Thaysenpersson9136

Electro-adsorption is attracting increasing attention as an emerging technology for removing ionic species from water but suffer from low selectivity. In this work, a bismuth/reduced graphene oxide nanocomposite electrode was fabricated by a facile and green method. Based on this material, an electrode with improved selectivity by electrochemistry deionization system was successfully fabricated. The bismuth nanoparticles were uniformly covered with reduced graphene oxide plates and the ratio of Bi on the whole materials is 79.56%. Bismuth/reduced graphene oxide showed ions selectivity in the order of Cl- > F- ≫ [Formula see text] . The average Cl- removal capacity can reach as high as 62.59 mg g-1. Moreover, bismuth/reduced graphene oxide electrodes have good regeneration performance. Typically, in the 10 adsorption-desorption multicycles, the salt absorption/desorption capacity of the hybrid capacitive deionization system is stable and reversible. This research opened a hopeful window to design and synthesize effective materials to selectively remove the ionic species to purify the water. Biogeochemical mobilization of arsenic in groundwater depends on the presence of dissolved organic matter (DOM) that likely promotes the As release, i.e., reductive dissolution, complexation, competition, and electron shuttling. We investigated the role of DOM in As release, along with its complete characterization, in the Indus plain of Pakistan, one of the worst arsenic impacted zones in the South Asian region. In total, 60 groundwater and 15 soil samples, collected at six sites from north to south within the flood plain of the Ravi River, Lahore, Pakistan were investigated. Arsenic concentration ranged from 9.61 μg/L to 386 μg/L in the groundwater samples (high As observed in areas close to the river). Dissolved organic carbon (DOC) in 29 groundwater samples ranged between 0 and 10.1 mg-C/L. A moderately positive correlation of As with DOC and Fe in the northern part of the study area suggest the reductive dissolution of FeOOH associated with dissolved organic matter (DOM). The reductive dissolution plays an essential role for As enrichment in the area evidenced by the lower concentrations of SO42-, NO3-, and PO34-and a non-correlative pattern with As. In contrast, a positive correlation of As with PO34-, DOC, and HCO3- in the southern part indicate competitive desorption behind the As release. Fluorescence excitation-emission matrix intensity data of DOM indicate the maximum presence of humic-like substances in the northern part that gradually shifts to aromatic, fulvic and protein type towards the southern part. Specific ultraviolet absorbance and fluorescence index display aromatic and terrestrial (allochthonous) sources of DOM near the riverbank and mixed (both allochthonous and autochthonous) source away from the river. The positive correlations of As with DOC and fluorescence intensity also attest that DOM played a vital role in the As mobilization in groundwater of the study area. This study aimed to compare the effectiveness of MAER and L20 resin for the adsorption treatment of secondary effluent, and evaluate the applicability of ozone oxidation for the reuse of desorption eluate. Bench-scale adsorption experiments showed that the MAER resin exhibited higher efficiency than L20 resin in removal of COD within 600 treated bed volumes (BV), which declined from 32.5% to 14.1% in the first and sixth treatment loading of 100 BV. On the other hand, the L20 resin displayed obviously higher removal efficiency of total nitrogen (TN) than MAER resin within 600 BV, which dropped from 74.6% to 9.8% at the same condition. The ozone oxidation treatment could achieve desirable reuse of desorption eluate, although its chemical oxygen demand (COD) concentration increased gradually in line with the reuse numbers. The uptake of COD, TN and total phosphorus declined steadily by using ozone treated eluate as the regenerant in successive adsorption-desorption cycles, but increased obviously with a new batch of regenerant. Overall, the resin adsorption could efficiently remove organic and inorganic matters from secondary effluent, while the treatment loop including desorption eluate oxidation and eluate reuse could markedly enhance the concentration ratio of treated effluent. selleck compound Heavy metals contaminate the environment and provide a threat to public health through drinking water and food chain. Microbial biosorption technology provides a more economical and competitive solution for bioremediation of toxicants such as heavy metals, and microbial genetic modification may modify microbes towards optimal sorption. It is very important to screen suitable strains for this purpose. In this study, three different types of microorganisms Escherichia coli, Bacillus subtilis and Saccharomyces cerevisiae were isolated and identified, from uncontaminated soils, and compared their sorption differences with respect to cadmium (Cd2+). We evaluated the effects of contact time and initial concentration on Cd2+ uptake, and found pseudo-second-order kinetic models were more suitable to describe biosorption processes. Adsorption isotherms were used to reflect their biosorption capacity. The maximum biosorption capacities of three strains calculated by the Langmuir model were 37.764, 56.497, and 22.437 mg Cd/g biomass, respectively. In bacteria, Cd2+ biosorption mainly occurred on cell wall, while the difference in biosorption between yeast inside and outside the cell was not significant. We found that due to the structural differences, the removal rate of E. coli surface decreased at a high concentration, while S. cerevisiae still had a lower biosorption capacity. FTIR spectroscopy reflected the difference in functional groups involved in biosorption by three strains. SEM-EDS analysis showed the binding of Cd2+ to microorganisms mainly relied on ion exchange mechanism. Based on the above results, we suggested that B. subtilis is more suitable to get genetically modified for heavy metal biosorption. In this work, a composite resin gel incorporating thiol-modified metal double hydroxide (TM-MDH) nanoparticles is developed for application in diffusive gradients in thin films (DGT) devices to sample and concentrate divalent Hg (Hg(II)) in water and sediment samples. The DGT device uses the TM-MDH resin as a sorption layer and an agarose gel as a diffusive layer. Complete digestion of the TM-MDH resin after sampling can be achieved in 5 mL of 12 N HCl solution for 30 min for direct aqueous Hg(II) analysis. The recovery of Hg(II) uptake onto the resin in aqueous solution reaches 95.4 ± 1.9%. The effect of ionic strength and pH on the performance of DGT device for Hg(II) is assessed. It is found that there is no significant difference on Hg(II) uptake over a pH range of 3.5-8.5 and an ionic strength range of 1-500 mM NaCl. The diffusion coefficient of Hg(II) at 25 °C was estimated to be 9.48 × 10-6 cm2/s at 50 μg/L solution. The sorption capacity of TM-MDH-DGT for Hg(II) reaches 41.0 μg/cm2. Field validations performed in reservoir water and in contaminated paddy soil demonstrate that the developed TM-MDH DGT device can accurately determine Hg(II) concentrations in these samples and outperform traditional sampling methods for both high and low Hg(II) concentrations. The Yangtze River Delta (YRD) is one of the regions with air pollution and high ammonia (NH3) emission in China. A high-resolution ammonia emission inventory for the YRD region was developed based on the updated source-specific emission factor (EFs) and the county-level activity data. The 1 × 1 km gridded emissions were allocated by using the appropriate spatial surrogate. The total NH3 emissions changed insignificantly from 2006 to 2014 and varied in the range of 981.65 kt - 1014.30 kt. The fertilizer application and livestock were the major contributors of total emission. Humans, biomass burning and vehicles were the top three contributors of non-agricultural sources, accounting for 37.24%, 31.02% and 10.85%, respectively. Vehicles were calculated to be the non-agricultural source with the fastest annual growth rate. link2 NH3 emissions from the nitrogen fertilizer application generally peaked in summer, corresponding to the planting schedule and relatively high temperature. High NH3 emissions occurred in the north as opposed to low emissions in the south of the YRD. The cities of Xuzhou, Yancheng and Nantong with more agricultural activities were demonstrated to have relatively high NH3 emissions, contributing 10.0%, 9.0 and 7.1% of total emissions, respectively. The validity of the emission estimates was further evaluated based on the uncertainty analysis by Monte Carlo simulation, comparison with previous studies, and correlation analysis between NH3 emission density and observed ground NH3 concentration. A detailed NH3 emission inventory is the basis of regional-scale air quality model simulation and can provide valuable information for understanding the formation mechanism of pollutants. The removal efficiency (RE) and bioaerosol emission of a perlite biofilter treating vapors of toluene (T) and/or ethyl acetate (EA) were assessed, under different operating conditions, during 171 days. Under the first stages of operation, a mixture of EA and T was treated, with equivalent inlet loads (ILs) of each compound (ranging from 26 to 84 g m-3 h-1), achieving a 100% RE of EA, and a maximum elimination capacity (EC) of T of 58.7 g m-3 h-1. link3 An inhibition of T removal was noted in presence of EA, as T was treated subsequently to EA, along biofilter depth. A 17 days starvation period induced no global deterioration of performance regarding EA removal, but a 50% lower RE of T. Suspension of one contaminant, with interspersed feeding of only one component of the mixture, caused a permanent drop of the RE of EA (to 87.3%), after a T only feeding of 41 days. Flow cytometry (FC) was applied for quantification of bioaerosols, allowing for differentiation between viable, dead and damaged cells. During the overall biofilter operation, bioaerosol emission was not statistically different from bioaerosol retention. However, the biofilter significantly emitted bioaerosols (mostly viable cells) during start-up and IL increase, whereas a global retention of dead cells was observed during the interspersed feeding of one contaminant. Bioaerosols measured by FC (107 Cells m-3) were three orders of magnitude greater than with plate counting dishes, indicating that FC does not underestimate bioaerosols as culture dependent techniques. The study provides cumulative data on the status of the two water bodies. The study designed revealed physicochemical properties (temperature, dissolved oxygen, pH, total dissolved solids and conductivity) to be in the desirable range, however, amongst the heavy metals excepting for Cd all were found to be higher than the permissible limits set by WHO and USEPA. It was observed that these elements cast their impact on bioindices (hepatosomatic index, condition factor, spleenosomatic index and kidney somatic index), renal marker enzyme (creatine kinase), hepatic marker enzymes (aspartate aminotransferase, alanine aminotransferase and alkaline phosphatase), histology of immune organs (liver, spleen, head-kidney and thymus) and level of serum immunoglobulin (IgM). Further, expression levels of Metallothionein (MT) and Glutathione peroxidase (GPX) genes in immune-related tissues (liver, spleen, head-kidney, thymus and blood) observed indicates metal pollution and abiotic stresses. These alterations are reliable indicators of the cellular and humoral immune response in Cyprinus carpio.