科研之友
微信
新浪微博
Facebook
分享链接
摘要
This study investigated a low-cost and sustainable use for microalgae and polyaluminium chloride (PAC) mixed waste collected during water treatment processes. The microalga Chlamydomonas microsphaera in the form of a dry powder (CM) and C. microsphaera collected by PAC flocculation (PCM) were evaluated as biosorbents of the toxic heavy metal contaminant Cu2+. The adsorption capacities of PCM and CM were determined in batch experiments at varying biosorbent concentrations, pH, contact times, and the presence of other metallic cations (Na+, Ca2+, Fe3+) at room temperature. After incubation, SEM and EDAX imaging detected copper ions adsorbed to the surfaces of both biosorbents. Adsorption capacity decreased and the adsorption ratio increased with increasing biosorbent concentration. The optimal initial pH for adsorption was between 5.0 and 6.0 for both biosorbents. The rate of adsorption for Cu2+ onto both biosorbents rose quickly within the first 30min and reached equilibrium in less than an hour. Adsorption kinetics followed the pseudo-second-order model. The pseudo-second-order model rate constant and adsorption capacity at equilibrium were higher for PCM than for CM. Of the three metallic cations evaluated, only Fe3+ produced a significant effect, reducing the adsorption of copper onto both biosorbents. The adsorption capacity of PCM is well-described by the Langmuir and Freundlich isotherm models. The maximum adsorption capacity of Cu2+ onto PCM (79.4mgg(-1)) was higher than that for CM (57.3mgg(-1)). Our results suggest that PCM waste from drinking water treatment processes could serve as a low-cost, efficient biosorbent for the removal of toxic heavy metals from water.
