ملخص البحث :

This study investigates the influence of the initial pH on the removal of reactive black 5 dye (RB5) from water using electrocoagulation (EC) reactor supplied with aluminium electrodes. The influence of the initial pH has been investigated by commencing several sets of continuous flow experiments at five different initial pH values (4, 5, 6, 7, and 8) keeping the current density, inter-electrodes distance, and the concentration of RB5 constant at 2 mA/cm 2 , 4 mm, and 25 mg/L, respectively. The obtained results showed that the removal efficiency increased gradually as the initial pH increased from 4 to 6 to reac h its maximum level (96%) at the neutral range of pH, then it decreased to 74% as the initial pH increased to 8. This change of the removal efficiency with the initial pH could be attributed to the predominant species of aluminium coagulants, where in alkaline and acidic conditions; the prevailing species have low adsorption capacity for pollutants. While, in the neutral range of pH, the predominant species have high adsorption capacity for pollutants

ملخص البحث :

This study investigates the influence of the current density on both removal of reactive black 5 dye (RB5) from water and energy consumption using aluminium-based electrocoagulation (EC) reactor. The influence of the current density was investigated by electrolysing coloured water samples containing 25 mg/l of RB5 for 60 min at three different current densities (1, 2, and 3 mA/cm2). While the initial pH, distance between electrodes, flow rate, and initial temperature of water were kept constant at 5, 4 mm, 1 L/h, and 20 ± 10C, respectively. The obtained results showed that both the removal of RB5 dye and energy consumption increased with the increase of the applied current density. For example, it has been found that the removal RB5 and the power consumption increased from about 95% to 99.5%, and the power consumption increased from 4.3 to 10.4 kWh/m3 as the current density increased from 1 to 3 mA/cm2, respectively.

ملخص البحث :

A batch leaching test was performed to measure the leached concentrations of chromium (Cr), lead (Pb), arsenic (As), nickel (Ni), copper (Cu), cadmium (Cd), and zinc (Zn) from dredged sediment samples from the Leeds & Liverpool canal/ Liverpool section. The obtained results confirmed that the leached concentrations of the studied heavy metals were less than the toxicity levels and followed the order: Zn > Cu > Ni > Pb > Cr > As > Cd. The highest concentration was of Zn (about 0.28 mg/L), followed by Cu at a concentration of 0.17 mg/L, while the lowest concentration was of Cd at 0.009 mg/L. Therefore, the dredged sediments from this canal can be safely relocated in dumping sites such as landfills, or reused such as by spreading on agricultural fields.