How to reduce secondary pollution in industrial wastewater treatment?

2025-05-13 10:09:30

Industrial wastewater treatment is an important part of environmental protection. However, if not controlled during the treatment process, it may cause secondary pollution and further increase the environmental burden. Secondary pollution mainly includes sludge, waste gas, noise generated during the treatment process, as well as residual pollutants after treatment. To reduce secondary pollution, measures need to be taken from multiple aspects such as technology, management and monitoring. The following are the specific strategies and methods:

1. Optimize the processing technology

1.1 Selecting Efficient Treatment Technologies: Different industrial wastewater has complex components, so choosing the appropriate treatment technology is of vital importance. For instance, for wastewater containing heavy metals, chemical precipitation, ion exchange or membrane separation technologies can be adopted; For organic pollutants, biological treatment, oxidation technology, etc. can be adopted. Choosing efficient and targeted treatment technologies can reduce the by-products and pollutants generated during the treatment process.

1.2 The adoption of combined processes: Single treatment processes often fail to remove pollutants from wastewater. The adoption of combined processes can enhance treatment efficiency and reduce secondary pollution. For instance, most pollutants are first removed through physical or chemical methods, then organic pollutants are degraded through biological treatment, and the effluent quality is ensured to meet the standards through advanced treatment (such as activated carbon adsorption and membrane filtration).

Industrial wastewater treatment

1.3 Reduce the use of chemical agents In the wastewater treatment process, the use of chemical agents may bring about new pollution problems. For example, the use of large amounts of coagulants or oxidants may produce harmful by-products. Therefore, the use of chemical agents should be minimized as much as possible, and physical or biological treatment methods should be preferred. If chemical agents must be used, environmentally friendly agents should be selected and the dosage should be strictly controlled.

2. Sludge treatment and resource utilization

2.1 Sludge Reduction: Sludge produced during the wastewater treatment process is one of the significant sources of secondary pollution. To reduce the generation of sludge, sludge reduction technologies can be adopted, such as biological enhancement technology and sludge digestion technology. In addition, optimizing the treatment process and reducing the amount of sludge produced are also important measures.

2.2 Sludge Resource Utilization: Sludge contains a large amount of organic matter and nutrients, and its pollution to the environment can be reduced through resource utilization. For instance, sludge can be subjected to anaerobic digestion to produce biogas for energy recovery. Or through composting treatment, it can be made into organic fertilizer. The resource utilization of sludge can not only reduce secondary pollution but also achieve waste utilization, bringing dual benefits to the economy and the environment.

2.3 Safe Disposal of Sludge: For sludge that cannot be resourcefully utilized, safe disposal must be carried out. Common disposal methods include incineration, landfill, etc. Incineration can reduce the volume of sludge, but it will produce waste gas, which requires the installation of efficient waste gas treatment facilities. For landfill, it is necessary to select a site that meets environmental protection requirements and take anti-seepage measures to prevent pollutants from seeping into groundwater.

3. Waste gas treatment and noise control

3.1 Waste Gas Treatment During the wastewater treatment process, especially in the anaerobic treatment and chemical oxidation stages, harmful gases such as hydrogen sulfide, ammonia, and volatile organic compounds (VOCs) may be produced. If these waste gases are discharged directly, they will cause pollution to the atmospheric environment. Therefore, it is necessary to be equipped with efficient waste gas treatment facilities, such as activated carbon adsorption, catalytic combustion, and biological filters, to ensure that the waste gas is discharged up to standard.

3.2 Noise Control: The mechanical equipment in the wastewater treatment plant (such as pumps, fans, mixers, etc.) generates noise during operation, which affects the surrounding environment. To reduce noise pollution, low-noise equipment can be adopted, or noise reduction facilities such as sound insulation covers and sound insulation walls can be installed around the equipment. In addition, reasonably arranging the operating time of equipment and avoiding the operation of high-noise equipment at night or during residents' rest periods are also effective measures to reduce noise pollution.