Abstract

LOPEZ BLANCO, Carlos. Optimization of water use in washing coffee.. Apthapi [online]. 2017, vol.3, n.1, pp. 24-38. ISSN 0102-0304.

The process of transformation of coffee in Bolivia is 100% wet, with water being the main input. In producing áreas such as the Yungas of La Paz, the available water is used in large quantities, making it difficult to estimate expenditure and pollution. The objective of this work was to study the optimization of water use in coffee washing in modified fermentation tanks carried out at AGROTAKESI SA, Chojlla, Yanacachi municipality, during 2010. The variables studied were: quality and Availability of water, "physical constants" and "conversión factors", coffee washing, in the conventional system and in modified tanks (laboratory and pilot level). The water quality at the field and laboratory level was classified as good, without restriction of use, with supply of 0,29 L.s¹, covering current demand. The constants and the factors indicated that the coffee of the zone is of smaller size and weight, requiring of 5 kg of cg to obtain 1 kg of cps. The washing under the conventional system in runner channel showed a water expense of 33,8 L.kg¹ cps. In a modified tank, at "laboratory level", drains with mucilage contents of 20,7 were obtained in discontinuous washing; 44,7; 22,5; 10,1 and 2,0% in yeast drainage (DF), I, II, III and IV rinse. After the second rinse, 55,1% of the total wastewater was accumulated with 87,9% of mucilage removal, converting DF and rinses I and II into the main sources of contamination. At "pilot scale", the water expenditure was 5,3 L.kg¹ cps. The technological innovation with the infernal adaptation of the conventional fermentation tank for the discontinuous washing, allowed to reduce the expenditure of water in 84%, compared to the conventional washing.

Keywords : Conventional system; drainage; wastewater; mucilage; dry parchment coffee (cps).