一.Introduction of equipment for advanced treatment and reuse of printing and dyeing wastewater
The printing and dyeing industry is a typical high-water consumption industry that consumes nearly 100 million tons of process softened water every year。The source and pollutant composition of printing and dyeing wastewater are very complicated and contain waterLarge quality changes, high organic content, high chroma (mainly colored dyes) and other characteristics, direct emission of human health and living environment has brought great harm,It also causes waste of water resources。With the increasing attention of the country and society to the requirements of environmental protection and the requirements of sustainable development, the traditional treatment methods have beenIt is increasingly difficult to meet the requirements of production and environmental protection。
Membrane separation technology is a new type of efficient and environmentally friendly separation technology. In recent years, with the continuous development and progress of membrane separation technology in China, it has made modern high technologyThe membrane separation technology (mainly ultrafiltration, nanofiltration and reverse osmosis technology) has been widely and successfully applied in the printing and dyeing industry, and has produced good resultsEconomic and social benefits, for the printing and dyeing industry to bring new opportunities for technological innovation。
二.Advanced treatment and reuse of printing and dyeing wastewater
1.The source and pollutant composition of printing and dyeing wastewater are very complex, with the characteristics of large water quality changes, high organic content and high chroma。直Exposure to emissions does great harm to human health and living environment。
印染废水处理若采取生化、物化相结合的处理工艺，出水可达到
2.The continuous increase of the economy, the continuous expansion of the scale of enterprises, and the shortage of water resources will inevitably lead to the continuous improvement of the price of water, therefore,Vigorously develop printing and dyeing wastewater reuse business, not only can save limited water resources, alleviate the increasingly prominent water tension contradiction, but also reduce sewageThe research and development center of Chunlei Company has carried out long-term research on "comprehensive treatment and reuse of printing and dyeing wastewater", and has formed its own system in combination with a large number of engineering practicesCore process treatment
3.The core process combination is as follows: Wastewater type Water Quality Type Recommended Process Remarks Secondary sedimentation tank effluent standard sand filter +UF+RO/NF suitable for small enterprises covering an areaStandard pretreatment +RO/NF is applicable to large enterprises that do not meet the standard MCR/MBR+RO/NF if other traditional processes are used, further pre-processing is requiredNo low concentration wastewater of any treatment system is substandard MCR/MBR+RO/NF. If other traditional processes are used, further pretreatment is required
4.Based on a large number of engineering practices and experimental studies, the recycling process of printing and dyeing wastewater is combined with the standard discharge and management discharge of printing and dyeing wastewaterPrinting and dyeing wastewater "energy saving and emission reduction reuse" requirements, Chunlei company established several sets of relatively perfect printing and dyeing wastewater water reuse process。
Third, sand filter +UF+RO/NF treatment process
After the pretreatment process of printing and dyeing wastewater, the CODcr, suspended matter and turbidity in the wastewater are reduced and enter the ultrafiltration treatment system, and the removal is smallerAfter the suspended matter, turbidity and chroma are entered into the subsequent RO/NF treatment system, the pollutants in the wastewater are intercepted, and the pollutants are separated and concentratedThe water meets the quality requirements of production reuse water。
4. Pretreatment +RO/NF treatment process
After the printing and dyeing wastewater is treated by the traditional biochemical or physicochemical process, the effluent from the secondary sedimentation tank (the effluent quality is good), and the suspended matter and CODcr in the wastewater are obtainedAfter effect treatment。二沉池上清液经过滤池或高效沉淀技术进一步去除废水中悬浮物和浊度，使出水SDI达到<5的要求下在Enter the subsequent RO/NF treatment system, intercept the pollutants in the wastewater, separate and concentrate the pollutants, and make the effluent meet the quality requirements of production reuse water.预处理系统：本系统采用砂滤池、快滤池或高效沉淀技术进一去除废水中的悬浮物和浊度，是出水SDI达到<5的要求。
Five, MCR/MBR+RO/NF processing process
1. Printing and dyeing wastewater is treated by traditional process or low concentration wastewater is not treated，The concentration of organic pollutants and suspended solids in wastewater is higher，By MCR or MBR processing technology，Reduce organic pollutants and suspended solids in wastewater，Enter the subsequent RO/NF processing system，Interception of pollutants in wastewater，The effluent meets the requirements for reuse water quality，Membrane bioreactor (MBR) is a new wastewater treatment technology which combines membrane separation technology with biotechnology。It uses membrane separation equipment to trap activated sludge and macromolecular organic matter in the biochemical reaction tank and separate clean water, realizing simultaneous biochemical reaction and clean water separation, eliminating the secondary sedimentation tank. MBR compact and simple unit structure is especially suitable for treating printing and dyeing wastewater with complex components and high pollutant concentration。
2.MCR process advantages: reduce the sedimentation tank, reduce the footprint, improve the reaction effect of traditional chemical coagulation compared with traditional chemical coagulation, no need to add chemicals effluent quality is good, flexible and simple operation
