The Effect of Polyacrylamide on Floc Structure of Typical Systems

Abstract:

Based on that floc structure is an important factor that influencing the coagulation effect and the post-treatment load, the effect of PAM on floc structure of typical system is analyzed and evaluated in this paper. The results show that PAM has a notable influence on floc morphological structure characteristics. For inorganic turbid system, the fractal dimension and diameter of kaolin flocs adding PAM are bigger than that formed by adding aluminum sulfate merely, and the shear-resistant ability of flocs is stronger. With regard to dissolved organic system, adding PAM under two typical pH conditions, the floc morphological characteristic has the same variation with that in inorganic turbid system. PAM could improve the floc morphological structure. However, the improving effect will be relatively weaker under slightly acidic condition, which indicates that the chemical effect of PAM is restrained under this condition. While for the coexisting system, PAM shows an obvious improvement on floc structure under two pH conditions, the floc is compact, bigger and with a higher strength. The chemical effect of PAM is not restrained under slightly acidic condition, which may owe to the interaction between PAM and inorganic suspended materials and dissolved organics in coexisting system.

• Periodical: Applied Mechanics and Materials (Volumes 260-261)
• Pages: 887-890
• DOI: https://doi.org/10.4028/www.scientific.net/AMM.260-261.887
• Online since: December 2012
• Authors: Peng Kang Jin, Yong Ning Feng, Jie Xu, Xian Bao Wang
• Keywords: Flocs, Morphological Structure, PAM, Typical System

References

[1] JIN Pengkang, WANG Xiaochang. Morphological characteristics of Al-humic floc and coagulation chemistry [J]. Acta Scientiae Circumstantiae, 2001, 21(supplement): 23-29. (In Chinese).

[2] WNAG Xiaochang, TAMBO Norihito. A study on the morphology and density of flocus I. The fractal structure of floc [J]. Acta Scientiae Circumstantiae, 2000, 20(3): 257-262. (In Chinese).

[3] Spicer P T, Pratsinis S E, Raper J, et al. Effect of shear schedule on particle size, density, and structure during flocculation in stirred tanks[J]. Powder Technol, 1998, 97(1): 26-34.

DOI: 10.1016/s0032-5910(97)03389-5

[4] Logan B E, Kilps J R. Fractal dimensions of aggregates formed in different fluid mechanical environments [J]. Water Research, 1995, 29(2): 443-453.

DOI: 10.1016/0043-1354(94)00186-b

[5] Jiang Q, Logan B E. Fractal dimensions of aggregates from shear devices [J]. J AWWA, 1996, 88(2): 100-113.

[6] Gregory D, Carlson K. Relationship of pH and Floc Formation Kinetics to Granular Media Filtration Performance[J]. Environ Sci Technol, 2003, 37(7): 1398-1403.

DOI: 10.1021/es025801b

[7] Wang, X.C., Jin, P.K., Gregory, J. Structure of Al-humicflocs and their removal at slightly acidic and neutral pH[J]. Water Sci. Technol.: Water Supply 2002, 2 (2), 99-106.

DOI: 10.2166/ws.2002.0051

[8] Jin P. K., Wang X. C. et al. Evaluation of floc strength by morphological analysis and PDA online monitoring[J]. Water Science and Technology, 2007, 56(10): 117-124.

DOI: 10.2166/wst.2007.781

[9] JIN Pengkang, WANG Xiaochang, WANG Guanghua. Comparison of the properties of coagulation between natural organic matter and inorganic suspended particle[J]. J. Xi'an Univ. of Arch. &Tech, 2005, 37(3): 307-310. (In Chinese).