Regardless of the source, industrial wastewater must not be discharged without treatment because it contains numerous harmful substances. These pollutants not only pose a threat to the ecological environment but also endanger human health. In this chapter, we will explore the harmful substances found in untreated industrial wastewater across different industries.
Industrial wastewater contains varying amounts of raw materials, finished products, semi-finished products, and by-products. The types of pollutants differ depending on the industry. Below is a simple overview based on ten categories:
1.Steel Plants: Wastewater from steel production primarily contains iron filings, oil, and pickling solutions.
2.Oil Refineries: Wastewater from refineries often includes harmful substances such as sulfuric acid compounds, alkalis, and oils.
3.Oil Tankers: Accidents at sea, such as oil spills or the discharge of ballast water, can result in large oil slicks on the ocean surface, disrupting the ecological balance.
4.Thermal Power Plants: The discharge of high-temperature water into surface waters reduces dissolved oxygen levels and promotes the excessive growth of algae, leading to water pollution.
5.Electroplating Industry: As a key sector in economic development, electroplating generates wastewater containing pollutants such as chromic acid, copper, zinc, cadmium, and cyanides.
6.Paper Manufacturing: Wastewater from paper production contains harmful substances like sodium sulfide, lignin, and cellulose.
7.Printing and Dyeing Industry: This common industry produces wastewater containing chromates, alkalis, detergents, and sulfides.
8.Chemical and Fertilizer Plants: Depending on the products manufactured, wastewater from these plants may contain a variety of harmful organic and inorganic compounds.
9.Food Processing: Wastewater from food production primarily contains organic materials that deplete dissolved oxygen in water.
10.Leather Tanning and Wool Washing: Wastewater from these industries not only contains large amounts of organic matter but may also harbor pathogenic microorganisms.
Regardless of the industry, wastewater must undergo disinfection, sterilization, and other treatment processes before discharge. Water Quality Detectors should then be used to test various indicators, ensuring that the treated water meets the required standards for safe discharge.
