Impact of recharge water source quality on Chlorella vulgaris growth and biomass: Strategies for eutrophication control in urban landscape lakes

Understanding the relationship between recharge water quality and algal metabolism is critical for managing eutrophication in urban landscape water bodies. This study investigates six landscape water bodies in Xi'an City, utilizing natural and reclaimed water recharge sources to cultivate and evaluate the growth and biomass composition of Chlorella vulgaris. The findings revealed that the growth and metabolic rate of C. vulgaris were faster in reclaimed water sources, whereas nitrogen (N) and phosphorus (P) conversion rates were higher in natural water sources. Redundancy and statistical analyses indicated that total nitrogen (TN) in reclaimed water was a major factor influencing C. vulgaris growth, contributing 74.3 % to its growth dynamics. In contrast, natural water sources did not significantly affect the growth characteristics of C. vulgaris. The biomass characteristics of C. vulgaris across different recharge water sources were similar, exhibiting a strong correlation with water quality. Environmental factors such as COD, N/P ratio, and PO₄-P contributed most significantly to biomass accumulation. These findings provide a strategy for preventing and controlling eutrophication in landscape water bodies that utilize reclaimed water recharge sources in Xi'an City.