Method for removing heavy metals from waste compost by united elution by ammonium sulfate and oxalic acid

A technology of garbage composting and combined leaching, applied in the direction of organic fertilizers, climate change adaptation, etc., can solve problems such as secondary pollution, and achieve obvious effects, obvious leaching effect, and remarkable rinsing effect

Inactive Publication Date: 2009-12-09
TIANJIN NORMAL UNIVERSITY
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0011] The purpose of the present invention is to overcome the secondary pollution problem caused by the residual artificial chelating agent and surfactant used in the matrix; use ammonium sulfate and oxalic acid combined leaching to remove heavy metals in garbage compost, and at the same time understand how the oxalic acid leaching effect is, and follow What about its leaching effect as the concentration increases, how the synergy of oxalic acid and ammonium sulfate can remove heavy metals, etc., in order to achieve the purpose of safe, effective and reasonable use of municipal solid waste composting, in order to achieve the above-mentioned purpose, the present invention provides the following Technical method:

Method used

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Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0025] 1) Compost the household garbage containing heavy metal pollution, sieve and sort, air-dry, grind, sieve, and set aside;

[0026] 2) The fine sand was treated with 1% H 2 SO 4 After cleaning, dry at 100°C for 24 hours to filter the bottom layer;

[0027] 3) Put the treated fine sand and garbage compost into the rinsing device, and use the mixture of ammonium sulfate and oxalic acid for rinsing. After rinsing, leave the leaching solution for 48 hours; the weight of the compost and the mixed solution The ratio of parts to numbers is 1:10; among them, 20mmol / L oxalic acid: 1g / L (NH 4 ) 2 SO 4 =1:2.5.

[0028] 4) Rinse the compost with water again, collect the eluate, let stand after rinsing until there is no more eluent dripping out, leave it for 24 hours, then rinse the compost for the second time, rinse three times in total, and collect the eluate;

[0029] 5) combining the eluents collected in 3), 4) and performing digestion treatment to obtain powder;

[0030]6)...

Embodiment 2

[0031] Embodiment 2 (more detailed test process is as follows)

[0032] Materials: compost (dried), sand (washed with sulfuric acid and dried), PVC pipes, oxalic acid, ammonium sulfate.

[0033] experimental design

[0034] Prepare

[0035] Take 18 PVC pipes, seal one end with a cloth, weigh 20g of sand and pour them into the pipes, then weigh 110g of compost and pour them into the pipes. Label the 18 PVC pipes as follows:

[0036] Control group: 3 were rinsed with water, and 3 were rinsed with ammonium sulfate.

[0037] Experimental group: 3 with 20mmol / L oxalic acid rinse, 3 with 40mmol / L oxalic acid, 3 with 20mmol / L oxalic acid and ammonium sulfate mixture, 3 with 40mmol / L oxalic acid and ammonium sulfate mixture .

[0038] Prepare eluent

[0039] 1) Preparation of 20mmol / L oxalic acid

[0040] Every kilogram of compost needs 20mmol oxalic acid, then 110g compost needs 2.2mmol oxalic acid, and 110g compost needs 39ml solution, if it is used with a 250ml volumetric bo...

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PUM

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Abstract

The invention discloses a method for removing heavy metals from waste compost by united elution by ammonium sulfate and oxalic acid, mainly comprising the following steps: drying the domestic waste compost and carrying out elution on the domestic waste compost with mixed solution of the ammonium sulfate and the oxalic acid, after elution, standing for 48h; carrying out elution with water every day in the same time and lasting for 2-3 times, collecting leacheate, filtering and carrying out digestion treatment and determining the change of the contents of such heavy metals as Cd, Cr, Cu, Ni, Pb and Zn in the solution; wherein, the weight ratio of the oxalic acid of 20-40mmol/L to (NH4)2SO4 of lg/L is 1:1-2.5, and the weight ratio of the compost to the mixed solution is 1:4-10.The method of the invention belongs to the phase of mature development of elution technique and is used for technical support and preparation for pushing forward remediation work of national contaminated substrates.

Description

technical field [0001] The invention belongs to the technical field of environmental protection and relates to a reasonable and safe use method of garbage composting. More specifically, it is a method for removing heavy metals in garbage compost by combined leaching with ammonium sulfate and oxalic acid. Background technique [0002] In recent decades, the global population has grown rapidly, and industrial facilities, energy development and municipal construction have also developed at an alarming rate. Due to global industrialization, large quantities of potentially toxic compounds, including heavy metals, are being released into the biosphere. A considerable part of the heavy metal discharge has entered the soil, which has polluted the soil in some areas, destroyed the normal function of the ecosystem, and also caused harm to human health. Therefore, the treatment and restoration of heavy metal-contaminated soil is very urgent Task. At present, there are two main appro...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C05F9/04A62D3/33A62D101/43
CPCY02A40/20
Inventor 多立安赵树兰保玉洁
Owner TIANJIN NORMAL UNIVERSITY
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