Quality of the residual water produced in the different stages of the wet coffee milling process

Abstract

Due to the water stress that one goes through, thinking about the fact of reusing wastewater is imperative. This study characterized and valued the residual water generated in the wet beneficiation process. It was sampled in one of the coffee exporting mills in the community of La Libertad in the municipality of La Democracia in the department of Huehuetenango, Guatemala. The objective was to determine its quality and the appropriate treatment for its reuse. The results were compared with the values recommended in Governing Agreement 236-2006 of the Ministry of the Environment of the Republic of Guatemala. Determining that they are not suitable to be discharged to receiving bodies. For which all must be treated. Additionally, biodegradability was analyzed, obtaining as a result that all of them can be treated by biological methods. It was determined that wastewater from pulping and washing potentially has added value if used in crop irrigation due to its high concentration of nutrients. The pulping wastewater has 12 mg / L and 53 mg / L of total phosphorus and total nitrogen respectively. And the recycle wash wastewater has 3308 mg / L total phosphorus and 117 mg / L total nitrogen.