Abstract

Colloidal particles are the main cause of turbidity in an aquatic environment. Water turbidity maintains pathogenic microorganisms against disinfection. In addition to increasing the consumption of antiseptic substances, mainly it causes a lot of aesthetic and non-sanitary problems such as the formation of toxic and carcinogenic side constituents in the treatment of water. In this study we investigated the efficiency of the use of tragacanth of Astraglus gossypinus (Catira) on the effectiveness of the electrocoagulation process in the removal of turbidity from brackish water. In this descriptive-analytic study, direct bentonite injections of 2 to 8 g/L were used to provide opacity. In the following, the effect of applying coagulant aid of Tragacanth of Astraglus gossypinus plant with values of 0.25 to 1.5 g/L on the efficiency of the electro-coagulation process equipped with iron electrodes in the removal of opacity from brackish water samples were examined in potential difference from 5 to 30 volts, and pH from 2 to 9 over a period of 60 min. Variation of turbidity was determined using the turbidity sensor in accordance with standard reference methods. The results showed that the highest opacity removal efficiency is about 99 for each 1 kg of opacity due to the addition of 7 g/L bentonite under neutral pH conditions, Tragacanth dose of 1.5 g/L, 8 g/L dose of NaCl, and voltage of 30 V for 30 min, along with the average consumption of iron and electrical energy of 0.18 kg and 0.53 Kwh, respectively. Thus, the use of Astraglus gossypinus tragacanth for removing turbidity as a natural coagulant aid dramatically improves the electrocoagulation process efficiency in the removal of turbidity from brackish water samples and reduces current costs of the electro-coagulation process. © 2018, HARD Publishing Company. All rights reserved.