tailieunhanh - Removals of chain like and pin like algae by positively charged bubble flotation

The objective of this study was to investigate the effects of positive ferric-bubble on behaviors of chain-like and pin-like algae (. Phormidium specie (sp.) and Nitzchia pungens, respectively). Two selected algae were cultured in a laboratory under the certain conditions. At stationary phase, algae were below 4 µm in diameter and in the range of 50 ~ 100 µm for chainlike algae, of 20 – 35 µm for pin-like shape in length; with negatively charged at cultivated conditions (pH from to 9). | Journal of Science and Technology 54 (2A) (2016) 128-133 REMOVALS OF CHAIN-LIKE AND PIN-LIKE ALGAE BY POSITIVELY CHARGED BUBBLE FLOTATION Thi Thuy Bui1, Viet Anh Nguyen2, * 1 Environmental Engineering Division, Faculty of Environment, Water Resources University, 175 Tay Son, Dong Da Dist, Hanoi, Vietnam 2 Institute of Environmental and Science Engineering, Hanoi University of Civil Engineering, 55 Giai Phong, Hanoi, Vietnam * Email: vietanhctn@ Received: 30 April 2016; Accepted for publication: 30 June 2016 ABSTRACT The objective of this study was to investigate the effects of positive ferric-bubble on behaviors of chain-like and pin-like algae (. Phormidium specie (sp.) and Nitzchia pungens, respectively). Two selected algae were cultured in a laboratory under the certain conditions. At stationary phase, algae were below 4 µm in diameter and in the range of 50 ~ 100 µm for chainlike algae, of 20 – 35 µm for pin-like shape in length; with negatively charged at cultivated conditions (pH from to 9). Positive ferric-bubbles were generated by adding coagulants (as Fe3+) and were injected at a pressure of 5 bars with a bubble rate of 30 % into a 10 L-acryl made reactor with algal-containing tap water. Removal efficiencies were assessed by the cells number, Chlorophyll a reduction and the morphological changes (. cell structure). For cells number, about 90 % of both algae were removed whilst pin-like algae obtained the higher reduction of Chlorophyll a, showing by 92 % in comparison with about 85 % of chain-like shape. The breakup of algal morphologies occurred for chain-like cells only. The structure of filaments affects performance of positively charged bubble flotation. Keywords: algal morphology; filamentous algal removal; bubble flotation; positively charged bubble. 1. INTRODUCTION Algal blooms are one of the major concerns in water bodies due to their harmful effects on humans, water treatment facilities and ecosystem [1]. Filamentous algae