Potential Analysis And Technical Research Of Energy Conservation And Emission Reduction In Washing Industry

In response to global warming, the international community has conducted a number of climate negotiations. Mandatory energy saving and emission reduction tasks of the developing countries become the focus of the negotiations. During the "11th five-year "plan, our country has made remarkable achievements in energy conservation and emissions reduction. But during the "twelfth five-year", we also have a long way to go. Under the global trend of energy saving and emission reduction, in order to further promote the pace of China’s energy conservation and emissions reduction, increasingly growing washing industry cannot stay aloof and continue to use non-sustainable model of development. Otherwise, it will cause many problem, such as a large waste of resources and excessive discharge of pollutants. Washing industry of some developed countries has developed relatively mature and reached the stage of industrialization. They pay more attention to energy saving and emissions reduction of washing industry and take some measures from various aspects.According to laundries number, size, equipment parameters of a second-tier provincial cities in our country, this paper calculates water and energy consumption and pollutant emissions of washing industry each year. So washing industry of our country has a great potential of energy conservation and emissions reduction. It will provide a basis for strengthening energy management and making emission reduction policies of washing industry.On this basis, it further studies on the technology and process for water conservation and emissions reduction, which is suitable for washing industry in China. From the view of reusing wastewater from washing, it is mostly reused to domestic water in the existing research. However, it will cause lots of problem such as that the treatment of LAS, renovation of pipeline and water balance is difficult. According to the characteristics of wastewater generated from the different washing program, this paper will adopt reasonable wastewater treatment and reuse project to avoid the above mentioned problems that may occur.Because of the bad quality of first washing wastewater and high cost of treatment, it is difficult to treat and reuse wastewater from the first washing program. While direct emissions will bring great pressure to the municipal sewage treatment. After preliminary treatment of coagulation and sedimentation, the first washing wastewater can be discharged on standard. Based on the comparison of processing effects of different coagulants for the first washing wastewater in different dosage. PAC was finally chosen as the best coagulant. And the best dosing quantity is180mg/L. The removal rate of LAS is81.83%, and turbidity is79.79%, and COD is54.23%, total phosphorus and ammonia nitrogen is97.93%and24.3%.Water quality of the second and third washing wastewater is relatively good, and its quantity is two-thirds of the total water consumption. So the effluent from the treatment of the second and third washing wastewater can be reused to the first washing program. Compared with biological and chemical method to treat wastewater, the physical method is better. So filtration-adsorption method is chosen to treat the second and third washing wastewater. In different conditions of filter height, water flow velocity and filters, granular activated carbon and ceramic is the final choice as the best combination filter. In order to reduce the water hardness and detergent dosage, there is ion exchange resin on the bottom of filter. Through the experiments, the COD removal rate of the second and third washing wastewater can reach83.9%of the maximum. And turbidity can be reduced by75.9%, hardness can be reduced by99.43%, ammonia nitrogen, total phosphorus and LAS can be reduced by66.39%,63.18%and59.74%. The effluent is basically colorless.According to the research results, the overall process of washing wastewater treatment and reuse is designed in this paper. The effluent from coagulation sedimentation treatment can be directly discharged. The effluent from filtration adsorption process is used for the first time washing process as the influent. The influent of the second and third washing program is urban water.According to the potential analysis of energy saving and emission reduction and technology research of washing wastewater treatment and reuse for washing industry, you can figure out that more than five million tons washing water can be saved every year in a provincial city of our country. And the reduction of COD will be about22.3million tons, the reduction of LAS will be about5.05million tons, the reduction of total phosphorus will be about70million tons, the reduction of ammonia nitrogen emissions will be about380,000tons.