Knightkumar3604

Carcass decomposition could be considered as a common phenomenon in nature. However, during degradation processes, animal carcasses produce many toxic and harmful metabolites, posing potential ecological risks to water safety, thereby threatening human health. However, the metabolites produced by decomposition of animal corpses are not well understood. In this study, building on our previous baseline study of microbial community between the experimental groups (with animal carcasses) and control groups (without carcasses), the samples at the ultimate stage (19th day) of carcass decomposition were chosen to investigate the metabolic profiles and uncover the relationships between water quality, microbes and noxious metabolites in two types of water (Yellow River water and tap water) using fish as animal model by widely targeted metabolomics. Our results showed amino acid metabolomics, indole and its derivatives, and pyridine and pyridine derivatives mainly occurred in the corpse groups, suggesting that these meoxious metabolites when exposed to animal carcasses in aquatic environment.The current technologies to treat hypersaline produced water (PW), such as thermal evaporation, are usually energy-intensive and cost-prohibitive. This study developed a low-cost, robust, solar-driven carbon black and airlaid paper-based evaporator (CAPER) for desalination of PW in the Permian Basin, United States. The study aims to better understand the removal of aromatic organic compounds and heavy metals during solar distillation, water output, and heat transfer. Outdoor experiments using CAPER assisted with polystyrene foam in a single slope, single basin solar still achieved an enhanced average evaporation rate of 2.23 L per m2 per day, 165% higher than that of a conventional solar still. Analysis of heat transfer models demonstrated that CAPER solar evaporation achieved an evaporative heat transfer coefficient of ∼28.9 W m-2·K-1, 27.9% higher than without CAPER. The maximum fractional energy of evaporation and convection heat transfer inside the solar still with and without CAPER was ∼81.4% and ∼78.2%, respectively. For the PW with a total dissolved solids concentration of 134 g L-1, solar distillation removed 99.97% salts and over 98% heavy metals. The high removal efficiency of 99.99% was achieved for Ca, Na, Mg, Mn, Ni, Se, Sr, and V. Organic characterization revealed that solar distillation removed over 83% aromatic compounds. Solar desalination using CAPER provides a low-cost and high-performance process to treat PW with high salinity and complex water chemistry for potential fit-for-purpose beneficial uses.Metal pollutants accumulation in the scales of drinking water distribution systems presents a potential threat to water quality. Therefore, a study was carried out on the accumulation of V(V) and As(V) by cast iron pipe scales. The accumulation of V(V) and As(V) by scales and the effects of scale dosage, pH, temperature, and anion content on the accumulation process were assessed. Results showed that scales could rapidly accumulate V(V) and As(V), with maximum accumulation amounts of 3.94 mg/g and 3.90 mg/g, respectively. An increase in pH (from 3.0 to 9.0) and sulfate concentration (from 0 to 250 mg/L) decreased V(V) and As(V) accumulation by scales. Increased chloride ion concentrations (from 0 to 250 mg/L) reduced the amount of As(V) accumulated, while increasing the amount of V(V) accumulated. The V(V) and As(V) accumulation kinetics were well described by the Elovich model, with thermodynamic and accumulation isotherms showing that the accumulation process occurred via an entropic endothermic reaction. The mechanisms of accumulation of V(V) and As(V) by the scales include surface complexation, ligand exchange, electrostatic attraction and repulsion, and competitive adsorption.This study examined an electrochemical method of H2 production and nutrient recovery from synthetic source separated urine (SSU). The efficacy of H2 production was examined through hydrogen recovery experiments (HRE) using Ni foam electrodes. Similarly, nutrient (N and P) recovery was also examined in post-nutrient recovery experiments (NRE) with sacrificial Mg electrodes. To achieve higher nutrient recovery in the post-nutrient recovery process, the most important operating parameters (initial solution pH (pHi) and current density) were optimized. Optimization of NRE revealed that > 90% NH3-N and PO43--P could be recovered at 8 mA cm-2 with a pHi of 6-8. Notable NH3-N and PO43--P reduction were observed at an equimolar Mg2+ dissolution ratio (11) of Mg2+NH4+ and a 1.11 ratio of Mg2+PO43- respectively. However, poor total Kjeldahl nitrogen (TKN) reduction was observed. Thus, we anticipate that direct electrochemical conversion of urea to N2 at the anode followed by H2 generation at the cathode is a more sustainable way to reduce TKN. Batch HRE showed that the initial TKN, 1094 mg L-1 (934 mg L-1 from urea-N and 160 mg L-1 from NH4Cl), was significantly reduced to 360 mg L-1 by Ni-Ni electrolysis, whereas around 53.8 g H2 gas was received from this Ni-Ni electrolysis system with a flow rate of 5-5.8 g mol-1 day-1. see more Overall, this work produced a 68% reduction in TKN due to electrochemical conversion of urea into H2.To better understand the transformation and photochemical fate of PAHs in aquatic environments, a custom-designed closed-circuit recirculation photodegradation system, combined with inline semi-continuous fluorescence and absorbance measurements, as well as modelling of excitation-emission (EEM) measurements with parallel factor analysis (PARAFAC), and GC-MS analysis, were combined to create a robust tool for holistically assessing the photodegradation of individual PAHs, their mixtures and photoproduct formation. Selected compounds included in the US EPA priority list, representing 2- to 6-ring compounds, were monitored individually and in mixtures, during 24 h photodegradation experiments. Experiments were conducted in solutions simulating ideal (ultrapure water) and environmentally relevant conditions (1.00 mg L-1 Suwannee River Natural Organic Matter (SRNOM)). The fluorescence, primary PARAFAC components and quantification data obtained by GC-MS, indicated that the decline in parent molecule concentration occurred rapidly within 200 min.