Treatment method and treatment equipment for remedying hexavalent chromium-polluted soil

Abstract

The invention discloses a treatment method and treatment equipment for remedying hexavalent chromium-polluted soil. The treatment equipment comprises a vibrating feeding machine, a stone scrubber, a vibrating screen, a ball milling machine, a pulping machine, an adjusting tank, a stirring tank, a thickening machine, a plate-and-frame filter press and water treatment equipment. The treatment method comprises the steps as follows: (1) the polluted soil is screened or ground by the vibrating screen; (2) a material is sent into the pulping machine for pulping; (3) then pulp is sent to the adjusting tank, and the pH value is adjusted to range from 2 to 4; (4) the pulp is sent into the stirring tank to form chromium hydroxide precipitate, and the pH value is adjusted to range from 6 to 8; (5) solid-liquid separation and filter pressing dehydration are performed, and mud cakes are formed. The equipment runs stably and reliably, is convenient to mount and dismount and has the good elution effect; waste water is recycled after treatment and can be used for the cylinder stone scrubber and the pulping machine, water resources are greatly saved, and secondary pollution caused by discharge of sewage is also avoided; and the method and the equipment can also be applied to elution remediation projects of other heavy metal-polluted soil, and the use efficiency of the equipment is improved.

Description

technical field [0001] The invention belongs to the technical field of remediation and treatment of heavy metal-contaminated soil, and specifically relates to a treatment method and treatment equipment for remediation of hexavalent chromium-contaminated soil. Background technique [0002] Chromium is a hard, silvery-white metal that mainly occurs in three forms: metallic chromium, trivalent chromium and hexavalent chromium. All chromium compounds are toxic, of which hexavalent chromium is the most toxic. Hexavalent chromium is an ingestion poison / inhalation extremely poison, skin contact may cause sensitivity; it is more likely to cause hereditary gene defects, inhalation may cause cancer, and has a persistent danger to the environment. Hexavalent chromium is easily absorbed by the human body, and it can invade the human body through digestion, respiratory tract, skin and mucous membranes. The most harmful is the risk of cancer in long-term or short-term exposure or inhala...

AI Technical Summary

Problems solved by technology

Hexavalent chromium is an ingestion poison / inhalation extremely poison, skin contact may cause sensitivity; it is more likely to cause hereditary gene defects, inhalation may cause cancer, and has persistent danger to the environment

Bioremediation generally includes microbial remediation and phytoremediation. It refers to the use of plants or microorganisms to extract and enrich heavy metals in the soil, and to change their chemical forms through biological action to fix or detoxify them, thereby reducing the harm of heavy metals in the soil. However, the remediation effect has certain limitations, and it is not very suitable for the remediation of contaminated soil such as chrome slag yards

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