Multistage bioleaching reactor process and equipment for sludge treatment

Abstract

The invention relates to a multistage bioleaching reactor process and equipment for sludge treatment. The equipment comprises bioleaching reactors of multiple stages, a sludge thickening pool, aeration devices, an internal sludge reflux pump, an external sludge reflux pump, a dewatering pump, a box type press filter and the like. Composite microbial flora mainly comprising acidophilic thiobacillus, acid-resisting heterotrophic bacteria and the like is utilized, sludge is subjected to acidification in the bioleaching reactors of multiple stages under the condition that the composite microbial flora is matched with nutritional substances in an aerobic environment with appropriate temperature, finally, the pH value is decreased to be smaller than 3, heavy metals in the sludge are transferred into an aqueous phase, and mud cakes with moisture content lower than 60% can be obtained through press filtering and dewatering. The aeration devices adopt flow jetting aeration or centrifugal flow diffusing aeration, so that the power consumption is decreased by over 30% compared with that of air blasting aeration. After the sludge is subjected to bioleaching reaction, no more odors are generated, pathogenic microorganisms of over 99% are killed, the dewatering is easy, the moisture content of the mud cakes is lower than 60% in the case of not adding any medicaments, and the amount of the sludge is reduced greatly.

Description

technical field [0001] The invention relates to a method for removing heavy metals from excess sludge produced by municipal and industrial wastewater treatment, improving sludge dewatering performance, and realizing high-quality sludge dehydration, and belongs to the technical field of environmental engineering. Background technique [0002] Excess activated sludge refers to the sediment produced in the process of purifying sewage in sewage treatment plants. It contains a large amount of organic matter, nitrogen and phosphorus and other plant nutrients, and is often enriched with certain heavy metals, which is difficult to use in farmland. Recycling of excess activated sludge is one of the problems that need to be solved in current environmental governance. [0003] At present, sludge disposal methods include many types, such as: landfill, incineration, throwing into the sea, and making construction materials, etc. The agricultural use of sludge is undoubtedly one of the bes...

AI Technical Summary

Problems solved by technology

The concentration of sludge in the bioleaching reactor is very high, and the oxygenation efficiency of the blast aeration method is very low. The aeration volume must be increased, which increases the power consumption and operating cost of the bioleaching process.

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