Water Science and Technology最新文献

This study investigates the sustainable management and utilization of water resources in the fruit processing industry, focusing on a case study from the EU-funded ULTIMATE project. Conducted in a juice factory in Nafplio, Greece, the primary objective is to explore the recovery of polyphenols from water by-product streams generated during orange juice production. The research aims to evaluate the effectiveness of a mobile wastewater treatment unit in selectively adsorbing polyphenols onto a polymeric resin. The following three extraction methods are compared: conventional solvent extraction, subcritical water extraction (SWE), and supercritical CO₂ extraction (SFE). To determine the most efficient extraction method, the polyphenol profiles of the extracts were analyzed using UHPLC-Q-Orbitrap-MS/MS, identifying flavonoids, terpenes, coumarins, and anthocyanins. SFE not only was the most efficient method but provided the most diverse and abundant profile. The research highlights the potential of converting industrial by-products that would otherwise be treated as wastewater, into valuable resources that generate revenue, promote circular economy practices, and enhance sustainability in the fruit and vegetable processing sector. The economic viability of polyphenol extraction is also discussed, emphasizing its significance and impact on various industries. The findings support integrating advanced extraction technologies to maximize resource recovery and minimize environmental impact.

Performance modeling of wastewater treatment systems has now become an attractive area of investigation for the design, analysis, and optimization of operations. Mathematical modeling of membrane bioreactor (MBR) treatment is a powerful tool for predicting effluent quality. In this study, a bioreactor coupled with a membrane filtration process (MBR) was employed to treat municipal wastewater. An experimental design based on the response surface methodology (RSM) was applied to investigate the effects of operating conditions, such as hydraulic retention time (HRT), aeration rate (AR), and transmembrane pressure (TMP), on the removal efficiencies of chemical oxygen demand (COD), total suspended solids (TSS), and total nitrogen (TN). The results demonstrated a strong agreement between experimental data and model predictions. Furthermore, the RSM results display the effects of the operating parameters and their interactive effects on pollution removal. The maximum removal efficiency was achieved, exhibiting 95% of COD, 99.7% of TSS, and 93% of TN. These findings provide the effective use of statistical modeling to enhance MBR process performance, achieving sustainable and energy-efficient conditions.

This study reports the preparation of granular ternary micro-electrolysis materials and their effectiveness in removing the emerging contaminant PFOA. Al/nZVI/C@F granules were synthesized using a liquid-phase reduction method combined with high-temperature calcination. By comparing the removal of methylene blue dye by granules, the optimum preparation conditions were determined as follows: Fe:C = 5:1, fly ash = 50%, calcination temperature = 800 °C, and holding time = 1 h. Static batch experiments revealed that under optimal conditions (PFOA concentration = 25 mg/L, solid-liquid ratio = 30 g/L, pH = 3, reaction temperature = 15 °C), Al/nZVI/C@F achieved a PFOA removal rate of 97.83%. The removal efficiency of Al/nZVI/C@F (93.90%) was significantly higher than that of commercial iron-carbon (12.75%). After 45 days of dynamic column experiments, the removal efficiency of nZVI/C@F and Al/nZVI/C@F for PFOA (50 mg/L) remained above 60%, demonstrating strong practical application potential. Further adsorption-desorption experiments revealed that nZVI/C@F and Al/nZVI/C@F primarily removed 50 mg/L PFOA through adsorption. For a lower PFOA concentration of 0.5 mg/L, the defluorination rates were 53.2% for nZVI/C@F and 68.9% for Al/nZVI/C@F. High-performance liquid chromatography-tandem mass spectrometry was used to analyze the intermediates formed during PFOA removal, leading to a proposed degradation pathway.

Guidelines are often set at urban catchments' outfalls to avert river pollution, where stormwater is discharged into the river. Analytical probabilistic models (APMs) in conjunction with particle swarm optimization (PSO) were used to design a detention pond system at three sub-catchments of a watershed that discharge into a common point. The objective is to design multiple ponds upstream such that the pollution control target downstream is met at the minimum cost. Given the cost of purchasing land plus the cost of construction/maintenance of the ponds in the sub-catchments, the result shows that pond depths of 2.0 m in all three sub-catchments give the least total cost. A runoff control of 88, 94, and 90%, and pollution control of 59, 45, and 66% were obtained in Ponds 1, 2, and 3, respectively, while satisfying the overall watershed's pollution control target. A sensitivity analysis was conducted by varying the land costs and different performances were obtained. The APM/PSO model can search for the optimum design parameters that satisfy upstream runoff control performances and the overall pollution control target downstream. The advantage of the approach is that it can be applied to any combination of ponds in a larger watershed.

Wickerhamomyces anomalus is a yeast-producing mycocins and has antimicrobial action. Escherichia coli is the predominant bacterium of the coliforms group; its presence in water indicates fecal contamination, being used as an indicator of microbiological analyses. The immobilization of cells and substances demonstrates great potential for biotechnological applications. This work aimed to assess the activity of free and immobilized mycocins, obtained from W. anomalus, against E. coli strains and fecal coliforms. The mycocins were immobilized in different concentrations of sodium alginate and calcium chloride and tested to verify the antimicrobial activity against the E. coli strain and fecal coliforms present in water samples. The mycocins were able to inhibit all strains used in broth microdilution. Considering the problem of multidrug-resistant antibiotic strains and the need for new alternatives to improve the quality of water and sewage effluents, these results demonstrate a possible application as an alternative to an antimicrobial agent.

A novel integration of the electrochemical process with electrodialysis and electro-oxidation (IEDEO) was designed for the effective pretreatment of chlorpyrifos manufacturing wastewater, with high concentrations of both salts and organic compounds. The effects of operating parameters including initial pH and constant voltage on the IEDEO process performance were investigated. The IEDEO process showed excellent performance for the simultaneous removal of bio-refractory organics and inorganics in the chlorpyrifos wastewater. In contrast with the single EO process, the results of energy consumption, UV-vis spectra, and GC-MS showed that the oxidation performance for chlorpyrifos wastewater by IEDEO was carried out more efficiently. The biodegradability of the chlorpyrifos wastewater pretreated by IEDEO was significantly improved. The total salt removal (90.3 ± 2.1%) from the chlorpyrifos wastewater obtained by IEDEO was significantly higher than the 5.8 ± 1.6% removal attained with the EO process. The COD removal of chlorpyrifos wastewater by the IEDEO process was 25.5 ± 1.2%, and the energy consumption of the IEDEO process was 15.1 ± 1.6 kWh kg^-1 COD at 2 h, representing a 60-65% reduction compared to the EO process. This indicated that the IEDEO process was a valuable pretreatment technique for biological treatment. Moreover, scanning electron microscopy and X-ray diffraction results demonstrated that the IEDEO concentrate was beneficial for subsequent evaporative desalination.

Wastewater treatment facilities use enhanced biological phosphorus removal (EBPR) to meet discharge quality limits. However, the EBPR process can experience upsets due to a lack of influent carbon or inadequate anaerobic zones. By using a sidestream EBPR (S2EBPR) process, carbon can be generated internally through fermentation processes and a higher anaerobic mass fraction can be attained in smaller volumes. This study investigates nutrient removal and microbial community trends in a full-scale S2EBPR demonstration at the Calumet Water Reclamation Plant. The study aims to improve a process model of the system by better representing the activity of glycogen-accumulating organisms (GAO) and potential competitors of phosphorus-accumulating organisms (PAO), which were found in high abundance in this study. Modifying anaerobic hydrolysis, GAO glycogen storage and ORP activity parameters resulted in model prediction improvements of approximately 5% for nitrate and nitrite and 10-60% for phosphorus. The study also uses shotgun metagenomic sequencing to profile denitrification pathways of PAO and GAO. It shows that denitrifying GAO may contribute to nitric oxide reduction to a greater degree than denitrifying PAO. This study improves process modeling predictions for S2EBPR and highlights the potential role of denitrifying PAO and GAO in combined phosphorus and nitrogen removal in S2EBPR.

Nanoplastics, commonly used in cosmetics, enter wastewater systems and interact with activated sludge, yet their effects on microorganisms, essential for wastewater treatment, remain poorly understood. The aim of this study was to investigate the effects of polyacrylic acid-based nanoplastics (PANPs) on microorganisms in activated sludge. The PANPs were characterized in terms of their material composition, size, zeta potential, and additive content. Acute (30 min) and prolonged (up to 6 h) toxicity tests were performed to evaluate negative effects on heterotrophic and nitrifying microorganisms in activated sludge. In addition, ready and inherent biodegradability tests were performed to assess their degradation in the environment and within wastewater treatment plants, respectively. The results showed a significant acute inhibition of heterotrophic and nitrifying activity (up to 55 and 72%, respectively) at the highest concentration tested (100 mg/L, 30 min), primarily attributed to the presence of 1-dodecanol detected in the PANPs. This effect decreased with prolonged exposure, likely due to the volatilization of 1-dodecanol. Nevertheless, the PANPs were found to be non-biodegradable in both the ready and inherent biodegradability tests. Although PANPs do not appear to pose a long-term threat to the activated sludge, their persistence in the environment raises concerns about possible accumulation.

Olive mill wastewater (OMW), a by-product of olive oil production, poses significant environmental risks due to its acidity and high polyphenol content, particularly in water-scarce regions like Jordan. This study developed a cost-effective approach to reduce the phenolic content in OMW using modified granular-activated carbon (GAC). Commercial GAC, chosen for its high surface area and adsorption capacity, was modified via oxidative treatment with concentrated nitric acid and reductive treatment using 10 wt.% ammonia solution. The modified GAC samples were tested for phenolic compound (PC) adsorption from OMW under varying surfactant types, concentrations, and pH levels using a batch method. The optimized conditions revealed that reduced GAC at pH 9 achieved the highest removal efficiency, reducing the phenolic content by 88% after 48 h. Surfactants had no significant effect on the performance of reduced GAC. Desorption tests after 7 and 32 days indicated a minimal release of PCs, confirming strong binding to the GAC surface. These findings demonstrate the potential of reduced GAC as a sustainable and cost-efficient solution for treating OMW, addressing the critical challenges in water resource management and environmental pollution in regions like Jordan.