Deep Phosphorus Removal from Industrial Wastewater

With the growth of industrial and agricultural production, the increase of population, and the extensive use of phosphorus containing pesticides and fertilizers, phosphorus pollution in water bodies is becoming increasingly serious. Phosphorus is one of the main nutrients required for crop growth, but if the phosphorus content in water exceeds 20mg/L, it will lead to eutrophication of the water, causing a large number of algae to reproduce, ultimately affecting the survival of aquatic organisms such as fish. Many algae also produce toxins, which affect human health through the food chain. Therefore, environmental protection departments require that wastewater must meet the secondary standard in GB8978-1996 "Comprehensive Wastewater Discharge Standard" before entering urban sewage networks.

Many treatment processes have been developed for phosphorus containing wastewater both domestically and internationally, and Table 1 compares the main processes.

Table 1 Comparison of Main Processing Techniques

Adsorption method relies on the physical or chemical adsorption between adsorbents and phosphorus in wastewater to achieve the goal of removing phosphorus. After adsorption saturation, the adsorbent is regenerated to recover phosphorus resources. This method does not produce sludge, has simple treatment equipment, generally uses a fixed bed, has no other strict requirements for incoming water, and has stable treatment effects. The key to adsorption method lies in the performance of the special adsorbent itself.

The special phosphorus removal adsorbent developed by our company has excellent adsorption performance for both inorganic and organic phosphorus in wastewater, and can treat total phosphorus in wastewater to below 0.5ppm. High adsorption capacity, fast adsorption speed, and large single batch treatment capacity for wastewater. For resin saturated with adsorption, the use of regenerants can desorb and regenerate the organic phosphorus adsorbed on the resin, and the desorbed phosphorus can be recovered as a resource. The regenerated adsorbent can be reused repeatedly, with a long service life and stable performance.

Figure 1 Process Flow Diagram

The phosphorus containing wastewater generated by a certain enterprise in Anhui province has a water quality as shown in Table 2. The lithium requirement is that the total phosphorus should be less than 1mg/L. After adsorption treatment by our company, the total phosphorus in the effluent should be within 0.5mg/L, which meets the customer's requirements.

Table 2 Water Quality Status