Industrial sludge has very large differences depending on its source, mainly in its viscosity, hygroscopicity, contaminant properties, oil content, water content, organic matter ratio, and inorganic matter ratio. Compared with other sludges, the viscosity is high, the oil content is high, and the proportion of inorganic substances is high, which sometimes makes it more difficult to handle. For example, petrochemical sludge components are relatively complex and contain different types of heavy metals. The sludge volume is relatively large, and it contains a lot of fiber. The tanning industry has a large amount of mud, which can be used every day. Produce 40-80 tons of sludge/10,000 tons of wastewater, high organic content, due to the large amount of fur and blood pollution in the leather processing process, so the organic content is very high, toxic substances, S2- and trivalent chromium content is high, and three The conversion of valence chromium to hexavalent chromium has a carcinogenic effect. The electroplating sludge contains cyanide and heavy metals such as hexavalent chromium, copper, zinc, cadmium and nickel. Because the sludges in different industries are very different, it is not possible to simply apply the previous experience to deal with sludge from different industries. However, with the strengthening of environmental protection and people’s understanding of the limitations of existing sludge treatment and disposal technologies, the world Countries are investing heavily in research and development of new technologies to find more economical and rational sludge treatment solutions.
Main problems facing industrial sludge
First, the capacity of sludge disposal facilities is insufficient. Before the sludge disposal facilities are completed and put into operation, a large amount of sludge needs to be simply disposed of through wasteland, gravel pits, and garbage dumps. There is odor pollution and the risk of contamination of groundwater and soil. The surrounding residents and local governments have strongly responded.
Second, the key technologies in the process of disposal still need to be further broken. For example, sludge source reduction technology is still under discussion; sludge compost covers a large area, and the odor emitted during the composting process has not been effectively solved; the final outlet of the product after the sludge lime is dried is not resolved; Environmental risks for agricultural use after composting remain.
Third, the industrial policy guarantee system has not been established.