Padgettlassen7736

Pulping and paper industries using non-woody feedstocks face the challenge of its notorious waste disposal problem. To resolve this problem, in this study, we evaluated a variety of properties of solid residues reclaimed from the effluents of both wheat straw ammonium sulfate and Kraft pulping processes as organic fertilizers. The results show that both residues from the ammonium sulfate (RAS) and Kraft pulping (RKP) processes possess desirable C/N ratios, appropriate nutritional compositions, and low levels of harmful heavy metals. The high solubilities (>35 g/L) of both residues allow their use for fertigation or foliar applications. The salt index (30-50) is within the range of commercial chemical fertilizers such as potassium sulfate (42.6) and magnum sulfate (44). The E3/E5 ratios of residues suggest that the residues have small molecular sizes, which are similar to fulvic acids. Overall, wheat straw pulping residues demonstrate the potential as the sustainable organic fertilizers and the beneficial soil amendments. This work has the potential to resolve the severer effluent disposal problem faced by the non-woody pulping and papermaking industries, open a door to effectively utilize residues as value-added byproducts, and lead to both environmental sustainability and economic benefits.Manganese accumulated in corrosion scales on drinking water distribution systems (DWDSs) can be released into bulk water, causing discolouration and thereby leading to customer concerns about drinking water quality. A static release experiment was conducted on iron pipe scales under three different temperatures, pH values, alkalinity values, sulfate (SO42-) concentrations, and disinfectants to study the separate effect of these factors on Mn release from pipe scales under stagnant conditions. Results showed that more Mn was released from corrosion scales under the conditions of lower pH, lower alkalinity, higher temperature, and higher SO42- concentrations. Three commonly used disinfectants, sodium hypochlorite (NaClO), chlorine dioxide (ClO2), and monochloramine (NH2Cl) were found to inhibit the release of Mn from iron corrosion scales, with the ranked order of inhibitory effect of ClO2≈NaClO > NH2Cl under the same CT (product of disinfectant concentration and contact time) value. The orthogonal experimental results indicated that SO42- and alkalinity had extremely significant effects on the release of Mn from pipe scales, while pH and disinfectant type had a significant impact on the release of Mn from pipe scales. Thus, the SO42- concentration and alkalinity of the bulk water should be determined to avoid excessive release of Mn into drinking water. Enasidenib However, further investigation of the effect of disinfectants on Mn release in DWDSs is necessary. This research helps establish a systematic understanding of the influential factors in Mn release from pipe scales into bulk water, as well as their significant relationships.Sequencing batch reactors (SBRs) were operated for 36 days to simulate the potential wastewater treatment impacts as well as fate and transport of per- and polyfluoroalkyl substances (PFAS) that could be associated with a release of alcohol resistant aqueous film forming foam (AR-AFFF) from on-site methanol fire suppression systems. The results of this study indicate that two days of exposure to AFFF were associated with small reductions in mixed liquor solids content and nitrification rates. No impacts on denitrification or biological phosphorus removal were observed. The addition of AFFF was associated with increases in 62 fluorotelomer sulfonate (62 FTS) in influent, effluent, and solids samples in the SBR. The following biotransformation pathway is proposed an unidentified fluorotelomer precursor quickly degraded to 62 FTS, which then slowly degraded to several identified degradation intermediates and terminal, short-chain perfluorocarboxylic acid products. Data for 62 FTS, which was used as a proxy for AFFF-associated PFAS, were extrapolated to estimate that a removal of approximately 70% of AFFF via effluent and solids wasting would occur after 4 days at a full-scale treatment plant. This information can be used to better understand potential impacts on downstream processes, including potable reuse and biosolids production.In order to improve the adsorption efficiency of ammonia nitrogen in low temperature wastewater, the modified activated carbon (Fe-AC) was prepared by impregnation-calcination modification of Fe(NO3)3. The characterization results indicated that the total pore volume, specific surface area and the point of zero charge of activated carbon increased after modification. A better adsorption effect was achieved under neutral condition than under alkaline or acidic condition. The effect of Ca2+ on competitive adsorption of NH4+ was greater than that of Na+ when both cations were present. Pseudo-first-order kinetic model was confirmed to be consistent with Fe-AC adsorption kinetic data, and Langmuir model was consistent with adsorption isotherm data. The adsorption thermodynamics demonstrated that the ammonia nitrogen adsorption process by Fe-AC was spontaneous and low-temperature was helpful to improve the adsorption capacity. The mechanism of adsorption of ammonia nitrogen by Fe-AC was the comprehensive effect of physical adsorption and chemical adsorption, which was the essential reason for improving the adsorption efficiency of ammonia nitrogen by Fe-AC at a low temperature. This research offered a new way for the modification of activated carbon and a new method for the removal of ammonia nitrogen at a low temperature.Fluoride generally exists in the natural environment, and has been reported to induce serious environmental hazard to animals, plants, and even humans via ecological cycle. Silkworm, Bombyx mori, which showed significant growth and reproductivity reduction when exposed to fluoride, has become a model to evaluate the toxicity of fluoride. However, the detailed mechanism underlying fluoride toxicity and corresponding transport proteins remain unclear. In this study, we performed RNA-seq of the larval midgut and fat body with fluoride exposure and normal treatment. Differential analysis showed that there were 4405 differentially expressed genes in fat body and 4430 DEGs in midgut with fluoride stress. By Gene Ontology and Kyoto Encyclopedia of Genes and Genomes analyses, we identified several key pathways involved in the fluoride exposure and poisoning. We focused on the oxidative phosphorylation and MAPK signal pathway. QRT-PCR confirmed that oxidative phosphorylation process was remarkably inhibited by fluoride exposure and resulted in the blocking of ATP synthesis.