Assessing the impact of treated coffee wastewater

In 2023, we maintained our partnership with the Civil and Environmental Engineering and Earth Sciences department of Notre Dame University in Indiana, US, world renowned for its applied research.

Two study lines have stemmed from the partnership:

1. 1. Building of groundwater simulations of our wet mills to assess the impact of treated wastewater irrigation, and to apply statistical methodologies to measure the potential impact on river water quality due to direct or indirect wastewater discharge.
2. 2. Investigating new treatment strategies and wastewater modelling for small and artisanal-sized mills. This project assesses the need for environmental protection, ease of implementation in remote locations, treatment efficiency, reliability, energy consumption or recovery, and resource recovery.

For groundwater protection, we have created models to assess the maximum organic loadings to be irrigated considering site-specific soil and groundwater characteristics. We have also produced groundwater flow models based on satellite data for wet mills that engage with the irrigation practice. Groundwater modelling like this can provide excellent insights into the management of our most precious natural resource and a roadmap for developing healthier ecosystems.

The application of these models, coupled with on-site measurements, confirmed that the environmental impact of our irrigation practices and direct wastewater discharge is not significant. This has enabled us to pilot the models in Guatemala and Brazil, and we plan to extend this to other origins, especially those that lack environmental regulation.

Regarding the new treatment strategies, we have been exploring the use of membrane aerated biofilm reactors and fungal membrane aerated biofilm reactors in treating high-strength wastewater, with promising initial results observed in lab-scale experiments. Additionally, a pond mechanistic model has been created to aid in the development of a technical user manual for wet mills utilising this technology, aiming for improved understanding and management practices.