Adsorption mechanism of shell powders on heavy metal ions Pb2+/Cd2+ and the purification efficiency for contaminated soils

The adsorption capacity of oyster shell powders (SPs) and the mechanism heavy metal ions (HMs; i.e., cadmium Cd 2+ lead Pb ) on SPs are discussed by means kinetics tests, adsorption-desorption scanning electron microscopy Fourier transform infrared spectroscopy. influences seepage velocity, types, SP addition amount/concentration effect in treatment HMs laterite as well quartz sand were analyzed. Studies have shown that i) can be divided into three stages, surface stage, internal pore diffusion equilibrium stage; ii) with increase effluent concentration will slightly increase, residual amounts at each section column generally decrease rapidly migration distance; iii) solution provides more points for HMs, finally, amount desorbed from is reduced, which also reduces effluent. Overall, possess high purification efficiency contaminated soils.