Cyclone electrofiltration recovery device and application thereof in treatment of heavy metals in sludge

Abstract

The invention provides a rotational flow electro-percolation recovery device and application of the rotational flow electro-percolation recovery device to treatment of heavy metal in sludge. The device comprises a cylinder body, an anode bar, a rotational flow unit, a filtering combination layer and a catholyte circulation system, the catholyte circulation system comprises a catholyte chamber and a circulation pipeline; a sludge inlet and a sludge outlet are respectively formed in two axial ends of the cylinder body, the cylinder body comprises an inner cylinder and an outer cylinder, a filter combination layer and a catholyte chamber are arranged between the inner cylinder and the outer cylinder, the anode bar is arranged in the cylinder body, and the filter combination layer comprises a cation permeable membrane far away from the inner cylinder. The application comprises the following steps: 1, filling a catholyte chamber with the catholyte, and electrifying the rotational flow electro-filtration recovery device; 2, feeding sludge into the rotational flow electro-filtration recovery device through a sludge inlet by adopting a sludge pump so as to remove heavy metals. The method is applied to removal of heavy metals in sludge, is simple to operate, and has the technical advantages of high removal efficiency, low energy consumption and environmental protection.

Description

technical field [0001] The invention relates to the technical field of heavy metal recovery, in particular to a cyclone electrodiafiltration recovery device and its application in treating heavy metals in sludge. Background technique [0002] With the rapid development of the urban sewage treatment industry, the sludge output, which is a by-product of sewage treatment, has also increased accordingly. In the sewage treatment process, more than half of the heavy metals will be transferred to the sludge, resulting in a general increase in the content of heavy metals in the sludge. Although sludge contains more nutrients such as nitrogen and phosphorus, it can be used as fertilizer for agricultural use, but when there are high levels of heavy metals in sludge, if it is used as fertilizer for agricultural use, it will not only cause soil heavy metal pollution, but also It will increase the heavy metal content of agricultural products; when precipitation occurs, some heavy metals...

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Problems solved by technology

Heavy metal immobilization technology can reduce the harm of heavy metals to a certain extent in a certain period of time, but it can only play a mitigating role, and cannot fundamentally reduce the content of heavy metals

When the external environment changes, the fixed heavy metals are at risk of being released

The main methods for removing heavy metals in sludge are: (1) Chemical leaching, which has a good effect on removing heavy metals from sludge, but acidification of sludge requires a large amount of chemical reagents, and it is difficult to properly handle high-concentration heavy metal leachates , so the cost of this method is high, the actual operation is complicated and not environmentally friendly; in addition, the acidification treatment will dissolve the organic matter such as nitrogen and phosphorus in the sludge to a certain extent, and reduce the fertilizer value of the sludge

(2) Bioleaching, which has the advantages of less acid consumption, low operating cost, and strong practicability; however, bioleaching requires stricter technological conditions for removing heavy metals under natural conditions, and is easily disturbed by external conditions, making heavy metals The removal effect is unstable

(3) The electrochemical method is an electrochemical method for effectively removing heavy metal ions in sludge. Although this method has the advantages of high removal efficiency, short treatment cycle, no secondary pollution, and easy recovery of heavy metals, it has high energy consumption and With the prolongation of treatment time, the anode is prone to fouling, which not only consumes more energy, but also reduces the removal effect of heavy metals due to the incomplete contact between heavy metals in the sludge and the anode; in addition, the existing electrochemical method has limited redox ability, Directly limit the removal effect of oxidizable and reducible heavy metals

[0004] In summary, there is an urgent need for a cyclone electrodiafiltration recovery device and its application in the treatment of heavy metals in sludge to solve the problems of low removal efficiency, high energy consumption and unenvironmental protection of heavy metals in sludge existing in existing electrochemical methods. The problem

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