Ozone oxidation of photocopy wastewater in a batch reactor

The photocopy wastewater comes from the photographic film fixing, developing and bleaching processes. This kind of wastewaters is bio-recalcitrant for conventional bio-treatment processes and has great impact on neighborhood environment because of containing high concentration noxious contaminants, such as cyanide, aniline and phenol compounds. Ozone oxidation is an effective method to treat the wastewater. The wastewater was taken from a studio discharge in Zhenjiang and the ozone oxidation was carried out in a batch reactor. The results showed that cyanide, aniline compounds and CODCr were removed 92% above, 89% above and 80% around, respectively. And more importantly, the biodegradation of the wastewater was enhanced significantly (BOD5/CODCr from 0.12 to 0.54). Over the followed treatment of SBR, aniline and CODCr concentrations decreased to 0.45 mg/L and 50mg/L, respectively. Based on the results, the wastewater could meet the demands of Integrated Wastewater First-degree Discharge Standard of China.