The use of NF and RO membrane system for reclamation and recycling of wastewaters generated from a hard coal mining

Abstract

In this study, the possibility of treatment of wastewater generated from underground hard coal mining excavation was experimentally investigated using Nano filtration (NF) and Reverse Osmosis (RO) membrane systems. Two-stage sequential treatment method was applied to perform the study. In the first stage, the raw wastewater was treated using NF membrane filtration system without any pre-processes. In the second stage, the effluents of NF membrane system were fed into RO membrane system for the treatment. To determine the treatment performance of the NF and RO membrane system, the operating pressures were fixed at 10, 20 and 30 bar (KN/m 2 ) for both systems during the experimental study. Turbidity, sodium, calcium, magnesium, manganese, iron, copper, aluminium, ammonium, sulphate and electrical conductivity were analysed in raw wastewater and permeate flow of NF and RO membrane systems to determine the treatment performances. Treatment performance of RO membrane system was observed to have highest yield of80% for all parameters examined at 20 bar operating pressure. Keywords: Polymeric membrane, wastewater treatment, coal excavation, water recycle and reuse