Abstract
The wastewater released by industries and communities into water bodies contains high concentrations of nutrients (pollutants) leading to eutrophication which has negative effects on the environment, public health and the economy. Hence this work is focused on the development of a practical and efficient water treatment method based on electrocoagulation (EC) technology because it is efficient, user friendly, dependable and affordable.
Recycled corrugated iron, aluminium and 3D-printed stainless steel electrodes were used as sacrificial electrodes for the simultaneous removal of the algal indicators ammonia, nitrate, and phosphate from raw water. The electrodes were also used for the removal of selected bacteria (heterotrophic bacteria, total coliforms, Esherichia coli, Enterococci, and Pseudomonas). The study determined the effects of electrocoagulation parameters such as initial pH, initial concentration, contact time, applied voltage, inter-electrode spacing and supporting electrolytes on these removals. Characterization techniques such as X-ray diffraction (XRD) for phase identification and crystallinity analysis, field emission scanning electron microscopy (FE-SEM) for high-resolution imaging of surface morphology, energy dispersive X-ray spectroscopy (EDS) for elemental analysis, Fourier-transform infrared spectroscopy (FTIR) for functional group identification, and Brunauer-Emmett-Teller (BET) analysis for surface area and porosity measurements, were employed to characterize the materials.
In the first section of the work, the optimal conditions for the recycled corrugated iron electrode were found to be pH 6, (40 mg/L) initial concentration, (20 min) contact time, (15 V) applied voltage, and (0.5 cm) inter-electrode distance. The results showed that the sludge was mainly composed of iron oxides and hydroxides, resulting in a large surface area that is beneficial for increasing the active sites available for electrochemical reaction. This is reflected in the results that show that the algal indicators were removed up to maximum percentages of 99.9, 97.0, and 99.8% for ammonia, nitrate and phosphate, respectively. The electrodes were reusable for three ...