Design On Azo Dyes Wastewater Treatment Process For A Dye Company In A Development Zone

A dye company is located in economic and technological development zone in the west of Inner Mongolia.Development zone is located in the upper reaches of the Yellow River.According to China’s Environment Bulletin,Chinese 2010-2013 years,the water quality of the Yellow River section where the zone located is excellent,belong to Ⅱ～Ⅲ class.In 2013 the water quality of the Yellow River is slightly polluted.The water section’s rates of Ⅰ～Ⅲ,Ⅳ～Ⅴ and substandard Vclass are respectively 58.1%、25.8%and 16.1%.The major pollution indicators are ammonia nitrogen,BOD5 and COD.The high-quality water must be protected,once water environment was polluted and destroyed,restoring it was a long and difficult process,it may cause the inestimable losses to the economy,society,environment and life.A dye company product azo dyes,including reactive brilliant red,acid red,reactive blue,reactive yellow and other 4 kinds of azo dyes,designed annual output of 25000 tons.The wastewater generated from the dye company including the dye wastewater in the process of production,which consists of the mother liquor and wash water of product process;boiler drainage and domestic wastewater.The recent total amount of wastewater is 2600～2850 t/d,forward 4200～5000 t/d.Recent water quality is mixed.Wastewater treated is excluded into the sewage treatment plant in industrial park,the wastewater can be reused after advanced treatment from sewage treatment plant.According to the ingredient of dye wastewater,which is discharged by dye production companies,the total amount of water,the indicators and limit emissions concentration in the effluent water quality indicators by emission standard execution,recommending two kinds of combined biological processes as the process for dye wastewater treatment,respectively bioelectrochemical technology(BEH-BCO)and biological hydrolysis and zeolite MBR(BH-MBR)technology,and made a investment estimation for two engineering project.According to" Dye Industrial Wastewater Treatment Technology Specification HJ 2036-2013”,the construction scale of each processing unit in sewage treatment plant designed by the the maximum daily flow,the capacity of wastewater is 2850 m3/d.Scheme 1 wastewater treatment process:coarse screen-fine screen-aeration adjustment mix pool-flocculation pool-sedimentation pool-bioelectrochemical hydrolysis pool_－biological contact oxidation pool-radial flow sedimentation pool-general rapid filter-disinfection contact pool,sludge treatment process:sludge pumping station-dewatering.The total investment of engineering is 27.3671 million yuan,in which the first part project investment is 23.19 million yuan,the second part other expenses of the engineering construction is 168.17 ten thousand yuan,basic reserve funds is 208.71 ten thousand yuan,working capital is 40.83 ten thousand yuan.The total cost of engineering is 679.25 ten thousand yuan,in which the operating cost is 544.46 ten thousand yuan,fixed assets depreciation is 116.27 ten thousand yuan,amortization cost is 13.45 ten thousand yuan,interest payment is 5.06 ten thousand yuan.Scheme 2 wastewater treatment process:coarse screen-fine screen-aeration adjustment mix pool-flocculation pool-sedimentation pool-biological hydrolysis pool-A2/O-membrane pool-general rapid filter-disinfection contact pool,sludge treatment process:sludge pumping station-dewatering.The total investment of engineering is 39.1077 million yuan,in which the first part project investment is 33.633 million yuan,the second part other expenses of the engineering construction is 204.54 ten thousand yuan,basic reserve funds is 302.70 ten thousand yuan,working capital is 40.23 ten thousand yuan.The total cost of engineering is 726.43 ten thousand yuan,in which the operating cost is 536.45 ten thousand yuan,fixed assets depreciation is 168.64 ten thousand yuan,amortization cost is 16.36 ten thousand yuan,interest payment is 4.98 ten thousand yuan.According to the nature of dye wastewater,final disposal of sludge is considered that sludge dewatered is pressured for mud cake sinotrans to landfill and conducted a sanitary landfill with city life garbage.By comparing economic and technology of these two process schemes,recommending bioelectrochemical technology as the core treatment process for sewage treatment.