Softened Water and Steam Boiler Water Condensate Quality used in the Milk Production Line of a Private Dairy Unit Located in Bechar Province (South-West of Algeria): Physicochemical and Bacteriological Analysis

Abstract

Background: This study aimed at assessing the physicochemical and bacteriological parameters of the water at the softener outlet and the steam boiler water condensate of a dairy unit located in Bechar province (South-West of Algeria). Methods: Some physicochemical and bacteriological parameters were analyzed based on standard methods given by the American Public Health Association (APHA). Result: The obtained results showed that the parameters: pH, EC, salinity, TA, TAC, sulfate, nitrate, and fluoride ions of most analyzed water samples at the softener outlet (SW) were in agreement with national regulations. However, the steam boiler water condensate samples (BW) were out of specification except for TA, TAC, nitrate, and fluoride ions. The SW and BW samples were qualified as very hard exceeding the standard set at 15°f and 10,5 to 11,5°f, respectively, with high salinity and TDS values. The bacteriological analysis showed that most of the steam boiler water condensate samples complied with national regulations with the absence of fecal coliforms, knowing that the BW5 and BW8 samples were contaminated with spores of sulfite-reducing Clostridia at a load of 3 and 1 spore/50 mL, respectively. However, an average of 6/10 (i.e. 60%) of the softened water samples were contaminated with the opportunistic species ‘Pseudomonas aeruginosa’, while the SW5, SW8 and SW10 samples were contaminated with spores of sulfite-reducing Clostridia (1 to 11 spores/50 mL). All samples were free from Salmonella spp. A high TH of the water at the softener outlet reveals a malfunction of the external treatment (softening). On the one hand, boiler scaling that may occur can reduce the steam flow (low efficiency of the heat treatment), which contributes to poor pasteurization of the milk, especially in the presence of bacterial contaminants, and on the other hand, increase the energy expenditure.