Phosphate Removal from Laundry Wastewater Using a Hybrid Biofilter–Phytoremediation System with Broken Roof Tile Media and Chlorella sp.

Abstract : Laundry wastewater is one of the primary sources of phosphate discharge into aquatic environments due to the extensive use of phosphate-based detergents. Excessive phosphate concentrations in aquatic environments can accelerate eutrophication, leading to excessive algal growth, depletion of dissolved oxygen, and ecological imbalance. Therefore, there is a need to develop an efficient, economical, and environmentally friendly treatment system. This study evaluated the performance of a hybrid biofilter-phytoremediation system using broken roof tiles as the biofilter medium and Chlorella sp. as the phytoremediation agent to reduce phosphate levels in laundry wastewater. The experiment consisted of three treatment groups: wastewater (control), a biofilter with microalgae (BF+MA), and a biofilter containing broken roof tile fragments combined with microalgae (BFg+MA). Wastewater quality was monitored through several sampling periods, and phosphate concentration was analyzed as the primary parameter. Supporting parameters, including pH, dissolved oxygen, ammonia, nitrate, total suspended solids, and temperature, were also evaluated. The data were analyzed using Welch’s ANOVA to assess differences among treatments. When significant differences were found, the analysis was continued with the Games–Howell post hoc test at a 95% confidence level (α = 0.05). The results showed that the hybrid system effectively reduced phosphate concentrations in laundry wastewater. Phosphate removal was attributed to adsorption by the broken roof tile media, microbial activity within the biofilm, and nutrient assimilation by Chlorella sp. Changes in supporting water quality parameters indicated favorable conditions for biological and physicochemical treatment processes. These findings suggest that the hybrid biofilter-phytoremediation system has significant potential as a sustainable and low-cost alternative for laundry wastewater treatment.