Using electric flocculation to treat domestic laundry wastewater with different types of detergents

Laundry wastewater contains a large number of surfactants, suspended solids and other pollutants, and the COD value is high. If the wastewater is discharged into the water without harmless treatment, it will cause serious environmental pollution. The electrocoagulation process was selected as a promising environmentally friendly technology for treating domestic laundry wastewater. In this paper, the contribution of the liquid and powder detergents to the composition of domestic laundry wastewater was investigated. Combination of stainless steel and aluminum anode electrodes were compared. The effect of electrolysis time and current density on the removal of COD, LAS and turbidity of liquid detergent and powder detergent laundry wastewater were evaluated. The experimental results showed the electrocoagulation process has significant removal. It was found that the electrolysis time in 25 minute, current density in 5 mA/cm2 had optimum efficiency when considering efficient removal and economic energy consumption. For Liquid detergent laundry wastewater, COD, LAS and turbidity removal rates were 84%, 93% and 96%. For powder detergent laundry wastewater, COD, LAS and turbidity removal efficiency were 80%, 83% and 91%, respectively. Energy consumption in the optimum conditions for liquid detergent and powder detergent laundry wastewater by electrocoagulation were 7.324KWh/m3, 3.642KWh/m3, respectively, while using combination of stainless steel and aluminum anode electrodes equals 1 to 1.

Effectiveness of doping zinc to the aluminum anode on aluminum-air battery performance

Many efforts have been devoted to the improvement of metal-air batteries. Aluminum (Al) is the most abundant metal in the Earth’s crust and has high electrochemical potential. Therefore, the aluminum-air battery is one of the most attractive metal-air batteries. To overcome some disadvantages of the aluminum-air battery, some alloys of aluminum and several metals have been proposed. In this study, the performance improvement of the aluminum-air battery by doping zinc (Zn) to the aluminum anode was investigated. Zinc was doped to aluminum by a simple process. The difference in the characteristics of Zn-doped Al due to different heating temperature during the doping process was also investigated. The maximum power density of the battery was 2.5 mW/cm2.