Pub Date : 2024-07-26DOI: 10.1021/acsestwater.4c00407
Kate Meyers, Megan Martin, Lee R. Kump, Miquela Ingalls
Wastewater-derived phosphate contributes to eutrophication if the phosphate is not efficiently removed before it is discharged to surface waters. In the Florida Keys (USA), shallow injection of treated wastewater into saline limestone aquifers is a common mode of wastewater disposal. We assessed the possibility of efficient and permanent phosphate removal following injection at a wastewater treatment facility in Marathon, Florida. The concentrations of nutrients, dissolved ions, and anthropogenic compounds in groundwater and nearshore waters were monitored over two years, as was the progression of a patch of fluorescent dye emplaced by the wastewater injection well. The density contrast between the wastewater effluent and saline groundwater caused the effluent plume to buoy to the shallow subsurface near the injection well. Soluble reactive phosphorus (SRP) and sucralose were both detected in nearshore waters, indicating incomplete removal of contaminants. However, ∼75% of the SRP is removed from the plume in the first 10 days of transit by adsorption followed by a slower removal mechanism, bringing the P removal efficiency above 90%. A positive relationship between excess calcium and phosphate removal efficiency, together with high levels of calcium phosphate mineral supersaturation, supports calcite dissolution followed by calcium phosphate mineralization as this slower removal process.
{"title":"The Efficiency of Phosphate Removal via Shallow Wastewater Injection into a Saline Carbonate Aquifer","authors":"Kate Meyers, Megan Martin, Lee R. Kump, Miquela Ingalls","doi":"10.1021/acsestwater.4c00407","DOIUrl":"https://doi.org/10.1021/acsestwater.4c00407","url":null,"abstract":"Wastewater-derived phosphate contributes to eutrophication if the phosphate is not efficiently removed before it is discharged to surface waters. In the Florida Keys (USA), shallow injection of treated wastewater into saline limestone aquifers is a common mode of wastewater disposal. We assessed the possibility of efficient and permanent phosphate removal following injection at a wastewater treatment facility in Marathon, Florida. The concentrations of nutrients, dissolved ions, and anthropogenic compounds in groundwater and nearshore waters were monitored over two years, as was the progression of a patch of fluorescent dye emplaced by the wastewater injection well. The density contrast between the wastewater effluent and saline groundwater caused the effluent plume to buoy to the shallow subsurface near the injection well. Soluble reactive phosphorus (SRP) and sucralose were both detected in nearshore waters, indicating incomplete removal of contaminants. However, ∼75% of the SRP is removed from the plume in the first 10 days of transit by adsorption followed by a slower removal mechanism, bringing the P removal efficiency above 90%. A positive relationship between excess calcium and phosphate removal efficiency, together with high levels of calcium phosphate mineral supersaturation, supports calcite dissolution followed by calcium phosphate mineralization as this slower removal process.","PeriodicalId":7078,"journal":{"name":"ACS Es&t Water","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-07-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141777822","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}
Pub Date : 2024-07-26DOI: 10.1021/acsestwater.4c00259
Mohammad Hafez Ahmed, Golnoosh Khajouei, Payton Seats, Karen Buzby, Harry Finklea, Nicholas Siefert, Heather Hunter, Lian-Shin Lin
Taking advantage of the complementary chemistries of the cooling blowdown water (BDW) and produced water (PW) from shale gas production, this pilot study evaluated their co-treatment feasibility to generate useful products while reducing treatment footprints. The process includes the mixing of BDW and PW, chemical softening, activated carbon (AC) filtration, and reverse osmosis (RO). The results showed that a simple mixing of BDW and PW (BDW/PW = 5) readily removed 98% of barium and 85% of sulfate and generated a high-density (4.1 g/cm3) barite-dominant solid with a yield of 1.92 kg/m3 mixed water. Softening using sodium carbonate and sodium hydroxide removed >95% scale forming divalent ions, and the AC filtration resulted in ∼90% total organic carbon removal. RO treatment of the AC effluent achieved ∼60% water recovery. Compared to BDW and PW treated separately, the co-treatment process resulted in a ∼70% chemical saving. The RO concentrate had high enough TDS (77 g/L) suitable for thermal evaporation to generate commercial-grade 10-lb brine. An initial technoeconomic analysis of a co-treatment scenario using a thermoelectric powerplant in West Virginia shows cost saving potential and revenue generation. This study demonstrates the potential of the co-treatment method as a useful tool for sustainable regional water management.
{"title":"Novel Co-treatment of Cooling Blowdown Water and Produced Water: A Regional Approach for Resource Recovery and Treatment Footprint Reduction","authors":"Mohammad Hafez Ahmed, Golnoosh Khajouei, Payton Seats, Karen Buzby, Harry Finklea, Nicholas Siefert, Heather Hunter, Lian-Shin Lin","doi":"10.1021/acsestwater.4c00259","DOIUrl":"https://doi.org/10.1021/acsestwater.4c00259","url":null,"abstract":"Taking advantage of the complementary chemistries of the cooling blowdown water (BDW) and produced water (PW) from shale gas production, this pilot study evaluated their co-treatment feasibility to generate useful products while reducing treatment footprints. The process includes the mixing of BDW and PW, chemical softening, activated carbon (AC) filtration, and reverse osmosis (RO). The results showed that a simple mixing of BDW and PW (BDW/PW = 5) readily removed 98% of barium and 85% of sulfate and generated a high-density (4.1 g/cm<sup>3</sup>) barite-dominant solid with a yield of 1.92 kg/m<sup>3</sup> mixed water. Softening using sodium carbonate and sodium hydroxide removed >95% scale forming divalent ions, and the AC filtration resulted in ∼90% total organic carbon removal. RO treatment of the AC effluent achieved ∼60% water recovery. Compared to BDW and PW treated separately, the co-treatment process resulted in a ∼70% chemical saving. The RO concentrate had high enough TDS (77 g/L) suitable for thermal evaporation to generate commercial-grade 10-lb brine. An initial technoeconomic analysis of a co-treatment scenario using a thermoelectric powerplant in West Virginia shows cost saving potential and revenue generation. This study demonstrates the potential of the co-treatment method as a useful tool for sustainable regional water management.","PeriodicalId":7078,"journal":{"name":"ACS Es&t Water","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-07-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141777821","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}
Pub Date : 2024-07-26DOI: 10.1021/acsestwater.4c00537
Zifei Qin, Haichao Wang, Renjie Bian, William A. Stubbings, Fangbai Li, Fengchang Wu, Shaorui Wang
The occurrences of antioxidants (AOs) in aquatic environments, including ultraviolet absorbents (UVAs), synthetic phenolic antioxidants (SPAs), and amino antioxidants (AOAs), are receiving concerns due to potential risks to ecosystems and humans. In this study, we systematically elucidated the spatial and seasonal variation, sources, and risk assessments of 4 SPAs, 14 AOAs, and 12 UVAs in surface water in the Pearl River Delta (PRD). The total concentration of AOs (Σ30AOs) displayed significant seasonal trends, with a higher concentration observed in dry seasons. The median concentrations of Σ30AOs were 95 and 42 ng/L for the dry and wet seasons, respectively. BHT-COOH and BHT-OH, DPA and DODPA, and UV-329 were the most abundant SPAs, AOAs, and UVAs, respectively. Strong significant and positive correlations were observed between the population of local residents and concentrations of SPAs and AOAs (p < 0.001), indicating that the occurrences of SPAs and AOAs were influenced by anthropogenic activities. Source apportionment first revealed that AO contamination in the PRD mainly encompassed rubber manufacturing and plastic, resin, and polymer manufacturing, accounting for 61 and 25% of AOs in the PRD. The ecological risks were identified to be high for DODPA while the human health risks were found to have no adverse effects.
{"title":"Spatial and Seasonal Distribution, Source Apportionment, and Risk Assessment of Dissolved-Phase Ultraviolet Absorbents and Synthetic Phenolic and Amino Antioxidants in the Pearl River Delta (PRD), China","authors":"Zifei Qin, Haichao Wang, Renjie Bian, William A. Stubbings, Fangbai Li, Fengchang Wu, Shaorui Wang","doi":"10.1021/acsestwater.4c00537","DOIUrl":"https://doi.org/10.1021/acsestwater.4c00537","url":null,"abstract":"The occurrences of antioxidants (AOs) in aquatic environments, including ultraviolet absorbents (UVAs), synthetic phenolic antioxidants (SPAs), and amino antioxidants (AOAs), are receiving concerns due to potential risks to ecosystems and humans. In this study, we systematically elucidated the spatial and seasonal variation, sources, and risk assessments of 4 SPAs, 14 AOAs, and 12 UVAs in surface water in the Pearl River Delta (PRD). The total concentration of AOs (Σ<sub>30</sub>AOs) displayed significant seasonal trends, with a higher concentration observed in dry seasons. The median concentrations of Σ<sub>30</sub>AOs were 95 and 42 ng/L for the dry and wet seasons, respectively. BHT-COOH and BHT-OH, DPA and DODPA, and UV-329 were the most abundant SPAs, AOAs, and UVAs, respectively. Strong significant and positive correlations were observed between the population of local residents and concentrations of SPAs and AOAs (<i>p</i> < 0.001), indicating that the occurrences of SPAs and AOAs were influenced by anthropogenic activities. Source apportionment first revealed that AO contamination in the PRD mainly encompassed rubber manufacturing and plastic, resin, and polymer manufacturing, accounting for 61 and 25% of AOs in the PRD. The ecological risks were identified to be high for DODPA while the human health risks were found to have no adverse effects.","PeriodicalId":7078,"journal":{"name":"ACS Es&t Water","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-07-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141777826","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}
Pub Date : 2024-07-25DOI: 10.1021/acsestwater.4c00210
Daniel Garcia, Tracy Matthews
Water contamination is a critical public health issue that has been linked to various adverse health outcomes including cancer. Research has shown that prolonged exposure to certain water contaminants can increase the risk of specific cancers. This study aimed to identify correlations between water contaminants and cancer incidence in Arizona. Cancer incidence data from the Arizona Cancer Registry’s data dashboard and water contamination data from the environmental working group (EWG) were analyzed using Spearman’s correlation. The contaminants studied included chromium, radium, uranium, nitrates, nitrites, arsenic, and disinfection byproducts (DBPs). Positive correlations were found between bladder and pancreatic cancer incidence and various contaminants studied. An association was found between colorectal cancer risk and exposure to radium and uranium in drinking water. Additionally, a statistically significant link was found between DBPs and leukemia. The findings suggest potential health risks associated with water contamination and emphasize the importance of monitoring and regulating drinking water quality to prevent adverse health outcomes.
{"title":"Contaminated Drinking Water and Its Effect on Cancer","authors":"Daniel Garcia, Tracy Matthews","doi":"10.1021/acsestwater.4c00210","DOIUrl":"https://doi.org/10.1021/acsestwater.4c00210","url":null,"abstract":"Water contamination is a critical public health issue that has been linked to various adverse health outcomes including cancer. Research has shown that prolonged exposure to certain water contaminants can increase the risk of specific cancers. This study aimed to identify correlations between water contaminants and cancer incidence in Arizona. Cancer incidence data from the Arizona Cancer Registry’s data dashboard and water contamination data from the environmental working group (EWG) were analyzed using Spearman’s correlation. The contaminants studied included chromium, radium, uranium, nitrates, nitrites, arsenic, and disinfection byproducts (DBPs). Positive correlations were found between bladder and pancreatic cancer incidence and various contaminants studied. An association was found between colorectal cancer risk and exposure to radium and uranium in drinking water. Additionally, a statistically significant link was found between DBPs and leukemia. The findings suggest potential health risks associated with water contamination and emphasize the importance of monitoring and regulating drinking water quality to prevent adverse health outcomes.","PeriodicalId":7078,"journal":{"name":"ACS Es&t Water","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-07-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141777756","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}
Pub Date : 2024-07-23DOI: 10.1021/acsestwater.4c00162
Alexander M. Schwiebert, John A. Bush, Christopher Bellona, Johan Vanneste, Tzahi Y. Cath
Haber-Bosch process allows for the production of modern fertilizers and is crucial for meeting increasing demands for agricultural production. The process requires large amounts of natural gas and contributes to global warming. An alternative to the Haber-Bosch process utilizes membrane contactors to recover nitrogen from the anaerobic digester centrate. In previous studies, high recoveries have been achieved, but membrane fouling decreased the performance and required maintenance to clean the membranes. This study investigated the effect of a settling and ultrafiltration system to pretreat centrate from an anaerobic digester to prevent fouling of the membrane contactor system. The system achieved high recoveries of over 90% for 10 cycles without any performance decline. Tests with increasing distillate concentrations of ammonium sulfate up to 165,000 mg/L-N could not identify a significant decline in membrane performance either. This allows for concentration up to crystallization in a single stage.
{"title":"Membrane Contactors for Ammonia Recovery from Anaerobic Digester Centrate: Pretreatment and Process Optimization","authors":"Alexander M. Schwiebert, John A. Bush, Christopher Bellona, Johan Vanneste, Tzahi Y. Cath","doi":"10.1021/acsestwater.4c00162","DOIUrl":"https://doi.org/10.1021/acsestwater.4c00162","url":null,"abstract":"Haber-Bosch process allows for the production of modern fertilizers and is crucial for meeting increasing demands for agricultural production. The process requires large amounts of natural gas and contributes to global warming. An alternative to the Haber-Bosch process utilizes membrane contactors to recover nitrogen from the anaerobic digester centrate. In previous studies, high recoveries have been achieved, but membrane fouling decreased the performance and required maintenance to clean the membranes. This study investigated the effect of a settling and ultrafiltration system to pretreat centrate from an anaerobic digester to prevent fouling of the membrane contactor system. The system achieved high recoveries of over 90% for 10 cycles without any performance decline. Tests with increasing distillate concentrations of ammonium sulfate up to 165,000 mg/L-N could not identify a significant decline in membrane performance either. This allows for concentration up to crystallization in a single stage.","PeriodicalId":7078,"journal":{"name":"ACS Es&t Water","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-07-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141777823","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}
Pub Date : 2024-07-22DOI: 10.1021/acsestwater.4c00226
Ahmed AlSayed, Moomen Soliman, Salma Hendy, Ahmed ElDyasti
This study explores the use of the alternating activated adsorption (AAA) system to achieve a balance between sustaining high COD redirection toward recovery streams and high effluent quality, in terms of COD and phosphorus removal. It investigates a novel integrative operational approach that includes hydraulic retention time (HRT), solid retention time (SRT), dissolved oxygen (DO) concentration, and effluent recirculation. Results indicated that integrating long HRT (4 h) with limited DO concentration (below 0.5 mgO2/L) effectively controlled COD oxidation while allowing for high COD redirection. Effluent recirculation further improved solid capture and COD redirection, while short SRT limited the associated oxidation through hydrolysis. Notably, this resulted in achieving COD redirection and removal above 50 and 80%, respectively. Meanwhile, such conditions achieved biophosphorus removal efficiencies as high as 55–60%, which surpasses other A-stage systems. To achieve higher phosphorus removal, enhanced biological phosphorus removal (EBPR) should be induced under conditions that slightly diminish the COD redirection and, to a lesser extent, the COD removal efficiency. Significantly, this research suggests a novel approach to designing and operating the A-stage process, particularly AAA, acknowledging its holistic role in fostering sustainable and energy-efficient wastewater treatment.
{"title":"Going Beyond Carbon Redirection: Integrating Operational Conditions to Maximize Carbon and Phosphorus Removal in the A-Stage Process","authors":"Ahmed AlSayed, Moomen Soliman, Salma Hendy, Ahmed ElDyasti","doi":"10.1021/acsestwater.4c00226","DOIUrl":"https://doi.org/10.1021/acsestwater.4c00226","url":null,"abstract":"This study explores the use of the alternating activated adsorption (AAA) system to achieve a balance between sustaining high COD redirection toward recovery streams and high effluent quality, in terms of COD and phosphorus removal. It investigates a novel integrative operational approach that includes hydraulic retention time (HRT), solid retention time (SRT), dissolved oxygen (DO) concentration, and effluent recirculation. Results indicated that integrating long HRT (4 h) with limited DO concentration (below 0.5 mgO<sub>2</sub>/L) effectively controlled COD oxidation while allowing for high COD redirection. Effluent recirculation further improved solid capture and COD redirection, while short SRT limited the associated oxidation through hydrolysis. Notably, this resulted in achieving COD redirection and removal above 50 and 80%, respectively. Meanwhile, such conditions achieved biophosphorus removal efficiencies as high as 55–60%, which surpasses other A-stage systems. To achieve higher phosphorus removal, enhanced biological phosphorus removal (EBPR) should be induced under conditions that slightly diminish the COD redirection and, to a lesser extent, the COD removal efficiency. Significantly, this research suggests a novel approach to designing and operating the A-stage process, particularly AAA, acknowledging its holistic role in fostering sustainable and energy-efficient wastewater treatment.","PeriodicalId":7078,"journal":{"name":"ACS Es&t Water","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-07-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141777824","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}
Pub Date : 2024-07-22DOI: 10.1021/acsestwater.4c00392
Berkley N. Anderson, Gabrielle P. Black, Thomas M. Young
Recent studies have implemented a calculated additive toxicity (CAT) approach that sums measured disinfection byproduct (DBP) concentrations weighted by their respective in vitro bioassay potencies to estimate their associated risk in disinfected waters. In this study, the CAT approach was used to systematically investigate 21 regulated and unregulated DBPs measured in drinking water at the household level. Water samples from the tap were collected from over 120 randomly selected participants supplied by eight public water systems using four distinct source water types, two types of disinfection processes, and across two seasons. The purpose of this study was to compare CAT using multiple biological end points, examine household variability, identify DBPs driving toxicity, and assess if current regulated DBPs are adequate predictors of unregulated DBPs. Our results support the significance of unregulated DBPs, particularly haloacetonitriles and iodoacetic acid, as drivers of toxicity. Simple linear models between regulated versus unregulated concentrations and CAT were overall weak with 67% considered poor (r2 < 0.3). These results reveal that current regulatory monitoring approaches may not be adequately capturing true household exposure due to higher contribution of unregulated DBPs to CAT and poor predictability between regulated and unregulated DBP-mediated CAT.
{"title":"Disinfection Byproducts in Drinking Water from the Tap: Variability in Household Calculated Additive Toxicity (CAT)","authors":"Berkley N. Anderson, Gabrielle P. Black, Thomas M. Young","doi":"10.1021/acsestwater.4c00392","DOIUrl":"https://doi.org/10.1021/acsestwater.4c00392","url":null,"abstract":"Recent studies have implemented a calculated additive toxicity (CAT) approach that sums measured disinfection byproduct (DBP) concentrations weighted by their respective in vitro bioassay potencies to estimate their associated risk in disinfected waters. In this study, the CAT approach was used to systematically investigate 21 regulated and unregulated DBPs measured in drinking water at the household level. Water samples from the tap were collected from over 120 randomly selected participants supplied by eight public water systems using four distinct source water types, two types of disinfection processes, and across two seasons. The purpose of this study was to compare CAT using multiple biological end points, examine household variability, identify DBPs driving toxicity, and assess if current regulated DBPs are adequate predictors of unregulated DBPs. Our results support the significance of unregulated DBPs, particularly haloacetonitriles and iodoacetic acid, as drivers of toxicity. Simple linear models between regulated versus unregulated concentrations and CAT were overall weak with 67% considered poor (<i>r</i><sup>2</sup> < 0.3). These results reveal that current regulatory monitoring approaches may not be adequately capturing true household exposure due to higher contribution of unregulated DBPs to CAT and poor predictability between regulated and unregulated DBP-mediated CAT.","PeriodicalId":7078,"journal":{"name":"ACS Es&t Water","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-07-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141777825","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}
Pub Date : 2024-07-22DOI: 10.1021/acsestwater.4c00298
Xinyu Tang, Haizhou Liu
Agricultural drainage water has great potential as a freshwater supply via reverse osmosis (RO) membrane desalination. However, high calcium and sulfate concentrations in the drainage water lead to gypsum (CaSO4(s)) scaling during the RO process. This study investigated the effects of three antiscalants, i.e., two phosphonate-based (DTPMP and NTMP) and one polymer-based (PAA), as well as pH and natural organic matter (NOM) on alleviating gypsum scaling during RO desalination of drainage water, and illustrated the gypsum inhibition mechanism of three antiscalants. Results showed that 1 μM of DTPMP was sufficient to prevent gypsum scaling within 24 h of RO desalination, while both NTMP and PAA required 5 μM of dosage. At acidic pH 3, the permeate flux with 5 μM of DTPMP remained relatively stable, whereas the flux with NTMP and PAA decreased by 35 and 80%, respectively. Furthermore, the presence of NOM did not significantly affect the antiscalant inhibitive capacity. The gypsum inhibition mechanism of DTPMP and NTMP was primarily contributed by negative charge repulsion, with higher pH increasing the total charge of antiscalant aqueous species, thereby strengthening the repulsive forces among calcium, sulfate, and gypsum nuclei. In contrast, PAA’s gypsum inhibition mechanism involved both negative charge repulsion and crystal lattice distortion, which distorted gypsum crystals into irregular shapes and smaller sizes, preventing the formation of large-size gypsum precipitates under neutral and alkaline conditions, but deteriorating membrane scaling under acidic conditions. Ultimately, an ideal antiscalant for preventing gypsum scaling during RO desalination of agricultural drainage water would preserve higher negative charges without changing the precipitate morphology.
{"title":"Mechanisms of Alleviating Gypsum Scaling by Antiscalants during Membrane Desalination: Implications on Agricultural Drainage Water Reuse","authors":"Xinyu Tang, Haizhou Liu","doi":"10.1021/acsestwater.4c00298","DOIUrl":"https://doi.org/10.1021/acsestwater.4c00298","url":null,"abstract":"Agricultural drainage water has great potential as a freshwater supply via reverse osmosis (RO) membrane desalination. However, high calcium and sulfate concentrations in the drainage water lead to gypsum (CaSO<sub>4(s)</sub>) scaling during the RO process. This study investigated the effects of three antiscalants, i.e., two phosphonate-based (DTPMP and NTMP) and one polymer-based (PAA), as well as pH and natural organic matter (NOM) on alleviating gypsum scaling during RO desalination of drainage water, and illustrated the gypsum inhibition mechanism of three antiscalants. Results showed that 1 μM of DTPMP was sufficient to prevent gypsum scaling within 24 h of RO desalination, while both NTMP and PAA required 5 μM of dosage. At acidic pH 3, the permeate flux with 5 μM of DTPMP remained relatively stable, whereas the flux with NTMP and PAA decreased by 35 and 80%, respectively. Furthermore, the presence of NOM did not significantly affect the antiscalant inhibitive capacity. The gypsum inhibition mechanism of DTPMP and NTMP was primarily contributed by negative charge repulsion, with higher pH increasing the total charge of antiscalant aqueous species, thereby strengthening the repulsive forces among calcium, sulfate, and gypsum nuclei. In contrast, PAA’s gypsum inhibition mechanism involved both negative charge repulsion and crystal lattice distortion, which distorted gypsum crystals into irregular shapes and smaller sizes, preventing the formation of large-size gypsum precipitates under neutral and alkaline conditions, but deteriorating membrane scaling under acidic conditions. Ultimately, an ideal antiscalant for preventing gypsum scaling during RO desalination of agricultural drainage water would preserve higher negative charges without changing the precipitate morphology.","PeriodicalId":7078,"journal":{"name":"ACS Es&t Water","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-07-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141753883","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}
Pub Date : 2024-07-20DOI: 10.1021/acsestwater.4c00208
Sepideh Sadeghi, William Andrew Jackson
The occurrence, fate, and source of phosphite (HPO32–), a highly soluble, reduced phosphorus (P) compound that is often overlooked in the P biogeochemical cycle, were investigated in municipal wastewater treatment systems. Wastewater samples were collected from influent wastewater, preprimary and postprimary clarifiers, postaeration basin, postsecondary clarifier, return activated sludge (RAS), final discharge, anaerobic digester influents, and effluents. HPO32– was present in wastewater samples but varied depending on the source. Highest concentrations were measured in anaerobic digester influents and effluents (50–60 μg L–1). Based on the studies to evaluate the source of HPO32–, it appears that the decomposition of organic matter, particularly solids rich in microbial biomass (secondary solids versus primary), is responsible for the elevated concentrations observed and that elevated temperatures increase its production and may prevent its use by dissimilatory phosphite oxidizers. It also helps to explain the previous reports of dissimilatory HPO32–-oxidizing bacteria in wastewater treatment systems, particularly digesters, and suggests organic matter decay as a possible source for previously observed HPO32– concentrations in sediments. The knowledge of the occurrence and source of HPO32– may shed light on its important and hitherto unrecognized role in the global P cycle.
{"title":"Occurrence and Source of Phosphite (HPO32–) during Municipal Wastewater Treatments","authors":"Sepideh Sadeghi, William Andrew Jackson","doi":"10.1021/acsestwater.4c00208","DOIUrl":"https://doi.org/10.1021/acsestwater.4c00208","url":null,"abstract":"The occurrence, fate, and source of phosphite (HPO<sub>3</sub><sup>2–</sup>), a highly soluble, reduced phosphorus (P) compound that is often overlooked in the P biogeochemical cycle, were investigated in municipal wastewater treatment systems. Wastewater samples were collected from influent wastewater, preprimary and postprimary clarifiers, postaeration basin, postsecondary clarifier, return activated sludge (RAS), final discharge, anaerobic digester influents, and effluents. HPO<sub>3</sub><sup>2–</sup> was present in wastewater samples but varied depending on the source. Highest concentrations were measured in anaerobic digester influents and effluents (50–60 μg L<sup>–1</sup>). Based on the studies to evaluate the source of HPO<sub>3</sub><sup>2–</sup>, it appears that the decomposition of organic matter, particularly solids rich in microbial biomass (secondary solids versus primary), is responsible for the elevated concentrations observed and that elevated temperatures increase its production and may prevent its use by dissimilatory phosphite oxidizers. It also helps to explain the previous reports of dissimilatory HPO<sub>3</sub><sup>2–</sup>-oxidizing bacteria in wastewater treatment systems, particularly digesters, and suggests organic matter decay as a possible source for previously observed HPO<sub>3</sub><sup>2–</sup> concentrations in sediments. The knowledge of the occurrence and source of HPO<sub>3</sub><sup>2–</sup> may shed light on its important and hitherto unrecognized role in the global P cycle.","PeriodicalId":7078,"journal":{"name":"ACS Es&t Water","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-07-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141740348","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}
Pub Date : 2024-07-19DOI: 10.1021/acsestwater.4c00151
Yingshan Lau, Siphanh Daovongdeuan
About 80% of the Lao PDR’s land area comprises mountains, and much of its economy depends on subsistence agriculture. Due to the predominantly rainfed nature of upland farming, the climate determines agricultural practices. Climate change thus puts rainfed farmers in a precarious position, with extreme dry weather events threatening the year’s harvest. Agricultural irrigation can provide a layer of climate resilience to these farmers, especially in mountains with springwater sources. However, access to irrigation is expensive and limited to the lowlands. Referring to literature on irrigation in the highlands, we developed an Upland Irrigation Feasibility Framework. Then, drawing on ethnographic fieldwork in 2019–2020, we applied the Framework to a mountainous village in northern Laos to explore the potential and challenges of irrigating the uplands. We found that while water was available, the supply network and the end-users’ demand could be improved. Social institutions that govern the use of agricultural water are important but need to formed. Agricultural irrigation is not a necessity but is beneficial to farmers, but the risks associated with any agricultural transition need to be managed and the value of conserving water needs to be emphasized.
{"title":"Irrigating the Uplands: A Case Study Analysis to Understand the Potential and Challenges in Northern Laos","authors":"Yingshan Lau, Siphanh Daovongdeuan","doi":"10.1021/acsestwater.4c00151","DOIUrl":"https://doi.org/10.1021/acsestwater.4c00151","url":null,"abstract":"About 80% of the Lao PDR’s land area comprises mountains, and much of its economy depends on subsistence agriculture. Due to the predominantly rainfed nature of upland farming, the climate determines agricultural practices. Climate change thus puts rainfed farmers in a precarious position, with extreme dry weather events threatening the year’s harvest. Agricultural irrigation can provide a layer of climate resilience to these farmers, especially in mountains with springwater sources. However, access to irrigation is expensive and limited to the lowlands. Referring to literature on irrigation in the highlands, we developed an Upland Irrigation Feasibility Framework. Then, drawing on ethnographic fieldwork in 2019–2020, we applied the Framework to a mountainous village in northern Laos to explore the potential and challenges of irrigating the uplands. We found that while water was available, the supply network and the end-users’ demand could be improved. Social institutions that govern the use of agricultural water are important but need to formed. Agricultural irrigation is not a necessity but is beneficial to farmers, but the risks associated with any agricultural transition need to be managed and the value of conserving water needs to be emphasized.","PeriodicalId":7078,"journal":{"name":"ACS Es&t Water","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-07-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141740238","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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