Question

Toxic substances and heavy metals are often present in the wastewater from industries like

• A. Chemical manufacturing
• B. Metal extraction and processing
• C. Petroleum and paper manufacturing
• D. All of the above

Answer 1

The correct option is D All of the above

Composition of wastewater generated from industries

• Wastewater is generated from industries from freshwater after using it for various purposes such as leaching, washing and flushing industrial products.
• Thus, wastewater generated from fossil fuel power plants contain traces of toxic metals such as lead, cadmium, and mercury.
• Paper manufacturing industries use chlorine compounds for bleaching of paper and thus generate wastewater containing chlorinated compounds, organic halides.
• Petroleum industry also generates toxic substances such as benzene, toluene, etc,. which are eventually released along with water.
• Metal extraction and processing industry generates metal sludge containing toxic metal hydroxides producing wastewater.
• Chemical manufacturing industries also produce toxic substances such as ammonia, phenol, etc,. in wastewater during processing and purification of chemicals such as oils, fertilisers.