The process of treating high-temperature heat treatment waste liquid mainly includes the following methods:
1、Preprocessing stage
(1)Cooling treatment: Natural cooling: Expose high-temperature wastewater outdoors and use natural wind and environmental temperature to gradually lower the temperature of the wastewater.
(2)Heat exchanger: Using a heat exchanger to exchange heat between high-temperature wastewater and low-temperature water or cooling medium, thereby achieving the cooling of wastewater.
(3)Precipitation method: Using precipitation to precipitate solid substances to the bottom and separate the supernatant liquid.
(4)Centrifugal method: A centrifuge is used to separate high-temperature wastewater,separating solid substances from liquids.
(5)Neutralization treatment: For waste liquids with pH imbalance, neutralization treatment is required to adjust their pH value to a suitable range to prevent corrosion or affect the treatment effect of subsequent treatment equipment.
(6)Filtration: Remove suspended solids from waste liquid to prevent nozzle blockage or affect incineration efficiency.
2、Heat treatment stage
(1)Incineration method: Applicable conditions: Suitable for organic waste liquids with high COD value, high calorific value, and poor biodegradability. When the COD value of the waste liquid is ≥ 100000mg/L and the calorific value is ≥ 2500kcal/kg, incineration treatment is more economical and reasonable.
(2)Incineration process: Under high temperature conditions (usually 900 ℃~1200 ℃), the organic matter in the waste liquid is oxidized and decomposed to generate harmless substances such as water and carbon dioxide, which are then discharged into the atmosphere. During the incineration process, it is necessary to ensure good atomization effect and supply sufficient combustion air to obtain stable combustion conditions.
(3)Incineration equipment: Common incineration equipment includes incinerators, rotary kilns, etc. The incinerator can choose the appropriate furnace type and incineration process based on the physical and chemical properties of the waste liquid.
(4)Other heat treatment techniques:
Wet oxidation method: suitable for organic waste liquids with COD values between 10000mg/L and 100000mg/L and low calorific value. Under high temperature and high pressure conditions, use oxidants to oxidize and decompose organic matter in waste liquid.
High temperature steam treatment: such as the high-temperature steam sterilization technology used in medical waste treatment, it can also be used for the treatment of certain specific waste liquids. By the action of high-temperature steam, pathogenic microorganisms in the waste liquid are killed, while achieving volume reduction and stabilization of the waste liquid.
3、Post processing stage
(1)Tail gas treatment: The tail gas generated during the incineration process needs to be purified to remove harmful substances such as sulfur dioxide and nitrogen oxides, ensuring compliance with emission standards.
(2)Residue treatment: The residue generated after incineration needs to be properly treated, such as landfilling, solidification and stabilization, to prevent secondary pollution to the environment.
4、Summary
The selection of high-temperature heat treatment waste liquid treatment methods and processes should be comprehensively considered based on factors such as the nature of the waste liquid, treatment requirements, and economic benefits. The cooling and impurity separation during the preprocessing stage are key to ensuring the effectiveness of subsequent processing; During the heat treatment stage, appropriate treatment techniques and equipment should be selected based on the physicochemical properties of the waste liquid; The post-processing stage is an important step in consolidating and ensuring the effectiveness of the processing.
Post time: Jul-22-2024