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 p-chloronitrobenzene(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 P-chloronitrobenzene 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.