Treatment Of Reverse Osmosis Concentrate By TiO₂/Ti Electrode Photoelectrocatalysis Oxidation

In recent years, membrane technology is widely used petrochemical, electricity, metallurgy,pharmaceutical and other many industries. The result leads to that a great quantity of reverseosmosis concentration. Because reverse osmosis concentrate usually contain higher dissolvedorganics, higher ammonia, higher color, higher salt and other pollutants. It will have a hugedamage to the environment if it directly discharged into natural water. However, the conventionalwater treatment processes have some limitations. In this paper, it is our purpose that developing awater treatment way that can effectively remove contaminant in reverse osmosis concentrate.In this paper, TiO2/Ti photocatalysis thin film electrode was as anode, stainless steel was ascathode and UV lamp was as the light source. Photoelectrocatalysis oxidation was used to dealwith reverse osmosis concentrate. The removal rate of COD, ammonia, color and UV254wereanalyzed particularly. In addition, the change of dissolved organic matter was analyzed in reverseosmosis concentration with UV-Vis absorption spectra, three-dimensional fluorescencespectroscopy(3DEEM) and gel chromatography(GPC). The continuous flow test system basedon the static test system is established. The feasibility of this technology was studied andanalyzed, to promote its use.(1)TiO2/Ti photo-electrode was manufactured with methods of sol-gel, dipping-pulling andburning under500℃high temperature. SEM spectra showed that electrode surface element issubstantially composed of Ti elemental and surface is smooth before coating. However, theelectrode is composed into Ti and O and surface showed the porous structure after coating. Aftercoating, the main components of the electrode surface is anatase phase that has a higherphotocatalysis performance. In addition, ESR showed that photoelectrocatalysis oxidation(PEC)has a certain ability to generate hydroxyl radicals, but photocatalysis oxidation(PC) andelectrochemical oxidation (EO) doesn’t have.(2)The target contaminants were dissolved organics, ammonia and other substances inreverse osmosis concentrate. The removal of COD, ammonia, color and UV254the outfall afterreaction time by photocatalysis oxidation (PC), electrochemical oxidation (EO) or photoelectro--catalysis oxidation(PEC) is compared. The removal effect was discussed about COD, ammonia,color and UV254on the different current densities, reaction time and the UV lamp power. Theresult showed that COD removal efficiency was92.06%, ammonia concentration decreased from44.61mg/L to2.84mg/L, color removal efficiency was100%, UV254removal rate was74.22%after treated150min on the current density2.0mA/cm2, UV light intensity of30μW/cm2 condition.(3) Based on the static test system, The PEC continuous flow test system is established.The continuous mainly focused on the influence to COD, ammonia, color and UV254removalon the different current density and hydraulic retention time.