Anaerobic bio-digestion of concentrate obtained in the process of ultra filtration of effluents from tilapia processing unit

Milena Alves De Souza,Fabrício Rogério Castelini,Milena Penteado Chaguri,Jorge De Lucas Junior,Rose Meire Vidotti

doi:10.1590/s1516-35982012000200002

Abstract

The objective of the present study was to evaluate the efficiency of the process of biodigestion of the protein concentrate resulting from the ultrafiltration of the effluent from a slaughterhouse freezer of Nile tilapia. Bench digesters were used with excrements and water (control) in comparison with a mixture of cattle manure and effluent from the stages of filleting and bleeding of tilapias. The effluent obtained in the continuous process (bleeding + filleting) was the one with highest accumulated population from the 37th day, as well as greatest daily production. Gases composition did not differ between the protein concentrates, but the gas obtained with the use of the effluent from the filleting stage presented highest methane gas average (78.05%) in comparison with those obtained in the bleeding stage (69.95%) and in the continuous process (70.02%) or by the control method (68.59%).

Highlights

In terms of raw materials, water supply and operating unit of fish processing plants vary widely
Gases composition did not differ between the protein concentrates, but the gas obtained with the use of the effluent from the filleting stage presented highest methane gas average (78.05%) in comparison with those obtained in the bleeding stage (69.95%) and in the continuous process (70.02%) or by the control method (68.59%)
In the data from the biodigestor effluent (Table 2) there is difference in bleeding and continuous process compared with other concentrates for K, and the control variables differed significantly in Ca, Cu, Fe and Mg, showing no statistical difference for Cu and Fe when compared with continuous process and bleeding, respectively

Summary

Introduction

In terms of raw materials, water supply and operating unit of fish processing plants vary widely. The generation of effluent on the different plants and forms of processing brings a high organic content, colloidal solutions and particles. The processing industries of fish and shellfish often encounter problems with the handling and disposal of waste, due to increased cost of waste treatment plants, with regard to energy. To deal with such problems and comply with government regulations, the effluent from the fish processing must be treated through a good waste management and treatment technologies (FAO, 1996) Depending on the particular operation, the level of contaminants may be minor, such as during washing; medium, such as in filleting and high, such as at bleeding (Chowdhury et al, 2010).

Objectives

Methods

Results