Silt pretreatment method for enhancing dehydration property and digestibility of silt

Abstract

The invention relates to a silt pretreatment method for enhancing dehydration property and digestibility of silt and belongs to the field of sewage treatment. The invention is characterized in that when the method is used for enhancing the dehydration property of the remained silt, adding a peroxide solution to the silt (0.4-0.6 g H2HO / g dry silt), evenly stirring, and treating the silt by microwaves at 60-80 DEG C for 3-5 minutes; and when the method is used for enhancing the anaerobic digestion efficiency of the silt, adding a peroxide solution to the silt (0.8-1.2 g H2HO / g dry silt), evenly stirring, and treating the silt by microwaves at 80-120 DEG C for 5-8 minutes. The method enhances the dehydration property of the remained active silt and reduces the amount of the silt by utilizing the feature of high-speed high-efficiency heating and the strong oxidizing action of the free hydroxide radicals resulting from peroxide under microwave radiation. The method can also be used for enhancing the anaerobic digestion efficiency of the subsequent silt, thereby reducing the energy consumption and the amount of the silt. The method has the advantages of simple equipment, convenient operation and maintenance, does not produce any secondary pollution, and has wide application prospects in sewage treatment plants in large, medium-and-small-sized cities, and at sewage treatment stations in enterprises.

Description

technical field [0001] The invention belongs to the field of solid waste treatment and disposal, and relates to a method for pre-treating sludge with microwave / hydrogen peroxide combined technology, in particular to a method of applying microwave / hydrogen peroxide advanced oxidation technology to treat sludge and improve sludge yield. Dehydration and digestibility, so as to reduce the volume and volume of sludge. Background technique [0002] Due to the increase in sewage treatment volume and the improvement of sewage treatment rate, the sludge production in my country has increased sharply in recent years. It is estimated that my country's sludge output will reach 35.6 million tons (80% water content) by 2015. Sludge dehydration can effectively reduce the volume of sludge that needs to be treated and disposed of, and is the most economical method in sludge reduction. In the sludge treatment and disposal methods such as incineration, composting, landfill, and comprehensive...

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Problems solved by technology

[0007] On the other hand, anaerobic digestion is usually used to stabilize sludge. The traditional anaerobic digestion process has the following disadvantages: the sludge residence time is long, requiring 20-30 days, so the facility occupies a large area and the infrastructure cost is high; The removal rate of organic matter is low, only about 40%

However, these methods have certain disadvantages: for example, acid-base treatment requires anti-corrosion equipment, high equipment requirements, and subsequent neutralization treatment must be carried out; ultrasonic, hydrothermal, freeze-thaw, magnetic field, etc. consume too much energy; although microwave radiation pre-treatment The thermal efficiency is high, the energy consumption is greatly reduced, but the effect is not very satisfactory, and the moisture content of the vacuum suction filtration is reduced from 85% of the raw mud suction filtration to 71% (Tian Yu et al., the effect of microwave radiation pretreatment on sludge structure and dewatering performance Influence, Chinese Environmental Science, 2006, 26(4): 459-463)

limit their application in practice

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