solving the special second order ozonation system by oham in tackling the liver cancer

Cyanobacteria (blue-green algae) such as microcystin, nodularins, saxitoxins, anatoxins, and cylin- drospermopsin are caused a dangerous disease through drinking water. one of these toxins is microcystin-lr that the existence of a tiny amount of it in drinking water leads to liver damage and cancer. also, it makes a high cost of social and health spending. even though cyanobacteria are resistant against disinfectants but it has been shown that ozone has high ability to cyanobacteria detoxification. the dissolved ozone in aqueous leads to more disinfection and oxidation by oh radical simultaneously. in this paper, we have presented the solution of the second-order ozone decomposition system with oh radical and microcystin-lr without dissolved organic content (doc). it is achieved that one can tackle with such a large problem by the least cost and time. the governing differential system is solved by optimal homotopy asymptotic method (oham), and the obtained results are illustrated by some plots. it has been shown that with a small amount of ozone and a little time, a high dosage of microcystin-lr can be altered to zero. for this purpose, the conditions ph=2, 4 and 7 have been evaluated at 10˚; 20˚; 30 ˚c.