Removal of copper from aqueous solutions using biosolids

The effect of pH, biosolid dosage, initial copper concentration, and contact time on copper removal from aqueous solutions using biosolids (waste sludge cake) was investigated through batch experiments. The copper removal increased by time and initial metal concentrations. The equilibrium time was achieved for copper ion after 35 min. According to final pH measurements and our observations, the main mechanism of copper removal should be the formation of insoluble complexes between Cu+2 and anionic species such as CO3−2, SO4−2 and OH− taking place in the structure of biosolids. XRD analyses were used to characterise the mineralogical composition of original and treated samples. The structural change on the sorbent was examined by infrared spectra analyses after its treatment with 100 mg/l copper (II). The biosolid was found as an efficient and economic material for the removal of copper from aqueous solutions.