Study On The Modification Of Coal Pyrolysis Semi-coke And Its Adsorption Performance

Nowadays, the waste water produced in printing and dyeing industry and coking industry, contains large harmful substance. This wastewater may have serious impact on our living environment and body health without strict treatment, so water treatment is very important. There is a very economic and effective way to remove the pollutants in industrial waste water named adsorption method. Adsorption method has simple operation, low equipment cost advantages. For adsorption the adsorbent is key, so preparation of adsorbent is very important. In this paper, activated semicoke was prepared with pyrolysis solid product of coal in Yan’an Zichang by HNO₃, KOH, Zn Cl2 chemical activated. we prepared a new adsorbent use semi-coke as its main raw material namely a new modified semi-coke adsorbent. In addition, the adsorption properties of modified semi-coke adsorbent also were research. The adsorption ability of modified semi-coke was investigated using rhodamine B, acid fuchsin, phenol and p-Nitrophenol as target contaminant. The main content and conclusion are listed as follows:（1） The modified semi-coke prepared from Yan’an Zichang coal of low temperature pyrolysis solid product was modified by HNO₃, in the high pressure hydrothermal reactor hydrothermal activated under 180 ℃ for 16 h. The adsorption property of modified semi-coke was investigated by changing the semi-coke dosage, the initial p H of solution,adsorption time with rhodamine B and acid fuchsin as target pollutant. The results showed that the semi-coke modified by HNO₃ had a good adsorption of rhodamine B and acid fuchsin. The adsorption process followed the pseudo-second-order kinetic models.（2） Activated semi-coke was prepared with pyrolysis solid product of coal in Zichang,Yan’an as raw materials and with the addition of KOH as the activator. The modification process was carried out in the the a vacuum atmosphere resistance furnace under 600℃for 2 hours. The obtained modified semi-cokes were characterized by XRD, SEM,nitrogen adsorption isotherms techniques and the phase composition, morphology and surface area were investigated. The adsorption properties of activated semicoke were detected by removal of phenol and p-Nitrophenol from aqueous solution under room temperature. The adsorption kinetic of phenol and p-Nitrophenol adsorbed on activated semicoke was studied. The influencing factors, such as dosage of adsorbent, initial concentration, and contact time, on the adsorption performance of activated semicoke were investigated. The result showed that the adsorptive properties of semi-coke modified by Zn Cl2 had a significant enhancement.（3） Activated semi-coke was prepared with pyrolysis solid product of coal in Zichang, Yan’an as raw materials and with the addition of Zn Cl2 as the activator. The modification process was carried out in the the a vacuum atmosphere resistance furnace under 600℃ for 2 hours. The obtained modified semi-cokes were characterized by XRD,SEM, nitrogen adsorption isotherms techniques and the phase composition, morphology and surface area were investigated. The adsorption ability of modified semi-coke was investigated with phenol wastewater contains catechol and hydroquinone as the simulated pollution, the optimum dosage of modifying agent were determined, and the adsorption ability of Zn Cl2 modified semi-coke was investigated by changing different influential factors. The result showed that the adsorptive properties of semi-coke modified by Zn Cl2 had a significant enhancement, which may provide potential applications in environmental fields.