LIJin,ZHANGXian-ming,NIEYu-dong,et al.Effect of Mg2+ and Ca2+ on Removal of Natural Organic Matter by Coagulation with Polymeric Titanium Chloride[J].China Water & Wastewater,2022,38(23):49-55.
Effect of Mg2+ and Ca2+ on Removal of Natural Organic Matter by Coagulation with Polymeric Titanium Chloride
China Water & Wastewater[ISSN:1000-4062/CN:12-1073/TU]
volume:
第38卷
Number:
第23期
Page:
49-55
Column:
Date of publication:
2022-12-01
- Keywords:
- polymeric titanium chloride; natural organic matter; water hardness; coagulation; response surface method
- Abstract:
- Coagulant polymeric titanium chloride (PTC) was prepared. With the water containing humic acid as treatment object, the single factor experiment was used to study the effects of PTC dosage, pH, and concentrations of Mg2+ and Ca2+ on the removal of natural organic matter (NOM) by PTC coagulation, and the interaction effects of the above four factors on the coagulation performance were analyzed by response surface method. In the single factor experiment, the optimal parameters such as dosage of PTC, pH and concentrations of Mg2+ and Ca2+ were 20 mg/L, 8, 50 mg/L and 50 mg/L, respectively. According to three-dimensional fluorescence spectrum analysis, Mg2+ had little effect on the removal of organic matter by PTC, while Ca2+ slightly improved it. Calculated by response surface analysis, the optimal dosage of PTC, pH and concentrations of Mg2+ and Ca2+ were 40 mg/L, 8.13, 70 mg/L and 30 mg/L, respectively. Under these conditions, the residual turbidity was no greater than 0.3 NTU, and the removal rates of UV254 and TOC were 79.8% and 75.3%, respectively, which were not significantly different from the theoretical predicted values. In addition, the removal efficiency of organic compounds was significantly improved compared with that without the presence of Mg2+ and Ca2+. Further analysis showed that the main coagulation mechanism was adsorption and electric neutralization at low PTC dosage and sweeping at high PTC dosage.
Last Update:
2022-12-01