Saraswat, ShwetaTewari, Pratibha2023-02-022023-02-022022-07https://krishikosh.egranth.ac.in/handle/1/5810193150The present study was carried out to reduce the fluoride contamination in groundwater using low-cost biosorbents viz. egg-shell powder (ES Powder), rice husk dust (RHD) and coconut Fibre Dust (CFD). The biosorbents were characterised using Fourier Transform Infrared (FTIR) analysis and their functional group peaks were identified. The optimization of different biosorbents was performed at various parameters such as pH, initial fluoride concentration, adsorbent dose, contact time,agitation speed and temperature. Fluoride adsorption efficiency was also compared using SPADNS method of fluoride testing and absorbance was taken using UV-visible spectrophotometer before and after adsorption. Among all biosorbents, maximum fluoride adsorption was obtained using egg shell powder at pH 6, 600 rpm, at 5 g/100ml of adsorbent dose and 1.5 mg/L initial fluoride concentration at 30°C temperature. The maximum fluoride removal efficiency of egg shell came out to be 88%. The biosorbents were reused four times and RHD showed maximum regeneration power of 56% in fourth stage. The results revealed that the low-cost biosorbents are promising resource for the defluoridation of groundwater which may ensure the availability of safe drinking water among the poorer sections of the society in fluoride contaminated areas.EnglishThesis