Chemical and microbiological characterization of effluents in dairy farms of Río Primero department (Córdoba, Argentina)

PETRUZZI LUCIANO; MERLO CAROLINA; VÁZQUEZ CAROLINA; CAMILETTI BORIS X; BRUNO MARINA; SALLOUM SORAYA; LUCINI ENRIQUE I

Córdoba

Congreso; XI Congreso Argentino de Microbiología General; 2015

Asociación Argentina de Microbiología

The main problem of milk production is the generation of effluents containing excreta, organic matter(OM), nutrients, etc. If effluents are not adequately managed affect the quality of water, soils andhuman health. Therefore the utilization of the effluents for irrigation of crops and fodder after of itstreatment with system of 2 or 3 lagoons is a good option to minimize effluents impact. There is littlelocal information on the quality of livestock effluents and the impact of its discharge. The objective wasto evaluate the effluents quality in order to determine the efficient of the treatments used. It is workedin three dairy farms of Río Primero Department, Cordoba. In the first (DF1) and second dairy farm(DF2) the water used is deposited in one lagoon that when is filled the content is discharged to thefield. The third dairy farm (DF3) presented two lagoons: one for the water of the first wash (T3-FW)and other for the second wash (T3-SW). Two water samples were taken in each lagoon: one near theeffluent input (I) and other in the farthest area (F). The samples were collected in sterile receptaclesand stored refrigerated until analyses. In each sample the following parameters were determined: a)pH, b) total organic matter (TOM), c) mesophilic bacteria, d) total and fecal coliforms and e)Escherichia coli. The obtained data were compared with the allowable limits for the use of effluents forirrigations (Environmental Protection Agency of EEUU-EPA) and effluent discharge to surface watercourses (Subsecretaría de Recursos Hídricos de Córdoba - SRH). The DF1 sample showed analkaline pH, while the other samples presented pH near the neutrality, except for DF3-FL that showedan acid pH. The TOM was higher in the samples near the effluent input, whereas the lower valueswere obtained in DF2-F. All samples presented an elevated number of mesophilic bacteria, total andfecal coliforms and E. coli. No effluent met the allowed values (£1000 fecal coliforms/100 mL)according EPA and SRH. The fecal coliforms exceeded the allowable limits, while pH values met thenorms, except for T3-FW (I). Our results show that the treatments settling lagoon is not an adequatesystem due to the great quantity of fecal and E. coli microorganisms founded which indicate that thedischarge or utilization of this effluents for irrigation present a health risk for workers and consumers.The high TOM values indicate low microbial degradation, which could be due to the lagoons lack ofaeration, generating anaerobic conditions that promote the development of anaerobic and fermentersmicroorganisms that produce bad smell, nutrient loss and slow degradation of OM. We suggest thatdairy farms perform a treatment that include effluent aeration due to it will be promoted aerobic activitywith high OM degradation and nutrient production. These effluents could be utilized for plant growth bycoupling of plant-animal production, leaving to be waste to become resources.