Treated cheese whey as a promising nutrient solution for hydroponic cultivation of lettuce, cabbage and tomato

Abstract

The dairy industry is among of the fastest-growing agro-industries worldwide, driven by the rising demand for dairy products. However, it is also a major source of environmental pollution within the food sector due to the large volumes of whey it generates. This study presents a comparative analysis of alkaline-treated whey as a nutrient solution in hydroponic systems for the cultivation of lettuce (Lactuca sativa), cabbage (Brassica oleracea), and tomato (Solanum lycopersicum), by assessing various plant growth parameters. Alkaline precipitation at pH 11 resulted in substantial reductions in chemical oxygen demand (92.82 %), biological oxygen demand (75.58 %), phosphorus (22.12 %), hardness (75.62 %), and total dissolved solids (48.26 %). When diluted with freshwater at a 1:20 ratio, the treated whey exhibited performance comparable to the commercial hydroponic solutions. Notably, tomato exhibited showed excellent results, with 94 % similarity in cluster count, 73.33 % similarity in comparison to the control, and 97.13 % similarity in dry weight. Therefore, treated cheese whey presents a viable alternative to chemical nutrients in hydroponic systems.