Water treatment using hybrid processes PAC/UF

The laboratory - scale ultrafiltration (UF) experiments were conducted to determine the effect of the presence of powdered activated carbon (PAC) on the UF process performance, in terms of flux decline and the possibilities of membranes cleaning during backwashing as well as effectiveness of the removal of organic contaminants. Polyacrylonitrile (PAN) membranes formed by the phase inversion technique were used in the UF experiments. Natural water from the Miedwie Lake was applied. Commercial powdered activated carbon CWZ 30 (Gryfskand Sp. z o.o., Hajnowka, Poland) was used as the adsorbent. PAC dosage was equal to 100 mg PAC 1'. The process was carried out in the cross - flow system. It was found that combination of UF and adsorption on PAC was more effective in organics removal than UF alone. During UF more than 57% of colour, 44% of UV254 absorbance and 42% of TOC were removed, whereas in PAC/UF hybrid processes colour removal was about 94%, UV254 absorbance - 64% and TOC - 55%. Moreover, no significant effect of PAC addition to the feed on the permeate flux was observed.