Feasibility of bubble surface modification for natural organic matter removal from river water using dissolved air flotation

Highlights

Surface modified bubbles were produced in DAF pump saturation system.

Hydrophobic NOM was preferentially removed by chitosan modified bubbles.

Removal of hydrophilic NOM was improved with an increase in chitosan charge density.

Chitosan modified bubbles performed efficiently in THMFP and HAAFP control.

Abstract

A novel, functionalized bubble surface can be obtained in dissolved air flotation (DAF) by dosing chemicals in the saturator. In this study, different cationic chemicals were used as bubble surface modifiers, and their effects on natural organic matter (NOM) removal from river water were investigated. NOM in the samples was fractionated based on molecular weight and hydrophobicity. The disinfection byproduct formation potentials of each fraction and their removal efficiencies were also evaluated. The results showed that chitosan was the most promising bubble modifier compared with a surfactant and a synthetic polymer. Tiny bubbles in the DAF pump system facilitated the adsorption of chitosan onto microbubble surfaces. The hydrophobic NOM fraction was preferentially removed by chitosan-modified bubbles. Decreasing the recycle water pH from 7.0 to 5.5 improved the removal of hydrophilic NOM with low molecular weight. Likewise, hydrophilic organic compounds gave high dihaloacetic acid yields in raw water. An enhanced reduction of haloacetic acid precursors was obtained with recycle water at pH values of 5.5 and 4.0. The experimental results indicate that NOM fractions may interact with bubbles through different mechanisms. Positive bubble modification provides an alternative approach for DAF to enhance NOM removal.

Graphical abstract

Keywords

Bubble surface modification / Chitosan / Disinfection by-product / Dissolved air flotation / Organic fraction

References

[1] Elmahdy A M, Mirnezami M, Finch J A. Zeta potential of air bubbles in presence of frothers. International Journal of Mineral Processing, 2008, 89(1–4): 40–43

[2] Bratskaya S, Schwarz S, Chervonetsky D. Comparative study of humic acids flocculation with chitosan hydrochloride and chitosan glutamate. Water Research, 2004, 38(12): 2955–2961

[3] Edzwald J K, Haarhoff J. Dissolved Air Flotation For Water Clarification.New York: AWWA and McGraw Hill, 2012

[4] Al-Zoubi H, Ibrahim K, Abu-Sbeih K. Removal of heavy metals from wastewater by economical polymeric collectors using dissolved air flotation process. Journal of Water Process Engineering, 2015, 8: 19–27

[5] Miranda R, Negro C, Blanco A, 0. Internal treatment of process waters in paper production by dissolved air flotation with newly developed chemicals. 1: Laboratory tests. Industrial & Engineering Chemistry Research, 2009, 48(4): 2199–2205

[6] Saarimaa V, Sundberg A, Holmbom B, Blanco A, Fuente E, Negro C. Monitoring of dissolved air flotation process by focused beam reflectance measurement. Industrial & Engineering Chemistry Research, 2006, 45(21): 7256–7263

[7] Wang W D, Fan Q H, Qiao Z X, Yang Q, Wang Y B, Wang X C. Effect of water quality on the coagulation performances of humic acids irradiated with UV light. Frontiers of Environmental Science & Engineering, 2015, 9(1): 147–154

[8] Henderson R K, Parsons S A, Jefferson B. The potential for using bubble modification chemicals in dissolved air flotation for algae removal. Separation Science and Technology, 2009, 44(9): 1923–1940

[9] Han M Y, Kim M K, Shin M S. Generation of a positively charged bubble and its possible mechanism of formation. Journal of Water Supply: Research & Technology-Aqua, 2006, 55(7–8): 471–478

[10] Henderson R K, Parsons S A, Jefferson B. Polymers as bubble surface modifiers in the flotation of algae. Environmental Technology, 2010, 31(7): 781–790

[11] Yap R K L, Whittaker M, Diao M, Stuetz R M, Jefferson B, Bulmus V, Peirson W L, Nguyen A V, Henderson R K. Hydrophobically-associating cationic polymers as micro-bubble surface modifiers in dissolved air flotation for cyanobacteria cell separation. Water Research, 2014, 61: 253–262

[12] Rao N R H, Yap R, Granville A M, Stuetz R M, Henderson R K. Algae flotation using PosiDAF: A comparison of polymers as bubble surface modifiers. In: Proceeding of the 7th International Conference of Flotation in Water and Wastewater Systems. Toulouse: France, 2016, 168–175

[13] Zhang M, Guiraud P. Colloidal gas aphrons in flotation separation of nanoparticles: bubble dispersion features and flotation performance. In: Proceeding of the 7th International Conference of Flotation in Water and Wastewater Systems. Toulouse: France, 2016, 134–142

[14] Wang X M, Mao Y Q, Tang S, Yang H W, Xie Y F. Disinfection byproducts in drinking water and regulatory compliance: a critical review. Frontiers of Environmental Science & Engineering, 2015, 9(1): 3–15

[15] Kam S K, Gregory J. Charge determination of synthetic cationic polyelectrolytes by colloid titration. Colloids and Surfaces. A, Physicochemical and Engineering Aspects, 1999, 159(1): 165–179

[16] Yang J X, Ma J, Song D, Zhai X D, Kong X J. Impact of preozonation on the bioactivity and biodiversity of subsequent biofilter under low temperature conditions-a pilot study. Frontiers of Environmental Science & Engineering, 2016, 10(4): 50–60

[17] Kitis M, Karanfil T, Wigton A, Kilduff J E. Probing reactivity of dissolved organic matter for disinfection by-product formation using XAD-8 resin adsorption and ultrafiltration fractionation. Water Research, 2002, 36(15): 3834–3848

[18] Hua G, Reckhow D A. Characterization of disinfection byproduct precursors based on hydrophobicity and molecular size. Environmental Science & Technology, 2007, 41(9): 3309–3315

[19] Clesceri L S, Greenberg A E, Eaton A D. Standard Methods for the Examination of Water & Wastewater, 20th ed. American Public Health Association, 1998

[20] Fan X J, Tao Y, Wei D Q, Zhang X H, Lei Y, Noguchi H. Removal of organic matter and disinfection by-products precursors in a hybrid process combing ozonation with ceramic membrane ultrafiltration. Frontiers of Environmental Science & Engineering, 2015, 9(1): 112–120

[21] Jungwirth P, Tobias D J. Specific ion effects at the air/water interface. Chemical Reviews, 2006, 106(4): 1259–1281

[22] Zhang W H, Zhang J Z, Zhao B, Zhu P H. Microbubble size distribution measurement in a DAF system. Industrial & Engineering Chemistry Research, 2015, 54(18): 5179–5183

[23] Park S H, Padhye L P, Wang P, Cho M, Kim J H, Huang C H. N-nitrosodimethylamine (NDMA) formation potential of amine-based water treatment polymers: Effects of in situ chloramination, breakpoint chlorination, and pre-oxidation. Journal of Hazardous Materials, 2015, 282(23): 133–140

[24] Calgaroto S, Azevedo A, Rubio J. Separation of amine-insoluble species by flotation with nano and microbubbles. Minerals Engineering, 2016, 89: 24–29

[25] Azevedo A, Etchepare R, Calgaroto S, Rubio J. Aqueous dispersions of nanobubbles: generation, properties and features. Minerals Engineering, 2016, 94: 29–37

[26] Fan M M, Tao D, Honaker R, Luo Z F. Nanobubble generation and its application in froth flotation (part I): nanobubble generation and its effects on properties of microbubble and millimeter scale bubble solutions. Mining Science and Technology, 2010, 20(1): 1–19

[27] Miranda R, Nicu R, Latour I, Lupei M, Bobu E, Blanco A. Efficiency of chitosans for the treatment of papermaking process water by dissolved air flotation. Chemical Engineering Journal, 2013, 231: 304–313

[28] Philippova O E, Korchagina E V. Chitosan and its hydrophobic derivatives: preparation and aggregation in dilute aqueous solutions. Polymer Science, Series A, 2012, 54(7): 552–572

[29] Ma J, Jiang J, Pang S, Guo J. Adsorptive fractionation of humic acid at air-water interfaces. Environmental Science & Technology, 2007, 41(14): 4959–4964

[30] Lenhart J J, Saiers J E. Adsorption of natural organic matter to air-water interfaces during transport through unsaturated porous media. Environmental Science & Technology, 2004, 38(1): 120–126

[31] Ishida N. Direct measurement of hydrophobic particle-bubble interactions in aqueous solutions by atomic force microscopy: effect of particle hydrophobicity. Colloids and Surfaces. A, Physicochemical and Engineering Aspects, 2007, 300(3): 293–299

[32] Zhang W Z, Chen X Q, Zhou J M, Liu D H, Wang H Y, Du C W. Influence of humic acid on interaction of ammonium and potassium ions on clay minerals. Soil Science Society of China, 2013, 23(4): 493–502

[33] Winter B, Faubel M, Vacha R, Jungwirth P. Behavior of hydroxide at the water/vapor interface. Faraday Discussions, 2009, 474: 242–247

[34] Kim H C, Yu M J. Characterization of natural organic matter in conventional water treatment processes for selection of treatment processes focused on DBPs control. Water Research, 2005, 39(19): 4779–4789

[35] Li A, Zhao X, Mao R, Liu H, Qu J. Characterization of dissolved organic matter from surface waters with low to high dissolved organic carbon and the related disinfection byproduct formation potential. Journal of Hazardous Materials, 2014, 271: 228–235

Acknowledgements

This research is funded by the National Natural Science Foundation of China (Grant No. 51378141) and the Science and Technology Department of Heilongjiang Province, China (Grant No. PS13H05). The authors would like to express thanks to their friends operating the Huainan first water treatment plant for their generous support. Sincerest thanks also to the staff at the Central Laboratory of Huainan Capital Water for their support in water sample analysis.

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