Mixer settler paint industry phenol wastewater treatment
Wastewater mainly comes from wet paint the air in the room washing with water spray paint room areas, paint in the air and formed by organic solvent was transferred to the water spray paint waste water.
wastewater contains a large number of paint particles, the water quality by the coatings (
With the nitro paint, amino paint, alkyd paint and epoxy paint)
, solvent (
Such as ethanol, acetone, esters, benzene class)
a, paint waste water sources and main pollutants 1.
Paint waste water sources and harmful material paint wastewater mainly comes from the pre skim, skim, table, phosphating, passivation and body before processing;
Cathodic electrodeposition process and coating, spray paint process.
Paint wastewater contains the main poisonous and harmful substances are as follows: coating pretreatment: nitrite, phosphate, emulsified oil, surfactant, Ni2 +, Zn2 +.
coat: low solvent cathodic electrophoretic paint film, lead-free cathode electrophoresis paint film, paint, powder, epoxy resin, butyl alcohol, ethylene glycol monobutyl ether, isopropyl alcohol, dimethyl ethanolamine, polybutadiene resin, dimethyl ethanol, paint, etc.
in the coating, surface coating, xylene, banana oil and other organic solvents, coating, paint, powder.
2, the main reason for the paint waste water to produce
degreasing waste liquid demulsification of degreasing waste liquid using the method of acidification pretreatment, waste liquid to skim the cic with inorganic acid to pH to 2 ~ 3, senior fatty acid soaps precipitation in the emulsifier, the senior fatty acid insoluble in water and soluble in oil, so that the degreasing liquid oil demulsification analyse.
in addition, after add acid defatted waste liquid of anionic surfactant in acidic solution losing stability of the easy decomposition, lost the original oil and water balance, so as to achieve the demulsification.
After preprocessing the CODCr reduced to 1500 from 2500 ~ 4000 mg/L ~ 2400 mg/L, the removal rate is around 40%;
While oil content from 300 to 950 mg/L fell to 50 to 70 mg/L, the removal rate is as high as 90% ~ 95%.
electrophoresis waste liquid in cathodic electrophoretic wastewater contains a large number of macromolecule organic matter, CODCr of up to 20000 mg/L, also contains a large number of electrophoresis slag, these substances in the water and fine suspended solids or electronegative colloid.
Adding appropriate cationic polyacrylamide (processing
And polyaluminium chloride (
As a coagulant, the use of flocculant adsorption bridging role to quickly remove the pollutants in the wastewater.
Electrophoresis liquid during pretreatment requirements pH between 11 ~ 12, precipitation has good effect.
After the reaction effluent CODCr in around 2000 mg/L.
spray paint waste water to spray paint waste water using Fenton reagent (first
On the pretreatment, that its oxidative decomposition of organic matter, CODCr removal efficiency is about 30% or so, and add the PAC and PAM coagulation sedimentation, after the two step processing, total CODCr removal rate can reach 60% ~ 80%, from 3000 to 20000 mg/L fell to 1200 ~ 4000 mg/L.
The mixed waste water discharged into water regulating pool.
mixer settler processing paint industry paint industry wastewater containing phenol wastewater after mixer settler extraction separation, due to the waste water volume is small, so the wastewater can be fully completed in the mixer settler, mass transfer and separation, which is part of the harmful material can be recycled effectively.
due to the chemical nature of formaldehyde and phenol is lively, so using Fenton extraction agent will become the biological toxicity of formaldehyde and phenol oxidation small and easy to be absorbed by the biological degradation of organic matter, COD after oxidation can drop to less than 1000 mg/L.
At the same time it also can make the macromolecular organic matter decomposition of refractory for easy degradation of small molecule organic matter, improve the wastewater can be biochemical, facilitate subsequent aerobic biochemical treatment.
Coagulation treatment can remove the suspended substances in the water, using coagulation floc adsorption of dissolved organic matter, at the same time can be efficient removal chromaticity.