Water Environment Research最新文献

{"title":"Maximizing the efficiency of single-stage partial nitrification/Anammox granule processes and balancing microbial competition using insights of a numerical model study.","authors":"Ahmed Elsayed, Taeho Lee, Younggy Kim","doi":"10.1002/wer.70059","DOIUrl":"10.1002/wer.70059","url":null,"abstract":"<p><p>Granulation is an efficient approach for the rapid growth of anaerobic ammonia oxidation (Anammox) bacteria ( <math> <semantics> <mrow><msub><mi>X</mi> <mi>ANA</mi></msub> </mrow> <annotation>$$ {X}_{ANA} $$</annotation></semantics> </math> ) to limit the growth of nitrite-oxidizing bacteria ( <math> <semantics> <mrow><msub><mi>X</mi> <mi>NOB</mi></msub> </mrow> <annotation>$$ {X}_{NOB} $$</annotation></semantics> </math> ). However, the high sensitivity of Anammox bacteria to operational conditions and the competition with other microorganisms lead to a critical challenge in maintaining sufficient <math> <semantics> <mrow><msub><mi>X</mi> <mi>ANA</mi></msub> </mrow> <annotation>$$ {X}_{ANA} $$</annotation></semantics> </math> population. In this study, a one-dimensional steady-state model was developed and calibrated to investigate the kinetic constants of <math> <semantics> <mrow><msub><mi>X</mi> <mi>ANA</mi></msub> </mrow> <annotation>$$ {X}_{ANA} $$</annotation></semantics> </math> growth and mass transport in individual granules, including the liquid film. According to the model calibration results, the range of the maximum specific growth rate constant of <math> <semantics><mrow><mspace></mspace> <msub><mi>X</mi> <mi>ANA</mi></msub> </mrow> <annotation>$$ {X}_{ANA} $$</annotation></semantics> </math> ( <math> <semantics> <mrow><msub><mi>μ</mi> <mi>ANA</mi></msub> </mrow> <annotation>$$ {mu}_{ANA} $$</annotation></semantics> </math> ) was 0.033 to 0.10 d<sup>-1</sup>. In addition the other kinetic constants of <math> <semantics> <mrow><msub><mi>X</mi> <mi>ANA</mi></msub> </mrow> <annotation>$$ {X}_{ANA} $$</annotation></semantics> </math> were 0.003 d<sup>-1</sup> for decay rate constant ( <math> <semantics> <mrow><msub><mi>b</mi> <mi>ANA</mi></msub> </mrow> <annotation>$$ {b}_{ANA} $$</annotation></semantics> </math> ), 0.10 mg-O<sub>2</sub>/L for oxygen half-saturation constant ( <math> <semantics> <mrow><msubsup><mi>K</mi> <msub><mi>O</mi> <mn>2</mn></msub> <mi>ANA</mi></msubsup> </mrow> <annotation>$$ {K}_{O_2}^{ANA} $$</annotation></semantics> </math> ), 0.07 mg-N/L for ammonia half-saturation constant ( <math> <semantics> <mrow><msubsup><mi>K</mi> <msub><mi>NH</mi> <mn>4</mn></msub> <mi>ANA</mi></msubsup> </mrow> <annotation>$$ {K}_{NH_4}^{ANA} $$</annotation></semantics> </math> ), and 0.05 mg-N/L for nitrite half-saturation constant ( <math> <semantics> <mrow><msubsup><mi>K</mi> <msub><mi>NO</mi> <mn>2</mn></msub> <mi>ANA</mi></msubsup> </mrow> <annotation>$$ {K}_{NO_2}^{ANA} $$</annotation></semantics> </math> ). The model simulation results showed that the dissolved oxygen of about 0.10 mg-O<sub>2</sub>/L was found to be optimal to maintain high <math> <semantics> <mrow><msub><mi>X</mi> <mi>ANA</mi></msub> </mrow> <annotation>$$ {X}_{ANA} $$</annotation></semantics> </math> population. In addition, minimal COD concentration is required to control heterotrophs ( <math> <semantics> <mrow><msub><mi>X</mi> <mi>H</mi></msub> </mro","PeriodicalId":23621,"journal":{"name":"Water Environment Research","volume":"97 3","pages":"e70059"},"PeriodicalIF":2.5,"publicationDate":"2025-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11928780/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143677326","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Correction to \"The application of duckweed (Lemna minor) and freshwater mussels (Anodonta cygnea) as living biofilters integrating with a filtration system to maintain water quality in juvenile trout (Oncorhynchus mykiss) rearing using the small scale RAS system\".","authors":"","doi":"10.1002/wer.70051","DOIUrl":"10.1002/wer.70051","url":null,"abstract":"","PeriodicalId":23621,"journal":{"name":"Water Environment Research","volume":"97 3","pages":"e70051"},"PeriodicalIF":2.5,"publicationDate":"2025-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143558121","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"New strategy for integration of anaerobic side-stream reactor with mainstream B-stage nitritation for short-cut nitrogen removal with granulation.","authors":"Zijun Meng, Yuan Yan, Guangyu Li, Yuang Li, Kenneth Wu, Zihao Zhang, Matthew C Reid, April Z Gu","doi":"10.1002/wer.70056","DOIUrl":"10.1002/wer.70056","url":null,"abstract":"<p><p>This study reported a successful mainstream B-stage nitritation reactor with sludge granulation that incorporated a side-stream anaerobic reactor to treat municipal wastewater A-stage effluent. With influent COD/N and COD/P ratios of 2.60 and 27.1, respectively, the system achieved a stable nitrite accumulating ratio (NAR) of 95.1% via partial nitrification with sludge granulations. Kinetic assessment,16S ribosomal RNA sequencing, and functional gene marker quantification confirmed successful nitrite-oxidizing bacteria (NOB) out-selection (<0.05% relative abundance), while none of the commonly employed approaches for NOB out-selection occurred in our study. Notably, approximately 90% of the total biomass was in the biofilm in the mainstream sequencing batch reactor (SBR), with the remaining 10% of the biomass in suspension as granules under the selective wasting strategy. The substrates and oxygen gradient along the depth of the biofilm's layered structure, alongside the anaerobic conditions in the side-stream reactor, were suggested to play roles in NOB suppression and out-selection. Overall, this study provided evidence for a possible new strategy for achieving stable mainstream B-stage nitritation, which is the prerequisite for the downstream anammox process. The novelty aspect of the systems, including the incorporation of an anaerobic sire-stream reactor, absence of the employment of any previously reported nitritation strategies, and granulation formation, provided possible new feasible routes to achieve mainstream short-cut nitrogen removal for efficient wastewater treatment. PRACTITIONER POINTS: Stable partial nitrification achieved in mainstream B-stage SBR under conditions distinct from previous reports. NOB out-selection confirmed by both activities' tests and molecular analysis. Thick biofilm and anaerobic side-stream reactor likely facilitated NOB suppression. Stable sludge granulation was maintained with selective wasting strategy.</p>","PeriodicalId":23621,"journal":{"name":"Water Environment Research","volume":"97 3","pages":"e70056"},"PeriodicalIF":2.5,"publicationDate":"2025-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143606444","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Advances in graphene-based nanomaterials for heavy metal removal from water: Mini review.","authors":"Milad Jalilian, Pooya Parvizi, Mohammad Reza Zangeneh","doi":"10.1002/wer.70062","DOIUrl":"10.1002/wer.70062","url":null,"abstract":"<p><p>The environment and public health are seriously at risk from the increasing levels of heavy metal (HM) pollution in water bodies, hence efficient remediation techniques must be developed. Unique physicochemical properties of graphene (Gn) such as its enormous surface area, chemical stability, and extraordinary adsorption capabilities have made it a promising candidate for application in various adsorption processes. Recent studies indicate the heavy metal removal capabilities of Gn-based materials such as Gn oxide (GO) and reduced GO (rGO) reach 99% efficiency rates for lead (Pb²⁺), cadmium (Cd²⁺), and mercury (Hg²⁺) through strong electrostatic bonds and metal coordination along with π-π stacking interactions. In addition, the selective nature of Gn-based adsorbents grows better through functionalization because it incorporates thiol, amine, and sulfonic acid groups. The integration of Gn-based materials with metal-organic frameworks (MOFs) combined with magnetic nanoparticles along with bio-based polymers enhances adsorption efficiency and increases stability while offering recyclability features. The conclusion of this study discusses the current obstacles such as cost, scalability, environmental impact, and selectivity and potential future developments for the widespread use of Gn-based adsorbents in water treatment, highlighting the significance of continued research to improve these substances for useful environmental applications. PRACTITIONER POINTS: Graphene-based materials exhibit high capacity for adsorbing various heavy metals, enhancing water purification. Functionalization of graphene improves its ability to selectively target and remove specific heavy metals like mercury and lead. Graphene derivatives can achieve heavy metal removal within minutes, making them efficient for water treatment. Despite high synthesis costs, graphene's superior performance may lower long-term operational costs in wastewater treatment.</p>","PeriodicalId":23621,"journal":{"name":"Water Environment Research","volume":"97 3","pages":"e70062"},"PeriodicalIF":2.5,"publicationDate":"2025-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143693588","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Comprehensive analysis of heavy metal contamination in the Mandakini (Payaswini) river: Multivariate and index-based perspectives.","authors":"Sameer Arora, Tukaram Khandade, Laxmi Narayan Gupta, Prasenjit Saha","doi":"10.1002/wer.70060","DOIUrl":"10.1002/wer.70060","url":null,"abstract":"<p><p>Contamination of drinking water sources with heavy metals poses a significant threat to humanity due to their complex behavior, high toxicity, and ability to infiltrate and accumulate in groundwater. Heavy metals in water samples can lead to various chronic and irreversible health issues. This study was performed to identify the concentration of heavy metals in the Mandakini (Payaswini) River in Madhya Pradesh, India, and to evaluate their potential health effects on the local population. A comprehensive analysis was conducted using the Heavy Metal Pollution Index (HPI), modified Heavy Metal Pollution Index (m-HPI), and chemometric methods, including Principal Component Analysis (PCA) and cluster analysis (CA) to assess contamination levels, identify critical pollutant affecting the water quality, and examine similarities in sampling locations, respectively. Water samples were collected and analyzed for 13 heavy metals at nine rivers and two drain locations. The HPI and m-HPI indices quantitatively assessed water quality, revealing significant heavy metal contamination, especially in downstream regions affected by human activity. Cluster analysis was applied to characterize the highly correlated heavy metals, and PCA was employed to ascertain the primary factors contributing to water contamination. Analysis suggested a high iron (Fe) and manganese (Mn) concentration in both seasons for river and drain samples primarily from untreated domestic wastewater, petroleum waste through petrol pump, and agricultural waste, which may induce significant health hazards, particularly to vulnerable groups. PRACTITIONER POINTS: The spatial and temporal variation in concentration of heavy metals was determined using violin plots and GIS. The cluster analysis suggested identically behaving heavy metals in terms of seasonal variation. The principal component analysis suggests the critical variables and significance of variables affecting water quality. The impact of the consumption of water has been derived on human health.</p>","PeriodicalId":23621,"journal":{"name":"Water Environment Research","volume":"97 3","pages":"e70060"},"PeriodicalIF":2.5,"publicationDate":"2025-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143693590","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Assessment of surface water quality parameters using multivariate analysis-A case study of Kurichi and big lakes in Coimbatore.","authors":"Venkatraman Yogeshwaran, Arunkumar Priya","doi":"10.1002/wer.70055","DOIUrl":"10.1002/wer.70055","url":null,"abstract":"<p><p>Water quality deterioration due to industrialization and urbanization is a growing environmental concern, particularly in developing regions. This study assesses the surface water quality of Kurichi and Big Lakes in the Ukkadam area, Coimbatore, India, using multivariate statistical techniques to identify key pollution sources and evaluate contamination levels. Despite prior research on water quality in urban lakes, limited studies have systematically analyzed multiple contaminants using advanced statistical approaches. A total of 12 water samples were collected between June 2023-June 2024 and analyzed for physicochemical, microbiological, and anionic parameters. Principal Component Analysis (PCA) and Factor Analysis (FA) revealed three dominant components explaining 68.42% and 42.81% of the total variance in Kurichi and Big Lakes, respectively. The Piper plot classified water types, while Cluster Analysis (CA) grouped sampling sites based on contamination levels. The Pearson correlation matrix determined pollutant interdependencies, and the Water Quality Index (WQI) categorized pollution severity against WHO and BIS standards. The results indicate that organic matter, industrial discharge, fertilizer runoff, and untreated wastewater are the primary contributors to water pollution. High pollution levels were detected near industrial zones, with Kurichi Lake exhibiting significantly poorer water quality than Big Lake. The findings highlight the urgent need for improved wastewater management and pollution control policies to safeguard aquatic ecosystems and public health. PRACTITIONER POINTS: Multivariate Statistical Analysis: Applied PCA, FA, Piper plot, CA, and Pearson correlation matrix to assess water quality. Water Quality Index (WQI) Classification: Identified pollution sources and categorized water quality based on WHO and BIS standards. Principal Component Analysis (PCA) Findings: Three major components explained 68.42% and 42.81% of the total variation in Kurichi and Big Lakes, respectively. Major Pollution Sources: Factor analysis identified organic compounds, human activity, fertilizers, chemical waste, and wastewater discharge as primary contaminants. Industrial Area Impact: CA and WQI results highlighted high pollution sensitivity near industrial zones.</p>","PeriodicalId":23621,"journal":{"name":"Water Environment Research","volume":"97 3","pages":"e70055"},"PeriodicalIF":2.5,"publicationDate":"2025-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143626000","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Enhancement of aerobic denitrification process on antibiotics removal: Mechanism and efficiency: A review.","authors":"Progress Mupindu, Yang-Guo Zhao, Chao Pan, Yanan Zhang, Jiannan Liu","doi":"10.1002/wer.70050","DOIUrl":"10.1002/wer.70050","url":null,"abstract":"<p><p>Traditionally, the removal of nitrogenous pollutants from wastewater relied on conventional anaerobic denitrification as well as aerobic nitrification and anoxic denitrification. However, anaerobic denitrification is complicated since it requires stringent environmental conditions as well as a large land, therefore, denitrification and nitrification were performed in two separate reactors. Although high pollutant removal efficiency has been achieved via aerobic nitrification and anoxic denitrification, the demerits of this approach include high operational costs. Other traditional nitrogen removal methods include air stripping, reverse osmosis, adsorption, ion exchange, chemical precipitation, advanced oxidation process, and breakpoint chlorination. Traditional nitrogen removal methods are not only complicated but they are also uneconomical due to the high operational costs. Researchers have discovered that denitrification can be carried out by heterotrophic nitrification-aerobic denitrification (HNAD) microorganisms which remove nitrogen in a single aerobic reactor that does not require stringent operating conditions. Despite the significant effort that researchers have put in, there is still little information known about the mechanisms of antibiotic removal during HNAD. This review begins with an update on the current state of knowledge on the removal of nitrogenous pollutants and antibiotics from wastewater by HNAD. The mechanisms of antibiotic removal via HNAD were examined in detail. Followed by, the enhancement of antibiotics removal via co-metabolism and oxidation of sulfamethoxazole (SMX) as well as the response of microbial communities to antibiotic toxicity. Lastly, the conditions favorable for antibiotic biodegradation and mechanisms for nitrogen removal via HNAD were examined. The findings in this review show that co-metabolism and oxidation of SMX were the main antibiotic biodegradation mechanisms, pathways for antibiotic removal by co-metabolism and oxidation of SMX were also proposed in the discussion. This research indicated the potential of aerobic denitrification in the removal of antibiotics from wastewater. Understanding the mechanisms and pathways of antibiotic removal by HNAD helps wastewater engineers and researchers apply the technology more efficiently. PRACTITIONER POINTS: The mechanisms of antibiotic removal via HNAD were examined in detail. Co-metabolism and oxidation of SMX were the main antibiotic biodegradation mechanisms. Pathways for antibiotic removal by co-metabolism and oxidation of SMX were also proposed. Conditions favorable for antibiotic biodegradation were examined. This research indicated the potential of aerobic denitrification in the removal of antibiotics from wastewater.</p>","PeriodicalId":23621,"journal":{"name":"Water Environment Research","volume":"97 3","pages":"e70050"},"PeriodicalIF":2.5,"publicationDate":"2025-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143597793","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Evaluation of biofilm scouring methods on the nitrification efficiency in a pilot-scale membrane-aerated biofilm reactor.","authors":"Priyanka Ali, Matt Reeve, Russell Carlson-Stadler, Jeseth Delgado Vela, Lu Liu, Dylan Christenson, Andrew Shaw, Lauren B Stadler","doi":"10.1002/wer.70044","DOIUrl":"10.1002/wer.70044","url":null,"abstract":"<p><p>Membrane-aerated biofilm reactors (MABRs) are being increasingly being implemented at full-scale for domestic wastewater treatment and effective biofilm control is critical to their performance. This study investigated the impact of three biofilm scouring strategies on nitrogen removal performance of a pilot-scale MABR operated in Houston, TX: (1) regular air scouring, (2) high intensity air scouring, and (3) high liquid flow scouring. Normal and high intensity air scouring regimes and a high liquid flow scour (10× baseline flow) were each tested sequentially. High NH₄ ⁺-N removal efficiency of 52% in flow-through mode was observed post-high liquid flow scouring, which was comparable to the performance during the intense scouring regime. The absolute abundance of amoA gene for ammonia oxidizing bacteria (AOB) increased significantly by over 200%, between pre- and post-high liquid flow scouring. The energy consumption was 43% lower for the combination of high liquid flow scouring with regular air scouring as compared to the intense air scouring. This study showed that high liquid flows may be utilized as an energy-efficient biofilm control strategy in nitrifying MABR systems. PRACTITIONER POINTS: Pilot-scale MABR reactors were operated with different scouring settings: regular aeration, intense aeration, and high liquid flow. High liquid flow scouring improved nitrification efficiency, comparable to intense scouring. High liquid flow scouring selected for nitrifiers as seen by an increase in AOB quantified as amoA gene abundance. Using high liquid flow with regular aeration scouring reduces electrical energy consumption by 43% as compared to intense aeration scouring. High liquid flows may be used as an energy-efficient biofilm control strategy to improve nitrification performance in MABR systems.</p>","PeriodicalId":23621,"journal":{"name":"Water Environment Research","volume":"97 3","pages":"e70044"},"PeriodicalIF":2.5,"publicationDate":"2025-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143524723","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Removal of polystyrene microplastics from wastewater by Ti-Al electrode electrocoagulation under pulse current: Efficiency and mechanism.","authors":"Bin Zheng, Haixia Wu, Min Zhang, Shaohua Lin","doi":"10.1002/wer.70057","DOIUrl":"10.1002/wer.70057","url":null,"abstract":"<p><p>As microplastic pollution in aquatic ecosystems continues to rise, research on wastewater treatment methods designed to address microplastics has gained significant attention. To reduce the power consumption of electrocoagulation, this study presents an approach using Ti-Al electrode under pulsed current conditions to address polystyrene (PS) microplastic contamination in wastewater. After selecting the appropriate electrode materials and shapes, we conducted a comprehensive investigation into the effects of various operational parameters-such as initial solution pH, electrolyte concentration, current density, pulse frequency, and pulse duty cycle-on PS removal efficiency. Under optimal conditions (electrode spacing of 1 cm, current density of 4 A·m^-2, pulse duty cycle of 40%, pulse frequency of 500 Hz, initial solution pH of 7, and electrolyte concentration of 0.05 mol·L^-1), the removal efficiency of PS reached 93.24%, with a power consumption of 0.00977 kWh·mg^-1. Analysis of the resulting flocs revealed that free radicals generated during the electrocoagulation process disrupted the microplastic surfaces and facilitated the formation of Ti and Al flocs, which ultimately removed the microplastics through a combination of adsorption, electro-neutralization, and capture mechanisms. This study demonstrates the effectiveness of Ti electrode electrocoagulation for treating microplastic-laden wastewater and provides valuable insights for advancing microplastic treatment technologies. PRACTITIONER POINTS: Using pulse current electrocoagulation to remove polystyrene microplastics from wastewater. Titanium electrodes outperforms traditional electrodes ()in terms of efficiency and energy consumption. The mechanism for removing polystyrene microplastics using titanium electrodes in pulse current electrocoagulation was proposed. Titanium electrode electrocoagulation is effective in removing microplastics from wastewater and provides a reference for actual wastewater treatment.</p>","PeriodicalId":23621,"journal":{"name":"Water Environment Research","volume":"97 3","pages":"e70057"},"PeriodicalIF":2.5,"publicationDate":"2025-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143650692","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Better left unsettled: Suspended air flotation for footprint-optimized management of thin primary and blended solids.","authors":"Fabrizio Sabba, Jon Liberzon, Eric Redmond, Gregory Knight, Jeff Knollenberg, Leon Downing","doi":"10.1002/wer.70043","DOIUrl":"10.1002/wer.70043","url":null,"abstract":"<p><p>The progress in reducing process footprints for primary treatment or sludge thickening has been limited compared to efforts in intensifying secondary treatment. The current focus on primary treatment is on improving settling rates or using advanced primary filters, which have reduced the footprint for solids separation but produce thinner and more variable sludges. Sludge thickening processes, particularly for primary sludge (PS), have received relatively little attention regarding footprint minimization but play a large role in the ability to intensify primary treatment. To minimize process footprints and maximize performance, the present study examined, for the first time, the suitability of a suspended air flotation (SAF) technology for both thin PS and a blend of PS and waste-activated sludge (WAS). A 4-week pilot test was conducted using a trailer-mounted pilot-scale SAF system fed with either thin PS, or a blend of PS and WAS. Solids capture performance was monitored, along with solids (solids loading rate [SLR]) and hydraulic loading rates (HLR), froth, surfactant, and polymer dosage. The pilot validated the SAF technology for thickening of both primary and blended sludges at significantly higher loading rates (and subsequently smaller footprints) than competing thickening technologies. The study also demonstrated that SAF of thin PS can maintain a >90% solids capture rate at roughly twice the SLR (186 kg m^-2 h^-1) and HLR (690 m³ m^-2 day^-1) of blended sludge (90 kg m^-2 h^-1 and 293 m³ m^-2 day^-1, respectively), validating the design values for a pending SAF installation. Results were also used to establish recommended polymer and froth dosing rates for the full-scale installation. Overall, this study demonstrates that SAF represents a viable, footprint-efficient solution for footprint-optimized management of thin primary and blended solids. Further testing of SAF with real primary filter backwash is recommended to accelerate the adoption of primary filtration for more intensified, carbon-efficient, and resilient wastewater treatment. PRACTITIONER POINTS: Pilot study confirms SAF tech effectively thickens primary and blended sludge, with more consistent performance for primary sludge processing. Primary sludge can be processed at 2× higher hydraulic and solids loading rates than blended sludge with over 90% solids capture performance. The study validates proposed SAF design values and demonstrates the importance of maintaining adequate froth and polymer dosage. SAF is an alternative footprint-efficient solution for thickening high-volume waste flows such as backwash from advanced primary treatment processes. Testing and optimizing SAF with primary and blended sludges could inform thickener selection and design at other wastewater treatment plants.</p>","PeriodicalId":23621,"journal":{"name":"Water Environment Research","volume":"97 3","pages":"e70043"},"PeriodicalIF":2.5,"publicationDate":"2025-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143558118","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}