Open AccessMicrobial reductions and physical characterization of chitosan flocs when using chitosan acetate as a cloth filter aid in water treatment
Author(s) -
Hemali H. Oza,
Eleanor B. Holmes,
Emily S. Bailey,
Collin K. Coleman,
Mark D. Sobsey
Publication year - 2022
Publication title -
plos one
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.99
H-Index - 332
ISSN - 1932-6203
DOI - 10.1371/journal.pone.0262341
Subject(s) - flocculation , chitosan , filtration (mathematics) , water treatment , turbidity , chemistry , pulp and paper industry , coagulation , chitin , microbiology and biotechnology , chromatography , environmental engineering , environmental science , biology , medicine , mathematics , ecology , organic chemistry , statistics , psychiatry , engineering
The World Health Organization (WHO) estimates 2.1 billion people lack access to safely managed water. Cloth filtration is often employed in rural and developing communities of South Asia for point-of-use water treatment, but bacteria and viruses are too small for efficient removal by this filtration method. Chitosan is a biodegradable, cationic, organic polymer derived from the chemical treatment of chitin that acts as a coagulant and flocculant of contaminant of microbes and other particles in water, thereby facilitating filtration of microbes. This research 1) evaluated the use of chitosan acetate as a pre-treatment coagulation-flocculation process followed by cloth filtration for microbial reductions and 2) assessed floc particle size under three stirring conditions. E . coli KO11 bacteria and MS2 coliphage virus removals were quantified using culture-based methods. Chitosan acetate coagulation-flocculation pre-treatment of water, followed by cloth filtration, met or exceeded the protective (2-star) WHO performance levels for bacteria (2 log 10 reduction) and viruses (3 log 10 reduction), and filtrate turbidity was consistently reduced to < 1 NTU, meeting United States Environmental Protection Agency (EPA) and WHO targets.