First, pre-treatment
The wastewater discharged by the leather industry contains a large number of solid particles, fats, pH and salts, which will affect the operation of the
wastewater treatment system.
Therefore, pre-treatment is required before entering the wastewater treatment system.
1 .Remove oil
Oil in wastewater is one of the critical factors that cause water pollution, and it is generally accepted that physical oil removal is combined with chemical precipitation for oil removal treatment. Physical degreasing is utilized Because of the different density and surface tension of oil and water, oil and water are separated by physical methods. Chemical precipitation is the use of chemical dosing methods to gather oil in a Oil removal is then achieved by gravitational sedimentation.
2. Neutralize and adjust pH
The hydrogen ions, hydroxide ions and bicarbonate ions produced by chemical agents and chemical reactions in the leather production process will affect the pH of the wastewater.
Before treating the wastewater, it is necessary to adjust the pH of the wastewater so that the pH value of the wastewater is in a more ideal range before it can enter the treatment system.
Second, biological treatment
Biological treatment refers to the use of microorganisms to convert organic matter into inorganic processing methods. Biological treatment technology has been widely used in leather
wastewater treatment. Commonly used Biological treatment technology includes biological contact oxidation and activated sludge treatment technology.
1. Biological contact oxidation
Biological contact oxidation refers to the treatment technology of the contact oxidation of wastewater with microorganisms in the contactor. The key to this technology is the ability of microorganisms to remove organic matter from wastewater The properties of conversion into inorganic substances such as biomass and carbon dioxide. The COD and chroma indexes of leather wastewater treated by biological contact oxidation were removed well.
2. Activated sludge treatment
Activated sludge process refers to the contact oxidation of wastewater with activated sludge. Activated sludge refers to a highly active microbial community mixed with solid sludge A substance made of. In the process of
wastewater treatment, activated sludge removes pollutants in wastewater by adsorption, utilization and phagocytosis. Activated sludge process in leather wastewater It has been widely used in processing.
Chemical treatment
Chemical treatment refers to the use of chemical methods to separate pollutants from waste water to achieve the purpose of reducing waste water pollution. In the process of leather
wastewater treatment, chemical treatment technology .It is also an indispensable part, and the technology is commonly used in oxidation and reduction methods.
1. Oxidation method
Oxidation method refers to the process of oxidizing organic matter to inorganic matter by physical or chemical methods. Oxidants generally choose KMnO4, H2O2, etc., which can effectively degrade skin
Organics and chromaticity in leather wastewater.
2. Reduction method
Reduction method refers to the technology of reducing pollutants to a form that can be easily treated by reducing agents. The reducing agent is generally selected FeSO4, etc., which can remove Cr6+, Cu2+,
Harmful substances such as Pb2+ are reduced to harmless substances such as Cr3+, Cu+, and Pb.
post-processing After wastewater treatment, it is also necessary to carry out post-treatment work such as filtration and disinfection again. Re-filtration generally accepts activated carbon adsorption, coagulation and other methods to further improve the waste Water quality. Disinfection inactivates microorganisms in wastewater by adding disinfectants to ensure the environment and human health.
Leather wastewater treatment simple scheme
Tannery
wastewater treatment process Leather production process will produce a lot of wastewater, which contains a lot of organic matter, nitrogen, phosphorus and other pollutants, if not through
The discharge of effective treatment into the environment will seriously harm the ecological environment and human health. Therefore, tannery
wastewater treatment is very important.
Tannery wastewater treatment usually requires multi-process treatment, mainly including the following steps:
1. Pretreatment: The wastewater is first passed through the grid, sedimentation tank or screen and other physical treatment equipment to remove large suspended particles and sediments to reduce the subsequent treatment process
Load.
2. Biochemical treatment: the pretreatment wastewater is sent to the biochemical tank, adding microorganisms and nutrients, and using microorganisms to absorb, decompose and transform pollutants such as organic matter. To degrade it into a more stable substance.
3. Precipitation and filtration: The effluent from the biochemical pond is put into the sedimentation tank or filter, and the residual suspended particles and colloidal substances are removed by precipitation or filtration.
4. Activated carbon adsorption: the filtered water is sent into the activated carbon pool, and the organic matter and chroma and other pollutants in the water are adsorbed by activated carbon to further purify
Water quality.
![](//v4-upload.goalsites.com/730/1712825351_wastewater treatment (2).JPG)
5. Disinfection: Through ultraviolet disinfection or adding chlorine-containing disinfectants, the wastewater is disinfected to kill bacteria, viruses and other microorganisms to ensure that the water quality meets the discharge Put the standard. It should be noted that the tannery
wastewater treatment process should be adjusted according to the actual situation, such as changes in wastewater quality and output factors, need to be timely Adjust and optimize the treatment process. At the same time, the
wastewater treatment process involves a variety of chemicals and equipment, safety measures and operating procedures need to be paid attention to, To ensure the safety of people and the environment.
The above is the introduction of the leather
wastewater treatment process, through the above analysis, it can be seen that the combination of biological treatment and chemical treatment is relatively reasonable
In this way, combining the advantages of various technologies, harmful substances such as organic matter and heavy metals in sewage can be effectively reduced to achieve the effect of regulating sewage.