| Popis: |
In the Mediterranean area where olives are grown and processed on a large scale, a huge amount of waste by-products such as olive pits and olive pomace is generated. For achieving environmental sustainability, huge efforts are being made in order to find a useful purpose for such waste. This type of biomaterial is most often burned to obtain energy, but it could be used in treatment of water polluted by heavy metals, and afterwards burned in a controlled atmosphere. Therefore, this research is focused on use of olive pits and olive pomace pellets of particle size 0.56-1.00 mm, in removal of lead and zinc of two initial concentrations (0.5 mmol/L and 1.5 mmol/L) from monocomponent aqueous solutions. The experiments were performed by batch method on the laboratory shaker for 24 h, at 250 rpm, at ambient temperature, and at solid/liquid ratio of 1/100. The efficiency of the olive pits was 32.6% for the higher, and 70.6% for the lower initial lead concentration, while for zinc was 30.9% for the higher, and 64.6% for the lower initial zinc concentration. The efficiency of the olive pomace pellets was 24.4% for the higher, and 36.6% for the lower initial lead concentration, while for zinc it was 24.2% for the higher and 48.3% for the lower initial concentration. In general, the olive pits were more efficient in lead removal, while olive pomace pellets were more efficient in zinc removal, especially for the lower initial concentration. The lowest achieved residual concentrations were 0.164 mmol/L for zinc, and 0.142 mmol/L for lead, which are both above the limit values in wastewater (0.031 mmol/L for zinc and 0.002 mmol/L for lead) according to the Croatian legislative. The obtained results suggest that use of wasted industrial by- products, in at least pre-treatment stage, could lead to more economically viable water treatment. |
