Papers by Author: Zhi Guang Ren

Abstract: In this study, a new method (negative pressure cavitation method, NPC) for metal ions removal from industry waste water has been studied. Under the identical adsorption conditions，we have seen some different effects among static adsorption, shaking adsorption and NPC adsorption. The results are as following: four kind metal ions showed the accordant phenomenon that the sequence of adsorption capacity is NPC adsorption>shaking adsorption>static adsorption. The different metal ions have different improvement of removal ratio. The sequence is Cd>Hg>Pb>Cu. The intercellular pH of absorbed yeast cells increased with the adsorption process from acidic to alkaline. These may suggest that the Candida utilis has certain resistance against heavy metals. The increased pH is also an environment stress response of Candida utilis. So NPC adsorption may have potential values to removal of metal ions.

Abstract: In this study, batch adsorption experiments were carried out for the biosorption of Cd2+ and Pb2+ from aqueous solutions by the invasive alien plant Iva Xanthifolia Nutt (IXN) biomass as adsorbent. Parameters effects such as contact time, pH, initial metal ions concentration, and biomass concentration on the biosorption process were studied. The Langmuir biosorption isotherm was applied to correlate the equilibrium data and fitted quite well. The maximum biosorption capacities for two metal ions were 30.35 mg Cd2+/g and 39.68 mg Pb2+/g, respectively. XRD studies combined with FTIR spectroscopy have also been investigated to represent the biosorption mechanism. Thermodynamic parameters such as enthalpy change (H0), entropy change (S0) and free energy change (G0) were calculated for predicting the nature of biosorption. This study proved that the invasive alien plant IXN can be used as an effective, low-cost and abundant absorbent for the treatment of Cd2+ and Pb2+ containing wastewater.