TREATMENT OF WASTEWATER OF POULTRY ABATTOIR BY COAGULATION

Abstract

There is dissolved air flotation has become widespread for treatment of food industry sewage, especially for meat plants. This type of purification is enough reliable and effective, especially in combination with preliminary coagulation. There are two main parameters of high physical and chemical cleaning efficiency: adjustment hydraulic mode of the dissolved air flotation unit and the selection of the most suitable reagents. However, this task is complicated due to the high dissimilarity of the waste of different enterprises among themselves, and, often, the technological parameters of the work of this site can’t be predicted. This article is studies the patterns of coagulation of wastewater from a meat processing plant using three types of coagulants: ferric chloride, ferrous sulphate, aluminum polyoxychloride. The wastewater of existing factory which produce turkey meat was chosen as object of the study. Inlet wastewater are coming from slaughter, washing and gutting birds and contain a large amount of contaminants such as blood, feather, cany. The study was conducted in two stages. At the first stage, relations of coagulation of pH of wastewater were determined experimentally in a wide range and graphics were obtained showing the dependence of the cleaning efficiency from suspended solids and color relation of the pH of wastewater. Relation of cleaning efficiency from coagulant dose was investigated at the second stage. The most kindly conditions of wastewater for coagulation and rational doses of coagulants were determined in results of this research. The most coverable conditions for coagulation with iron sulfate usage are dose is 30 mg/l and pH 5 ÷ 6, for ferric chloride – dose 40 mg/l, pH 5 ÷ 6, and dose 60 mg/l, pH 5,5 ÷ 7 for aluminum polyoxychloride. An important component of effective wastewater treatment at the flotation cell is the correct selection of the type of coagulant, its dose and the pH of the wastewater for coagulation.