Application of Electrocoagulation with a New Steel-Swarf-Based Electrode for the Removal of Heavy Metals and Total Coliforms from Sanitary Landfill Leachate

Abstract

Sanitary landfill leachate (LL) composition varies according to climate variables variation, solid waste characteristics and composition, and landfill age. Leachate treatment is essentially carried out trough biological and physicochemical processes, which have showed variability in efficiency and appear a costly solution for the management authorities. Electrocoagulation (EC) seems a suitable solution for leachate treatment taking into account the characteristics of the liquor. One of the problems of EC is the electrode passivation, which affects the longevity of the process. One solution to this problem could be the replacement of the electrode by one made of recyclable material, which would make it possible to change it frequently and at a lower cost. The objective of the present work was to evaluate the removal of heavy metals (As, Ba, Cd, Cr, Cu, Fe, Pb, Mn, Ni, Se and Zn) and coliforms from a LL by EC using electrodes made from steel swarf (SfE) up to 8 h. Removal efficiencies of detected heavy metals were 51%(Cr), 59%(As), 71%(Cd), 72%(Zn), 92%(Ba), 95%(Ni) and >99%(Pb). The microbial load of coliforms in leachate was reduced from 10.76 × 104 CFU/mL (raw leachate) to less than 1 CFU/mL (after treatment with SfE) (i.e., approximately 100% reduction). The use of SfE in EC of LL is very effective in removing heavy metals and coliforms and can be used as alternative treatment solution for such effluents.

Concept of Flocks Fragmentation and Averaging Method for the Application of Electrocoagulation in Process for Coke Oven Wastewater Treatment

“…The economic analysis presented for the replacement of conventional coagulation with electrocoagulation for coke oven wastewater showed that if the process was applied to plants with an external power supply, its economics were not yet justified, but if a coke oven plant possessed its own power supply, the electrocoagulation treatment was more beneficial than conventional coagulation. However, it is worth noting, that the process of electrocoagulation is also used in other industries [ 29 , 30 , 31 , 32 , 33 , 34 , 35 , 36 , 37 ]. The process has considerable potential for practical applications.…”

“…Currently, the electrocoagulation process is widely used for different types of pollution [ 29 , 30 , 31 ]. It has found application in many different industries, including the cleaning and neutralization of oil emulsions used in machining and abrasive handling, wastewater from the textile industry, wastewater from agro-food processing businesses, wastewater from car washes, heavy metals, and other pollutants such as coke oven wastewater [ 32 , 33 , 34 , 35 ].…”

Novel Materials for Heavy Metal Removal in Capacitive Deionization

“…EC is a process involving the in situ generation of coagulants such as aluminum/iron ions and corresponding hydroxides from the electrical dissolution of "sacrificed anodes" under direct electrical currents [14]. Generated iron or aluminum flocs serve as coagulants and subsequently precipitate HMs, and an aluminum plate, steel/iron plate/mesh, and Ti plate/mesh are applied as anode and cathode materials to remove Cr(VI), Cu(II), Ni(II), Cd(II), Pb(II), Zn(II) , Ba(II), and As(III) [15][16][17][18][19][20][21][22][23]. The EC process can dispose of multiple contaminants in one process; has low sludge production and maintenance costs; can easily handle water quality variations; and can achieve over 95% removal efficiency for HMs.…”

Frontiers in Freshwater Ecology, Conservation and Water Treatment Technologies

“…Contributions [7,8] focused on freshwater ecosystem monitoring. The contribution [9] proposed measures to improve water efficiency in a public building, contributions [10][11][12] investigated methods to improve wastewater treatment methodologies, contribution [13] evaluated how treated effluent impacted the health of the recipient river, contribution [14] evaluated the economic sustainability of wastewater treatment plants. Bird et al [7] monitored different species of freshwater mussels.…”

“…The results showed that the symbiotic process between microalgae and bacteria was present in the treatment of the paper pulp wastewater, allowing for a good efficiency in the removal of organic matter and nutrients while increasing biomass harvesting and producing sedimentable photogranules. Meanwhile, for the first time, de Oliveira et al [12] proposed the use of filling wastes from metallurgy to manufacture electrodes for electrocoagulation in order to remove heavy metals and total coliforms from sanitary landfill leachate. These electrodes could remove 51% to 95% of the heavy metals and 100% of the thermotolerant coliforms.…”