Sludge treatment process

Abstract

The invention discloses a sludge treatment process which comprises the following steps of: (1) diluting sludge with water; (2) pouring the diluted sludge to a stirring tank, and then adding a sludge modifier according to the weight before the sludge is diluted and then stirring, wherein the sludge modifier is prepared from the following raw materials: 40-70 percent of modified dolomite and 30-60 percent of magnesium chloride; (3) pumping the sludge in the step (2) to a plate-and-frame filter press and carrying out filter pressing and dewatering, wherein a spring is arranged between every two filter frames of the plate-and-frame filter press, the springs are uniformly distributed around the filter frames, and a feeding valve is arranged on a feeding pipe; (4) naturally drying the sludge dewatered in the step (3) at normal temperature; and (5) taking sludge as a combustion raw material, a cement raw material or a fertilizer raw material and bagging. By adopting additives and the mechanical filter pressing method, moisture in the sludge is removed, the moisture content in the sludge is lower than 45 percent, and heavy metals are solidified in the sludge and cannot be absorbed by root systems of plants, therefore damages to soil and human bodies cannot be caused.

Description

technical field technical field [0001] The invention relates to waste treatment, which is a sludge treatment process. Background technique [0002] The sludge produced after the treatment of domestic water and industrial wastewater contains extremely complex heterogeneous bodies such as organic debris, bacterial cells, inorganic particles, and colloids. Since the water content of the sludge is as high as 85%, it is very easy to rot. Smelly, seriously polluting the environment. Since the dehydration of sludge is an extremely difficult technology, countries all over the world initially used the landfill method for sludge treatment. However, with the advancement of technology, it was found that the landfill of sludge did not eliminate pollution and caused serious damage to water. Resources and crops have serious harm. After entering the 1980s, the treatment of sludge has been greatly improved. At present, the better method that can really dehydrate and treat the sludge is:...

AI Technical Summary

Problems solved by technology

At present, the better method that can really dehydrate and treat the sludge is: ① Fry the sludge to remove the water and reach below 75%. The method of using solids as raw materials for fuel is insufficient. Yes: Investing in a sludge treatment production line requires more than 80 million yuan, and the operating cost is extremely high. Based on the 10-year life of the equipment in the process, it costs 500,000 yuan to process one ton of sludge, and the operating cost is about 180 yuan / ton; ②Many countries use power generation tail gas to dry sludge and use solids as raw materials for fuel. The disadvantages of this method are: large investment and high operating costs, and it takes 10-12 to process one ton of sludge. 10,000 yuan, the operating cost is about 200 yuan / ton; ③The sludge is fermented and made into fertilizer. Its shortcoming is that heavy metals such as mercury and zinc in the sludge are easily absorbed through the root system of the plant, making the food and vegetables Heavy metal content exceeds the standard, which is harmful to human health

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