Organic pollutants in sludge mainly include benzene, chlorophenol, polychlorinated biphenyls (PCBs), polychlorinated dibenzofurans (PCDFs) and polychlorinated dibenzodioxins (PCDDs). The organic pollutants contained in the sludge are not easily degraded and have long toxic residues. These toxic and harmful substances will cause environmental pollution when they enter the water and soil. In the sewage treatment process, 70% to 90% of heavy metal elements are transferred to the sludge by adsorption or precipitation. Some heavy metal elements are mainly derived from industrial wastewater such as cadmium and chromium. In addition, there are heavy metals derived from household life piping systems such as copper and zinc. The secondary pollution of the sludge to the environment also includes the pollution of sludge salt and the pollution of nutrients such as nitrogen and phosphorus. Higher sludge salinity will significantly increase soil conductivity, destroy plant nutrient balance, inhibit plant nutrient uptake, and even cause direct damage to plant roots.
The mud material drying system developed by Zhengzhou Dingli Group is suitable for the drying of various sludges with high viscosity. The wet sludge with about 85% water content can be dehydrated and dried into dry powder with water content below 10%. The sludge drying system operates under negative pressure and is directly heat-transferred with a heat transfer enhancement device. The dry moisture control of the material is convenient, the operation flexibility is large, and the flow rate of the product is allowed to have a large fluctuation range. The system has low temperature mechanical equipment, simple and reliable, simple structure, easy cleaning, low failure rate, continuous operation, low maintenance cost and wide application range. The sludge dryer system is widely used in activated sludge drying, sewage sludge drying, petrochemical sludge drying, paper sludge drying, printing and dyeing sludge drying, tannery sludge drying, electroplating sludge drying, municipal sludge drying. High-humidity materials such as various kinds of sludge and various kinds of sludge such as biological fermentation bacteria residue are dried.
The working principle of the new sludge dryer system is as follows: the sludge enters the guide plate of the dryer through the chute through the chute, and as the cylinder rotates, the sludge is led to the inclined lifting plate and is lifted to The center position of the cylinder gradually scatters to form a curtain, and the high-temperature airflow passes through it, so that the sludge is preheated and partially evaporated. When the sludge is spilled and moved to the movable purlins, the material is then mixed with the preheated purlinal flaps to transfer heat to the material to allow some of the water to evaporate. At the same time, the material entrained by the wing plate is lifted and sprinkled, and repeated, the material and the hot air flow are convective and contact heat exchange. At the same time, the cleaning device buried in the material also slides along the inner side of the circular arc-shaped lifting plate, and the material adhering to the inner wall of the lifting plate is swept down. After the cleaning device rotates along the vertical line with the cylinder, it is dragged on the back of the circular arc-shaped plate, and the material adhered to the outer wall of the lifting plate is cleaned. As the cylinder rotates continuously, part of the water evaporates and the sludge is further dried. At the same time, the cleaning device also plays a role in breaking up the sludge ball, and the drying speed is increased. Finally, after the sludge is dried, it becomes a loose material with low moisture and is discharged from the discharge port. For those who are interested in the sludge dryer project, you can contact our company to learn more, choose the best, quality assurance.