Keywords: phenolic wastewater treatment, CWS, coal gasifier, coal gasification, coal gas, producer gas

1 Phenolic several conventional sewage treatment
For gas station phenolic wastewater treatment is generally divided into two stages: first, the pretreatment phase, which aims to remove the majority of suspended solids in wastewater and tar, etc.; Second, phenol processing stage, the aim is to pretreated wastewater most phenols and some organic matter removal.
1.1 Pretreatment
Natural sedimentation separation method which can be set directly in the gas station circulating water process systems, although the effect is not very satisfactory, but lower operating costs, has been the most Gas Station as phenolic wastewater pretreatment method used. Other seven methods must be separately provided equipment for processing, handling charges much higher relative.
1.2 dephenolizing treatment
1.2.1 Physical chemistry
1.2.1.1 chemical vapor dephenolizingFrance
With a strong high-temperature steam heating phenol effluent to sewage phenol evaporated with the steam to escape, and then pass into the alkali absorption as sodium salt, so as to achieve the purpose of phenol removal. The method is simple, less investment, but the steam consumption is greater and phenol removal efficiency is not ideal, generally reach a thorough treatment purposes. Northeast factory has used the treatment of phenolic wastewater, due to steam consumption is too large to stop;Zhejiangfactory has adopted any of the phenol removal, the results are still out.
1.2.1.2 steam dephenolizing France
The phenolic wastewater heating, phenols volatile with water vapor out, then this part of phenol vapors pass into the furnace hearth mixed with air as a gasifying agent, phenol at high temperatures in the furnace combustion eventually decompose into CO2 and H2O achieve the purpose of phenol removal. The disadvantage to this method can only be removed in the low boiling phenol homologues, and greater energy consumption per 1 ton of sewage evaporation takes about 180 kg of standard coal equivalent fuel.Inner Mongoliahas a factory so that this method the treatment of phenol wastewater, energy consumption due to the saturation temperature and the gas furnace hearth is difficult to control and the disabled.
1.2.1.3 incineration
The phenolic wastewater is injected into the incinerator, the phenols at about 1100 ℃ high temperature, oxidation reaction, the resulting emissions of CO2 and H2O, this process is simple, easy to operate, but the large energy consumption, burning one ton per phenolic wastewater which cost about 200 yuan. Early 1990s abroad and domestic supporting the two-stage gas furnace basically incinerator equipped with phenol water facilities, but basically because of energy issues while idle. The use of incineration treatment of phenolic wastewater Another key drawback is that once careless operation, temperature drop, often cause incomplete combustion, easy to form secondary pollution.
3.1 "coal - phenol water" modulation CWS governance principles of phenolic wastewater
CWS technology development began in the country in the 1980s, after 20 years of research and practice, has become more systematic and mature technology. Is the coal slurry (60-70%), water (30-40%) and minor amounts of additives (about 1%) were mixed, after grinding, vigorous stirring, to form a coal - water two-phase flow of slurry as fuel. CWS appearance like oil, good fluidity, is a new, less polluting substitute for oil fuel, its calorific value of approximately half of heavy oil, has been successfully used in metallurgy, building materials and other industries a variety of industrial furnaces and boilers in, with good prospects for development. According to CWS application technology, the use of gas stations under the screen itself pulverized coal and phenol wastewater by mixing, then add appropriate amount of additive is made by the powerful grinding modulated CWS, then became fuel phenolic wastewater Coal effective carrier. CWS combustion temperature is generally 1100-1300 ℃, at this temperature the water in the phenol and other harmful organic substances burn vigorously into H2O and CO2, and then with the combustion gas into the atmosphere, so as to control phenol sewage purposes, dephenolizing same mechanism and incineration.
3.2 Phenol Wastewater modulation CWS
Although you can use to prepare a slurry wastewater containing phenol, but depends largely on the characteristics of coal-water slurry additive selection and grading of coal particle size selection.
As characteristics of the effluent phenol and water are different, the type and amount of additives should be selected for the waste water itself, and other organic compound of phenol and the amount of oil to determine if the type and amount of additives, improper selection, phenol wastewater Some chemical substances will be the dispersant additives or stabilizers react, thereby reducing the effect of the additive and the effect of the coal-water slurry into the slurry. Different additives "Datong Coal - phenol water" CWS coal slurry performance.

3.3 phenolic wastewater treatment using the CWS technology advantages

The use of "coal - phenol water" CWS Gas Station phenolic wastewater treatment technology, the CWS application technology and wastewater treatment technology combined with phenol, phenol-containing wastewater can not only achieve the purpose of treatment, and phenol-containing wastewater can be used to prepare a slurry for industrial production of an ideal substitute for oil fuel. Phenolic wastewater treatment using the CWS technology advantages are:
4 Conclusion

(1) Gas Station conventional treatment methods due to the presence of phenol wastewater complex process, investment is large, inefficient and prone Dephenol formation of secondary pollution problems, largely restricted to its promotion on the treatment of phenol wastewater Application.
(2) the use of the gas station itself sieve pulverized coal and phenol wastewater by mixing, then add the appropriate amount of additive is made by the powerful grinding modulated CWS, you can achieve the purpose of treatment of phenol wastewater, but CWS characteristics depend largely on the choice of additives and coal particle size grading choice.
(3) the use of coal-water slurry technology Gas Station phenolic wastewater treatment, both the use of coal gas stations under the screen and a phenolic wastewater treatment to resolve the long-standing Gas Station environmental pollution problems, and achieved remarkable economic and environmental benefits of governance Gas Station phenolic wastewater contaminated effective new technology.