catalytic ozonation-activated carbon adsorption coupled processes for the treatment of pharmaceutical wastewater containing p-nitrochlorobenzene

Treatment of pharmaceutical wastewaters, especially compounds resistant to biological degradation, is very important, and various methods have been introduced to treat such wastewaters on a laboratory and experimental scale. a new designed reactor consisting advanced oxidation and activated carbon adsorption was undertaken for treating toxic pharmaceutical wastewater containing p-nitrochlorobenzene (pncb) in the pilot scale. during paracetamol manufacturing some pncb may be remained without any chemical changes depended on reaction condition. the effluent from reactor may have some concentration of the pncb, which can cause a lot of problems if discharged directly into the environment. organic substance and pncb concentration of the influent and effluent of the reactor was investigated for 30 days in two phases. the first phase of operation included the achievement of stable conditions and the second phase included the survey of removal efficiency by changing the operational parameters. raw wastewater was entered directly into the reactor through overhead distillation column in process of paracetamol manufacturing. the wastewater flow ranged from 3.8 to 16 m3/day during two phases. the average efficiencies for the pncb concentration removal were 99.4 % for the phase i and 98.0% for phase ii. cod removal efficiency of 97.8% was achieved for the reactor. although oxidation process is effective in removing pncb, but the most effect was related to absorption process. this study demonstrates that application of simultaneous ozonation and adsorption processes is effective for treating wastewater containing pncb.