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This objective of this research was to study is to investigate several factors affecting the removal efficiency of hexavalent chromium from synthetic wastewater and natural organic matter (NOM) by a dead-end nanofiltration membrane under controlled conditions. Different factors were the concentrations of hexavalent chromium derived from synthetic wastewater, natural organic matter (NOM) concentration, pH solution, mixed solution’s speed, and controlled pressure. Experimental results found that increased concentrations of hexavalent chromium from synthetic wastewater caused more fouling on nanofiltration membrane surface, thus enhancing flux decline and decreasing chromium rejection. Hexavalent chromiums from synthetic wastewater containing NOM showed greater flux decline than those without NOM. Increased pH solution from 3 to 10 resulted in greater flux decline and hexavalent chromium removal. Increased mixed solution’s speeds from 0 to 400 rpm decreased flux decline caused by a reduced solution accumulation on NF membrane surface. Increased operating pressures caused a reduction in chromium rejection. This was attributed to high operating pressure allowing hexavalent chromium passing through membrane surface. Increased NOM concentration resulted in increased hexavalent chromium rejection due to the combination between NOM and hexavalent chromium separated from NF membrane surface.
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