Due to the pretreatment of the activated carbon for water demand is high, and the activated carbon is expensive, so in waste water treatment, activated carbon is mainly used to remove the trace pollutants in the waste water, in order to achieve the purpose of deep purification.
Activated carbon is used to treat wastewater containing chromium
Chromium is a kind of metal material with large dosage in electroplating. Hexavalent chromium exists in different forms with different pH values in wastewater.
The microporous structure of the activated carbon has a very rich and higher specific surface area, with a strong physical adsorption capacity, effective adsorption in the wastewater Cr (Ⅵ). The surface of the activated carbon is a lot of oxygen containing groups such as hydroxyl group (OH), carboxyl (-cooh) group - and so on, they all have electrostatic adsorption function, chemical adsorption of Cr (Ⅵ) to produce.Completely can be used in the treatment of electroplating wastewater in Cr (Ⅵ), after adsorption of wastewater can meet the national discharge standard.
Test showed that Cr (Ⅵ) mass concentration in the solution of 50 mg/L, pH = 3, 1.5 h adsorption time, the adsorption properties of activated carbon and the removal rate of Cr (Ⅵ) achieves the best effect.
Therefore, the use of activated carbon treatment process of wastewater containing chromium is activated carbon on Cr (Ⅵ) in the solution of physical adsorption and chemical adsorption, a result of the combined action of chemical reduction, etc.Activated carbon treatment of chromium-containing wastewater, stable adsorption performance, high treatment efficiency, low operating costs, a certain social and economic benefits.
Activated carbon treatment of cyanide containing wastewater
In industrial production, the production of gold and silver wet extraction, chemical fiber, coking, synthetic ammonia, electroplating, gas production and other industries are using cyanide or by-product cyanide, therefore in the process of production must discharge amount of cyanide waste water.
Activated carbon has been used to purify wastewater for a long time, and more and more reports have been reported on its application to treat cyanide containing wastewater.However, due to the small adsorption capacity of CN_ and HCN on activated carbon, it is generally 3mgCN/gAC ~ 8mgCN/gAC(depending on the variety), which is not cost-effective in processing costs.
Activated carbon is used to treat mercury containing wastewater
Activated carbon has the property of adsorbing mercury and mercury containing compounds, but its adsorption capacity is limited.If the concentration of mercury is high, it can be treated with chemical precipitation method first. After treatment, the mercury content is about 1mg/L, and at high time, it can reach 2-3mg/L, and then the activated carbon can be used for further treatment.
Activated carbon is used to treat phenolic wastewater
Phenol containing wastewater comes from petroleum chemical plant, resin plant, coking plant and refinery plant.The results show that the adsorption capacity of activated carbon to phenol is decreased because the adsorption performance of activated carbon is good.But the time it takes to increase the temperature to reach the adsorption equilibrium is shorter.The optimal value of the amount and adsorption time of activated carbon was found.Under strong alkaline condition, the removal rate of phenol drops sharply.
Activated carbon is used to treat methanol-containing wastewater
Activated carbon can absorb methanol, but its adsorption capacity is not strong, which is only suitable for treating wastewater with low methanol content.Project running results show that the mixture of COD can be from 40 mg/L fell to below 12 mg/L, removal rate reached 93.16% ~ 100% of methanol, the effluent water quality can meet the reuse to desalted water system of the boiler feed water quality requirements.
Deep processing of oil refinery
Oil - containing wastewater from oil refinery is treated by oil separation, air flotation and biological treatment.The phenol content of wastewater decreased from 0.1mg/L(after biological treatment) to 0.005mg/L, the cyanogen decreased from 0.19mg/L to 0.048mg/L, and the COD decreased from 85mg/L to 18mg/L.
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