Study On Approval Of Permit Limits For Key Industries In Zhangjiakou Region Based On Water Environmental Capacity

In recent years,the form of water pollution in Zhangjiakou City is severe,and the task of improving the water environment quality of the river basin is very difficult.Zhangjiakou City and the capital Beijing have a natural ecological pattern of "mountainous veins,homogeneous water,and natural gas communication".The unique geographical location also determines the urgency of improving the quality of the water environment in Zhangjiakou City.Water pollutant discharge standards are an important basis for pollutant discharge in various industries and play an irreplaceable role in improving water quality.This article mainly investigates the status of pollution emissions from key industries in the Yongding River Basin in Zhangjiakou.Key industries mainly include electricity,heat and supply,ferrous metal smelting and rolling processing,non-metallic mineral products,coal mining and washing,agricultural and sideline food processing,chemical raw materials and chemical products,wine,beverages and refining Tea manufacturing,leather,fur,feathers and their products,and footwear industries,including 9 industries.Select a one-dimensional water quality model to calculate the water environment capacity of the Yongding River Basin in Zhangjiakou,and then predict the load of the dyeing source based on the calculation results.The equal proportion allocation method was used to obtain the chemical oxygen demand,ammonia nitrogen,and total phosphorus emissions limit values for the key industries in Zhangjiakou.Finally,the concentration limits were calculated through routine analysis.Based on the above,more stringent concentration limit calculations have been performed for the discharge concentration limits of Huailai,Mule Deer,Xuanhua,Yuxian,and Zhangbei under high water environmental pressure.The main conclusions of this study are as follows:(1)According to the actual hydrological conditions of the Yongding River Basin in Zhangjiakou City and the conditions for using the water environment capacity calculation model,a one-dimensional water quality model is selected to calculate the water environment capacity.The water environmental capacities of COD,ammonia nitrogen and total phosphorus in the Zhangjiakou area of the upper reaches of the Yongding River were calculated to be 16264.44 t/a,789.15 t/a,and 183.64 t/a,respectively.(2)Based on the calculation results of the water environmental capacity and the analysis of the current state of the water environmental pressure in Zhangjiakou,the discharge limits for 9 key industries in Zhangjiakou were obtained.The emission limits for COD concentration in Huailai,Zhuolu,Xuanhua,Yuxian,and Zhangbei are as follows: Electricity,Electricity,heat and supply industry concentration limit is 34mg/L,20 mg/L for the mining industry and 23 mg/L for the coal mining and washing industry.Liquor,beverage and refined tea manufacturing industry is 99 mg/L,chemical raw materials and chemical products industry is 61 mg/L,Leather,fur,feathers and their products and footwear,agricultural and sideline food processing industry,non-metallic mineral products industry,ferrous metal smelting and rolling processing industry limit concentration of 150 mg/L emission standards.The concentration limits of ammonia nitrogen are as follows: 1mg / L for mining,2 mg/L for coal mining and washing,2 mg/L for ammonia in chemical raw materials and chemical products,and 4 mg/L for wine,beverage and refined tea manufacturing,The leather,fur,feather and its products and the footwear industry,agricultural and sideline food processing industry,non-metallic mineral products industry,ferrous metal smelting and rolling processing industry emission limits all implement 25 mg/L emission standards,The total phosphorus concentration limits in this area are in accordance with the emission standard of 0.1 mg/L.The concentration limits of COD emissions in other districts and counties are as follows: 63 mg/L for power,heat and supply industries,24 mg/L for mining,and 28 mg/L for coal mining and washing.The chemical raw materials and chemical products industry is 82 mg/L,and other industries emit according to the national standard of 150 mg/L.The limits for ammonia nitrogen emissions are as follows: 3 mg/L for the power,heat and supply industries,2 mg/L for the coal mining and washing industry,1 mg/L for the mining industry,12 mg/L for the chemical raw materials and chemicals industry,wine and beverage And refined tea manufacturing is 7 mg/L,Other industries emit in accordance with the national standard of 25mg/L.Regarding total phosphorus,all pollutant discharge units discharge in accordance with the national standard 0.3 mg/L.(3)Economic benefit analysis and environmental benefit analysis of the proposed emission limits based on the actual situation of enterprises in Zhangjiakou area,If the water pollutant discharge limits for key industries formulated in this study are implemented,the total COD emissions to the environment in Zhangjiakou’s key industries will be reduced from 1726 tons to 1180.78 tons,the reduction is about545.22 tons,the total ammonia nitrogen emissions will be reduced from 128 tons to101.49 tons,and the reduction is 26.51 tons.The reduction rates are 31.58% and20.7%.The results show that the limits of this study are practical for key industrial industries in Zhangjiakou,and provide important reference for relevant departments in Zhangjiakou.