Efficiency of Water Treatment Sludge in Processes of Wastewater Purification from Copper and Iron Ions

The paper investigates the efficiency of a sludge prepared from a water treatment site of a combined heat and power plant (CHPP) when used as a sorbent for wastewater purification from copper and iron ions. In model solutions, the efficiency of purification from copper ions was determined to range from 80 to 100% at the initial copper concentration in the solution exceeding 0.5 mg/L. The purification efficiency in model solutions comprised 70–100% at the same initial concentration. The presence of both components in a model solution was determined to maintain the purification efficiency at iron and copper concentrations exceeding 0.5 mg/L. In addition, an increase in the purification efficiency was observed at iron and copper concentrations below 0.5 mg/L. An additional treatment of the sorbent by heat exposure to 200°C for 1 hour provides an increase in the purification efficiency at lower concentrations. At concentrations above 0.25 mg/L, the efficiency of purification from copper and iron ions comprises 80–100 and 60–100%, respectively, depending on the initial concentration. The efficiency of industrial wastewater purification from iron and copper ions using the proposed sorbent ranges from 30 to 70%, depending on the initial ion concentration.