Toxicity of free and various aminocarboxylic ligands sequestered copper(II) ions to Escherichia coli

Enhanced disinfection of Escherichia coli and bacteriophage MS2 in water using a copper and silver loaded titanium dioxide nanowire membrane

“…Therefore, loading metal ions such as silver and copper onto photocatalysts was carried out to increase the activity of the photocatalyst by separating the electrons and holes more effectively [7][8][9]. Silver and copper were also recognized for their antimicrobial effects [8,10] and the antibacterial capabilities of Ag-TiO 2 nanoparticles and CuTiO 2 nanoparticles under UV illumination have been studied previously [7,11]. However, the virucidal properties of the metal-ion deposited TiO 2 was seldom examined [12,13], hampering the development of commercially viable applications of photocatalysts such as for drinking water treatment.…”

“…This study experimentally established the individual and combined effects of silver and copper loaded TiO 2 nanowire membrane on the inactivation of bacteria and virus. Escherichia coli (E. coli) was used as the model bacteria that is also frequently used in the literature for bacterial inactivation study [10,11,16]. It is relatively more UV resistant [17] and is a typical biologic indicator of water disinfection quality [18].…”

“…The TiO 2 membrane, Ag-TiO 2 membrane, Cu-TiO 2 membrane, and Cu-Ag-TiO 2 membranes were tested under both UV light irradiation (l = 254 nm, 11 W, Phillips, NJ, USA) and dark conditions, each test being repeated in triplicate. The challenge solution contained 10 7 CFU$mL -1 of E. coli or 10 5 PFU$mL -1 of bacteriophage MS2. The amount of bacteria in water was determined by the heterotrophic plate counts with a pour plate method using USEPA Method 9215.…”

“…5). For comparison, copper (II) concentrations of 3.18 to 127 ppm were studied for its toxicity to E. coli [10] and the inactivation was found to increase with higher copper content [16]. However, a high copper content may suppress the membrane photocatalytic activity if exposed to UV irradiation because it may form recombination centers of photo-induced charges [15]; therefore, there exists an optimal ratio of copper adsorbed onto the membrane.…”

An investigation of low biofouling copper-charged membranes for desalination

“…To prevent the growth of microorganisms, successful doses of copper ions have been reported as few tenths of 1 mg/L when discharged directly into the water [23]. Copper, being cytotoxic, causes the loss of permeability barrier of the plasma membrane [37]. The focus of this study was to develop low biofouling membranes by modifying CA membrane surfaces with copper ions.…”