Study On Modification Of Activated Clay And Its Application In Phenol Wastewater

All the time, water pollution is a global problem which is focused on by the public. With the rapid development of society and the improvement of the level of industrialization, the water pollution caused by industrial wastewater is getting more and more attention. Industrial wastewater is the main pollute source of water, and phenolic wastewater is one of an important kind of industrial wastewater which was greatly poisonous and hard to be degraded. Phenol is the representative phenolic compound, which is an important and wide used chemical material. However, phenol is harmful to human bodies. The utilization of phenol-contaminated water causes protein degeneration, paralysis of the central nervous system and damages liver, kidney function. So it is necessary to do some wastewater treatment before discharging. In this thesis, the aqueous solution of phenol was selected as the simulated wastewater, its treatment was researched by adsorption method.In the first part, the source and harm of phenolic wastewater were introduced, and showed the damage of phenolic wastewater to human survival and environment. The methods of phenolic wastewater were reviewed in details, including chemical, biological and physical treatment methods. Then attentions were focused on the properties and modification methods of bentonite. Finally, the purpose, content and innovation of this research were introduced.In the second part, the experimental instruments, reagents, and the analysis methods were presented.In the third part, it mainly introduced the preparation of a modified bentonite adsorbent CTAB/Ca-Bent, and the influence of synthetic factors were studied, and a mixture of CaO, CTAB and bentonite in a3.5:3:10mass ratio was obtained and the optimal preparation temperature and time were323K and12h, respectively. The characterization of the prepared adsorbent was performed using FTIR Spectroscopy, XRD, BET, SEM.In the fourth part, the effect of various factors of phenol adsorption with CTAB/Ca-Bent were discussed, and the optimal conditions were obtained:contact time30min, initial pH-7, adsorbent dosage3.0g, phenol initial concentration100mg L-1, reaction temperature298K, the result showed the removal rate of phenol was78.13%. The behavior of adsorbent on the adsorption of phenol was investigated, which including adsorption kinetics, adsorption isotherm and adsorption thermodynamics. The experiments showed that the adsorption of phenol onto CTAB/Ca-Bent agreed well with the pseudo-second-order kinetic model and the Freundlich model, and the adsorption of phenol was a spontaneous and exothermic process.In the fifth part, the influence of six kinds of salts(NaCl, KCl, MgCl2, ZnCl2, Na2SO4, Na3PO4)on phenol abatement at different ionic strength by CTAB/Ca-Bent was studied. At the same time, the behavior of adsorbent on phenol adsorption in the presence and absence of salt was studied. The results showed that the presence of salt had a greet effect on phenol abatement.