Wastewater membrane filtration technologies

Vourch et al49 studied the applicability of the RO process for the dairy industry wastewater. The treated wastewater total organic carbon (TOC) was <7 mg/L. It was found that in order to treat a flow of 100 m3/d, 540 m2 of the RO unit is required with 95% water recovery. Dead-end NF and RO were studied for the treatment of dairy wastewater.50 Permeate COD, monovalent ion rejection, and multivalent ion rejection for the dead-end NF were reported as 173-1095 mg/L, 50-84%, and 92.4-99.9%, respectively. When it comes to the dead-end RO membranes, the values for permeate COD, monovalent ion removal, and multivalent ion removal were 45-120 mg/L, >93.8%, and 99.6%, respectively. Membrane filtration technology can be better utilized as a tertiary treatment technology and the resultant effluent quality will be high. There can be situations where the treated effluents can be reused (especially if RO is used for the treatment). 

On the other hand, membrane filtration technology has been highly effective in the removal of turbidity and bacteria. Membrane filtration technology is a simple technology that provides high reliability, and it is approved for tap water tieatinent. Furthermore, membrane filtration technology is being considered for wastewater treatment in municipal wastewater or plant wastewater. 

Different technologies have been developed in recent years to treat the wastewaters contaminated with heavy metals. Chemical precipitation, coagulation-flocculation, flotation, ion exchange, and membrane filtration can be employed to remove heavy metals from contaminated wastewater.6 However, they have inherent limitations in application mainly due to the lack of economical feasibility for the treatment of large volumes of water with a low metal concentration. Furthermore, the major disadvantage of conventional technologies is the production of sludge.9... 

Treatment processes for wastewater reuse and water treatment usually have adopted process such as biological treatment, coagulation, sand filtration, membrane filtration and activated carbon adsorption [168]. Recently, membrane filtration in water treatment has been used worldwide for reduction of particle concentration and natural organic material in water. Among the membrane processes, nanofiltration (NF) is the most recent technology, having many applications, especially for drinking water and wastewater treatment [169]. 

---