Biochemical treatment technology is currently the most widely used technology for treating pharmaceutical wastewater, including aerobic biological methods, anaerobic biological methods, and combined aerobic-anaerobic methods.
I. Aerobic Biological Treatment
Since pharmaceutical wastewater is mostly high-concentration organic wastewater, aerobic biological treatment generally requires dilution of the raw solution, resulting in high energy consumption. Furthermore, the wastewater has poor biodegradability, making it difficult to directly achieve discharge standards after biochemical treatment. Therefore, aerobic treatment alone is not commonly used; pretreatment is usually required. Commonly used aerobic biological treatment methods include activated sludge processes, deep well aeration, adsorption biodegradation (AB process), contact oxidation, sequencing batch reactor (SBR), and circulating activated sludge process (CASS).
II. Anaerobic Biological Treatment
Successfully applied methods for treating pharmaceutical wastewater include upflow anaerobic sludge blanket (UASB), anaerobic combined bed reactor (UBF), anaerobic baffled reactor (ABR), and hydrolysis. The hydrolysis-acidification method, also known as the hydrolysis upflow sludge blanket (HUSB), is an improved version of the UASB (Ultra-Aerobic Sludge Blanket). UASB reactors offer advantages such as high anaerobic digestion efficiency, simple structure, short hydraulic retention time, and no need for a separate sludge return device. A comparative experiment was conducted between UASB and UBF (Uneven Burst Fluid) methods. Results showed that UBF exhibits better mass transfer and separation in the reaction liquid, larger biomass and more diverse biological species, higher treatment efficiency, and stronger operational stability, making it a practical and efficient anaerobic bioreactor.
III. Anaerobic-Aerobic and Other Combined Treatment Processes Since aerobic or anaerobic treatment alone often cannot meet requirements, combined processes such as anaerobic-aerobic and hydrolysis-acidification-aerobic processes demonstrate significantly better performance than single treatment methods in improving wastewater biodegradability, shock resistance, investment cost, and treatment effect. Therefore, they are widely used in engineering practice.
