PTA wastewater sectionalizing separating and cobalt-manganese recycling method

Abstract

The invention relates to a PTA wastewater sectionalizing separating and cobalt-manganese recycling method. The method comprises three independent reaction steps, wherein the first step is a PTA wastewater fine particle foreign material filtering step comprising removing a fine particle foreign material through a solid-liquid separation device and adjusting the pH value to recycling PA and PT acids with the pH value of 3-5; the second step is a pH value-adjusting and iron-removing step comprising introducing the wastewater into a first-section regulating tank and carrying out oxidation coagulation with the pH value of 6-6.5; and the third step is a pH value-adjusting and cobalt-manganese removing step comprising introducing the wastewater into a second-section regulating tank and carrying out oxidation coagulation with the pH value of 9-9.5. The steps are simple and are independently separately performed, the PA and PT acids are recycled, cobalt and manganese ions in the wastewater are greatly reduced, the load of wastewater treatment is reduced, and the cost is saved.

Description

technical field [0001] The invention relates to a wastewater treatment method, in particular to a PTA wastewater treatment method. Background technique [0002] In the process of PTA production, in addition to a large amount of organic compounds such as benzoic acid, polyphthalic acid, and isophthalic acid, the wastewater produced also contains metal compounds such as cobalt and manganese, which are derived from terephthalic acid. The catalyst in the production process, when the catalyst is used for a period of time, the activity of the catalyst weakens, and cobalt and manganese ions enter the sewage treatment system along with the wastewater. After being treated by the activated sludge method, cobalt and manganese ions enter the sludge phase from the liquid phase and are gradually enriched, and the sludge is sent out for treatment after dehydration and pressure filtration. [0003] The accumulation of cobalt and manganese metal ions in the sludge of PTA sewage treatment sy...

AI Technical Summary

Problems solved by technology

[0003] The accumulation of cobalt and manganese metal ions in the sludge of PTA sewage treatment system is one of the important reasons leading to the decrease of sludge activity and poor settling performance. Even if flocculant is added, sludge dehydration is still difficult. Mud treatment cost, but also brought secondary pollution to the environment

The content of cobalt and manganese metal ions in the waste sludge discharged every year exceeds the standard. Due to the limitation of traditional recycling technology, the separation of cobalt and manganese cannot be realized, which not only wastes metal resources but also brings harm to the environment. The stench seriously pollutes the environment, and the treatment of sludge has become a difficult problem in the environmental protection work of the chemical industry