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Investigation of quaternary ammonium silane‐coated sand filter for the removal of bacteria and viruses from drinking water
Author(s) -
Torkelson A.A.,
da Silva A.K.,
Love D.C.,
Kim J.Y.,
Alper J.P.,
Coox B.,
Dahm J.,
Kozodoy P.,
Maboudian R.,
Nelson K.L.
Publication year - 2012
Publication title -
journal of applied microbiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.889
H-Index - 156
eISSN - 1365-2672
pISSN - 1364-5072
DOI - 10.1111/j.1365-2672.2012.05411.x
Subject(s) - library science , engineering , computer science
Aims To develop an anti‐microbial filter media using an attached quaternary ammonium compound ( QAC ) and evaluate its performance under conditions relevant to household drinking water treatment in developing countries. Methods and Results Silica sand was coated with dimethyloctadecyl [3‐(trimethoxysilyl) propyl] ammonium chloride via covalent silane chemistry. Filter columns packed with coated media were challenged with micro‐organisms under different water quality conditions. The anti‐bacterial properties were investigated by visualizing E scherichia coli ( E . coli) attachment to coated media under fluorescence microscopy combined with a live/dead stain. A 9‐cm columns with a filtration velocity of 18 m h −1 achieved log 10 removals of 1·7 for E . coli , 1·8 for MS 2 coliphage, 1·9 for Poliovirus type 3 and 0·36 for Adenovirus type 2, compared to 0·1–0·3 log 10 removals of E . coli and MS 2 by uncoated sand. Removal scaled linearly with column length and decreased with increasing ionic strength, flow velocity, filtration time and humic acid presence. E scherichia coli attached to QAC ‐coated sand were observed to be membrane‐permeable, providing evidence of inactivation. Conclusions Filtration with QAC ‐coated sand provided higher removal of bacteria and viruses than filtration with uncoated sand. However, major limitations included rapid fouling by micro‐organisms and natural organic matter and low removal of viruses PRD 1 and A denovirus 2. Significance and Impact of the Study QAC ‐coated media may be promising for household water treatment. However, more research is needed on long‐term performance, options to reduce fouling and inactivation mechanisms.