Zolfaghari Ghasem, Kargar Mehdi
Department of Environmental Sciences and Engineering, Faculty of Environmental Sciences, Hakim Sabzevari University, Razavi Khorasan, Sabzevar, P.O. Box: 397, Iran.
MethodsX. 2019 Mar 18;6:549-557. doi: 10.1016/j.mex.2019.03.012. eCollection 2019.
This study was designed to evaluate the hybrid system performance of nanofiltration (NF) and microfiltration (MF) processes in removing the hexavalent chromium (Cr) and sulfate from water. To do so, we made a hybrid pilot, including 1 μm and 5 μm filters, sand filter, activated carbon filters, and a nanofilter. We studied the effects of various parameters on the removal of Cr from polluted water and drinking water such as pH, pressure, concentrations of chromium, concentrations of sulfate, and total dissolved solids (TDS). The selected parameters were as follows: pressure: 0.1-0.4 MPa, pH: 2-10, Cr concentration: 0.1-0.4 mg/l, and sulfate concentration: 40-500 mg/l. According to the results, the efficiency of chromium removal increased with increasing the pH, while increasing the pressure from 0.1 to 0.4 MPa decreased the removal rate of chromium. In addition, increasing the concentrations of sulfate led to a decreasing trend in the removal efficiency. According to the findings of the study, the hybrid pilot made is able to reduce the chromium and sulfate to the levels under the WHO standard (Cr = 0.05 mg/l and sulfate = 500 mg/l). •The optimal conditions for removal of Cr included the initial chromium concentration of 0.1 mg/l, pressure of 0.1 Mpa, pH of 10, and the sulfate concentration of 40 mg/l.•In general, the experimental results revealed that the fabricated hybrid system including MF, NF, sand filter, and carbon filter has the ability to remove chromium and sulfate from drinking water (tap water) at a rate of 99%.•At sulfate concentration of 40 mg/l, the TDS elimination efficiency was 97.75% and increased by 99.87% as the concentration increased to 500 mg/l. The presence of sulfate ions increases the TDS in water.
本研究旨在评估纳滤（NF）和微滤（MF）工艺的混合系统在去除水中六价铬（Cr）和硫酸盐方面的性能。为此，我们制作了一个混合中试装置，包括1μm和5μm过滤器、砂滤器、活性炭过滤器和一个纳滤器。我们研究了各种参数对从污染水和饮用水中去除Cr的影响，如pH值、压力、铬浓度、硫酸盐浓度和总溶解固体（TDS）。所选参数如下：压力：0.1 - 0.4MPa，pH值：2 - 10，Cr浓度：0.1 - 0.4mg/l，硫酸盐浓度：40 - 500mg/l。根据结果，铬的去除效率随pH值升高而增加，而将压力从0.1MPa增加到0.4MPa会降低铬的去除率。此外，硫酸盐浓度的增加导致去除效率呈下降趋势。根据该研究的结果，所制作的混合中试装置能够将铬和硫酸盐降低到世界卫生组织标准（Cr = 0.05mg/l，硫酸盐 = 500mg/l）以下的水平。•去除Cr的最佳条件包括初始铬浓度为0.1mg/l、压力为0.1MPa、pH值为10和硫酸盐浓度为40mg/l。•总体而言，实验结果表明，所制作的包括MF、NF、砂滤器和碳滤器的混合系统能够以99%的速率从饮用水（自来水）中去除铬和硫酸盐。•在硫酸盐浓度为40mg/l时，TDS去除效率为97.75%，当浓度增加到500mg/l时，去除效率提高到99.87%。硫酸根离子的存在会增加水中的TDS。
