Vegetation Filters for brewery wastewater treatment: Results of a ‘lab-to-field’ procedure under Mediterranean conditions compared to a conventional WWTP

Abstract

Water is a vital element in the brewing industry, being present in all facets of its operation. This industry generates substantial wastewater quantities, requiring intensive and expensive treatment in Wastewater Treatment Plants (WWTP). Vegetation Filters (VF) are a type of Nature-Based Solution (NBS) for wastewater treatment that offers a sustainable alternative to these WWTP. In this work, an innovative ‘Lab-to-field’ procedure including several trials at different scales was conducted to assess the applicability of VFs to the brewing industry, starting from trials under greenhouse conditions to a real scale pilot plantation under Mediterranean conditions (Spain). This represents the first attempt to assess the use of VF in the brewing industry. The occurring processes during the trials under controlled conditions match those observed on the field, thus validating the experimental procedure as a quick and simple tool for new scenarios. While total phosphorous (TP), chemical oxygen demand (COD) or total suspended solids (TSS), among other parameters, were easily removed from the wastewater, nitrogen (N) leaching towards the aquifer was observed, especially during the second period of the VF operation. This was caused by the detrimental effects of the high salinity (especially sodicity) on soil and plant health, highlighting the need for rigorous control and maintenance. Minimizing the sodium (Na⁺) amounts in influent wastewater and the addition of soil amendments and proper soil and cultural management practices would be most beneficial for the overall system performance. More research is needed addressing the effects of suggested limitations on Na⁺-rich compounds during wastewater pretreatment