A green approach to milkmaid wastewater: Evaluating up-flow anaerobic sludge blanket-biofilter effluent for fodder shrubs cultivation and drought resistant

Abstract

The agricultural industry is highly dependent on using water quality due to challenging soil and climatic conditions. Hence, this study investigated the potential reuse of treated effluents from a pilot-scale coupled UASB-Biofilter system for the cultivation of drought-resistant fodder shrubs using wastewater generated from the buffalo milkmaid process. The milkmaid wastewater was treated in a sedimentation tank, with the aim of removing large suspended solids and settleable organic matter, and then in an up-flow anaerobic sludge blanket (UASB). The UASB effluent was treated in a biofilter. A field experiment was carried out at the Experimental Farm of Veterinary Faculty, Suez Canal University, from March to October 2023 to study the effect of different quality of treated buffalo milkmaid wastewater with COD (Null, 1000 ± 28, 130 ± 33, 520 ± 27, 100 ± 30 mg.L−1, respectively)on the growth of Acacia saligna and Moringa oleifera shrubs. Split plot designed with five Treatments: Control (freshwater) (T1), sedimentation tank effluent (T2), Up-flow Anaerobic Sludge Blanket (modified UASB with rice straw biochar) effluent unit (T3), conventional UASB effluent unit (T4), and biofilter effluent unit (T5), of each species. Vegetative growth, the biomass of shrubs, and the soil NPK, organic matter, and organic carbon were determined. Moringa oleifera shrubs showed higher biomass (2330.3 g)and nitrogen content (62.02 mg kg−1) in soil compared to A. saligna. UASB treatments (T3 and T4) promoted the best growth, with treated buffalo milkmaid wastewater increasing nitrogen concentrations in the soil. Overall, UASB proved to be the most effective treatment for enhancing growth in A. saligna and M. oleifera shrubs in sandy loam soil. This study evaluates the performance of a pilot-scale UASB-Biofilter system for treated effluent reuse in drought-resistant fodder shrubs cultivation. It also conducts a bibliometric analysis using VOSviewer and RStudio 4.4.1, analyzing trends in wastewater reuse research from 1999 to 2024 based on data from the Web of Science. The review provides insights into the evolution of wastewater reuse in sustainable agro-hydrology and highlights emerging research areas for further investigation.