TY - JOUR T1 - Investigation of Coagulation and Flocculation Process in Chemical Pre-Treatment of Livestock Wastewater TT - بررسی عملکرد فرایند انعقاد و لخته سازی در پیش تصفیه شیمیایی فاضلاب گاوداری JF - jehe JO - jehe VL - 6 IS - 1 UR - http://jehe.abzums.ac.ir/article-1-580-en.html Y1 - 2018 SP - 99 EP - 110 KW - Livestock Wastewater KW - physicochemical Treatment KW - Coagulation and Flocculation KW - COD KW - Turbidity N2 - Background: Development of communities, population growth, and enhancement of the health indicators has led to a significant increase in dairy and meat consumption, and consequential growth in the livestock industry. As the result, the environmental problems which cause by such industrial wastewater has increased. Livestock wastewater considered as a very non-biodegradable and polluted wastewater. In this study, the performance of livestock wastewater pre-treatment, by using coagulation and flocculation method, in order to reduce the pollutants concentration and improve wastewater properties were investigated. Methods: In the experimental methods, the Jar test unit was used as a batch reactor; FeCl3, PAC, and Alum as coagulants; and two polyelectrolytes: Zetafloc and Megafloc as cationic and anionic flocculants. The effects of coagulant dosage and type, flocculant type, and pH on the removal of COD and turbidity from wastewater were investigated in three stages. The wastewater with initial COD and turbidity of 12250 mg/L and 7125 NTU, respectively, was collected from a livestock unit. Results: The optimum conditions in the coagulation and flocculation process to achieve the maximum removal efficiency for COD (29.6%) and turbidity (52.8%) were obtained in an experiment with FeCl3 at a concentration of 400 mg/L, pH=8, and using an anionic flocculant. Conclusion: The results of the present study showed that the coagulation and flocculation process can be an effective method for livestock wastewater pre-treatment. M3 10.29252/jehe.6.1.99 ER -