Process for treating chemical wastewater by phenolphthalein coagulation

Abstract

The invention provides a process for treating chemical wastewater by phenolphthalein coagulation, belonging to the field of energy conservation and environment protection. The process comprises the steps as follows: firstly, feeding an amount of alkali liquor to sewage to regulate the pH value of the sewage to 9-10 and feeding a phenolphthalein solution prepared from alcohol, wherein phenolphthalein is intrinsically easily soluble in the alcohol and is insoluble in water, and when the phenolphthalein solution is fed to the sewage, phenolphthalein is separated out greatly to form plenty of colloidal insoluble substances due to the effect that the alcohol is soluble in the water; then, feeding 0.3-1.2% of coagulant FeSO4 and 0.01-0.03% of aided mixer polyacrylamide (PAM) and then stirring uniformly to form a lot of high-density flocculent easily-settled complexes; and settling the sewage by an inclined-tube sedimentation tank, thereby removing suspended organic matters in the sewage. According to the process, the treatment efficiency can be improved by 10-20% in general; and meanwhile, as an amount of phenolphthalein with low cost is fed, the concentration of the suspended matters in the sewage is increased and the addition of the coagulant is reduced; and therefore, the operating cost can be saved by 5-10%.

Description

technical field [0001] The invention is mainly aimed at the fields of energy saving and environmental protection, and is mainly aimed at a large amount of high-concentration organic wastewater with refractory biodegradable organic matter discharged from chemical enterprises. The invention is expected to well solve the problem of difficult removal of refractory biodegradable organic matter in chemical wastewater. Background technique [0002] Life is inseparable from chemical products, and chemical companies also discharge a large amount of chemical wastewater while producing chemical products. The biggest feature of chemical wastewater is that the content of organic matter is extremely high, and it is difficult to be digested and decomposed by microorganisms. Traditional biological aerobic oxidation tanks and anaerobic digestion tanks cannot remove organic matter in chemical wastewater very well. Therefore, the removal effect of physical and chemical methods on this type o...

AI Technical Summary

Problems solved by technology

[0003] The biggest disadvantage of coagulation treatment of organic wastewater is that a large amount of coagulant needs to be invested. The cost of coagulant itself is relatively high. Simply adding coagulant will make the cost or expense of treatment relatively high, which is unbearable for enterprises.

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