Performance of an integrated process combining ozonation with ceramic membrane ultra-filtration for advanced treatment of drinking water

• Integrated process includes coagulation, ozonation, ceramic UF and GAC filtration.
• Full-performance evaluations of the pilot-scale integrated process of 120 m3/d
• Turbidity, DOC, ammonia, geosmin, 2-MIB, EDCs and PPCPs are efficiently removed.
• UF membrane fouling can be controlled in situ by ozonation.

An integrated process including coagulation, ozonation, ceramic membrane ultra-filtration and activated carbon filtration was investigated for the treatment of drinking water from the micro-polluted surface water in the southern China. A pilot-scale plant with the capacity of 120 m3/d was set up and operated. Submerged flat-sheet ceramic membranes were selected with the average pore diameter of 60 nm and the filtration area of 50 m2. Quite a number of water quality parameters were evaluated including turbidity, particle counts, coliform bacteria, Cryptosporidium and Giardia cysts, dissolved organic carbon (DOC), ammonia, geosmin, 2-methylisoborneol (2-MIB), 4 trihalomethanes, 6 haloacetic acids, 8 endocrine disrupting compounds (EDCs) and 14 pharmaceutical and personal care products (PPCPs). The experimental results showed that the removal efficiencies of all the evaluated parameters ranged from 64% to 100%. The ozonation in membrane tank is very helpful both in enhancing the performance of removing multiple contaminants and in controlling the membrane fouling with ozone dosage of 2–5 mg/L at the permeate flux of 100 L/m2·h. The innovation of the integrated process was discussed based on the concept of nano-reactor to probe into the reaction activities inside the membrane pores. However, the detailed mechanisms need to be explored in the future.

The integration of UF with ozonation (i.e. UF/ozonation) in this paper merged 5 units (including pre-oxidation, sedimentation, filtration, main oxidation and UF) into one unit. Such a hybrid treatment train is much shorter and suitable for the upgrade of conventional water treatment plants in dealing with micro-polluted water sources for better supply of drinking water.Figure optionsDownload as PowerPoint slide