| Autor: |
Wan, Yang1,2 18252501781@163.com, Huang, Xin1 xinhuang@rcees.ac.cn, Shi, Baoyou1,3 byshi@rcees.ac.cn, Shi, Jian2,4 shij413@126.com, Hao, Haotian1 tienhh@outlook.com |
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| Zdroj: |
Chemosphere. Mar2019, Vol. 219, p28-35. 8p. |
| Abstrakt: |
Abstract Typical Chinese source water has high content of low molecular weight and aromatic protein-like organic matter which is difficult to remove and poses a great challenge to conventional coagulation/flocculation. To investigate coagulation performance of this typical water, this research focused on organic matter removal characteristics and the associated disinfection byproducts formation potentials (DBPFPs) during the coagulation process by titanium salts compared with traditional aluminum and ferric salts. Results showed that based on the dissolved organic matter (DOM) removal, the optimal coagulant dosages of AlCl 3 , FeCl 3 and TiCl 4 were 0.5 mM and the optimal initial pH values were 8, indicating that the DOM in the typical Chinese water could be effectively removed through sweeping and adsorption by metal hydroxides rather than the complexation and charge neutralization effect under acidic conditions. Compared these three coagulants, the highest ultra violet absorbance at 254 nm removal rate of 72.9% was achieved by TiCl 4. The three-dimensional excitation emission matrix results showed that the removal ability of humic acids by AlCl 3 was poorer than FeCl 3 and TiCl 4. The removal rate of low molecular weight components (1600 Da) by TiCl 4 was 20% higher than using AlCl 3 and 14% higher than FeCl 3. Comparing with AlCl 3 and FeCl 3 , TiCl 4 had a better performance on the control of DBPFPs, especially for chloroform and dichloroacetic acid, due to its higher removal ability of aromatic organics. The trihalomethane formation potentials removal rate by TiCl 4 was three times higher than that by AlCl 3 and twice by FeCl 3 , by which could be inferred that titanium salts achieved better removal of low molecular weight organic matter than aluminum and ferric salts. Graphical abstract Image 1 Highlights • Low molecular weight (Mw)/protein-like organics is hard to remove by coagulation. • The low Mw and aromatic organics removal was mainly based on adsorption/sweeping. • Low Mw and aromatic organics were more effectively removed by Ti salt. • TiCl 4 coagulation better controlled disinfection byproducts than AlCl 3 and FeCl 3. • The decrease of trihalomethane by TiCl 4 was three times by AlCl 3 , twice by FeCl 3. [ABSTRACT FROM AUTHOR] |
| Databáze: |
GreenFILE |
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Full Text from ScienceDirect