Introduction:
Coking wastewater primarily originates from the water used in the initial cooling of coke oven gas and the coking production process, as well as steam condensation wastewater. It is a typical type of toxic and refractory organic wastewater.
Characteristics:
Coking wastewater has a high concentration of pollutants that are difficult to degrade. The presence of nitrogen in coking wastewater leads to an excessive nitrogen source required for biological purification, posing significant challenges in achieving treatment standards.
Large volume of wastewater discharge, with water consumption exceeding 2.5 tons per ton of coke produced.
Coking wastewater is highly hazardous. It contains polycyclic aromatic hydrocarbons (PAHs), which are not only difficult to degrade but are also typically carcinogenic substances, posing serious environmental pollution and direct threats to human health.
Sources:
Produced in coking plants during the production of coke, commercial gas, ammonium sulfate, and light benzene, among other chemical products.
Coking oil recovery systems adopt ammonium sulfate processes, while coking oil processing involves continuous distillation in a double-tower pipe furnace. The industrial production process includes double-furnace double-tower continuous distillation, washing, and refining.
Industrial wastewater containing phenol, cyanide, oil, ammonia, and a large amount of organic compounds is generated during coke oven gas cooling, washing, crude benzene processing, and coking oil processing.
Important Notes:
Control of influent water quality and quantity:
Based on the original statistical data of the main water sources for coking wastewater and the requirements of the design scheme, the water quality and quantity of the wastewater entering the treatment system must meet the design requirements.
Wastewater pretreatment:
To reduce the subsequent biochemical treatment load, mitigate the impact of toxic substances, stabilize the effectiveness of the subsequent biochemical treatment, and facilitate operational management, pretreatment of wastewater is necessary before entering the system.
a) Control of influent COD content:
Excessive fluctuations in influent COD can greatly impact the system operation. Therefore, it is essential to strictly control the influent COD within the design requirements.
b) Control of influent water temperature:
Wastewater from the final cooling of the old plant area, ammonia stripping, and coke oven ammonia stripping should be cooled to below 38°C through plate condensers and atomization coolers before being discharged into the equalization tank.
c) Control of oil content in influent:
Wastewater from gas condensation and turbid water from various locations should undergo gravity oil separation and flotation oil removal treatment (oil content below 30 mg/L) to reduce the oil concentration to a level that does not hinder normal microbial growth before being discharged into the equalization tank.
d) Reduction of ammonia nitrogen:
Wastewater from ammonia stripping should be initially processed through a fixed ammonia decomposition device to reduce the ammonia nitrogen concentration from 800 mg/L to 250 mg/L before being discharged into the equalization tank.
Translation in English:
Coking wastewater is primarily derived from the water used in the initial cooling of coke oven gas and the coking production process, as well as steam condensation wastewater. It is a typical type of toxic and refractory organic wastewater.
Characteristics:
Coking wastewater has a high concentration of pollutants that are difficult to degrade. The presence of nitrogen in coking wastewater leads to an excessive nitrogen source required for biological purification, posing significant challenges in achieving treatment standards.
Large volume of wastewater discharge, with water consumption exceeding 2.5 tons per ton of coke produced.
Coking wastewater is highly hazardous. It contains polycyclic aromatic hydrocarbons (PAHs), which are not only difficult to degrade but are also typically carcinogenic substances, posing serious environmental pollution and direct threats to human health.
Sources:
Produced in coking plants during the production of coke, commercial gas, ammonium sulfate, and light benzene, among other chemical products.
Coking oil recovery systems adopt ammonium sulfate processes, while coking oil processing involves continuous distillation in a double-tower pipe furnace. The industrial production process includes double-furnace double-tower continuous distillation, washing, and refining.
Industrial wastewater containing phenol, cyanide, oil, ammonia, and a large amount of organic compounds is generated during coke oven gas cooling, washing, crude benzene processing, and coking oil processing.
Important Notes:
Control of influent water quality and quantity:
Based on the original statistical data of the main water sources for coking was
tewater and the requirements of the design scheme, the water quality and quantity of the wastewater entering the treatment system must meet the design requirements.
Wastewater pretreatment:
To reduce the subsequent biochemical treatment load, mitigate the impact of toxic substances, stabilize the effectiveness of the subsequent biochemical treatment, and facilitate operational management, pretreatment of wastewater is necessary before entering the system.
a) Control of influent COD content:
Excessive fluctuations in influent COD can greatly impact the system operation. Therefore, it is essential to strictly control the influent COD within the design requirements.
b) Control of influent water temperature:
Wastewater from the final cooling of the old plant area, ammonia stripping, and coke oven ammonia stripping should be cooled to below 38°C through plate condensers and atomization coolers before being discharged into the equalization tank.
c) Control of oil content in influent:
Wastewater from gas condensation and turbid water from various locations should undergo gravity oil separation and flotation oil removal treatment (oil content below 30 mg/L) to reduce the oil concentration to a level that does not hinder normal microbial growth before being discharged into the equalization tank.
d) Reduction of ammonia nitrogen:
Wastewater from ammonia stripping should be initially processed through a fixed ammonia decomposition device to reduce the ammonia nitrogen concentration from 800 mg/L to 250 mg/L before being discharged into the equalization tank.