Method for repairing cadmium contaminated soil

A cadmium-contaminated soil and cadmium-contaminated technology, applied in the field of soil remediation, can solve problems such as occupation of large land and dust pollution.

Active Publication Date: 2016-03-23
SICHUAN LOMON TITANIUM IND CO LTD +1
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

Titanium gypsum is usually disposed of in open-air accumulation. Long-term accumulation will inevitably occupy a large amount of land, and the dust generated by long-term accumulation will pollute the environment.

Method used

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  • Method for repairing cadmium contaminated soil
  • Method for repairing cadmium contaminated soil
  • Method for repairing cadmium contaminated soil

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0047] Weigh 5kg of cadmium-contaminated soil in Mianzhu City, Sichuan Province, pH=4, CEC=14.25cmol / kg, soil cadmium content 1.5mg / kg. After soaking the cadmium-contaminated soil, add 0.1kg raw material composition including 73% CaSO 4 , 14% Fe 2 o 3 , 5% MgO, 1% Al 2 o 3 , 2% SiO 2 , 1.5%P 2 o 5 , 2%TiO 2 , 1.5% of impurities such as zirconia and strontium oxide, of which Fe 2 o 3 It is titanium gypsum in the form of ferric hydroxide colloid, mix it evenly, and keep the soil water content at 30% of the field water holding capacity. After 90 days, the effective cadmium content in the cadmium-contaminated soil was reduced by 24% when DTPA was used as the extractant.

Embodiment 2

[0049] Weigh 10kg of cadmium-contaminated soil in Mianzhu City, Sichuan Province, pH=6, CEC=16.32cmol / kg, soil cadmium content 0.6mg / kg. After soaking the cadmium-contaminated soil, add 0.6kg raw material composition including 82% CaSO 4 , 10% Fe 2 o 3 , 3% MgO, 0.5% Al 2 o 3 , 1.5% SiO 2 , 1%P 2 o 5 , 1%TiO 2 , 1% of impurities such as zirconia and strontium oxide, of which Fe 2 o 3 It is titanium gypsum in the form of ferric hydroxide colloid, mix it evenly, and keep the soil water content at 40% of the field water holding capacity. The effective cadmium content in the cadmium-contaminated soil was reduced by 33% when DTPA was used as the extractant.

Embodiment 3

[0051] Cadmium-polluted soil in Mianzhu City, Sichuan Province, pH=5.32, CEC=14.14cmol / kg, soil cadmium content 1.36mg / kg. Evenly spread the cadmium-contaminated soil on the plastic film to prevent leakage. The thickness of the soil is 15cm. After soaking the cadmium-contaminated soil, the raw material composition includes 4 (75.09%), Fe2 o 3 (11.53%), MgO (3.76%), Al 2 o 3 (0.85%), SiO 2 (1.95%), P 2 o 5 (1.27%), TiO 2 (1.55%), other impurity zirconia, strontium oxide etc. (4%), pH=8.9, the titanium gypsum of CEC=16.6cmol / kg is pulverized to particle diameter≤8mm, adds 4% of cadmium polluted soil mass, uses rotary tillage Apply it evenly to the cadmium-contaminated soil, and keep the soil water content at 35% of the field water capacity. The effective cadmium content in the cadmium-contaminated soil was reduced by 31% when DTPA was used as the extractant.

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Abstract

The invention relates to a method for repairing cadmium contaminated soil and provides a method for repairing soil cadmium contamination through titanium gypsum. The method is short in repairing period, low in cost and free of secondary pollution to the soil, and improves the use value of waste solid titanium gypsum. After the cadmium contaminated soil steeps in the field, the titanium gypsum is evenly added into the soil, and the water content of the soil keeps 30-40% of the field capacity; the raw titanium gypsum comprises CaSO4, Fe2O3, MgO, Al2O3, SiO2, P2O5 and TiO2; the Fe2O3 exists in a ferric hydroxide colloid form. The method has the beneficial effects that the titanium gypsum is added into the soil, so that the pH, CEC and Eh of the soil are effectively improved, the content of cadmium easily absorbed by plants is reduced, the bio-availability of the cadmium is decreased, and the repairing period is short; the titanium gypsum contains a large number of microelements needed by growth of plants, such as Fe, Mg, Ca and S, so that the yield of crops is improved, and no pollution is generated to the soil; efficient utilization of the titanium gypsum soil is achieved, the cost is low, and popularization is easy.

Description

technical field [0001] The invention relates to the technical field of solid waste utilization and soil remediation of heavy metal pollution, in particular to a method for remediating soil cadmium pollution. Background technique [0002] Cadmium is a non-essential element for the human body. When the soil is polluted, cadmium can accumulate in the organism, enter the human body through the food chain, accumulate in the human body, and seriously endanger human health. Because cadmium damages the renal tubules, the patient develops diabetes, proteinuria and amino acid urine, especially the metabolism of bones is blocked, resulting in a series of symptoms such as osteoporosis, atrophy and deformation. The main sources of soil cadmium pollution are deposition in the atmosphere, use of pesticides, fertilizers and plastic films, sewage irrigation, sludge fertilization, and accumulation of heavy metal wastes. [0003] In the soil-plant-human transmission pathway, the role of soil ...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): B09C1/08C09K17/08C09K109/00
CPCB09C1/08B09C2101/00C09K17/08C09K2109/00
Inventor 范先国陈葵黄佳乐武斌廖纪华姚恒平周晓葵
Owner SICHUAN LOMON TITANIUM IND CO LTD
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