Research on pollution control of dyeing wastewater in hairwork industry by ultrafiltration membrane method

In order to study the feasibility of ultrafiltration membrane technology in pollution control of hairwork industry, the dyeing wastewater with characteristics of high chroma, high chemical oxygen demand and high ammonia nitrogen was researched. The microfiltration membrane pretreatment-ultrafiltration treatment experiments were carried out in water recovery range of 50%-90%, and the trends of ultrafiltration membrane performance and pollutant interception effects analyzed. The results showed that at relatively low water recovery rate of 50%, the ultrafiltration membrane treatment intercepted 75.0% of chroma, 45.9% of UV₂₅₄, 43.7% of COD_Cr, 10.8% of electrical conductivity and 12.1% of ammonia nitrogen, respectively. When water recovery rate increased from 50% to 90%, the interception rate of the ultrafiltration membrane to each main pollution index showed a decreasing trend. At water recovery rate of 50%, the ultrafiltration membrane revealed a good interception effect on particles larger than 15 μm, but its effect on the removal of large particles decreased significantly with the increase of water recovery rate. It was concluded that 64% was the optimal water recovery rate to balance the operating effectiveness and contaminant removal capacity of ultrafiltration membrane treatment.