Journal of Water and Health Vol 11 No 3 pp 410–418 2013.

Development of a quaternized chitosan with enhanced antibacterial efficacy

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Gurpreet Kaur Khaira, Rashmi Kumariya, Manmohan Chibber and Moushumi Ghosh. Department of Biotechnology and Environmental Sciences, Thapar University, Patiala-147004, Punjab, India E-mail: mghosh@thapar.edu
School of Chemistry and Biochemistry, Thapar University, Patiala-147004, Punjab, India

The antibacterial activity of a water-soluble chitosan derivative prepared by chemical modification to quaternary ammonium compound N,N,N-trimethylchitosan (TC) was investigated against four selected waterborne pathogens: Aeromonas hydrophila ATCC 35654, Yersinia enterocolitica ATCC 9610, Listeria monocytogenes ATCC 19111 and Escherichia coli O157:H7 ATCC 32150. An inactivation of 4 log CFU/ml of all waterborne pathogens was noted for the quaternized chitosan as compared with chitosan over a short contact time (30 min) and low dosage (4.5 ppm) at ambient temperature. A marked increase in glucose level, protein content and lactate dehydrogenase (LDH) activity was observed concurrently in the cell supernatant to be a major bactericidal mechanism. The results suggest that the TC derivative may be a promising commercial substitute for acid-soluble chitosan for rapid and effective disinfection of water.

Procedia Engineering, Volume 33, 2012, Pages 254–260

Coagulation Flocculation Test of Keddara’s Water Dam Using Chitosan and Sulfate Aluminium

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Hassiba Zemmouria, et al.

Chitosan is a natural polymer prepared from crab, shrimp and lobster shells. It has been used as coagulant in watertreatment to avoid the human health problems caused by the residual aluminum and chemical polymers in water. In this study, the raw water from Keddara dam characterized by low turbidity was treated using chitosan as primary flocculant and as coagulant aid with aluminum sulfate. The result shows that chitosan was not too efficient as alum, if it is used as primary coagulant for treating Keddara raw water.

However, when chitosan was applied as coagulation aid agent with aluminum sulfate, highest turbidity removal (97%) was carried out with 0.2 mgl-1of chitosan after 45 minutes of settling time. The organic carbon contribution on the coagulation flocculation performance is negligible because chitosan is used in small doses. Hence, chitosan could be used as natural coagulant aid for drinking watertreatment with lowest risks of organic release.

A biopolymer–coagulant for household A biopolymer coagulant for household water treatment

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Feb 1,  2012 Seminar by: Ampai Soros, PhD Student, ESE

Nearly a billion people still lack access to safe drinking water, and more than 80% of them are living in developing countries. Household water treatment and safe storage (HWTS) is a promising intervention to solve this problem and to provide safe water for many people, especially the rural poor.

There are several low-cost technologies which have been employed for water treatment at the household level in developing countries, including ceramic pot filter, solar disinfection, combined
flocculation-disinfection, boiling, and biosand filters. Coagulation-flocculation is another simple technology that can be used at household level, and can be used in conjunction with other household water treatment methods to improve their effectiveness. Conventional coagulants such as aluminum sulfate have been used widely in large-scale water treatment plants; however, these coagulants are difficult to apply at the household level.

Chitosan, a bio-polymer from seafood waste, is a promising alternative coagulant for point of use household water treatment. It has the potential to remove contaminants in water, including microbes. It is favorable for use at the household level because it is biodegradable and non-toxic. In initial lab studies, results indicate that chitosans can remove bacteria and virus from water up to 99%. This showed its potential to be used alone or combined with other technologies for making microbially safe drinking water in the home.