Sludge pretreatment combined method

Abstract

The invention relates to the waste treatment technical field, in particular to a combined method used for sludge pretreatment. The combined method comprises the following steps that excess sludge generated during sewage treatment is adjusted to the appropriate concentration, pH value and temperature, and is conveyed to an ultrasonic / ozone reactor; and after treated with both ultrasonic wave and ozone, the excess sludge is finally conveyed to a sludge anaerobic digestion reactor so as to undergo post treatment or is directly dewatered to be made into agricultural fertilizer. The combined method has the advantages that the method applies ultrasonic wave and ozone to sludge pretreatment for the first time; after treatment, the dissolution rate of solid phase COD is between 5 and 35 percent, and the output of methane is increased by 50 to 75 percent; compared with treatment carried out through adopting ultrasonic wave or ozone independently, the removal rate of benzo [a] pyrene in the sludge can reach 4 to 10 percent, and energy consumption is reduced by 5 to 20 percent; therefore, the method reduces the cost in sludge treatment, and is suitable for the treatment of sludge in a sewageplant and a sewage treatment station; moreover, the method can be used in sludge pretreatment for manufacturing agricultural fertilizer, and has broad application prospect.

Description

A kind of sludge pretreatment combined method technical field The invention relates to the technical field of waste treatment, in particular to a combined method for sludge pretreatment. Background technique With the rapid development of economy and continuous progress of society, people pay more and more attention to environmental issues, and the sewage treatment rate increases year by year. However, with the use of a large number of sewage treatment plants and treatment stations, a large amount of excess sludge is produced during the treatment process. The excess sludge has a high moisture content, contains a large amount of pathogenic microorganisms and biotoxic substances, is difficult to dehydrate and stabilize, and is expensive to treat. The disposal of excess sludge has become a bottleneck problem that all sewage treatment plants and treatment stations must face at present and in the future. At present, anaerobic digestion is commonly used in sludge disposal meth...

AI Technical Summary

Problems solved by technology

The main purpose of the present invention is to overcome the shortcomings of low efficiency or high energy consumption of pretreatment of sludge with ultrasonic or ozone alone in the prior art, and to provide a combined method of ultrasonic / ozone sludge pretreatment