Reduction of Escherichia Coli using ceramic disk filter decorated by nano-TiO2: A low-cost solution for household water purification

Lack of access to safe water is a challenge in many developing countries, especially in rural areas. It is urgent to develop cost-effective water purification technologies to guarantee drinking water safety in these areas. The present study investigated the reduction of Escherichia coli (E. coli) using ceramic disk filters (CDFs) decorated by nano-TiO_2. The production of CDFs coated with nano-TiO₂ in terms of rice-husk ratio, rice-husk particle size, heating hold time and nano-TiO₂ mass fraction was optimized. The results show that the optimum conditions for CDFs with nano-TiO₂ coating included rice-husk ratio of 29.03%, rice-husk particle size of 0.28mm, heating hold time of 1.41h and nano-TiO₂ mass fraction of 2.21%. Additionally, the morphological and crystal phase characteristics of CDFs were revealed after the decoration by nano-TiO₂. The effects of temperature, influent E. coli concentration, lamp power and their interactions were explored via factorial analysis. Influent E. coli concentration and lamp power had significant effects on E. coli removal efficiency. This study provided the solid theoretical support for understanding the production and bacteria inactivation relevant to CDFs impregnated with nano-TiO₂. The results have important implications for finding a safe and cost-effective approach to solve drinking water problems in developing countries.