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.