New Approach To Produce Water Free of Bacteria, Viruses, and Halogens in a Recyclable System

Abstract

The antimicrobial activity of a new cross-linked N-halamine polymer against bacteria and viruses was evaluated. The polymer achieved a 9-log 10 reduction of bacteria (both Escherichia coli and Staphylococcus aureus) in 1.5 h and a 5-log 10 reduction of bacteriophage PRD1 in 3 h. At the same time, the ability of the nonhalogenated polymer to trap halide ions was examined. The polymer was incorporated into a multifiltration system to study the ability to produce water free of bacteria, viruses, and halide ions. The antimicrobial activity, useful lifetime, halide ion level, and recycling possibilities of the system were quantified on a laboratory scale. A design for a large-scale multifiltration system based on this polymer is proposed.The latest report from the WHO and UNICEF Joint Monitoring Programme shows that the world is on track to meet goal 7, target 7c, of the millennium development goals (MDGs) (21) with respect to access to improved water supplies. Nevertheless, despite the progress that has been made during the last 10 years, over 850 million people do not have access to improved sources of drinking water, with almost all of them living in developing regions. In Europe most people are connected to a piped water supply managed by a water utility. The remainder, around 10% of the population, receive their water from small, or very small, private water supplies (17). A recent survey of the microbiological quality of water from private water supplies in the United Kingdom has shown that just over one-third show evidence of fecal contamination and, by projection, that 54% of all such supplies are likely to be unsatisfactory (17).

N-halamines from rice straw

“…Many applications (such as production of paper, animal food, fertilizers and biofuel) have been suggested as uses for such waste but the amount of straw produced remains too large (Navaee-Ardeh et al 2004;Prasad et al 1998;Sallam et al 2007;Toor and Beri 1991;Chou et al 2009). In our trials to produce low cost disinfectants, mainly for water treatment (Ahmed et al 2011b), we have found that rice straw waste can be a good source for cellulose that can be modified to produce polymers with antimicrobial properties. Their commercial value starts from the fact that rice straw is currently freely available from farming communities.…”

“…The column was then closed, filled with sodium hypochlorite and left for 6 h followed by washing copiously with distilled water. The lifetime determination experiment was repeated, as described above, up to 3 times (Ahmed et al 2011b).…”

“…Error bars have been removed as the error is too small to show on a of each run, example inFig. 6(Ahmed et al 2011b)…”

Natural and synthetic polymers for water treatment against dissolved pharmaceuticals

“…The perfused solution was returned again to the column for recycling up to 10 cycles (Figure ) with identifying the drug concentration after each cycle using HPLC (an example in Figure ). It can be seen from Figure that the column has succeeded in removing more than 40% or drug concentration which is encouraging the application of such materials in slow filtration techniques in water treatment systems.…”

Hydrogels for water filters: Characterization and regeneration

“…1-12 N-halamine polymers exchange halogen ions with the cells of microorganisms resulting in their death. [1][2][3][4][5][6][7][8][9] Poly Quat's attracts these cells as the polymer carries positive charges while cells carry negative charges at certain physiological state. 1,2,12 This results in cells being adsorbed and expired.…”