Resumen
Laboratory batch experiments were carried out to evaluate the impacts of H2O2 and copper sulfate on M. aeruginosa PCC7820, microcystin-LR (MC-LR) and its degrading bacteria Bacillus sp., previously isolated from Hulupi Lake in Taiwan. The study shows that 3 mg·L-1 hydrogen peroxide removed only 9% M. aeruginosa within seven days of exposure, from an initial cell concentration of 2 × 106 cells/mL. With copper sulfate, a concentration of 2 mg·L-1 removed 99% M. aeruginosa cells, but showed negligible efficacy in removing 0.05 mg·L-1 MC-LR. At a higher dosage, 20 mg·L-1 H2O2 led to 40% and 95% removal, respectively for MC-LR and M. aeruginosa cells. Copper sulfate and H2O2 were both lethal to Bacillus sp. population, with mortality rate constants of k = 0.04 h-1 and 0.03 h-1 under 1 mg·L-1 copper sulfate and 5 mg·L-1 H2O2, respectively. H2O2 is competitive in terms of cost, with a capability of degrading organic compounds with the assistance of ultraviolet (UV) light, and it may be considered as an alternative algaecide to copper sulfate in reservoirs for algae growth control.