Treatment of pharmaceutical wastewater with polyaluminum chloride

Generation of pharmaceutical wastewater

Pharmaceutical wastewater is mainly generated in the production process, auxiliary processes, equipment cleaning, and employee living of pharmaceutical enterprises. Specifically:

Production process wastewater: This is the main source of pharmaceutical wastewater, including wastewater generated during the production of raw materials, synthesis reactions, extraction and separation processes. These wastewater typically contain high concentrations of organic matter, inorganic salts, acidic and alkaline substances, as well as drug residues.

Auxiliary process wastewater: including cooling circulating water, equipment flushing water, etc. Although these wastewater have a relatively low concentration, their volume is large, and if not treated properly, they can also have a certain impact on the environment.

Cleaning wastewater: Pharmaceutical equipment, production lines, floors, etc. need to be cleaned regularly, and the resulting cleaning wastewater also contains certain pollutants.

Domestic sewage: Wastewater generated by pharmaceutical company employees in their daily lives, although of low concentration, also needs to be treated.

Characteristics and hazards of pharmaceutical wastewater

Characteristics: Complex water quality and composition: Pharmaceutical wastewater contains various organic compounds, inorganic salts, acid-base substances, etc., with complex and variable composition. High concentration of organic matter: The COD (chemical oxygen demand) in pharmaceutical wastewater is usually very high, and organic matter is difficult to degrade. There are many substances that are difficult to biodegrade: pharmaceutical wastewater often contains antibiotics, halogen compounds, ether compounds, and other substances that are difficult to biodegrade. High impact load: Pharmaceutical wastewater discharge usually has intermittency, and the fluctuation range of pollutant concentration and acidity/alkalinity is large, causing significant impact on the treatment system. High chromaticity and strong odor: Pharmaceutical wastewater often appears dark or turbid, accompanied by a pungent odor.

Harm: Consumption of dissolved oxygen in water: The oxidation and decomposition of organic matter in water consumes a large amount of dissolved oxygen, leading to hypoxia or deoxygenation of the water and affecting the survival of aquatic organisms. Disrupting the ecological balance of water bodies: Certain substances in pharmaceutical wastewater may have bactericidal or bacteriostatic effects, affecting the metabolism of microorganisms in water bodies and disrupting ecological balance. Environmental pollution caused by drug metabolites: Pharmaceutical wastewater may contain drug metabolites, which may react chemically with other substances in the water body, producing new pollutants. Potential threat to human health: Long term exposure or ingestion of water bodies containing pharmaceutical wastewater pollutants may pose a potential threat to human health.

The principle and advantages of treating pharmaceutical wastewater with poly aluminum chloride

Principle: Poly aluminum chloride (PAC) is an efficient inorganic polymer coagulant, and its principle for treating pharmaceutical wastewater mainly includes charge neutralization and adsorption bridging. PAC produces positively charged hydrolysis products after hydrolysis in water, which can attract negatively charged suspended particles, colloidal substances, etc. in pharmaceutical wastewater, neutralize their surface charges, reduce electrostatic repulsion between particles, and make it easier for particles to aggregate and form flocs. At the same time, the polymer formed by PAC hydrolysis has a linear structure, and the active groups on its molecular chain can adsorb on the surface of multiple suspended particles, forming a "bridging" structure, further promoting particle aggregation and precipitation.

Advantages: Efficient removal of pollutants: PAC can effectively remove suspended solids, colloidal substances, and some organic matter in pharmaceutical wastewater, improving water quality. Strong adaptability: PAC is suitable for treating various types of pharmaceutical wastewater, including high concentration and difficult to biodegrade wastewater. Easy to operate: The addition and stirring process of PAC is relatively simple, easy to operate and manage. Economical: PAC has a relatively low price and stable treatment effect, which can effectively reduce the treatment cost of pharmaceutical wastewater. Environmental performance: PAC does not generate secondary pollution during use and can balance the pH value of wastewater, improving the efficiency of subsequent treatment processes.

In summary, poly aluminum chloride has significant advantages and effects in treating pharmaceutical wastewater, and is one of the important choices for pharmaceutical wastewater treatment.