Preliminary analysis of four defluoridation agents

This study compared four commonly used defluoridation agents, including aluminum salt (old defluoridation agent A from the company’s wastewater treatment station), iron salt (1# new defluoridation agent B), calcium salt (2# new defluoridation agent C), and a new composite defluoridation agent (4# new defluoridation agent D). The results indicated that aluminum salt (old defluoridation agent A) and iron salt (1# new defluoridation agent B) showed good fluoride removal effects under low pH conditions, but they produced more precipitates and high chromaticity in the treated water. Calcium salt (2# new defluoridation agent C) performed stably under neutral pH conditions with good fluoride removal efficiency, but its cost is relatively high. The new composite defluoridation agent (4# new defluoridation agent D) exhibited excellent fluoride removal performance, maintaining high efficiency across a wide pH range and producing less sludge with minimal environmental impact. However, its initial investment cost is higher than that of traditional inorganic salt-based defluoridation agents. Overall, the new composite defluoridation agent (4# new defluoridation agent D) has advantages in long-term operation and environmental benefits, while aluminum salt (old defluoridation agent A) and iron salt (1# new defluoridation agent B) are suitable for cost-sensitive scenarios with lower treatment requirements.