Device for removing heavy metals in sludge by using electro-dynamic method and synchronously and deeply dehydrating sludge

Abstract

The invention relates to a device for removing heavy metals in sludge by using an electro-dynamic method and synchronously and deeply dehydrating sludge in a process of conveying digested sludge. The device comprises a sludge conveying pipeline, a sludge pump, a direct-current power supply, electrodes and ion exchange membranes / porous medium membranes, wherein the treatment object of the device is anaerobic digestion sludge; the electric remediation is implemented in the sludge conveying process in the pipeline; a positive electrode and a negative electrode are arranged on the inner wall of the pipeline; a positive chamber and a negative chamber are formed in two sides of the pipeline; the ion exchange membranes / porous medium membranes are arranged in the positive chamber and the negative chamber; the gap between the electrodes and the ion exchange membranes / porous medium membranes is filled with an electrolyte solution; the positive electrode and the negative electrode are connected with the power supply by virtue of a lead. By virtue of the device, the heavy metals in the sludge are removed by electrodialysis and electrolysis techniques in the process of conveying the anaerobic digestion sludge via the pipeline; meanwhile, the partial water in the sludge can be removed under the action of the ion exchange membranes / porous medium membranes; the device can be used for effectively utilizing the conveying power, and is convenient to operate; the subsequent resource utilization of the sludge can be facilitated.

Description

technical field [0001] The invention belongs to the technical field of environmental protection, and in particular relates to a synchronous deep dehydration device for removing heavy metals in sludge by electrokinetic method in anaerobic digestion sludge. Background technique [0002] In recent years, my country's urban sewage treatment rate has increased year by year, and the sludge output of urban sewage treatment plants has also increased sharply. Sludge is rich in organic matter, which can be used as a biomass energy source. The rich nitrogen, phosphorus, and potassium in sludge are indispensable nutrients for the growth of plants and crops, and can be used as fertilizers and soil improvers. At the same time, a certain amount of heavy metals will accumulate in the sludge. Heavy metals are non-degradable and toxic. If the sludge is not properly treated, it will cause secondary pollution to the environment and directly affect the resource utilization of the sludge. Theref...

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Problems solved by technology

[0003] In the prior art, the treatment methods of heavy metal polluted sludge mainly include: (1) solidification / stabilization, which is to chemically transform or introduce harmful waste into a certain stable lattice, or use inert materials to In the process of being contained, heavy metals may be leached and redissolved in this method, and in terms of resource utilization, this method will also be gradually replaced; (2) Chemical reagent extraction method, using chlorination, ion exchange, acidification The complexation of chelating agents and surfactants makes insoluble metal compounds form soluble metal ions or metal complexes, but this method consumes a lot of chemical reagents, and the residual chemicals will also affect the sludge. (3) Microbial leaching method, through the oxidation of iron and sulfur in the sludge by bacteria, the oxidation-reduction potential of the sludge increases and the pH value decreases, thereby dissolving heavy metals, and then leaching the dissolved heavy metals (4) Incineration, the incineration method to treat sludge can decompose toxic and harmful components in sludge and enrich heavy metals, but it is necessary to effectively control combustion conditions and post-combustion (5) Phytoremediation, the restoration of heavy metals in sludge by plants is achieved through plant stabilization, plant volatilization and plant absorption. This method is based on theoretical system, restoration mechanism and Restoration technology needs to be improved

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