency of the oil/water mixture and simplify the separation process, a superhydrophilic/underwater superoleophobic quartz sand filter media (PR@QS) was prepared by coating potato residue onto the quartz sand surface, and an oil/water mixture separator containing two horizontally placed filter columns and one inlet chamber was proposed. One filter column was filled with the PR@QS, and the other column was filled with the superhydrophobic/superoleophilic quartz sand filter media. The experimental results showed that the separation efficiencies of five kinds of oil/water mixtures (petroleum ether, engine oil, diesel oil, cyclohexane, and methylene chloride) were up to 99.4%. Except for engine oil, the hydraulic conductivities of the other four oils and water are all greater than 3.5 m/h. When the filter layer is invaded by the lyophobic liquid, its filtration performance can be restored by backwashing. In summary, the separator can separate oil/water mixtures continuously and efficiently without filter contamination. Therefore, it has a broad prospect for practical application.</p>","PeriodicalId":17556,"journal":{"name":"Journal of Water Reuse and Desalination","volume":"25 1","pages":""},"PeriodicalIF":2.3,"publicationDate":"2022-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138530383","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. Kalteh, Farshad Hamidi, Mahdi Ahmadi Nasab, Narges Mohseni Gharibdoosti, Mohammad Rezvani Ghalhari, Mina Parvizishad, A. Mahvi
Nitrate is a common contaminant of drinking water. Due to its adverse health effects, this study aimed to determine nitrate levels in six southern districts of Tehran. A total of 148 samples were taken from tap waters. In 84.46% (n = 125) of the samples, the nitrate concentration was below national and WHO limits (50 mg/L); however, 15.54% (n = 23) were in violation of the criteria. The total mean concentration of nitrate was 36.15 mg/L (±14.74) ranging from 4.52 to 80.83 mg/L. The overall hazard quotient (HQ) for age groups were ordered as Children (1.71) > Infants (1.24) > Teenagers (1.2) > Adults (0.96). In all districts, the HQ values for infants and children groups were greater than 1, indicating potential adverse health risks. In teenagers age group, only the HQ estimations of districts 10 (HQ = 0.93) and 11 (HQ = 0.74) were lower than 1 and in adults age group, the estimated HQ values for districts were lower than 1 with the exception for district 19 (HQ = 1.19). The sensitivity analysis (SA) showed that nitrate content plays a major role in the value of the assessed risk.
{"title":"Quantification and health risk assessment of nitrate in southern districts of Tehran, Iran","authors":"S. Kalteh, Farshad Hamidi, Mahdi Ahmadi Nasab, Narges Mohseni Gharibdoosti, Mohammad Rezvani Ghalhari, Mina Parvizishad, A. Mahvi","doi":"10.2166/wrd.2022.007","DOIUrl":"https://doi.org/10.2166/wrd.2022.007","url":null,"abstract":"\u0000 Nitrate is a common contaminant of drinking water. Due to its adverse health effects, this study aimed to determine nitrate levels in six southern districts of Tehran. A total of 148 samples were taken from tap waters. In 84.46% (n = 125) of the samples, the nitrate concentration was below national and WHO limits (50 mg/L); however, 15.54% (n = 23) were in violation of the criteria. The total mean concentration of nitrate was 36.15 mg/L (±14.74) ranging from 4.52 to 80.83 mg/L. The overall hazard quotient (HQ) for age groups were ordered as Children (1.71) > Infants (1.24) > Teenagers (1.2) > Adults (0.96). In all districts, the HQ values for infants and children groups were greater than 1, indicating potential adverse health risks. In teenagers age group, only the HQ estimations of districts 10 (HQ = 0.93) and 11 (HQ = 0.74) were lower than 1 and in adults age group, the estimated HQ values for districts were lower than 1 with the exception for district 19 (HQ = 1.19). The sensitivity analysis (SA) showed that nitrate content plays a major role in the value of the assessed risk.","PeriodicalId":17556,"journal":{"name":"Journal of Water Reuse and Desalination","volume":" ","pages":""},"PeriodicalIF":2.3,"publicationDate":"2022-05-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42034319","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}
There is a significant demand for water recycling in low-income countries. However, wastewater infrastructure is primarily decentralised, necessitating the development of affordable household-scale reclamation technology. In this study, a batch open-loop reverse osmosis (RO) system is therefore investigated as a low-cost clean water reclamation route from highly saline concentrated blackwater. In a single-stage configuration, increasing feed pressure from 10 to 30 bars improved selective separation at water recovery exceeding 85%, whereas lower cross-flow velocity improved product recovery, reducing specific permeate energy demand from 21 to 4.8 kWh m−3. Rejection achieved for total phosphorous (99%), chemical oxygen demand (COD, 96%), and final pH (8.7) of the RO permeate was compliant with the ISO30500 reuse standard for discharge. However, the rejection of total nitrogen in the RO permeate was non-compliant with the reuse standard due to the transmission of low-molecular weight (MW) uncharged organic compounds. It is suggested that rejection may be improved by increasing feed pressure to rebalance selectivity but may also be controlled by reducing fluid residence time (storage) to constrain the hydrolysis of urea. The economic analysis identified that a high-pressure 1812 element cost of ∼US$30 meets the sanitation affordability index of US$0.05 capita−1 day−1. However, the unit cost of a high-pressure feed pump must be reduced to ∼US$500 to obtain an affordable system cost. These unit costs can be achieved by manufacturing 1812 elements at economies of scale, and by adopting pumping solutions that have been developed for other applications requiring high pressures and low flows. Overall, our findings suggest that RO in the batch open-loop configuration has the potential to deliver affordable and safe water production from blackwater in a decentralised (single-household) context.
{"title":"Downscaling reverse osmosis for single-household wastewater reuse: towards low-cost decentralised sanitation through a batch open-loop configuration","authors":"C. Davey, N. Thomas, E. McAdam","doi":"10.2166/wrd.2022.084","DOIUrl":"https://doi.org/10.2166/wrd.2022.084","url":null,"abstract":"\u0000 There is a significant demand for water recycling in low-income countries. However, wastewater infrastructure is primarily decentralised, necessitating the development of affordable household-scale reclamation technology. In this study, a batch open-loop reverse osmosis (RO) system is therefore investigated as a low-cost clean water reclamation route from highly saline concentrated blackwater. In a single-stage configuration, increasing feed pressure from 10 to 30 bars improved selective separation at water recovery exceeding 85%, whereas lower cross-flow velocity improved product recovery, reducing specific permeate energy demand from 21 to 4.8 kWh m−3. Rejection achieved for total phosphorous (99%), chemical oxygen demand (COD, 96%), and final pH (8.7) of the RO permeate was compliant with the ISO30500 reuse standard for discharge. However, the rejection of total nitrogen in the RO permeate was non-compliant with the reuse standard due to the transmission of low-molecular weight (MW) uncharged organic compounds. It is suggested that rejection may be improved by increasing feed pressure to rebalance selectivity but may also be controlled by reducing fluid residence time (storage) to constrain the hydrolysis of urea. The economic analysis identified that a high-pressure 1812 element cost of ∼US$30 meets the sanitation affordability index of US$0.05 capita−1 day−1. However, the unit cost of a high-pressure feed pump must be reduced to ∼US$500 to obtain an affordable system cost. These unit costs can be achieved by manufacturing 1812 elements at economies of scale, and by adopting pumping solutions that have been developed for other applications requiring high pressures and low flows. Overall, our findings suggest that RO in the batch open-loop configuration has the potential to deliver affordable and safe water production from blackwater in a decentralised (single-household) context.","PeriodicalId":17556,"journal":{"name":"Journal of Water Reuse and Desalination","volume":" ","pages":""},"PeriodicalIF":2.3,"publicationDate":"2022-04-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48947444","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}
Akarawin Jirasaranporn, Krittayapong Jantharadej, K. Wongwailikhit, C. Chawengkijwanich, Jenyuk Lohwatcharin, B. Suwannasilp
This research aims to investigate the performance of a pilot-scale anaerobic moving-bed biofilm reactor (AnMBBR) using PVA gels as media for the treatment of real wastewater from a fish canning factory. The chemical oxygen demand (COD) removal efficiencies at different organic loading rates (OLRs) were investigated at 3.0, 4.3, 6.5, and 8.7 kg COD/m3day by adjusting the flow rates to 350, 500, 750 and 1,000 L/d, respectively. The soluble COD removal efficiencies of the system at flow rates of 350, 500, 750, and 1,000 L/d were 81.0 ± 12.4%, 76.8 ± 8.2%, 74.7 ± 6.2%, and 70.6 ± 12.4%, respectively. According to the residence time distribution (RTD) tests at the highest and lowest flow rates, the mean residence times of both flow rates were significantly higher than the theoretical residence time, indicating very strong external recirculation inside the AnMBBR. The results suggest a 3-pass flow pattern through the AnMBBR. From 16S rRNA gene amplicon sequencing (MiSeq, Illumina) and scanning electron microscopy (SEM) analysis, Methanosaeta, acetoclastic methanogens, were the predominant microorganisms in the system. Most of the microorganisms were located within a 1.994 ± 0.266 mm depth from the PVA gel surface, with two distinct layers.
{"title":"A pilot-scale anaerobic moving-bed biofilm reactor with PVA gel beads as media for the treatment of fish canning industry wastewater","authors":"Akarawin Jirasaranporn, Krittayapong Jantharadej, K. Wongwailikhit, C. Chawengkijwanich, Jenyuk Lohwatcharin, B. Suwannasilp","doi":"10.2166/wrd.2022.090","DOIUrl":"https://doi.org/10.2166/wrd.2022.090","url":null,"abstract":"\u0000 This research aims to investigate the performance of a pilot-scale anaerobic moving-bed biofilm reactor (AnMBBR) using PVA gels as media for the treatment of real wastewater from a fish canning factory. The chemical oxygen demand (COD) removal efficiencies at different organic loading rates (OLRs) were investigated at 3.0, 4.3, 6.5, and 8.7 kg COD/m3day by adjusting the flow rates to 350, 500, 750 and 1,000 L/d, respectively. The soluble COD removal efficiencies of the system at flow rates of 350, 500, 750, and 1,000 L/d were 81.0 ± 12.4%, 76.8 ± 8.2%, 74.7 ± 6.2%, and 70.6 ± 12.4%, respectively. According to the residence time distribution (RTD) tests at the highest and lowest flow rates, the mean residence times of both flow rates were significantly higher than the theoretical residence time, indicating very strong external recirculation inside the AnMBBR. The results suggest a 3-pass flow pattern through the AnMBBR. From 16S rRNA gene amplicon sequencing (MiSeq, Illumina) and scanning electron microscopy (SEM) analysis, Methanosaeta, acetoclastic methanogens, were the predominant microorganisms in the system. Most of the microorganisms were located within a 1.994 ± 0.266 mm depth from the PVA gel surface, with two distinct layers.","PeriodicalId":17556,"journal":{"name":"Journal of Water Reuse and Desalination","volume":" ","pages":""},"PeriodicalIF":2.3,"publicationDate":"2022-04-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47683425","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}
X. Zhen, Miao Luo, Haiying Dong, L. Fang, Weiwei Wang, Lei Feng, Qin Yu
The semi-continuous digestion experiment of food waste was carried out based on a solar-assisted heat anaerobic digestion reactor. The effects of organic load regulation (OLR of 2.0, 4.0, 6.0 and 7.0 kg m−3 d−1 VS (volatile solid)) on methane production, physical and chemical parameters, and microbial community structure were studied. The results showed that 6.0 kg m−3 d−1 VS could achieve the optimal methane production as the anaerobic digestion limit OLR of kitchen waste. At this stage, the accumulation of organic acids in the reactor led to a great fluctuation of pH. Artificial alkali regulation could restore the stable operation of the reactor, but the reactor could not withstand the OLR shock of 7.0 kg m−3 d−1 VS. In addition, Qualcomm sequencing results showed that microorganisms showed high functional concentration and poor community richness under low OLR, and increasing OLR could promote microbial richness. At the same time, the Methanosaeta of acetic acid methanogens was relatively abundant in the low OLR stage, while the hydrogen trophic methanogenic bacteria Methanoregula and Methanospirillum showed high activity in the high OLR stage, but the excessive reproduction of acidogenic bacteria in the digestive system would affect the stability of the archaea community when the OLR was too high.
在太阳能辅助加热厌氧消化反应器上进行了餐厨废弃物的半连续消化实验。研究了有机负荷调节（OLR为2.0、4.0、6.0和7.0 kg m−3 d−1 VS（挥发性固体））对甲烷产量、物理化学参数和微生物群落结构的影响。结果表明，6.0 kg m−3 d−1 VS可达到餐厨垃圾厌氧消化极限OLR的最佳甲烷产量。在此阶段，有机酸在反应器中的积累导致pH值的大幅波动。人工碱调节可以恢复反应器的稳定运行，但反应器无法承受7.0 kg m−3 d−1 VS的OLR冲击。此外，高通测序结果表明，在低OLR条件下，微生物表现出较高的功能浓度和较差的群落丰富度，增加OLR可以促进微生物丰富度。同时，乙酸产甲烷菌的甲烷菌在低OLR阶段相对丰富，而氢营养产甲烷菌Methanogula和Methanospirillum在高OLR阶段表现出较高的活性，但当OLR过高时，产酸菌在消化系统中的过度繁殖会影响古菌群落的稳定。
{"title":"Effect of organic load regulation on anaerobic digestion performance and microbial community of solar-assisted system of food waste","authors":"X. Zhen, Miao Luo, Haiying Dong, L. Fang, Weiwei Wang, Lei Feng, Qin Yu","doi":"10.2166/wrd.2022.107","DOIUrl":"https://doi.org/10.2166/wrd.2022.107","url":null,"abstract":"\u0000 The semi-continuous digestion experiment of food waste was carried out based on a solar-assisted heat anaerobic digestion reactor. The effects of organic load regulation (OLR of 2.0, 4.0, 6.0 and 7.0 kg m−3 d−1 VS (volatile solid)) on methane production, physical and chemical parameters, and microbial community structure were studied. The results showed that 6.0 kg m−3 d−1 VS could achieve the optimal methane production as the anaerobic digestion limit OLR of kitchen waste. At this stage, the accumulation of organic acids in the reactor led to a great fluctuation of pH. Artificial alkali regulation could restore the stable operation of the reactor, but the reactor could not withstand the OLR shock of 7.0 kg m−3 d−1 VS. In addition, Qualcomm sequencing results showed that microorganisms showed high functional concentration and poor community richness under low OLR, and increasing OLR could promote microbial richness. At the same time, the Methanosaeta of acetic acid methanogens was relatively abundant in the low OLR stage, while the hydrogen trophic methanogenic bacteria Methanoregula and Methanospirillum showed high activity in the high OLR stage, but the excessive reproduction of acidogenic bacteria in the digestive system would affect the stability of the archaea community when the OLR was too high.","PeriodicalId":17556,"journal":{"name":"Journal of Water Reuse and Desalination","volume":" ","pages":""},"PeriodicalIF":2.3,"publicationDate":"2022-03-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48117866","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}
T. Adane, Sintayehu Mekuria Hailegiorgis, E. Alemayehu
The present research work investigated the removal efficiency of acid-activated bentonite blended with a sugarcane bagasse ash (SCBA) adsorbent for the removal of reactive red 198 (RR198) from a synthetic dye solution. The effect of the adsorption parameters of bentonite on SCBA blending ratio, dye solution pH, adsorption contact, adsorbent dosage, and initial dye concentration was investigated, and the parameters were optimized for maximum RR198 removal from the synthetic dye solution. At an optimum condition of 1:1 bentonite to the SCBA blending ratio, a solution pH of 2, 3.7 g/L of adsorbent dosage, and 15 mg/L of initial dye concentration 150 min of adsorption time, the properties of adsorbents such as adsorbent specific surface area, crystalline phase structure, functional groups, and surface morphologies of the adsorbents were investigated. At optimum conditions, 97% RR198 removal efficiency of the adsorbent was achieved. In order to determine adsorption kinetics and isotherm models, different adsorption models were employed. It was observed that the adsorption of the RR198 dye into the acid-activated bentonite blended with the SCBA adsorbent was represented well by the Langmuir isotherm model and the adsorption kinetics order was found to be the pseudo-second order.
{"title":"Acid-activated bentonite blended with sugarcane bagasse ash as low-cost adsorbents for removal of reactive red 198 dyes","authors":"T. Adane, Sintayehu Mekuria Hailegiorgis, E. Alemayehu","doi":"10.2166/wrd.2022.056","DOIUrl":"https://doi.org/10.2166/wrd.2022.056","url":null,"abstract":"\u0000 The present research work investigated the removal efficiency of acid-activated bentonite blended with a sugarcane bagasse ash (SCBA) adsorbent for the removal of reactive red 198 (RR198) from a synthetic dye solution. The effect of the adsorption parameters of bentonite on SCBA blending ratio, dye solution pH, adsorption contact, adsorbent dosage, and initial dye concentration was investigated, and the parameters were optimized for maximum RR198 removal from the synthetic dye solution. At an optimum condition of 1:1 bentonite to the SCBA blending ratio, a solution pH of 2, 3.7 g/L of adsorbent dosage, and 15 mg/L of initial dye concentration 150 min of adsorption time, the properties of adsorbents such as adsorbent specific surface area, crystalline phase structure, functional groups, and surface morphologies of the adsorbents were investigated. At optimum conditions, 97% RR198 removal efficiency of the adsorbent was achieved. In order to determine adsorption kinetics and isotherm models, different adsorption models were employed. It was observed that the adsorption of the RR198 dye into the acid-activated bentonite blended with the SCBA adsorbent was represented well by the Langmuir isotherm model and the adsorption kinetics order was found to be the pseudo-second order.","PeriodicalId":17556,"journal":{"name":"Journal of Water Reuse and Desalination","volume":" ","pages":""},"PeriodicalIF":2.3,"publicationDate":"2022-03-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43662471","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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