Adsorptive Removal of p-chloronitrobenzene (pCNB) by Mesoporous Silica HMS from Aqueous Solution

Adsorption of p-chloronitrobenzene(pCNB) onto mesoporous molecular sieves (HMS) from aqueous solution has been investigated systematically using batch experiments in this study. Results indicate that p-chloronitrobenzene(pCNB) adsorption is initially rapid and the adsorption process reaches a steady state after 1 minute. The adsorption isotherms are well described by the Langmuir and the Freundlich models. The effects of temperature and pH are also examined. According to the experimental results, the amount of pchloronitrobenzene(pCNB) adsorbed decreases with increases of temperature from 288 to 308 K and pH from 2.0 to 11.0. The desorption process shows a reversibility of pchloronitrobenzene adsorption onto HMS. Based on the results, it suggests that the adsorption is primarily brought about by hydrogen bonding between p-chloronitrobenzene and HMS surface.