Efecto de la adición de lodos centrifugados de la PTAR – Ambato sobre el proceso de biodigestión de residuos verdes provenientes de mercados

Abstract

In Ecuador there is no adequate waste collection system, a large amount of this waste ends up returning to the streets and rivers. The accumulation of these organic waste can generate various environmental problems if adequate treatment is not carried out. In this project, the biodigestion of organic matter from markets was studied, and the effect of the addition of centrifuged sludge from the WWTP - Ambato on the generation of biogas was identified. For this, four biodigesters were operated during the 12 weeks, which all started the same. The biodigesters initially contained the same components: inoculum (ten percent by volume), basal medium (sixty percent by volume) and liquefied green waste (thirty percent by volume). From the third week onwards, the biodigesters were fed with basal medium and green waste for the controls, while centrifuged sludge was added to the feed for the others. The analyzes showed a high concentration of nutrients in the centrifuged sludge (phosphorus, nitrogen and magnesium) that contribute to the microbiological transformation of organic matter into methane. Likewise, it was determined that the concentration of heavy metals such as chromium and cadmium, which can act as inhibitors, remained at values below the toxic threshold. However, these concentrations of heavy metals in the digestion liquor make its subsequent use as a biofertilizer difficult. Regarding biogas production, no significant difference could be observed between the control and sludge digesters.