Water Science and Technology最新文献

Industrial symbiosis approach was established between an industrial company and a water utility to prioritize the reuse of urban wastewater for industrial purposes. This requires low-salinity water, but this area is frequently affected by saline intrusion, thus creating water-related conflicts between the different economic activities. This study proposes a digital solution that combines dynamic simulation model (that predicts seawater intrusion and runoff) with digital tools, i.e., smart equalization (control algorithm) and matchmaking platform (decision support system). The models aim to predict the periods where significant peaks of salinity occurs, whereas the tools aim to distribute the wastewater and reclaimed water streams to diverse applications (industrial, agricultural) and/or treatments (conventional treatment, reverse osmosis) to maximize the amount of wastewater reused in efficient and sustainable way. During the 2D simulated period, wastewater conductivity was in range of 2100-2700 µS·cm^-1. Although this conductivity was over the limit required for industrial reuse, the digital solution implemented in this study enabled to recover 71% of the total wastewater produced for industrial purposes and 10% for irrigation, only discharging 19% of the total. The approach implemented in this study would be very useful to be replicated in coastal areas where saline intrusion is relevant.

Electrochemical pretreatment and anaerobic digestion (AD), as well as a combination of both processes, were studied for the treatment of waste-activated sludge (WAS) to evaluate microbial inactivation, for faecal coliforms, Salmonella spp., bacteriophages, and helminth eggs. Electrooxidation (EO) of WAS was performed in a commercial cell with boron-doped diamond electrodes. 1 L of WAS (3% total solids) was fed to the electrochemical cell in recirculation mode. The conditions tested were 19.3 mA/cm², 30 min, and 3.8 L/min. For AD tests, raw and pretreated WAS were digested in an OxiTop^® OC 110 apparatus for 15 days. Inactivation of faecal coliforms, Salmonella spp., and bacteriophages reached more than 5 logs when EO was combined with AD. In contrast, EO alone did not inactivate these parameters, while AD achieved eliminations around 3 logs. Moreover, the combined process inactivated 91% of the initial viable helminth eggs, considerably higher than AD (29%) and EO (0%). The results suggest that EO separates extracellular polymeric substances and segregates particles, including microorganisms, that are exposed to environmental factors (e.g., volatile fatty acids or ammonia) during AD, showing a synergistic effect.

This study aims to address a common issue in current research: the neglect of the calibrating model parameters when estimating evapotranspiration (ET) from green roofs (GRs) using the Priestley-Taylor model, with most studies limited to a single substrate depth (SD). To overcome this limitation, this research improves the accuracy of ET estimation for different SDs on GRs by calibrating the Priestley-Taylor coefficient α. The study period was 692 days in total, from 25 April 2021 to 26 April 2023. Daily ET data from the outdoor GR experimental group were used to calibrate and validate the model. Uncalibrated models perform well for medium SDs (150 mm) but decline for deeper (300 mm) or shallower (50 mm) ones. NSGA-II optimization significantly improved model performance across all SDs, notably at 300 mm. The research underscores the importance of parameter calibration for water management in GRs and sets a foundation for future research on optimizing water retention and regulation functions in GRs.

This work addresses the role of accurate input data in hydrological model simulations and explores the often-overlooked errors associated with evapotranspiration (ET). While existing literature primarily focuses on uncertainties in rainfall, this study underscores the necessity of considering errors in ET, as evidenced by some studies suggesting their substantial impact on hydrological model responses. A comprehensive exploration of uncertainty quantification resulting from errors in ET in hydrological model simulations is presented, highlighting the imperative to scrutinize this facet amidst diverse uncertainties. There are two approaches for addressing uncertainty in potential evapotranspiration (PET) inputs as discussed: directly considering uncertainty in PET data series or accounting for uncertainty in the parameters used for PET estimation. Furthermore, details are provided about the existing error models for PET measurements, revealing a limited number of studies that specifically account for ET-related uncertainties. Researchers commonly address ET errors by considering both systematic and random errors; some studies suggest that systematic errors in PET have a more substantial impact compared to random errors on hydrological model responses. In summary, the objective of this paper is to offer an in-depth exploration of uncertainty associated with PET inputs and their influence on hydrological modeling.

This research aimed to investigate the influence of ferry operations and religious activities on the water quality of the Hooghly River in Kolkata, West Bengal, during 2022, while pinpointing pollution hotspots and suggesting mitigation strategies. As a crucial distributary, the Hooghly River is significantly impacted by human activities, particularly near ferry terminals and pilgrimage locations. Water samples (4 L) were taken from eight critical sites during pre- and post-monsoon periods at high tide, concentrating on important physico-chemical and biological attributes. Though pre-monsoon water quality largely adhered to BIS guidelines, heightened chemical oxygen demand and total coliform (TC) levels indicated potential pollution hotspots, likely caused by ferry movements and religious gatherings. Post-monsoon data revealed acceptable pH and temperature ranges but flagged concerns due to increased biochemical oxygen demand and TC counts, especially in high-traffic zones. The water quality index varied between 213 and 282, with a higher pre-monsoon value of 282 and a post-monsoon value of 213, primarily influenced by total dissolved solids, hardness, alkalinity, and conductivity. The comprehensive pollution index ranged from 1.30 to 1.33, surpassing the acceptable limit. These assessments reveal the impact of ferry and religious activities on the Hooghly River's water quality, stressing the need for targeted pollution control.

Life cycle assessment (LCA), coupled with process modeling to develop the life cycle inventory, is a valuable tool to assess differences in environmental performance when evaluating alternatives based on sustainability (triple-bottom-line) principles. Coupled with a whole plant process model (SUMO21), an LCA assessed the environmental performance of options to upgrade biosolids management for the Great Lakes Water Authority water resource recovery facility. All five alternatives evaluated (composting plus four anaerobic digestion alternatives) were able to meet the core objectives of the biosolids management system upgrade: (1) address ageing incinerators, (2) minimize the mass of biosolids landfilled, and (3) reduce greenhouse gas emissions, compared to the existing (baseline) system. The mass of solids to be managed was reduced for the anaerobic digestion alternatives but not for the composting alternatives. Environmental impacts were reduced for the composting alternative for all six impact categories considered (global warming, eutrophication, carcinogenics, ecotoxicity, respiratory effects, and fossil fuel depletion) relative to the baseline, and further reduced for all four anaerobic digestion alternatives evaluated. The results allowed a phased implementation plan to be developed, which could be evaluated based on other factors, such as costs and operational factors.

Dark fermentation has the potential to produce biohydrogen using raw material waste, such as wastewater from the corn industry (cornWW), which is characteristically alkaline and improperly discharged. This study aimed to assess the impact of different hydraulic retention times (HRT) on hydrogen production in a sequencing batch reactor system using raw cornWW as feedstock. Different HRTs were evaluated (4, 2, and 1 day(s)). Higher biohydrogen productivity was observed in HRT value of 1 day (893.6 ± 10.1 NmL H₂/L_reactor/day), indicating its favorable metabolic pathways leading to the generation of hydrogen, carbon dioxide, acetate, butyrate, and caproate. Microbial analysis revealed that the Atopobium and Clostridium (genera) played key roles in hydrogen and organic acid production. Additionally, during the fermentation of cornWW, lactic acid in the feedstock facilitated the production of caproic and propionic acids, further enriching the range of valuable byproducts obtained through this process.

Ultrafiltration membranes are widely used in the treatment of surface water. However, membrane fouling is a core issue that needs to be addressed in its application. Magnetotactic bacteria (MTB) show early film-forming and magnetotactic behaviour in the presence of external magnetic fields. The objective of this study was to alleviate membrane fouling in ultrafiltration membranes using MTB, which can prioritise film formation and show directional movement under external magnetic fields. The concentration of Cr⁶⁺ in the water was 10 mg/L, and the dosage of MTB was 10 mg/L. Results show that the transmembrane pressure of the ultrafiltration membrane decreased by 5 kPa following the application of a magnetic field of 33.71 mT for a period of 90 min, and the membrane fouling could therefore be effectively controlled. With the addition of MTB, the average removal of Cr⁶⁺ from water by the ultrafiltration system was 20.10%, which was 14.56% higher than that of the conventional ultrafiltration system. The average removal of chromaticity was 20.13%, which was 10% higher than that achieved by the conventional ultrafiltration system. Furthermore, MTB progressively developed into the predominant flora during the operational phase, thereby enhancing the efficiency of the ultrafiltration system.

One of the most costly stages of activated sludge wastewater treatment plants is the treatment and dewatering of waste sludge. Chemical conditioning of sludge, as one of the most widespread methods to enhance sludge dewaterability, accounts for a significant portion of operational expenses due to the consumption of expensive polymeric compounds. This research aims to assess the cost-effectiveness of ochre soil, modified with hydrochloric acid, as an affordable mineral for conditioning waste sludge in an activated sludge system. The optimal conditions for acid modifications are obtained using response surface methodology. Then, its performance is compared with conventional coagulants (ferric chloride and alum) and in combination with cationic polyacrylamide (CPAM). To assess the conditioning process efficiency, the specific resistance to filtration (SRF) parameter was employed. At an optimal dose of modified ochre soil (MOS) equal to 300 (mg/g dry solids), the SRF value decreased from 31.96 to 2.7 Tm/kg. The combination of 100 (mg/gDS) MOS with 0.5 (mg/gDS) CPAM showed as the most cost-effective among the coagulants tested, with a 31% greater SRF reduction compared to CPAM used alone. This study shows the practical efficacy of an eco-friendly natural mineral as a polymer alternative, with the potential for sludge dewatering.