Evaluation of irrigation suitability potential of brewery effluent post treated in a pilot horizontal subsurface flow constructed wetland system: implications for sustainable urban agriculture

Abstract

The use of untreated or partially treated wastewater reuse for urban and peri-urban agricultural irrigation is a common practice in developing countries like Ethiopia. Such practices, however, pose significant environmental and public health risks. The objective of this study was to evaluate the irrigation suitability of anaerobic digestion brewery effluent (ADBE) and two-stage horizontal subsurface constructed wetland post-treated ADBE (CWPBE). A series of pot experiments were conducted in a plastic - greenhouse system arranged in three sets of irrigation schemes: Treatment Group1 (TG1): municipal pipe tap water (MPTW) irrigated pots; Treatment Group2 (TG2): ADBE irrigated pots, and Treatment Group3 (TG3): CWPBE irrigated pots. Pots packed with the same amount of sandy clay loam soil and local tomato seeds sown were irrigated following an updated tomato irrigation schedule derived from the FAO CROPWAT stimulation model for 120 days. The findings from key irrigation water quality parameters showed that the CWPBE achieved the prescribed irrigation water standards with values of pH (7.4 ± 0.15), electrical conductivity (1.9 ± 0.11 dS.m −1 ), total suspended solids (25 ± 4.17 mgL -1 ), chemical oxygen demand (185.1 ± 1.66 mgL -1 ), total nitrogen (17.4 ± 0.7 mgL -1 ), total phosphorous (8.8 ± 0.26 mgkg -1 ), calcium (10.5 ± 3.6 mgkg -1 ), magnesium (4.9 ± 0.98 mgkg -1 ), sodium (4.4 ± 1.51 mgkg -1 ), potassium (2.3 ± 1.15 mgkg -1 ), sodium adsorption ratio (1.6 ± 0.34), and total coliform (8 ± 0.16×10 −5 CFU/100 mL). Moreover, tomato plants grown in TG3 attained higher growth such as number of leaves (85.6 ± 4.68), plant height (92.2 ± 1.29 cm), stem diameter (13.1 ± 2.35 cm) and leaf area (35.5 ± 1.03 cm 2 ) as well as higher biomass (61.2 ± 1.33 kgm −2 ) and fruit (46.4 ± 3.51 kgm −2 ) yields over other treatment groups. The results revealed that irrigation waters significantly improved both growth and yield parameters of tomato plants with the ascending order of TG1 < TG2 < TG3. Moreover, CWPBE showed minima short-term residual effect on soil physicochemical properties as compared to ADBE, and thus, it has potential suitability for agricultural irrigation reuse.

By-Product Valorization as a Means for the Brewing Industry to Move toward a Circular Bioeconomy

“…However, soil irrigated with AD-treated BWW showed an increase in pH and exchangeable cation (Ca 2+ , Mg 2+ , K + and Na + ) concentration. This negative impact was lowered with additional constructed wetland treatment [77]. In another study, soil modification was linked to a high salt concentration, or conductivity of around 3-4 mS•cm −1 [78].…”

“…Indeed, AD-treated BWW demonstrated fertilizing action on mustard greens, basil and lettuce crops [76]. Alayu and co-workers investigated irrigation effects on tomato cultivation with two BWWs: ADtreated BWW with and without additional constructed wetland treatment [77]. Both treated wastewaters affected tomato growth, i.e., plant height, number of leaves, biomass Another application of BSY is valorization as carrier material to encapsulate bioactive compounds, like carotenoids from pumpkin peel extract [70] or curcumin [71].…”

The Use of Constructed Wetlands to Treat Effluents for Water Reuse

“…The treatment system was subjected to a pre-treatment phase (coarse sieving), followed by a Imhoff tank and an equalization tank. The hybrid CW presented a total area of around 230 m 2 and consisted of a VF + HF + SCW bed, producing water for reuse in suitable conditions for food crops to be consumed raw with edible parts produced above the ground, as described by the EU regulation [73]. When treating effluents from a brewery, a system made of an HFCW in two stages was used to produce tomato irrigation water [69].…”

Testing Zeolite and Palygorskite as a Potential Medium for Ammonium Recovery and Brewery Wastewater Treatment

“…Notably, within the spectrum of wastewater treatment options, constructed wetlands (CWs) have gained favor as an eco-friendly technology, while offering numerous benefits through the treatment of variable wastewater volumes. CW systems have been tested for treating different types of industrial wastewater [15], including those from brewery operations [8]. In the CWs, wastewater purification is achieved through a comprehensive array of physical, chemical, and biological processes that occur within their components [16].…”