Abstract
With the continuous advancement of society and rapid development of the pharmaceutical industry, the discharge of pharmaceutical and chemical wastewater has emerged as a pressing challenge—its volume is expanding, and it poses non-negligible risks to environmental health. Pharmaceutical and chemical wastewater is typically characterized by high salinity, complex composition, and high organic load, making its treatment extremely challenging. Nevertheless, efforts to treat such wastewater and implement real-time water quality monitoring must be sustained. This paper aims to elaborate on the fundamental characteristics of pharmaceutical and chemical wastewater targeted for detection, focusing on the following three aspects:
1.High Inorganic Salt Content
The high inorganic salt content in pharmaceutical and chemical wastewater stems from the extensive use of acidic and alkaline reagents during pharmaceutical manufacturing processes. Neutralization reactions between these reagents generate inorganic salts, and the total salinity of some wastewater streams can exceed 100,000 mg/L. Such high salt concentrations inhibit microbial growth in aquatic environments: for instance, excessive chloride ions (Cl⁻) cause osmotic stress in microbial cells, leading to plasmolysis and even cell death. The depletion or inactivation of microorganisms impairs the biodegradation of macromolecular organic compounds in water, potentially triggering sludge bulking and subsequent effluent non-compliance with discharge standards.
2.Elevated BOD₅and COD Concentrations
Untreated pharmaceutical and chemical wastewater discharged into natural water bodies leads to rapid depletion of dissolved oxygen (DO), inducing hypoxia that threatens the survival of aquatic microorganisms and disrupts aquatic ecosystems. The complex and highly variable nature of this wastewater results in a high content of refractory organic matter, which perturbs the nutrient balance of the receiving water. Therefore, rigorous treatment is imperative prior to discharge. Post-treatment, water quality must be verified using analytical instruments to ensure compliance with regulatory standards—this step is critical for safeguarding ecological integrity and public health.
3.Presence of Hazardous Pollutants
In addition to the aforementioned characteristics, pharmaceutical and chemical wastewater contains toxic contaminants such as phenols, cyanides, and nitrogenous compounds. Untreated discharge of these pollutants into natural water bodies causes persistent pollution, posing substantial risks to both ecosystems and human health.
