The first part of the water quantity, water quality prediction and discharge standards and sewage water quality prediction and discharge standards
1. Sewage water quantity: leachate volume. Leachate is generally composed of two parts: one part for rainwater into the landfill reservoir to form leachate, the other part of the landfill waste itself contains water by compaction loss of leachate. As the project adopts a rigid scheme (using reinforced concrete structure) with a steel canopy above the landfill, rainwater cannot enter the landfill to form leachate. Therefore, the leachate generated by the landfill is mainly produced by the water contained in the landfill waste itself through the compaction outflow. According to the "Hazardous Waste Landfill Pollution Control Standards" (GB 18595-2001), the water content of landfill waste should be less than 85%. Hazardous waste that meets the admission requirements has a low water content and does not lose much water after crushing. Therefore, the amount of leachate produced during the operation is less, and the amount of leachate produced is estimated to be about 1.0t per day conservatively.
2. Other wastewater water volume. Other production wastewater water volume is as follows: washing wastewater of each workshop 12.0t/d; laboratory wastewater 2.0t/d; *** count 14.0t/d. The total production wastewater water volume generated by the hazardous waste disposal center is 15t/d. Considering 20% of unforeseen water volume, the design scale of the wastewater treatment station is 18t/d, and the treatment is done for 6h per day with the wastewater treatment volume of 3t per hour.
2.Other production wastewater volume. p>Part II. Sewage water quality prediction and discharge standards:
1. The components of landfill waste are very complex, it is difficult to accurately estimate the water quality of the leachate. However, all hazardous wastes entering the landfill should comply with the "Hazardous Waste Landfill Pollution Control Standards" (GB 18598-2001) in the "hazardous waste allowed to enter the landfill area of the control limits", therefore, this limit is used as leachate water quality.
2. Workshop rinsing sewage and laboratory wastewater is mainly rinsing the ground, equipment and experimental vessels of the rinse water, sewage contains some heavy metals. Conservative estimates, in addition to SS, the concentration of pollutants in the sewage is 20% of the concentration of pollutants in the leachate.
3. According to the water volume and water quality of each production of sewage, to determine the quality of production wastewater to be treated is shown in the table. As can be seen from the table, the concentration of organic pollutants in the wastewater is low, but the heavy metals in it will cause serious pollution of the environment. According to the owner's requirements, the production wastewater to remove heavy metals and then transported for treatment. Heavy metals in the treated wastewater are required to meet the "Comprehensive Emission Standards for Sewage" "maximum permissible discharge concentration of pollutants in the first category" and "maximum permissible discharge concentration of pollutants in the second category" Level III standards. Therefore, it is determined that the primary objective of this wastewater treatment project to remove heavy metal pollutants.
Pollutants Quality Concentration/(mg-L-1) Pollutants Quality Concentration/(mg-L-1)
Total Mercury 0.06 Total Nickel 3.80
Total Lead 1.27 Total Arsenic 0.63
Total Cadmium 0.13 Inorganic Fluoride 25.33
Total Chromium 3.04 Cyanide 1.27
Hexogenous Prices 0.63 pH 7-12
Total Copper 19.00 CODcr 76.00
Total Zinc 19.00 BOD5 25.33
Total Beryllium 0.05 NH3-N 38.00
SS 106.67