Effectiveness of Water Hyacinth (Eichhornia crassipes) and Water Spinach (Ipomoea aquatica) to Reduce Nitrate and Phosphate Concentrations in Cimulu River Water, Tasikmalaya City, Indonesia

Water hyacinth and water spinach can be used as phytoremediation agents in the Cimulu River because these two plants can grow and adapt in the Cimulu River. This study compared the effectiveness of the two plants in reducing nitrate and phosphate in Cimulu river water. The research was conducted from September to October 2021. The research was conducted ex-situ and in-situ. Media retrieval from the Cimulu River was carried out in situ in the middle of the Cimulu River, Tawang District, Tasikmalaya City, Indonesia. aquatic plants, analysis of pH, temperature, and sampling were carried out ex-situ in the backyard of the house at the LIK Complex, Tasikmalaya City, Indonesia. Analysis of water samples such as DO, BOD, nitrate, and phosphate was carried out ex-situ at the Water Resources Management Laboratory of FPIK Padjadjaran University. The method used is an experimental method, with three treatments consisting of control treatment, treatment A (water hyacinth), and treatment B (water spinach). Each aquarium in treatments A and B contained aquatic plants weighing 200 g each. The results of the research conducted for 28 days showed that water hyacinth weighing 200 g was more effective in reducing nitrate and phosphate than water spinach with the same weight. Furthermore, water hyacinth can reduce nitrate by 61.72% and phosphate by 78.27% with the absorption rate of nitrate in one day reaching 0.006 g/m2 and phosphate 0.038 g/m2. The growth rates of water hyacinth in weeks I, II, III, and IV were 5.03±0.971%, 6.31±0.971%, 6.80±0.321%, and 7.18±0.277%. Meanwhile, other water parameters that can be reduced are BOD from 37.3 mg/L to 8.10 mg/L.