Experimental study on paraquat wastewater with membrane separation technology

The application of the reverse osmosis (RO) and nano-filtration (NF) membranes in the ammonia nitrogen separation of paraquat wastewater was studied. The parameters of membrane flux, operating pressure, concentration and pH, and temperature etc, which affect membrane separation performance were investigated. The results showed that the rejection rate of the ammonia nitrogen were 37% and 65%, the removal efficiency of the COD were 72% and 85%, as the RO and NF membranes were operated in the best condition. The ammonia nitrogen concentration of the RO dialysate does not meet the national emission standards which need further processing.