Olsen Boyer (artcamp91)
The economic analysis depicted a significant influence of operating costs, and the electricity consumed in the processes is responsible for the largest share of expenses. The reuse water presented a cost ranging between US$ 1.08/m3 and US$ 1.80/m3. INCB054329 nmr The systems with pretreatment by coprecipitation with Ca(OH)2 and CaCO3 and monoacids to adjust the pH of the final effluent showed to be more eco-efficient than the other options under analysis.A high-performance thin film nanocomposite (TFN) membrane containing graphene oxide (GO) nanosheets was constructed using a support-free interfacial polymerization (SFIP) technique. In this study, an ultrathin composited polyamide (PA) nanofilm was synthesized at the free piperazine (PIP)-GO suspension/trimesoyl chloride (TMC) interface, followed by transfer onto a polysulfone (PSf) UF substrate. The impact of GO loading (0, 0.1, 0.5, or 1 mg/mL) on the physiochemical properties, surface morphology, and hydrophilicity of the composited PA layer and membrane separation performance was investigated. It was found that the GO-modified TFN membranes showed ultra-high hydrophilicity due to the increase in the number of carboxyl and hydroxyl groups in the PA layer. We propose that GO nanosheets play a key role in improving membrane permeability because a strong hydration layer is formed between the water molecules and GO (embedded in the PA layer), acting as a protective film and minimizing the chance of foulants contacting the membrane surface. Compared with TFC, TFN-GO-0.5 simultaneously exhibited a higher water permeability of up to 12.8 L·m-2·h-1·bar-1 (58.1% higher than the TFC membrane) and a higher Na2SO4 rejection of approximately 98.4%. Moreover, the introduction of GO nanosheets into TFN membrane resulted in an improved antifouling performance. This facile SFIP method reveals the potential of GO nanosheets for the development of high performance TFN membranes.The uranium (U) concentrations and isotopic composition of waters and sediment cores were used to investigate the transport and accumulation of U in a water system (tailings pond, two lakes, and the Kalix River) receiving mine waters from the Kiruna mine. Concentrations of dissolved U decrease two orders of magnitude between the inflow of mine waters and in the Kalix River, while the concentration of the element bound to particulate matter increases, most likely due to sorption on iron‑manganese hydroxides and organic matter. The vertical distribution of U in the water column differs between two polluted lakes with a potential indication of dissolved U supply from sediment's pore waters at anoxic conditions. Since the beginning of exposure in the 1950s, U concentrations in lake sediments have increased >20-fold, reaching concentrations above 50 μg g-1. The distribution of anthropogenic U between the lakes does not follow the distribution of other mine water contaminants, with a higher relative proportion of U accumulating in the sediments of the second lake. Concentrations of redox-sensitive elements in the sediment core as well as Fe isotopic composition were used to re-construct past redox-conditions potentially controlling early diagenesis of U in surface sediments. Two analytical techniques (ICP-SFMS and MC-ICP-MS) were used for the determination of U isotopic composition, providing an extra dimension in the understanding of processes in the system. The (234 U)/(238 U) activity ratio (AR) is rather uniform in the tailings pond but varies considerably in water and lake sediments providing a potential tracer for U transport from the Kiruna mine through the water system, and U immobilization in sediments. The U mass balance in the Rakkurijoki system as well as the amount of anthropogenic U accumulated in lake sediments were evaluated, indicating the immobilization in the two lakes of 170 kg and 285 kg U, respectively.China encounters heavy air pollution caused by coal consumption. China and the EU aim to decrea