EFFECT OF THE USE OF NATIVE MICROORGANISMS IN THE EFFLUENTS TREATMENT FROM TABLE OLIVE INDUSTRY

FLAMARIQUE JULIETA; MARIELA B. MALDONADO; MARIO BAIGORI; LAFI JORGE

Tucumán

Congreso; Congreso Argentino de Microbiología General; 2017

Congreso Argentino de Microbiología General

Mendoza is a province that produce table olives in large quantities, where the water resource is limitedso it is fundamental a sustainable use of it to preserve its quality. During the production process ofSpanish style fermented green olives, large amounts of effluents are generated, with physicochemicalcharacteristics that give them high pollutant power. The wastewaters from the debittering stage isa dark brown liquid due to its content of polyphenols and high quantity of organic matter; presentshigh salinity and alkalinity due to the use of a 2% sodium hydroxide solution. In order to reduce thesecontamination parameters, different bioremediation tests were carried out, using microorganisms fromevaporation ponds from the originated effluents during the elaboration of table olives. The aim of thiswork was to evaluate the use of microorganisms from an evaporation pond on the contamination parameters,measuring the variation of pH, total acidity, polyphenol content and organic matter contentfrom the debittering wastewaters of Spanish style fermented green olives. Two tests were carried outusing equipment with constant agitation and controlled temperature, one of them with the additionof an exogenous source of carbon (Test 1) and the other without the addition of the same one (Test 2).The volume of work was 15 liters in each one, corresponding to 25% of the debittering effluent; 10%of mud rafts (inoculum) and 65% of distilled water. It was supplemented with mineral salts and antifoamingagents. The content of organic matter, such as COD and BOD, was measured at the initial andfinal moment; every day was measured pH, total acidity, polyphenol content and microbial growth bysurface plate counts. Isolates of cultivable microorganisms were carried out in a selective medium withthe effluent to determine their nature. The duration of each trial was 14 days. The results obtained, inthe Test 1, showed a great decrease of pH, arriving to 5 pH units. In contrast, in the Test 2, there wasno marked pH decrease. Regarding the organic matter content, the percentage of decrease of CODand BOD5 was 91% and 94%, respectively, in the Test 1; while, in Test 2, the percent reduction of CODand BOD5 was 48% and 49%, respectively. The maximum percentage of total acidity was higher in thefirst test; as well as the polyphenol content declined sharply in this experiment. The presence of mixedcultures of bacteria and yeasts was detected. The results obtained are encouraging to achieve the bioremediationof the effluent and thus contribute to the reduction of the pollution generated.