Molecular structure factors in adsorptive removal of pyridinium cations, 1,4-pyrazine and 1-quinoline at high-area C-cloth electrodes for waste-water remediation

Adsorptive/electrosorptive removal of pyidinium (PyH+), N-methylpyridinium (PyMe+), 1,4-pyrazine (Prz) and PrzH+, and 1-quinoline (Qul) and QulH+ from simulated waste-waters was investigated in 0.1 M H2SO4, 0.1 M KH2PO4+KOH (pH 7.0) buffer and 0.1 M KOH solutions using quasi-3-dimensional, high area C-cloth electrodes as interfaces. The adsorption/electrosorption, monitored kinetically by in situ UV spectrophotometric techniques, follows first-order kinetics. Rates of adsorption of the above N-heterocyclic solutes are enhanced by polarization of the C-electrodes, preferably by negative currents. Reversible electrosorption was observed in 0.1 M H2SO4 or in 0.1 M KH2PO4+KOH (pH 7.0) buffer solution for pyridinium cations (PyMe+ and PyH+), leading to the possibility of easy and in situ regeneration of the surfaces of C-cloth electrodes in practical adsorptive removal applications. Negative, and alternate positive and negative polarization were found to have a strong and particular effect in promoting extents of adsorption for N-heterocyclic compounds such as PyMe+, Prz and Qul in buffer (pH 7) and KOH solutions, leading to complete removal in those cases.