Passivator for treating Cd/Pb-polluted soil and polluted soil in-situ restoration method by using passivator

A technology of polluted soil and passivating agent is applied in the field of remediation of heavy metal polluted soil, which can solve the problems of complex process and high production cost, and achieve the effects of simple components, simple operation and reduced mobility.

Active Publication Date: 2016-09-21
ZHENGZHOU UNIVERSITY OF AERONAUTICS
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  • Abstract
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  • Claims
  • Application Information

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Problems solved by technology

The above passivators have achieved certain effects in soil restoration, but each method has its sco

Method used

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  • Passivator for treating Cd/Pb-polluted soil and polluted soil in-situ restoration method by using passivator
  • Passivator for treating Cd/Pb-polluted soil and polluted soil in-situ restoration method by using passivator

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Example Embodiment

[0021] The passivating agent used in the treatment of Cd and Pb contaminated soil includes three materials: biochar, red mud and monoammonium phosphate;

[0022] Biochar is prepared by 3:1 parts by weight of corn stover powder and wheat straw powder with a particle size of less than 1mm, which are pyrolyzed and carbonized under anoxic conditions at 350°C, and stored for use after measuring and packaging;

[0023] Red mud is the raw material of red mud (the tailings produced by aluminum smelting in aluminum plants). It is washed with an aqueous solution of pH=5 in the ratio of phosphoric acid and nitric acid at a ratio of 1:1 to pH=10, then air-dried naturally, and then ground into nanometers by a ball mill Grade powder, stored for later use after measuring and packaging, among which Fe in the finished red mud powder 2 O 3 The content is 8.3%, Al 2 O 3 The content is 5.8%;

[0024] Monoammonium phosphate is a commercially available chemical agent, white crystal, also known as ammoniu...

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Abstract

The invention discloses a passivator for treating Cd/Pb-polluted soil. The passivator is proportionally composed of biochar, red mud and monoammonium phosphate. When the passivator is in use, a TCLP (toxicity characteristic leaching procedure) process is utilized to evaluate the heavy metal pollution conditions in soil, the weight of the passivator is determined according to the mass ratio of the soil, and the passivator is applied into the soil many times at appropriate time intervals, thereby effectively improving the soil microenvironment. In the slightly alkaline high-reducibility soil, the mobility of Cd and Pb is greatly lowered, and the biochar can absorb abundant Cd and Pb in the soil. The nano red mud has fine particles, contains rich iron aluminum oxides, and can effectively combine Cd-Pd; the applied monoammonium phosphate and red mud further enhance the Cd/Pb adsorptivity, thereby obviously lowering the bioavailable-state Cd/Pb content in the soil, and greatly lowering the Cd/Pb content in crops. Meanwhile, the passivator has high soil environment friendliness, can not generate secondary pollution, and thus, has popularization and application values.

Description

technical field [0001] The invention relates to the remediation of heavy metal polluted soil, in particular to a passivator for treating Cd and Pb polluted soil, and also relates to a method for using the passivator to restore Cd and Pb polluted soil in situ. Background technique [0002] Heavy metal pollution has become one of the major environmental problems that threaten soil quality and agricultural product safety. Cadmium (Cd) and lead (Pb) in heavy metals are relatively common and highly toxic serious pollutants, and the two often exist together. In 2014, the Ministry of Environmental Protection and the Ministry of Land and Resources issued the National Soil Pollution Survey Bulletin. The results of the survey showed that the soil environmental quality of cultivated land in some areas is seriously polluted by heavy metals, and the Cd and Pb points exceeded the standard rate by 7.0% and 1.5%, respectively. After these toxic heavy metals enter the soil, they first affect...

Claims

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Application Information

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IPC IPC(8): C09K17/08B09C1/08C09K101/00
CPCB09C1/08B09C2101/00C09K17/08C09K2101/00
Inventor 李庆召秦小艳薛茹罗旭高军侠李春光姜灵彦
Owner ZHENGZHOU UNIVERSITY OF AERONAUTICS
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