Treatment And Recycling Of Dye Intermediate H Acid Production Wastewater

Aiming at the characteristics of H acid production wastewater from a chemical industry in Shandong, the appropriate extraction agent and diluent were selected, the wastewater was pretreated by complex extraction method. The organic matter in the wastewater was enriched in the extracted organic phase, to reduce the COD of the original wastewater; The organic matter-rich extractant is regenerated and recycled after stripping, and the H acid product in the original waste water is recovered to realize the resource application of the waste water. In this paper, a new treatment method for wastewater production of H acid was developed, and the technical bottleneck of restricting the production of H acid was successfully solved.In this paper, the properties of H acid wastewater and the form of H acid in water were determined. The process conditions, such as the selection of complexing agent, the composition of extractant, the initial pH of wastewater, oil/water ratio and stripping agent concentration were studied. Based on the complexation extraction equilibrium experiment and hypothesis of reaction extraction quilibrium model, the complex extraction mechanism of extractant to H Acid was discussed. The depth treatment of wastewater was carried out by oxidation and adsorption method. The main results are as follows:1. The H acid production wastewater was pretreated with C152 extraction system, under the optimum process conditions, COD removal rate was 98.92%,raffinate COD was 784 mg·L-1;2. The extracted organic phase enriched pollutants was stripped by adding NaOH solution with 10% mass fraction to realize the regeneration of the extractant.The cycle extraction experiment showed that the extractant has good regeneration performance;3. The stripping liquid was acidified to recover the H acid product, and the product quality reached the production standard;4. The mechanism of complexation reaction shows that: The extractant was used for the complexation of H acid, three types of extracts (1:1), (1:2), (2:1) were formed in the system;5. The treatment of H acid production wastewater was carried out by activated carbon adsorption-sodium hypochlorite oxidation method, and the technical needs of enterprises for wastewater treatment was achieved.