Characterization of a stirred tank electrochemical cell for water disinfection processes

Application of Advanced Oxidation Methods for Water Disinfection

“…A utilização de métodos eletroquímicos tem-se mostrado eficaz na redução significativa da quantidade de contaminante presente nas águas residuais industriais e também com nível da cor, em particular quando a água residual contém contaminantes orgânicos bioresistentes ou substâncias tóxicas. 34 Por outro lado, os métodos eletroquímicos seguem demostrando ser uma promessa como um método de desinfecção da água potável com baixos níveis de cloro livre, hipoclorito de sódio e ácido hipocloroso que são produzidos mediante os mecanismos explicados anteriormente, devido a sua formação in situ em soluções que contém NaCl. Cryptosporidium parvum oocysts e os esporos de Clostridium perfringens são muito resistentes ao cloro e outros desinfetantes de água potável, por isso, Venczel et al (1997), utilizaram um sistema de desinfecção eletroquímica que produz a mistura oxidante que contém, cloro livre, dióxido de cloro, peróxido de hidrogênio, ozônio e outros oxidantes de curta duração de vida ativa para alcançar 99,9% de desinfecção dos microorganismos em 4 h. 37 Oxidar a solução parece ser consideravelmente mais eficaz que o cloro na desinfecção de micro-organismos.…”

Conductive diamond electrodes for water purification

“…Patermarakis and Fountoukidis 45 exposed total coliforms at population density of 200-26,800 cell.mL -1 in natural surface water to 2.5 mA.cm -2 and they reduced the culturable counts by an order of magnitude in 15.7 minutes. Matsunaga et al 46 reduced E. coli from a population density of 1 x 10 2 cell.mL -1 in water to less than 2% of the initial number with a 10 minutes exposure to 0.7 V. The good efficiency of the direct electrochemical disinfection achieved at BDD anode in diluted Na 2 SO 4 solutions indicates the important role of the anode material 42 . Moreover, new evidences of the role of oxygen species in the electrochemical disinfection using boron-doped diamond electrodes in a chlorine-free media were reported by Yoon 43 ; thus avoiding any confusion caused by the generation of chlorine and by-products.…”

“…In consequence, new evidences for disinfecting water have been reported by Polcaro 41,42 and Yoon 43 where no chlorides were added to the aqueous solutions and good performances were obtained using diamond electrodes. Polcaro et al performed several experiments at diamond films using bacterial suspensions with Escherichia coli, Enterococchi and Faecal coliforms and during the direct oxidation process were achieved results about of 98% of disinfection 41,42 .…”

“…Polcaro et al performed several experiments at diamond films using bacterial suspensions with Escherichia coli, Enterococchi and Faecal coliforms and during the direct oxidation process were achieved results about of 98% of disinfection 41,42 . The results indicate that the reduction of microorganism populations from 1 x 10 3 CFU.mL -1 to the detection limit is achieved in 60, 100 and 300 seconds for E. coli, coliforms and enterococci, respectively.…”

“…Based on the literature, several groups have reported different experimental results using diamond electrode for purification/disinfection water, under different conditions [29][30][31][32][33][34][35][36][37][38][39][40][41][42][43][44][45][46] . However, the most relevant publications were taken into consideration here for illustrating the advances of this kind of electrochemical application.…”