Pharmaceutical intermediates wastewater is organic wastewater with complex water quality, high concentration, high chroma, and refractory degradation. Pharmaceutical intermediates wastewater is some chemical raw materials or chemical products in the pharmaceutical synthesis process. In response to pharmaceutical intermediates wastewater with the characteristics of high COD, high salinity, high chroma, complex composition, and poor biodegradability, the currently used treatment methods are generally physicochemical pre-treatment, biological treatment, chemical treatment, reduction method, and electrolytic treatment.
(1) Physicochemical treatment
Due to the water quality characteristics of pharmaceutical intermediates wastewater, most pharmaceutical wastewater cannot be treated by biochemical method alone, so the necessary pre-treatment must be carried out before the biochemical treatment. The physicochemical treatment methods currently used mainly include coagulation, air flotation, adsorption, ammonia stripping, electrolysis, ion exchange, and membrane separation. According to the water quality characteristics of pharmaceutical wastewater, physicochemical treatment should be used as a pre- or post-treatment process of biochemical treatment in its treatment process. The pre-treated wastewater can be treated by certain anaerobic and aerobic technologies according to its water quality characteristics.
(2) Biological treatment
Biological treatment method is a conventional method for the treatment of pharmaceutical intermediates wastewater, and it is also one of the commonly used treatment methods for dye wastewater. Commonly used biological methods include activated sludge method, biofilm method, oxidation pond method, and anaerobic biological method. Biochemical treatment technology is a widely used treatment technology for pharmaceutical wastewater at present. Different pre-treatment methods and combinations of biochemical systems are used for different wastewater. Through the pre-treatment system, the inhibitory effect of some wastewater on microorganisms is reduced, and the biodegradability of wastewater is improved.
(3) Chemical treatment
Advanced oxidation technology: the purpose of the oxidation method is to destroy the chromophore or the molecular structure of the dye through the oxidation of a strong oxidant, so as to achieve the purpose of decolorization and removal. Commonly used oxidation methods include chemical oxidation, electrolysis, ozone oxidation, photooxidation, wet air oxidation, etc.
(4) Micro-electrolysis technology
Micro-electrolysis technology is currently an ideal technology for treating pharmaceutical intermediates wastewater and high-concentration organic wastewater, also known as internal electrolysis technology. It uses the potential difference generated by the micro-electrolysis material filled in the wastewater to electrolyze the wastewater without electricity, so as to achieve the purpose of degrading organic pollutants.