Environmental Science: Water Research & Technology最新文献

The recovery of dwindling materials from wastewater could be helpful in resolving the rising need for resources in society. Phosphate is a nutrient that all living organisms require, but a reduction in global phosphate rock deposits could severely impact human food security in the near future. To mitigate this problem, we developed a Zn(II) coordinated 1-aminoguanidine (ag) functionalized cellulose-based biopolymer. The chemical structure of the synthesized biopolymer was characterized using several analytical techniques, including Fourier transform infrared spectroscopy (FT-IR), field emission scanning electron microscopy (FESEM), FESEM-energy dispersive X-ray spectroscopy (FESEM-EDX), and X-ray photoelectron spectroscopy (XPS). The phosphate binding to the polymer was investigated by FT-IR, FESEM–EDX, XPS and ion chromatography (IC) analyses. The IC analysis revealed strong and fast phosphate removal efficacy of the polymer, with a maximum adsorption capacity of 310 mg g⁻¹ (pH 7.0). Interestingly, the sequestered phosphate could be readily retrieved, and the biopolymer could be easily recycled by changing the pH (∼13) of the aqueous solution. Further studies revealed that the presence of guanidinium moieties was essential for its exfoliation in aqueous media and antibacterial activity against both Gram-negative and Gram-positive bacteria. The present work will assist in improving the design of water-insoluble biopolymers that could efficiently extract and recover phosphate from wastewater, thus reducing the detrimental effect of water eutrophication.

The presence of pharmaceuticals in water bodies has become a growing concern due to their potential effects on aquatic life. These compounds enter the environment through various routes, including untreated wastewater, wastewater treatment plants, rainwater runoff, and improper disposal of drugs. Therefore, there has been increasing interest in monitoring the occurrence of pharmaceuticals in natural waters, demanding the development of analytical methods for their detection. In this work, a UHPLC-MS/MS method was developed and validated to quantify acetaminophen, caffeine, diclofenac, and sulfathiazole in a working range varying from 1 to 100 000 ng L⁻¹, in order to assess their occurrence and risk to aquatic life in rivers and creeks located in three southeastern Brazilian metropolitan areas and cities (São José do Rio Preto, Campinas and Belo Horizonte) with different levels of urbanization. Preto, Turvo and Atibaia Rivers and Anhumas, Arrudas, Onça, and Isidoro Creeks were sampled during the dry and wet seasons. The presence of acetaminophen (157–7449 ng L⁻¹), caffeine (60–122 520 ng L⁻¹), diclofenac (62–176 ng L⁻¹), and sulfathiazole (34–40 ng L⁻¹) was confirmed more than once in the samples. The frequency of detection was different for each compound, being higher in the rivers more impacted by urban areas. The risk to aquatic life based on the risk quotient, calculated using the most sensitive PNEC (predicted non-effect concentration) for freshwaters, indicated concern about the concentrations of caffeine and diclofenac in some of the samples analyzed.

To meet the growing demand for lithium sustainably, secondary resources must be explored. Among nontraditional resource alternatives, brines co-produced from oil and gas (O&G) operations are of particular interest owing to their abundance and considerable lithium concentrations. Whereas previous work has highlighted potential O&G brines of interest for lithium extraction, the criteria to distinguish optimal from suboptimal O&G produced waters are still unclear. In the following, we provide perspectives on assessing the feasibility and challenges of produced waters from key U.S. formations as lithium resources based on their water chemistry, production rates, and geographic placement. Specifically, we clarify the impact of production rates on the estimated lithium resources and how it may aggrandize evaluations. We assess how key secondary cation concentrations and ratios complicate downstream separation, and evaluate the role of the geographic coexistence of lithium resources and lithium consumers (i.e., the manufacturing sector). Among the U.S. O&G formations evaluated herein, the Marcellus shale emerges as an attractive formation for lithium extraction, with an estimated annual lithium metal output of 930 metric tons and lower secondary cation concentrations. The potential feasibility of brines from the Marcellus formation is enabled by its reduced need for downstream separation and purification, as well as its proximity to major lithium end-user facilities (i.e., battery manufacturers). Overall, we provide an initial set of criteria to help evaluate O&G formations for their potential to serve as lithium resources and provide an assessment of the lithium resources in key U.S. O&G plays.

The COVID-19 pandemic presented an opportunity to collect wastewater (WW) from a defined population of individuals within a building and monitor the sewage for viral RNA as a leading indicator of COVID-19 infections. The evaluation of the effectiveness of building-level WW surveillance programs as an early warning system has been limited by a lack of frequent asymptomatic surveillance of the defined residential population under WW surveillance. In this study we present the epidemiologic diagnostics of WW surveillance (sensitivity (Se), specificity (Sp), positive predictive value (PPV) and negative predictive value (NPV)) from university residence halls. WW surveillance was layered on top of a rigorous asymptomatic testing program (three times per week) and serves as the gold standard for comparison. This study also spanned across both the Spring 2021 semester when students were unvaccinated and the Fall 2021 semester when >95% of students were vaccinated for COVID-19 to understand how increased immunity may affect viral detection in WW. We analyzed composite WW samples from nine residential buildings that were collected twice weekly. The overall positive WW sample detection rate was 5.5% indicating the low-incidence context of this study population to allow for evaluation of WW surveillance as an early warning system. WW surveillance showed the best performance as a leading indicator of an infected individual when compared in a time inclusive of 1–2 days prior to the date of a clinical positive. The building-level WW surveillance sensitivity and specificity was found to be 60% and 94.9% (PPV: 47.4%; NPV: 96.9%), respectively in the Spring 2021; in the Fall 2021 sensitivity was reduced to 6.3% and specificity remained at a similar level of 97.5% (PPV: 14.3%; NPV: 94.1%). Combined for both semesters, the overall sensitivity and specificity were 32.3% and 96.4% (PPV: 38.5%; NPV: 95.3%). Convalescent shedding may explain up to 31% of false positive WW samples, contributing to decreased surveillance performance. This study demonstrates the greater effectiveness of building-level WW surveillance as an early warning system at the beginning of the COVID-19 pandemic when population-level immunity was naïve and fecal shedding of SARS-CoV-2 was likely more prevalent.

We investigated the effect of droughts and floods on the removal of antibiotic resistance genes and co-selectors in a 60 MLD sewage treatment plant (STP) in Perungudi town, Chennai city. Samples were collected once a month for 13 months and analysed for 7 antibiotic resistance genes (sul1, ermF, tetW, mcr5, sul2, parC, and bla_OXA-1), the most used antibiotic in the region (ciprofloxacin), a non-pharmaceutical antibiotic (triclosan), and 3 co-selective heavy metals (copper, chromium, and lead). It was found that the total bacterial count decreased significantly in the STP (p-value = 0.03, Wilcoxon rank sum test), but the relative abundance of ARGs was not reduced in the STP. In fact, the relative abundances of tetW and bla_OXA-1 increased in the maturation pond and were higher in the effluent than in the influent (p-value = 0.03, Wilcoxon rank sum test). On the other hand, the relative abundances of most ARGs were reduced significantly in the anaerobic digester (p-value < 0.05, Wilcoxon rank sum test). Overall relative abundances of mcr5, tetW, ermF, intI1, and sul2 in the raw sewage were higher in the dry summer than in the monsoon. The relative abundance of intI1 was correlated (Spearman correlation) with the relative abundances of mcr5 (ρ = 0.54), ermF (ρ = 0.52), and tetW (ρ = 0.61). Except for chromium, all the other targeted co-selectors were significantly removed from the STP throughout the year (p > 0.05, Wilcoxon rank sum test). Overall, the targeted ARGs were not removed in the STP, and this underperformance was unaffected by periods of droughts and floods.

Exploration and application of unconventional water sources, particularly brackish water, have emerged as key strategies for addressing freshwater scarcity. Electrodialysis (ED) is utilised in brackish water desalination to eliminate Ca²⁺ owing to its cost-effectiveness and eco-friendliness. This study integrated electrochemical impedance spectroscopy to examine the effects of voltage, flow rate, and initial concentration on the migration numbers of Na⁺ and Ca²⁺ ions as well as the selectivity coefficient for Ca²⁺ during ED. The experimental results revealed that a lower voltage, flow rate, and initial concentration enhanced the selective removal of Ca²⁺ compared to Na⁺, which was linked to variations in the boundary layer thickness near the membrane. The maximum reached 2.48 at an initial concentration of 3.3 mmol L⁻¹, with a voltage of 6 V and an influent flow rate of 36 L h⁻¹. In addition, a 2 month pilot study was conducted using brackish groundwater from northwestern China. This indicates a stable effluent and high efficiency of Ca²⁺ removal during brackish water treatment via the ED process. The Ca²⁺ concentration in the effluent remained below 20 mg L⁻¹ with a daily water production efficiency of 90%. This study offers valuable insights into ED technology applicable to the desalination and hardness reduction of brackish water.

Advanced oxidation processes, such as heterogeneous photocatalysis, can break down recalcitrant compounds. The overall effectiveness of the majority of semiconductor-based photocatalysts during continuous operation and in actual wastewater matrices is still insufficient. This research examines the concurrent removal of chemical oxygen demand and chromium(VI) from real tannery wastewater. This is achieved through the application of a photocatalyst namely zinc oxide nanoparticles prepared using Ficus Religiosa leaf extract. The Tauc plot revealed the bandgap energy of zinc oxide to be 3.40 eV and the XPS survey picture confirmed that the binding energy between two peaks of Zn_3/2 and Zn_1/2 is 23.15 eV, confirming the formation of zinc oxide. 97.25% chromium(VI) and 89.3% chemical oxygen demand removal was achieved under optimal conditions of pH, H₂O₂ and the catalyst dosage level of 7, 19.5 mM, and 4 mg L⁻¹, respectively. Also, the degradation studies followed pseudo first order kinetics with a rate constant value of 0.0827 min⁻¹ and an R² value of 0.98. Furthermore, the catalyst's reusability was confirmed under optimal conditions. This article shows an eco-friendly method for synthesizing zinc oxide nanoparticles.

Potable water reuse is becoming more common as communities deal with increased water demands and climate change. Understanding the risks associated with potable reuse is essential to ensuring that public health is protected from waterborne pathogens. This paper provides a review on the studies that have performed quantitative microbial risk assessments (QMRAs) on potable reuse. The 30 articles included here studied direct potable reuse (DPR), indirect potable reuse (IPR), and/or de facto reuse (DFR), and a variety of pathogens, including norovirus, adenovirus, Cryptosporidium, Giardia, Campylobacter, and Salmonella. The QMRAs were either ‘top-down’ or regulations-focused, where log reduction targets (LRTs) were determined based on initial (e.g., raw wastewater) pathogen concentrations and risk goals (e.g., 10⁻⁴ annual risk benchmark), or ‘bottom-up’ or risk-estimation-focused, where risks were calculated based on known pathogen concentrations and observed/credited log reduction values (LRVs). Some studies incorporated process failures and pathogen decay, which were often a driving factor for risk, but several studies omitted one or both. Many studies compared multiple treatment trains (e.g., carbon-based advanced treatment (CBAT) vs. reverse-osmosis-based advanced treatment (RBAT)). They found that treatment-based differences were pathogen-dependent because certain processes are better able to inactivate or remove certain pathogens. Many factors influence the risks reported in the various studies, including the assumed ratios of gene copies to infectious units (GC : IU), assumptions related to ingestion volume and frequency, dynamic vs. static modeling, and Bayesian approaches. The LRTs for the top-down QMRAs varied within and between studies, depending partially on the pathogen concentrations used and whether redundancy was included. The key findings from this review were that while QMRAs often have different goals warranting different assumptions, it is essential that researchers report these assumptions and their justifications so that policymakers and regulators fully understand their implications to avoid overly stringent or nonprotective regulations.

As the current and past Editors-in-Chief of Environmental Science: Water Research & Technology (ES:WRT), we are thrilled to celebrate the journal's 10-year anniversary!

Fenton oxidation technology is an effective pretreatment method for saline organic wastewater, yet it suffers from issues such as low hydrogen peroxide utilization efficiency, large dosages of reagents and sludge production, high-cost operation, and potential secondary pollution. This study aims to enhance the Fenton oxidation treatment of saline organic wastewater using nanobioparticle-prepared biochar in a traditional Fenton system to address these shortcomings. Initially, nano-bioparticles of FeS were synthesized using Bacillus cereus and carbonized at 700 °C under the protection of argon to produce biochar, which was characterized by SEM, EDS, and XRD. Subsequently, the efficiency and optimal operational conditions of the enhanced Fenton system for treating saline organic wastewater were investigated. Results indicated that the optimal dosage of biochar was 0.1 g L⁻¹, with a reagent ratio (mass ratio) of COD : Fe²⁺ : H₂O₂ = 1 : 1 : 0.8, pH = 3, and a reaction time of 40 minutes. Under these conditions, the COD removal efficiency of the enhanced Fenton system reached 50.5%, showing a significant improvement compared to the traditional Fenton system (38.8%). Finally, the mechanism of strengthening the Fenton reaction by FeS nano-biochar was explored from four aspects: ·OH generation, H₂O₂ consumption, Fe(II) to Fe(III) conversion, and redox capability. The study demonstrated that FeS nanoparticles could activate molecular oxygen to produce ·O₂⁻, promote Fe(II)/Fe(III) cycling, indirectly enhance ·OH generation from H₂O₂, reduce its ineffective decomposition, and utilize the electronic conductivity of biochar to enhance the system's redox capability, thereby improving the COD removal efficiency of the enhanced Fenton system for saline organic wastewater. This research advanced the operational cost and treatment efficiency of traditional Fenton technology, providing parameters and scientific foundations for accelerating the practical application of novel enhanced Fenton technology in treating refractory industrial wastewater.