What is pharmaceutical wastewater?

What is pharmaceutical wastewater?

1. Pharmaceutical wastewater refers to the wastewater generated by pharmaceutical factories during the production of traditional Chinese medicine or Western medicine.
2. Classification of pharmaceutical wastewater: It mainly includes four categories: wastewater from antibiotic production (biopharmaceutical), wastewater from synthetic drug production (chemical pharmaceutical), wastewater from traditional Chinese medicine production, and washing and rinsing wastewater from various preparation production processes.
3. Characteristics of pharmaceutical wastewater:

(1) Drug production involves obtaining raw materials through chemical synthesis and separation and purification from medicinal plants. Due to the different types of drugs, different production processes, and complex procedures, there are many types of raw and auxiliary materials. The production process requires strict quality control of raw materials and intermediates, resulting in low net material yield and numerous by-products. Consequently, pharmaceutical wastewater exhibits characteristics such as large differences in composition, complex components, high pollutant content, high COD, low and fluctuating BOD5/CODcr ratio, poor biodegradability, many recalcitrant substances, high toxicity, intermittent discharge, and large fluctuations in water quantity, quality, and pollutant types, posing significant challenges to treatment. (2) Although the quality of pharmaceutical wastewater varies depending on the products, raw materials, and processing methods, it is generally characterized by high levels of organic pollutants, numerous toxic substances, a high content of non-biodegradable substances, and high salt content. It is a highly hazardous type of industrial wastewater, and its indiscriminate discharge can cause significant environmental damage.

4. Main hazards of pharmaceutical wastewater:

(1) Pollutants in pharmaceutical wastewater can react chemically with each other or with substances in the water, producing new pollution. For example, nitrosamines are potent carcinogens. If the wastewater contains substances such as oxytetracycline, azithromycin, and aminopyrine, these substances can react with sodium nitrite in an acidic medium to produce dimethylnitrosamine.

(2) When organic matter undergoes biological oxidation and decomposition in water, it consumes dissolved oxygen. Excessive organic matter content can lead to oxygen deficiency or deoxygenation in the water, causing the death of aerobic aquatic organisms and the proliferation of anaerobic microorganisms. Anaerobic digestion produces substances such as methane, hydrogen sulfide, alcohols, ammonia, and amines, further inhibiting aquatic life and causing the water to turn black and smelly. (3) Some drugs and their synthetic intermediates often have certain bactericidal or bacteriostatic effects, thereby affecting the metabolism of microorganisms such as bacteria and algae in the water and ultimately disrupting the balance of the entire ecosystem of the water body. For example, when penicillin, tetracycline and chloramphenicol are present in the water, they can inhibit the growth of green algae.