The effect of catalyst on the formation of disinfection by-products in catalytic ozonation

• Main Authors: Yu-Sum Tsai, 蔡育松
• Other Authors: Kuan-Chung Chen
• Format: Others
• Language: zh-TW
• Published: 2009
• Online Access: http://ndltd.ncl.edu.tw/handle/94993883667651076720

碩士 === 國立屏東科技大學 === 環境工程與科學系所 === 97 === There are two kinds of research. First, were be used of difference catalysts and catalyst dosage on heterogeneous catalytic ozonation for degrade of para-chlorobezonic acid (pCBA). Experimental parameters included ozone dose(2.5mg/L), catalyst dosage(0、0.5、1.0、1.5、2.0 mg/L) and catalyst type(TiO2/α-Al2O3、FeMn-oxide). In the part of actual water treated, were applied heterogeneous catalytic ozonation system with ultrafiltion unit and heterogeneous catalytic ozonation system with biotreatment unit for the control of chlorinated disinfection by-products(THMs and HAA9). Raw water was carried out on sample taken from Wo-Luo River Wetland , Pingtung. The experimental control parameters included ozone dose(2.5mg/L), catalyst dosage (0.5、1.0、1.5 mg/L)、ceramic membrane pore size(5KD)and biotreatment date(1 day). Result of pCBA experiment, when TiO2/α-Al2O3 catalyst in different catalyst dosage condition, response initial 5 minutes react, the pCBA concentration fell to 5.81, 5.39, 5.06, 4.59μM, and FeMn-oxide catalyst were 4.83, 4.36, 3.93 as well as 4.25μM, respectively. The way of independent ozone only has 6.63μM. That meant catalytic ozonation to compare the independent ozone ways could be able to produce the massive hydroxyl free radical, and may degeneration the effective promotion pCBA. In raw water treated, when the catalyst dosage parameter was 0.5mg/L on ozonation system, DOC and UV254 removed rate were 21.6 and 58.5%. Furthermore, after the ultrafiltion and biotreatment unit, DOC and UV254 removed rate could up to 58.8、73.1 and 76.8、76.3%, respectively. The enhanced of DOC and UV254 removal efficiency accompany increase with the catalyst dosage for difference processes. The show of results, adsorb capability of NOM and generated OH radical to mineralize NOM ability that will be increase with the catalyst dosage. The influence of THMs and HAA9, when the catalyst dosage parameter was 1.5mg/L on ozonation system with UF unit, THMs and HAA9 removed rate were 80.9 and 76.1%, respectively. Also its elimination effect is approximate in the biotreatment ability and that meant catalytic ozonation system following ultrafiltration ways to be possible the short time effective control and removes the DBPs. In bromate production of influence, the increase of catalyst dosage, only has 0.91～0.96μg/L in the catalytic ozonation system to production for the bromate. Furthermore, following after ultrafiltration and biotreatment unit, regarding bromide as well as bromate concentration all not obvious changed.