Treatment of a poultry slaughterhouse wastewater using advanced oxidation processes

In the present study, different chemical species such as hydrogen peroxide, potassium persulfate, titanium dioxide, and iron salts were employed for the treatment of a real poultry slaughterhouse wastewater (poultry-SWW) under UV-C light (254 nm). The experiments lasted 150 min and were carried out in a batch photoreactor aiming at investigating the most efficient operating conditions in terms of total organic carbon (TOC) removal. UV photolysis or Fe-doped TiO2 photocatalysis were practically inefficient, while application of un-doped TiO2 resulted in 44% TOC removal after 60 min of UV irradiation. The use of 98 mM H2O2 under UV light led to 74% TOC removal after 150 min. The addition of Fe(II) ions to this system coupled with initial pH adjustment to 3 increased the TOC removal to 82.5% after 150 min. Finally, the combination of UV with 15 mM of K2S2O8 resulted in 85% TOC removal. This was the first time when the persulfate oxidation was successfully applied for SWW treatment. To assess the energy efficiency of the various photochemical treatment processes tested, estimation of the electric energy per order (E-EO, kWh/m(3)/order) was conducted. The lowest E-EO value of 226 kWh/m(3)/order was observed for the UV/K2S2O8 process and compared with other photochemical treatment technologies. The effluent quality of UV/K2S2O8 treatment complies with the discharge water quality standards of the developed countries. Therefore, it is possible to use UV/K2S2O8 process as a post-treatment after biological treatment of SWW to meet the discharge water standards and reuse the wastewater.