Effects and mechanistic aspects of absorbing organic compounds by coking coal

Abstract

Coal is a porous medium and natural absorbent. It can be used for its original purpose after adsorbing organic compounds, its value does not reduce and the pollutants are recycled, and then through systemic circulation of coking wastewater zero emissions can be achieved. Thus, a novel method of industrial organic wastewater treatment using adsorption on coal is introduced. Coking coal was used as an adsorbent in batch adsorption experiments. The quinoline, indole, pyridine and phenol removal efficiencies of coal adsorption were investigated. In addition, several operating parameters which impact removal efficiency such as coking coal consumption, oscillation contact time, initial concentration and pH value were also investigated. The coking coal exhibited properties well-suited for organics' adsorption. The experimental data were fitted to Langmuir and Freundlich isotherms as well as Temkin and Redlich-Peterson (R-P) models. The Freundlich isotherm model provided reasonable models of the adsorption process. Furthermore, the purification mechanism of organic compounds' adsorption on coking coal was analysed.

Adsorption of Organic Constituents from Reverse Osmosis Concentrate in Coal Chemical Industry by Coking Coal

“…This may be due to the fact that the surface of coking coal contains different active sites that can combine organic compounds with different characteristics in ROC. consistent with the Freundlich model [14] but the present study shows that it is closer to the Langmuir model (Langmuir, R 2 =0.9997; Freundlich, R 2 =0.9945). This may be due to the fact that the surface of coking coal contains different active sites that can combine organic compounds with different characteristics in ROC.…”

“…These three isotherms are very close to the fitting results of the two models, indicating that the organic matter adsorbed by coking coal belongs to single-layer adsorption, which is consistent with the previous research work. In previous studies on the adsorption of single organic matter by coking coal, since the surface of coking coal is not an ideal surface, its adsorption of organic matter is more consistent with the Freundlich model [14] but the present study shows that it is closer to the Langmuir model (Langmuir, R 2 = 0.9997; Freundlich, R 2 = 0.9945). This may be due to the fact that the surface of coking coal contains different active sites that can combine organic compounds with different characteristics in ROC.…”

“…In the previous work, on the one hand, advanced oxidation processes were used to treat ROC of coal chemical industry and certain effects were achieved (chemical oxygen demand removal reached more than 50%) [13] but the direct treatment economy was poor and the effect was not ideal. On the other hand, the potential of using coal as adsorbent to purify coking wastewater has been recently verified and the coal adsorbent has a good adsorption effect on refractory organic matter [14]. Based on this, we proposed the treatment process of pre-adsorption of coking coal to improve the efficiency of subsequent treatment process by separating the organic components in ROC.…”

Effect of surface modification on quinoline adsorption onto coking coal

“…Adsorption by using low-cost materials is one of the most promising methods to remove quinoline from wastewater [10]. There are few reports on the application of raw or modified coking coal in the removal of quinoline from simulated wastewater in recent years [11][12][13][14].…”

Adsorptive Removal of Pyridine in Simulation Wastewater Using Coke Powder

“…Treating pyridine-containing wastewater was also attempted using coking coal as an adsorbent by Ning et al [23]. In their study, the removal rate of pyridine reached up to 65% without adjusting acidity and alkalinity at a treatment time of 60 min and a coking coal concentration of 30 g/L.…”