Method for treating coking biochemical effluent by microwave-oxidation-coagulation technology

Abstract

The invention provides a method for treating coking biochemical effluent by microwave-oxidation-coagulation technology, which comprises the following steps of: A, adding a mixed reagent consisting of H2O2 and Fe2+ into the coking biochemical effluent until the mass concentration of hydrogen peroxide in water is between 0.01 and 1 percent, and controlling the pH to between 2.0 to 6.0; B, delivering the mixed liquid into an industrial microwave oven for processing for 5 to 60s; C, regulating the pH value of the mixed liquid to between 6.0 and 6.5 or 7.5 and 8.5, and carrying out oxidation treatment for 1 to 4 hours under an aeration condition that the aeration rate is 10 to 40m<3>/h; D, adding a coagulant into the liquid until the mass concentration of the coagulant in the liquid is betweenone millionth and one hundred thousandth; E, precipitating and separating; F, filtrating the liquid to obtain process effluent for recycling; and G, collecting sludge, separating the liquid from the sludge; and returning the liquid to the step D, and filter-pressing the sludge to obtain sludge cakes. The method realizes recycling, does not discharge sewage, and effectively solves the problem thatpresent coking sewage is difficult to treat and to recycle.

Description

technical field [0001] The invention relates to a method for treating coking biochemical effluent, in particular to a method for treating coking biochemical effluent by microwave-oxidation-coagulation technology, which belongs to the technical field of sewage treatment. Background technique [0002] Coking sewage is the sewage formed during the high-temperature carbonization process of coal, as well as the process of gas purification and chemical product refining. The pollutants in the sewage are various and complex, except for NH 3 -N, cyanide, thiocyanate, phenolic compounds, polycyclic aromatic compounds, heterocyclic organic compounds containing nitrogen, oxygen, sulfur, the overall property is NH 3 -N, high concentration of phenols and oils, many toxic and inhibitory substances, so it is a typical industrial organic wastewater with high concentration, high pollution, high toxicity and refractory degradation, which is very difficult in the existing biochemical treatment ...

AI Technical Summary

Problems solved by technology

[0003] At present, the sewage produced in my country's coking production process contains high concentrations of pollutants such as phenol, cyanide, ammonia nitrogen, and COD. After being treated with the existing biochemical system, it is still difficult to meet the discharge and reuse standards for COD, total cyanide, and chroma. Achieving standard treatment and reuse of coking sewage has become one of the difficult problems in sewage treatment

For example, a company in Yunnan uses a nitrification-denitrification process system to treat sewage generated in the coking production process. The design treatment capacity of the system is 50m 3 / h, the actual processing capacity is 105m 3 / h, plus the dilution water and defoaming water in the system, the total water output is 200m 3 / h, daily average sewage discharge 4800m 3 / d, the system is in good condition. Although the content of phenol, cyanide, ammonia nitrogen and other pollutants in the treated external drainage is lower than the national discharge standard, the average concentration of COD in the external drainage of the system is close to the national standard critical value, sometimes exceeding the standard phenomenon, it needs to be diluted to meet the standard before it can be discharged, and the effluent color is relatively high. Therefore, the external discharge of the nitrification-denitrification sewage treatment system in the prior art cannot meet the requirements of production reuse

At the same time, the daily discharge is 4800m 3 biochemical effluent of 1,752,000m per year 3 The biochemical effluent has not realized the internal circulation of coking production water. On the one hand, it causes a great waste of water resources, and on the other hand, the environmental water body still needs to bear a considerable degree of pollution.