Investigation of Coagulation and Flocculation Process in Chemical Pre-Treatment of Livestock Wastewater

  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. 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. 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