Green bio-dispersant removal efficacy estimation for controlling biofilms in cooling towers

In this study the effect of green bio-dispersants on cooling water biofilm attachment has been investigated. As monitoring biofilm growth in industrial cooling systems is extremely complex and difficult, we developed a simple method to additively evaluate the effectiveness of green bio-dispersants on biofilms grown in two different lab-scale systems using, as inoculum, make-up water from an industrial cooling tower. The proposed method uses spectrophotometry to estimate the detached biomass after bio-dispersant action. The biofilm detachment rate and the removal percentage of biofilm were calculated after the use of six green bio-dispersants, two non-green dispersants and three controls at two different concentrations. Under all tested conditions, green bio-dispersants showed higher biofilm removal percentage and detachment rate than non-green additives. These results suggest that highly performing green additives could be recommended as a reasonable replacement for non-green additives for controlling biofilms in cooling towers, in accordance to the European Union's REACH regulation.