Method for modifying straw biochar for remediating heavy metal contaminated soil

A technology for polluted soil and straw organisms, which is applied in the restoration of polluted soil, soil conditioning materials, chemical instruments and methods, etc. The method is simple and easy to implement, and the repair efficiency is stable and reliable.

Inactive Publication Date: 2019-03-01
SHENYANG INST OF APPL ECOLOGY CHINESE ACAD OF SCI
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0004] At present, biochar has been used to remediate soil polluted by heavy metals. However, biochar is a rough carbon-rich material with complex physical and chemical properties, and it is difficult to have prominent chemical functional properties. It is widely used in environmental applications. have certain limitations and need further improvement

Method used

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  • Method for modifying straw biochar for remediating heavy metal contaminated soil
  • Method for modifying straw biochar for remediating heavy metal contaminated soil
  • Method for modifying straw biochar for remediating heavy metal contaminated soil

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0034] Example 1: Comparison of restoration effect with non-modified biochar

[0035] The specific implementation process is as follows:

[0036] 1. Bake corn stalks at 70°C for 9 hours, then dry, crush and sieving through 50 mesh;

[0037] 2. Put the powdered corn stalks into a box-type atmosphere furnace (KSFQ1100, Jiangsu Qianjin Furnace Equipment Co., Ltd.), pour nitrogen into it to maintain anaerobic conditions, heat it to 500°C and then pyrolyze it for 3 hours, then cool it to room temperature. After repeated washing with deionized water, the original biochar can be obtained after drying at 70°C for 4 hours;

[0038] 3. Then invade 30% sodium hydroxide at a mass ratio of 1:7.5, stir and repeatedly rinse with deionized water, and dry at 70°C for 4 hours to obtain alkali-modified biochar;

[0039] 4. Apply the original biochar and alkali-modified biochar into the soil (moist brown soil) contaminated by Cd (total amount 2.3mg / Kg) at a mass ratio of 1%, and then naturally age for 3 m...

Embodiment 2

[0044] Example 2: The effect of alkali-modified biochar to remediate red soil polluted by multiple heavy metals

[0045] 1. After drying the rice straw at 70°C, crush it and sieve 50 meshes;

[0046] 2. Put the powdered rice straw into a box-type atmosphere furnace, bubbling with nitrogen to maintain anaerobic conditions, heat to 400°C and then pyrolyze for 2 hours, cool to room temperature, repeatedly wash with deionized water, and dry at 70°C for 4 hours Then get the original biological carbon;

[0047] 3. Then invade 30% sodium hydroxide at a volume ratio of 1:5, stir and rinse with deionized water repeatedly, and dry at 70°C for 4 hours to obtain alkali-modified biochar;

[0048] 4. Apply alkali-modified biochar into the soil (red soil) polluted by multiple heavy metals (Pb, Cu and Zn) (total 1122.5, 153.9 and 950.2 mg / kg) at a mass ratio of 1%, and naturally age after mixing 2 months;

[0049] 5. Use 0.01moL CaCl 2 The solution extracts the effective Pb, Cu and Zn in the soil, an...

Embodiment 3

[0053] Example 3: The effect of alkali-modified biochar to remediate black soil contaminated by various heavy metals

[0054] 1. After drying the rice straw at 70°C (8 hours), crush it through a sieve of 50 mesh;

[0055] 2. Put the powdered rice straw into a box-type atmosphere furnace, bubbling with nitrogen to maintain anaerobic conditions, heat to 400°C and then pyrolyze for 2 hours, cool to room temperature, repeatedly wash with deionized water, and dry at 70°C for 4 hours The original biochar is obtained afterwards;

[0056] 3. Then invade 30% sodium hydroxide at a volume ratio of 1:5, stir and rinse with deionized water repeatedly, and dry at 70°C for 4 hours to obtain alkali-modified biochar;

[0057] 4. Apply the alkali-modified biochar into the soil (red soil) polluted by multiple heavy metals (Cr and As) (total 321.5 and 56.3 mg / kg) at a mass ratio of 1%, and naturally age for 2 months after mixing;

[0058] 5. Use 0.01moL CaCl 2 The solution extracts the available Cr and As...

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Abstract

The invention relates to a method for modifying straw biochar for remediating heavy metal contaminated soil. The method comprises the following steps: (1) feeding crop straw as a biochar raw materialto a drying oven, and smashing and sieving the crop straw to obtain powdery crop straw; (2) weighing the crop straw, placing the crop straw in a box-type atmosphere furnace, introducing nitrogen to keep an anaerobic condition, performing programmed heating to a target temperature, and keeping the final temperature for pyrolysis for 2-4 h to obtain original biochar; (3) repeatedly washing the biochar with deionized water to be neutral and drying the biochar; (4) weighing the straw biochar, soaking the straw biochar in 30% sodium hydroxide and performing stirring; (5) repeatedly washing the straw biochar with deionized water, and placing the straw biochar in the drying oven to obtain the target product, namely, alkali modified biochar. The crop straw subjected to reduction and harmless treatment can effectively immobilize heavy metal pollutants after being added to the heavy metal contaminated soil, durable and stable remediation effect is realized, secondary pollution is avoided, and the biochar is an ideal low-cost remediation agent for the heavy metal contaminated soil.

Description

Technical field [0001] The invention relates to a soil remediation agent for heavy metal pollution, in particular to a new preparation method of a soil remediation agent for heavy metal pollution. Background technique [0002] Unreasonable heavy metal mining and smelting, solid waste disposal, sewage irrigation, pesticide and fertilizer application, and atmospheric deposition and other factors have caused a large amount of heavy metals to enter the water and soil environment. They can enter the human body through direct drinking or the food chain to bring human health. It is extremely harmful to public health and ecosystem safety (Aksu et al., 2005). [0003] The in-situ passivation remediation technology of soil heavy metal pollution has attracted much attention in the application of soil heavy metal pollution remediation due to its low cost, easy operation and quick effect, and suitable for large-scale pollution control (Li Jianrui et al., 2014). At present, the key technology f...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C09K17/40B09C1/08C09K101/00
CPCB09C1/08B09C2101/00C09K17/40C09K2101/00
Inventor 徐永刚宇万太马强周桦
Owner SHENYANG INST OF APPL ECOLOGY CHINESE ACAD OF SCI
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