Combined use of coagulation (M. oleifera) and electrochemical techniques in the treatment of industrial paint wastewater for reuse and/or disposal

Landfill Leachate Treatment by Combining Coagulation and Advanced Electrochemical Oxidation Techniques

“…On the other hand, old RLL is characterized by pH > 7.5 and low organic loads (< 4000 mg/L), resulting from high molecular weight organic compounds. This method has been applied for the treatment of several types of effluents, [12,[23][24][25][26][27] using chemical (aluminum sulfate, ferric chloride, polyaluminum chloride) or vegetable salts (biocoagulants). [13] To overcome this problem, several methods of treatment of RLL have been proposed as an alternative to the biological process, some of them with good results, such as flotation, [14] coagulation-flotation, [15] chemical precipitation, [16] reverse osmosis, [17] ultrafiltration, [18] activated carbon adsorption [19] and advanced oxidative processes (AOPs).…”

“…[12] This characteristic hinders the application of biological processes, since numerous organic compounds in young leachate cannot be degraded by the microorganisms in these treatments. [26,28,29] In this process, the hydrolyzed coagulant species come into contact with impurities, forming destabilized particles during the fast mixing step. [20][21][22][23] Coagulation-flocculation is a widely accepted pretreatment method employed to remove materials that are in colloidal suspension (organic and/or inorganic) or that remain dispersed in the solution and cannot be removed by conventional physical processes.…”

“…[27] The main parameters employed to evaluate the efficiency of this process are pH and coagulant dosage. [25,26,31,[32][33][34][35][36][37][38][39] The degradation of organic compounds in aqueous mediums occurs via the generation of intermediary species, such as the hydroxyl radical ( * OH), which is formed through electrochemical water oxidation. [28] The use of AOPs has been considered the best solution to degrade refractory compounds in wastewater.…”

“…[28] The use of AOPs has been considered the best solution to degrade refractory compounds in wastewater. [22,25,26,34,[40][41][42][43][44][45] Given the extraordinary properties of BDD electrodes, such as inert surface, low adsorption, high corrosion resistance in acidic media and high OER, [40] they are considered the most efficient inactive electrodes for the mineralization of several organic compounds. [32] Electrochemical methods (a typical AOP), in particular, have been extensively investigated for the treatment of organic and inorganic pollutants that are found in several types of effluents.…”

“…[20][21][22][23] Coagulation-flocculation is a widely accepted pretreatment method employed to remove materials that are in colloidal suspension (organic and/or inorganic) or that remain dispersed in the solution and cannot be removed by conventional physical processes. This method has been applied for the treatment of several types of effluents, [12,[23][24][25][26][27] using chemical (aluminum sulfate, ferric chloride, polyaluminum chloride) or vegetable salts (biocoagulants). [26,28,29] In this process, the hydrolyzed coagulant species come into contact with impurities, forming destabilized particles during the fast mixing step.…”