Method for removing harmful substances in sludge by using nano zero-valent iron

A nano-zero-valent iron and harmful substance technology, applied in the fields of sludge treatment, chemical instruments and methods, water/sludge/sewage treatment, etc. Advanced problems, to achieve the effect of low cost, simple structure and obvious effect

Inactive Publication Date: 2013-01-23
TONGJI UNIV
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

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Problems solved by technology

These methods generally have high operating costs, long processing time, and largely cannot remove the odor of sludge, and are also ineffective for the storage of heavy metals.

Method used

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  • Method for removing harmful substances in sludge by using nano zero-valent iron
  • Method for removing harmful substances in sludge by using nano zero-valent iron
  • Method for removing harmful substances in sludge by using nano zero-valent iron

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Experimental program
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Effect test

Embodiment 1

[0040] The sludge is collected from anaerobic digestion sludge of a sewage treatment plant. The content of sulfide (hydrogen sulfide, methyl mercaptan, dimethyl sulfide, dimethyl disulfide) in the sludge is between 0.0001-0.00047 ppm. The pH is between 7.3-7.7. In this study, several sludge samples with the same sulfide content were designed, and the amount of nano-zero-valent iron was increased sequentially (0.5-5 kg). storage capacity. In order to make the experimental effect more obvious, the method of adding sulfide sludge was adopted. According to the process flow of this study, the water and the spiked sludge were mixed and stirred for 5-20 h in the mixing reaction device, and the sulfide sludge in the mixed liquid water and the sludge were respectively measured. For sulfide content, add different amounts of nanometer zero-valent iron, mix thoroughly for 1-3 hours, measure the pH and Eh of the reaction mixture, and fit the function of the pH and Eh of the solution with ...

Embodiment 2

[0042] The sludge is collected from an anaerobic digestion sludge of a sewage treatment plant. The metal (arsenic, cadmium, chromium, cobalt, copper, lead, manganese, mercury, nickel, molybdenum, selenium, titanium, zinc) content in the sludge is 0.1 -2000 mg / kg. This study is designed as two sludge samples with the same specific metal content (1000-2000 mg / kg). The same amount of nanometer zero-valent iron and micrometer zerovalent iron is added to the two samples. After the reaction is sufficient, the adsorption Metallic zero-valent iron is separated, and the removal rate of metals in sludge is determined. Here the amount of sludge is 500-1000 g and the volume of water is 5-10 L. According to the technological process of this study, the water and heavy metal-containing sludge were mixed and stirred for 5-20 h in the mixing reaction device, and the metal content in the mixed liquid water and sludge were respectively measured, and nano-sized zero-valent iron and micro-sized z...

Embodiment 3

[0044] The sludge was collected from anaerobic digested sludge of a sewage treatment plant, and the content of HCH in the sludge interstitial water was 600-800 μg / L. In this study, several sludge samples with specific content of organic pollutants (100-800 μg / L) were designed. Different amounts of nanometer zero-valent iron were added to these samples. Separation of zero-valent iron and determination of the removal rate of organic pollutants in sludge. In order to make the research effect more obvious, the method of adding standard organic pollutant sludge was adopted. According to the process flow of this research, the water and the spiked sludge were mixed and stirred for 5-20 h in the mixing reaction device, and the mixed liquid water and sludge were measured respectively. The content of organic pollutants, then 2-30 g / L nano-zero-valent iron, fully mixed for 2-50 h, and then the reaction system was separated from the sludge and nano-zero-valent iron through an electromagne...

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Abstract

The invention relates to a method for removing harmful substances in sludge by using nano zero-valent iron. The sludge is solid precipitate generated by a sewage treatment process, and is composed of microbes, organic and inorganic solids, trace heavy metals and the like. By adopting nano technology, sludge and nano iron are thoroughly mixed, so that organic compounds and heavy metals in the sludge are reduced by the nano iron, inorganic substances and reduced heavy metal ions in the sludge are adsorbed to the surface of the nano iron, and the reacted sludge and nano iron are effectively separated by an electromagnetic rake device. Compared with the conventional sludge treatment method, the invention using nano iron technology to degrade pollutants in the sludge has the characteristics of low cost, time saving and the like, and is simple to operate; the active iron, especially nano iron, can quickly degrade and stabilize the pollutants in the sludge; and the traveler-type electromagnetic rake device is utilized to recover the nano iron, thereby avoiding secondary pollution.

Description

technical field [0001] The invention belongs to the technical field of environmental protection, and relates to a technology for removing and purifying harmful substances in sludge, in particular to a method for removing harmful pollutants such as sulfides and heavy metals in sludge with nanometer zero-valent iron. Background technique [0002] In order to effectively control the severe water pollution situation, my country has gradually increased urban sewage treatment plants of different types and sizes. With the continuous increase of urban sewage discharge, as a by-product of the sewage treatment process - the generation of sludge is also increasing. According to relevant statistics, by the end of 2010, my country had built and put into operation 2,832 urban sewage treatment plants, with a daily processing capacity of 102.62 million m 3 , The national dewatered sludge production is close to 22 million tons. In addition to microorganisms and inorganic substances, sludge...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C02F11/00
Inventor 张伟贤张亚雷代朝猛陈惠玲
Owner TONGJI UNIV
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