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Yilmaz Oakley posted an update 1 day ago
The adsorptive mechanisms operating in, and the effect of two different thiol modification methods on, the removal of five iodinated trihalomethanes (I-THMs) by the zeolite imidazolate framework (ZIF-8) were investigated in single and mixed solutions. The direct postgrafting of dithioglycol to the zinc complex node of ZIF-8 (ZF-SH) can increase the mesopore structures that enhance inner pore accessibility; this increase is a critical property required for excellent adsorption of I-THMs. The synergetic adsorptive interactions consist of Lewis acid-base interactions via the Zn-Zn complex, ion-dipole interactions involving the protonated hydroxyl and thiol groups, and hydrophobic interactions at the imidazole ring. In contrast to ZF-SH, the (3-mercaptopropyl)-trimethoxy functionalized silica coating on ZIF-8 (ZF-Si-SH) causes a lower thiol moiety and a steric effect that is reflected in its lower adsorption capacity. In both single and mixed solutions, the small molecular size and hydrophobic nature of I-THMs can promote better adsorption capacity on all thiol-modified ZIF-8, while the minus dipole charge distribution of the I-THMs structure plays a more critical role in selective adsorption on pristine ZIF-8. Interestingly, the dehalogenation of triiodomethane to diiodomethane due to a nucleophilic substitution (SN2) reaction can be accelerated by the thiol functionalized silica layer on ZIF-8.The emergence of triclosan (TCS) in the environment has caused extensive concern, but its role in waste activated sludge (WAS) anaerobic fermentation (AF) is still uncertain. This work investigated the impact of TCS on volatile fatty acids (VFAs) recycling from WAS. The results showed that TCS of 200 mg/kg TSS increased the maximum VFA accumulation from 7284 to 15,083 mg COD/L. The increase in total VFA production is attributed to the massive increase in acetic acid. Mechanism exploration showed that TCS promotes WAS solubilization by facilitating cell breakage and extracellular polymeric substances disruption, and stimulates AF by enhancing the activity of key enzymes among all stages. TCS promotes acidification stronger than methanogenesis, which makes VFA production faster than consumption, leading to increased VFA accumulation. These findings provide novel insights for revealing the role of TCS in WAS resource recovery, and offer thoughts for the selective production of final recycling products of TCS-containing WAS.Manure amendment has been shown to effectively prevent red soil (Ferralic Cambisol) acidification from chemical nitrogen (N) fertilization. However, information is lacking on how much manure is needed to mitigate acidification and maintain soil productivity while preventing accumulation of other nutrients and heavy metals from long-term inputs. This study determined the effects of various combinations of manure with urea-N on acidification and changes in soil P, K, and heavy metals in a 9-year maize field experiment in southern China. Treatments included chemical N, P and K fertilization only (NPKM0), and NPK plus swine manure, which supplied 20% (NPKM20), 40% (NPKM40), and 60% (NPKM60) of total N at 225 kg N ha-1 year-1. Soil pH, exchangeable acidity, available P and K, and maize yield were determined annually from 2009 to 2018. Soil exchangeable base cations, total and phytoavailable Cr, Pb, As, Ni, Cd, Cu, and Zn were measured in 2018. A significant decrease in soil pH occurred under NPKM0 and NPKM20 from initial 4.93 to 4.46 and 4.71, respectively. Whereas, under NPKM40 and NPKM60 no change or a significant increase in soil pH (to 5.47) occurred, as well as increased exchangeable base cations, and increased yields. Manure application markedly increased soil available P (but not K) to 67.6-182.6 mg kg-1 and significantly increased total Pb, Cu, and Zn and available Cu and Zn in soil. The results indicate sourcing 40% or greater of total N from manure can prevent or reverse acidification of red soil, and provide all P required, however, additional K inputs are required for balanced plant nutrient supply. An integrated approach of increasing N use efficiency, reducing chemical input, and reducing heavy metal concentrations in animal feed are all necessary for sustainable use of manure in soil acidity and nutrient management as well as minimizing environmental risks.Lead is a toxic environmental contaminant associated with current and historic mine sites. Here we studied the natural attenuation of Pb in a limestone cave system that receives drainage from the ancient Priddy Mineries, UK. Extensive deposits of manganese oxides were observed to be forming on the cave walls and as coatings in the stream beds. Analysis of these deposits identified them as birnessite (δ-MnO2), with some extremely high concentrations of sorbed Pb (up to 56 wt%) also present. We hypothesised that these cave crusts were actively being formed by microbial Mn(II)-oxidation, and to investigate this the microbial communities were characterised by DNA sequencing, enrichment and isolation experiments. The birnessite deposits contained abundant and diverse prokaryotes and fungi, with ~5% of prokaryotes and ~ 10% of fungi closely related to known heterotrophic Mn(II)-oxidisers. A substantial proportion (up to 17%) of prokaryote sequences were assigned to groups known as autotrophic ammonia and nitrite oxss the globe.Anastrozole (ANZ) is a breast cancer drug that was introduced onto the pharmaceutical market in the 1990s and is still one of the most widely consumed cytotoxic compounds. Due to the persistence of the drug, its continued presence after passing through wastewater treatment plants can lead to harm to aquatic environments. The present study investigates use of the solar photo-Fenton (SPF) process applied for ANZ degradation, considering the fate of ANZ and its transformation products (TPs). The SPF process was performed using different concentrations of ferrous iron (Fe2+) and H2O2 in solutions produced with deionized water (DW) and hospital wastewater (HWW), at pH close to neutrality. YKL-5-124 concentration When solar irradiation in the SPF process was carried out the best ANZ removal rates were found under the following conditions (i) for the DW matrix, [ANZ]0 = 50 μg L-1, [Fe2+] = 5 mg L-1, and [H2O2]0 = 25 mg L-1, achieving 95% primary ANZ elimination; (ii) for the HWW matrix, [ANZ]0 = 50 μg L-1, [Fe2+] = 10 mg L-1(multiple additions), and [H2O2]0 = 25 mg L-1, achieving 51% primary ANZ elimination.