Drying Technology
Printing and dyeing wastewater occupies a large proportion of industrial wastewater treatment, which will produce large amounts of sludge after treatment. In the past, the printing and dyeing sludge was mainly treated by temporary landfill way. This method not only occupied a large amount of land, but also caused damage to the ecological environment. In particular, the leachate in the printing and dyeing sludge would pose a serious threat to groundwater resources. With the improvement of national environmental protection policies and people's awareness of environmental protection, the problem of reducing, harmless, and resourceful treatment of printing and dyeing sludge is imminent. Today we will mention the characteristics of printing and dyeing sludge and its current advanced disposal technology in this article.
Classification of Printing and Dyeing Textile Sludge
Printing and dyeing sludge is mainly classified by composition, which is divided into two types: organic sludge and inorganic sludge.
The sludge produced by biological treatment of sewage is organic sludge, which is mainly composed of organic matter. In addition, it also includes oil sludge and sludge formed by the precipitation of solid organic matter in wastewater, etc.
Inorganic sludge is mainly composed of inorganic substances. Also called sludge, it is the sludge produced after the sewage is treated by chemical treatment methods, such as coagulation sedimentation and chemical sedimentation.
Main Characteristics of Printing and Dyeing Textile Sludge
The characteristics of organic sludge are high organic matter content, easy to decay and smell, fine sludge particles, often in the state of flocs, low relative density, high moisture content, strong water holding capacity, not easy to sink, compact or dehydrate. Therefore, it is convenient for pipeline transportation due to good fluidity.
Inorganic sludge is mainly composed of inorganic substances, whose characteristics are high relative density, large group particles, and easy to be precipitated, compacted and dewatered. The particles have poor water holding capacity, low water content, good sludge stability, non-corrosion, and poor fluidity, so it is not easy to transport by pipeline.
Current Advanced Disposal Technology of Printing and Dyeing Textile Sludge
Notice: Although it is the same printing and dyeing sludge, due to the different printing and dyeing process, the generated sludge is divided into two types: general solid waste and hazardous waste. Be sure to distinguish when disposing.
Treatment of printing and dyeing sludge with hazardous waste properties:
Due to its special nature, the sludge can only be entered into a hazardous waste treatment plant with professional treatment qualifications for professional treatment, mainly high-temperature incineration, and the remainder is fly ash, which is finally landfilled. However, the cost of disposal is high, usually several thousand yuan per ton, which is not a small economic burden for many companies. As a result, some unscrupulous companies take risks, stolen and evacuated are not uncommon, which has a bad impact on the environment. Shincci's drying equipment for the reduction of hazardous waste before leaving the factory is highly sought after by enterprises. This equipment is easy to install, stable in operation, significant reduction and low energy consumption, which can greatly reduce the volume of hazardous waste, thereby greatly reducing the transportation and disposal costs of hazardous waste printing and dyeing sludge, and reducing corporate expenditures.Up to now, the Luohuang Sludge Disposal Center has processed more than 87,167 tons of wet sludge， and more than 23,360 tons of dry sludge has been incinerated in the boiler.
General waste solid printing and dyeing sludge:
Printing and dyeing sludge contains a large amount of chemical residues. The internal water content is high and it is difficult to be dewatered. The composition is very complicated, the content of harmful substances is equal to that of domestic sludge, and it has certain special characteristics such as viscosity. After mechanical dehydration, the moisture content is about 80%. In terms of treatment technology, it has been dry landfill before and then dry incineration.
Dry landfill: Direct landfill through simple mechanical dehydration, simple process and extensive treatment methods regardless of the consequences, which have a great impact on the environment.
Dry incineration: How can sludge with 80% moisture content achieve the purpose of incineration? The first is to dehydrate and dry, reduce the moisture content to about 40%, and reach the target of incineration. The problem of how to dehydrate is presented to people. The goal of drying and dewatering can be achieved through many processes such as mechanical dewatering, plate and frame, electric power, etc., but the operating cost is too high, so that enterprises cannot afford.
The printing and dyeing enterprises themselves have coal-fired boilers, steam boilers, and biomass boilers to maintain the high-temperature heat energy required in the printing and dyeing process. Printing and dyeing enterprises will generate a large amount of flue gas waste heat in the boiler during the heating process. If the waste heat flue gas is used in the drying and dewatering of printing and dyeing sludge, the drying and dewatering cost will be greatly reduced, and the drying efficiency will be greatly increased. The industrial waste heat sludge drying equipment SBWHD series and the new generation SHS-WHD series developed by Shincci perfectly interpret this concept and apply it. The dried sludge after drying has a calorific value of about 2000 calories, which can completely replace part of the coal for blending. Burning and utilization, so as to solve the problem of high dehydration and drying costs and difficult later utilization and disposal.
Shincci waste heat sludge drying equipment has been applied to printing and dyeing sludge treatment projects. As of today, there are 33 projects at home and abroad that have been commissioned and the equipments are operating stably. Among them, the largest printing and dyeing project has a daily processing capacity of 385 tons of wet sludge. Some of the projects are in production, transportation, installation and commissioning, and the data will be updated in real time. The technology of Shincci waste heat sludge drying equipment is mature and fully achieves the expected goal, which has been well received by printing and dyeing enterprises.
In recent years, it has been discovered that printing and dyeing enterprises produce some ash after incineration during their own sludge disposal process, which needs further treatment. With the help of the government, the ash and slag finally enter the building materials enterprises to make bricks and tiles, and finally the sludge is treated to zero residue.
The brick and tile kiln enterprises that receive the ash and slag also smelled business opportunities. As the pressure on environmental protection increases year by year, the country is gradually shutting down high-energy-consuming and high-polluting enterprises. Although brick factory building materials companies continue to invest in environmental protection equipment to reduce pollution, they are still at risk. If they can assist the government in disposing of solid waste, it can change the nature of the company and become an environmentally friendly solid waste disposal company.
So how can brick and tile building materials companies make a good transition? As early as 2011, building materials companies in Jiangsu, Zhejiang, Guangzhou and other regions used Shincci's waste heat equipment to combine electric energy with kiln waste heat and flue gas, dry sludge, and mix it with shale after drying to make bricks and tiles.
The company has transformed itself as well as succeeded in solving part of the brick-making raw materials, and was able to get the government sludge treatment fee. This is a solution that kills three birds with one stone for the brick and tile kiln enterprises.
