Pretreatment of Real Wastewater from the Chocolate Manufacturing Industry through an Integrated Process of Electrocoagulation and Sand Filtration

Abstract

The purpose of this study was to evaluate the efficiency of removal of suspended solids in terms of turbidity, color, and chemical oxygen demand (COD) when integrating the electrocoagulation process using aluminum sacrificial anodes and the sand filtration process as a pretreatment of wastewater from the chocolate manufacturing plant in Toluca, México. Wastewater from the chocolate manufacturing industry used in this study is classified as nontoxic, but is characterized as having a high content of color (5952 ± 76 Pt-Co), turbidity (1648 ± 49 FAU), and COD (3608 ± 250 mg/L). Therefore, enhanced performance could be achieved by combining pretreatment techniques to increase the efficiencies of the physical, chemical, and biological treatments. In the integrated process, there was a turbidity reduction of 96.1 ± 0.2% and an increase in dissolved oxygen from 3.8 ± 0.05 mg/L (inlet sand filtration) to 6.05 ± 0.03 mg/L (outlet sand filtration) after 120 min of treatment. These results indicate good water quality necessary for all forms of elemental life. Color and COD removals were 98.2 ± 0.2% and 39.02 ± 2.2%, respectively, during the electrocoagulation process (0.2915 mA/cm2 current density and 120 min of treatment). The proposed integrated process could be an attractive alternative of pretreatment of real wastewater to increase water quality of conventional treatments.

Optimization of the operating parameters of electrocoagulation using aluminum electrode and application to the Dam waters of Sidi Said Ben Mâachou

“…During this first phase, when the increase can be attributed to hydroxide ions (OH -) due to water reduction reaction 3, the suspended matter is removed by electrostatic coagulation. Over time, the pH stabilizes following the formation of Al(OH)3 reaction 5 or other solids, as suggested by some authors 23,18 , coagulation of suspended matter, in this case, is done by adsorption on the solids thus formed 24 . Figure 6 shows an increase, probably due to the release of Al 3+ and OH-ions reactions 1, 2, and 3 25 .…”

Interaction Effect of Operating Parameters during Oxidation of Different Dyes via the Fenton Process. Application of the Plackett-Burmann Design

“…Concentric aluminum tubes were used as electrodes and obtained positive results. Marco-Morales et al 5 evaluated the removal efficiency of suspended solids from the chocolate manufac-turing industry wastewater by integrating the coagulation process with sand filtration. Substantial reduction in turbidity, color, and chemical oxygen demand (COD) was observed using this combination treatment technique.…”

Enhancing the Performance of the Electrocoagulation−Filtration System Treating Mariculture Tailwaters by Using Alternating Pulse Current: Effects of Current Density and Current Conversion Period

“…Recently, EC has been combined with filtration (EC−filtration) in different scenarios, including industrial wastewater treatment [5,6], surface water purification [7,8], and other fields. This approach has been found to effectively decrease turbidity, remove total suspended solids (TSS) [9], chemical oxygen demand (COD Mn ), total nitrogen (TN) [2], natural organic matter (NOM) [10], dissolved organic carbon (DOC) [11,12], and eliminate microorganisms [4,13].…”