1. Compost landfill site
Some sludge can accumulate directly after drying. Due to poor management of sanitary landfill, secondary pollution is prone to occur. In addition, relevant standards and technical policies for sanitary landfill have been formulated, and the moisture content of the mixed landfill of printing and dyeing sludge is less than 60%. In fact, the moisture content of cement cake exceeds 80%, and the direct landfill method is limited by current regulations and is not allowed. In this regard, law enforcement has been strengthened. Composting treatment is an essential fertilizer component for crop growth, as organic sludge contains nitrogen, phosphorus, and potassium. The crude protein or globulin of organic components in activated sludge is a good soil amendment. The sludge has stable properties and can be used as fertilizer, with agricultural utilization value. However, so far, the composting of printing and dyeing sludge is still unacceptable to society and has not been promoted.
2. Incineration treatment
The calorific value of dry sludge is approximately 1300-1500 kcal. Three tons of dry sludge is equivalent to 4500 kilocalories of coal, which can be mixed with coal and burned in a boiler. One ton of dry sludge can produce one ton of steam. The ratio of dry sludge to coal is 100-200 kilograms of sludge per ton of coal.
3. Using sludge to make bricks
It can be added to clay to make bricks with a mass ratio of 1:10. Its strength is equivalent to ordinary red bricks and has a certain calorific value. During the brick making process, it will self ignite and increase heat.
4. Manufacturing biochemical fiberboard
Under alkaline conditions, a series of physical and chemical changes (globulin denaturation) occur after heating, drying, and pressurization. This denaturation is used to prepare activated sludge resin (protein glue) to bond its fibers and press the board.
Generally speaking, these are all purposes mentioned above. With the maturity of sludge treatment technology, the subsequent utilization of sludge will become more diversified, and the secondary utilization of sludge will continue to be achieved, achieving true pollution-free treatment.