Pretreatment Of Fosfomycin Sodium Pharmaceutical Wastewater By Catalytic Wet Air Oxidation

Wet air oxidation (WAO) is a technology based on the elevated pressure (oxygen pressure) and temperature to oxidize toxic and non-biodegradable compounds to some simple small molecular compounds and eventually to inert end-products instead of various toxic by-products.This research was aimed at the feasibility of the treatment of the strength recalcitrant organic fosfomycin sodium pharmaceutical wastewater (Northeast Pharmaceutical Group Co., LTD) through WAO process.A discussion was first given of the influence of the main operating variables, such as temperature and oxygen partial pressure, on the removal efficiency of organics.The oxidation characters of fosfomycin sodium model wastewater with diverse concentration were studied. The results indicated that temperature is the most important factor in the WAO process, with an emphasis on the toxic structure of organophosphorus. Carbon-phosphorus bonds broke up and the toxicity of wastewater was reduced.Berberine pharmaceutical wastewater, the copper ions in which was used as the source of catalyst, and fosfomycin sodium pharmaceutical wastewater were mixed in a fixed volume ratio. The effects of copper catalyst on WAO results through the treatment of fosfomycin sodium pharmaceutical wastewater were studied. At 250℃, an oxygen partial pressure of 1.3Mpa and residence time of 30 min, the results showed the average COD (Chemical oxygen demand) removal was up to 50%, and more than 95% of organophosphorus transformed into inorganic PO43- ions, which then precipitated with Cu(II) in the form of Cu3(PO4)2.Moreover, in the presence of Cu(II), the influence of homogeneous catalyst types (Mn, Ce and Mn/Ce) on WAO process was also investigated. The COD removal of Mn/Cu, Ce/Cu and Mn/Ce/Cu catalysts was increased to 72.4%,66.7% and 57.8%. The combination of Cu(II) and Mn(II) exhibited the highest catalytic activities and the COD removal and organophosphorus transformation rate were up to 72% and 99%, respectively. Through WAO process, the B/C ratio of the wastewater increased from 0 to 0.85, which promoted the biodegradability of the wastewater.The dipping precipitation process was chose to prepare the heterogeneous catalyst. Two types of active components, copper and manganese, were carried on the support of zeolite stepwise. Roasted at 600℃for 3 h, the catalysts showed higher performance and higher stability. The COD removal were up to 82.5% and the leaching concentrations of Cu(II) and Mn(II) were 0.402 mg/L and 0.311 mg/L, respectively. The nature of the optimal catalyst was characterized with XRF (X-ray fluorescence), SEM (scanning electron microscopy), TGA (Thermo gravimetric Analysis), N2 adsorption, X-ray diffraction (XRD), and Fourier transition infrared spectroscopy (FT-IR).