Chemical industrial parks bring together numerous different types of enterprises, generating wastewater characterized by complex composition, high toxicity, and wide concentration fluctuations. This makes treatment much more challenging than single-source industrial wastewater. The key question for park management is, "What special considerations are needed when treating this complex chemical wastewater?"
The primary consideration for treating chemical industrial park wastewater is establishing a system that combines quality-based pretreatment with centralized treatment. Wastewater from all enterprises must not be mixed and treated directly. Each enterprise in the park must pre-treat high-concentration, highly toxic wastewater at the workshop outlet to meet the park's acceptance standards before discharge to a centralized sewage treatment plant. Inclined plate sedimentation tanks play a crucial role in the primary treatment unit of centralized treatment plants. Their efficient sedimentation capacity can handle the large amounts of inorganic suspended solids and heavy metal hydroxides that may be present in industrial park wastewater, and their compact design is also suitable for treating large water volumes.
Secondary biological treatment is the core of degrading organic pollutants, but the bioinhibitory properties of chemical wastewater present the greatest challenge. Therefore, the installation of dissolved air flotation (DAF) as a backup unit prior to biological treatment is essential. Dissolved air flotation (DAF) can effectively remove emulsified oil, colloids, and some toxic substances from wastewater, providing a more stable and safer environment for subsequent microbial growth and significantly improving the biochemical system's ability to withstand shock loads. For certain specific pollutants, such as persistent organic matter that is difficult to degrade, advanced treatment processes such as advanced oxidation may be necessary.
Given the critical importance of wastewater treatment in chemical parks, system stability and redundancy are crucial considerations. Many large parks tend to adopt a modular, integrated treatment equipment concept to construct certain treatment units or pilot plants. This modular design facilitates future expansion, and maintenance of a single module does not affect overall system operation. A well-designed industrial park wastewater treatment system often incorporates a combination of technologies, including inclined plate sedimentation tanks, DAF, bioreactors, and advanced oxidation equipment, supported by a highly automated monitoring system to ensure 24/7 stable and standard discharge.
