Adsorption And Ozone Oxidation Combined Experimental Research On Treatment Of Biologically Treated Coal-chemical Engineering Wastewater

Coal chemical industry wastewater is a kind of refractory wastewater, and thewater pollution it caused seriously restricts the development of the industry. Itsprocessing has been a big problem in the field of industrial wastewater treatment inChina and abroad. Due to the large investment, high operation cost anddisadvantages of the domestic coal chemical wastewater advanced treatment, mostof the coal gasification plants have not used wastewater advanced treatment.Therefore, to optimizate the process by technology means, improve the use effectof drugs, improve circulation efficiency, realize the coal chemical industrywastewater’s emission on standard and seek an economic and feasible advancedprocessing method are imperative.This test is divided into three stages. Firstly it studied the treatment effect of thebiochemical processed coal chemical industry wastewater in the adsorption systemof five kinds of adsorbent, in order to obtain the best operating conditions andcompound type in adsorption system. Secondly it used ozone oxidation treatmentto deal with coal chemical industry wastewater in the biochemical process，and thebest ozone oxidation conditions were determined. Finally it examined the ozoneoxidation and the compound adsorbent coupled to the effect of coal chemicalindustry wastewater in the biochemical process, and got the best operatingconditions and the best coupled way, and the comparative analysis of its treatmenteffect.The first phase adsorption test results: Selected the best type of activated carbon,powder activated carbon, which treatment effect for the coal chemical industrywastewater is better than other types of activated carbon. Got the optimumoperating conditions of powder activated carbon adsorption: determined theoptimal PAC dosing is100mg/L, the best adsorption time is60min, the optimal pHis in neutral range, the optimum temperature is at room temperature, thus there isno need to adjust the pH and temperature. Got compound adsorbent type, the twocoupling with the best treatment effect is activated carbon in combination withmacroporous resin. The COD removal rate reached65.38%, and the chromaremoval rate reached88.59%; the three coupling with the best treatment effect isactivated carbon in combination with macroporous resin and zeolite. The CODremoval rate reached75.65%, and the chroma removal rate reached93.27%. Anddetermined macroporous resin, fly ash, zeolite and active carbocoal’s optimaldosages are0.3g/L,2.5g/L,3.0g/L,0.5g/L. Optimal velocity of wastewater indynamic adsorption experiments by granular activated carbon was determined 7.09m/h. However, adsorbent will reach saturation easily, and often need to changethe activated carbon, not as convenient and simple as static adsorption experiment.Finally, researched the powder activated carbon’s adsorption kinetics andthermodynamic models for coal chemical industry wastewater, and found that theadsorption kinetics accords with Lagergren quasi level of adsorption kineticsmodel, and the adsorption isotherm accords with Frecndlich equations.The second phase adsorption test results: Reseached the advanced treatmenteffect of the ozone oxidation on the coal chemical industry wastewater, and got theozone oxidation conditions: determined the optimum ozone dosage is2.1g/h, ozoneinflow rate is60L/h, ozone concentration is35mg/L, and it gained the best effectwhen pH is9, and selected the HRT for30min as the hydraulic retention time ofcontinuous water test.The third phase adsorption test results: On the basis of ozone oxidationtreatment, adsorption experiment was carried out. Three kinds of adsorbentcatalytics are studied in ozone performance experiment, and found activated carbontreatment effect is the best, followed by zeolite, finally the resin. Determined theadsorbent optimal dosages are: powder activated carbon dosage is100mg/L,macroporous resin dosage is0.5g/L, and zeolite dosing amount to3.0g/L，and thedosing point is10min after ozone oxidation shots. Removing ammonia nitrogenhas a very big enhancement in adsorption phase. Oxidized adsorption phase pHoptimal values is8, the best temperature range is25~30℃, and the optimumreaction time is80~100min.To sum up, using ozone oxidation and adsorption treatment to deal with coalchemical industry wastewater has good treatment effect, and the economy isfeasible.