I. Project Overview
This plan aims to deal with wastewater that has high concentrations of organic matter, ammonia nitrogen, complex pollutant components, and in some special cases, high levels of heavy metals and salts.
II. Characteristics of Wastewater
High organic matter concentration: The wastewater contains a large amount of organic matter, such as proteins, fats, carbohydrates, etc.
High ammonia nitrogen concentration: The wastewater contains a relatively high concentration of ammonia nitrogen, which requires denitrification treatment.
Complex pollutant composition: The wastewater may contain various harmful substances such as heavy metals and salts, making the treatment more difficult.
High content of heavy metals and salts in certain special circumstances: In some specific production processes, the content of heavy metals and salts in the wastewater may suddenly increase, posing a challenge to the treatment process.
III. Common treatment processes
Equalization tank + coagulation sedimentation + anaerobic reactor + A/O + MBR + NF + RO
- Equalization tank: Homogenizes and equalizes the wastewater to ensure the stable operation of subsequent treatment processes.
Coagulation and sedimentation: By adding coagulants and flocculants, suspended solids and colloidal substances in wastewater are removed.
Anaerobic reactor: By utilizing the metabolic action of anaerobic bacteria, it decomposes organic matter in wastewater into substances such as methane and carbon dioxide.
The A/O process, which stands for anoxic/aerobic biological nitrogen removal, eliminates ammonia nitrogen from wastewater through nitrification and denitrification.
MBR: Membrane bioreactor, through the filtration effect of the membrane, removes suspended solids and organic matter in wastewater.
-NF: Nanofiltration, which removes harmful substances such as hardness, color, and heavy metals from wastewater.
-RO: Reverse Osmosis, which removes salt and the vast majority of organic matter from wastewater.
Regulation tank + coagulation sedimentation + DTRO/mechanical evaporation (MVR/MVC)
- Regulation tank: Homogenizes and equalizes the wastewater to ensure the stable operation of subsequent treatment processes.
Coagulation and sedimentation: By adding coagulants and flocculants, suspended solids and colloidal substances in wastewater are removed.
-DTRO/Mechanical Evaporation (MVR/MVC): Disc tube reverse osmosis/mechanical vapor recompression technology, which removes salt and the vast majority of organic matter from wastewater through the filtration effect of reverse osmosis membranes; mechanical vapor recompression technology achieves the purpose of evaporation and concentration by compressing steam to increase its temperature and pressure.
IV. Process Overview
The "pretreatment + A/O + ultrafiltration + nanofiltration + reverse osmosis" process is currently the most common and mature technology in the field of
Leachate Treatment in China. This process can stably meet the discharge standards specified in Table 2 of the "Pollution Control Standards for Domestic Waste Landfills" (GB16889-2008).
1. Pretreatment: Through processes such as the regulating tank and coagulation sedimentation, suspended solids, colloidal substances and some organic matter in the wastewater are removed.
2. A/O: Anaerobic/Aerobic Biological Denitrification Process, which removes ammonia nitrogen from wastewater through nitrification and denitrification.
3. Ultrafiltration: Through the filtration effect of ultrafiltration membranes, suspended solids and large-molecule organic substances in wastewater are removed.
4. Nanofiltration: Through the filtration effect of nanofiltration membranes, harmful substances such as hardness, color, and heavy metals in wastewater are removed.
5. Reverse Osmosis: Through the filtration effect of reverse osmosis membranes, salt and the vast majority of organic matter in wastewater are removed.
V. Main Equipment
Regulation tank: Submersible
Mixer, liquid level controller, etc.
Coagulation and sedimentation: agitators, dosing devices, sedimentation tanks, etc.
Anaerobic reactors: anaerobic reactors, biogas collection systems, etc.
A/O: Anoxic tank, aerobic tank, aeration system, reflux system, etc.
MBR: Membrane bioreactor, membrane module, cleaning system, etc.
NF: Nanofiltration membrane modules, high-pressure pumps, cleaning systems, etc.
RO: reverse osmosis membrane modules, high-pressure pumps, cleaning systems, etc.
DTRO/mechanical evaporation (MVR/MVC): DTRO membrane columns, high-pressure pumps, cleaning systems, etc.; mechanical vapor recompression systems, heat exchangers, compressors, etc.
VI. Operation and Maintenance
Regularly inspect, maintain and service the equipment to ensure its normal operation.
Monitor water quality indicators and adjust process parameters as per actual conditions.
Timely clean the sediment and contaminants in the sedimentation tank, membrane modules and other equipment.
Regularly replace membrane modules such as ultrafiltration, nanofiltration and reverse osmosis.
Train the operators to make them familiar with the operation procedures and the performance of the equipment.
VII. Notes to Bear in Mind
The organic matter concentration in the wastewater is relatively high, which is prone to generating foam in the anaerobic reactor, and defoaming measures need to be taken.
The ammonia nitrogen concentration in the wastewater is relatively high, so it is necessary to control the operation parameters of the A/O process well to ensure the denitrification effect.
Wastewater may contain harmful substances such as heavy metals, and it is necessary to select appropriate treatment processes and equipment to ensure that the effluent quality meets the standards.
During operation, it is necessary to pay attention to preventing membrane fouling and clogging, and regular cleaning and maintenance should be carried out.
For high-concentration leachate, pretreatment is necessary to reduce the concentrations of organic matter and ammonia nitrogen, thereby alleviating the burden on subsequent treatment processes.
Jinkebotong Environmental Protection Technology (Jiangsu) Co., Ltd
