DMTS production and water quality variation during decomposition of algal mats
1.School of Energy and Environment, Southeast University, Nanjing, Jiangsu 210096, China; 2.Key
Laboratory of Environmental Medicine and Engineering of Ministry of Education, Southeast
University, Nanjing, Jiangsu 210009, China
Abstract:Under the conditions of static state, thermostatic and shading, the mass concentration
of typical smelly substrate dimethyl trisulfide (DMTS) and the change characteristics of other
water quality indicators were determined. According to the observing apparent phenomena and
analyzing smelly substrate, the relationship between two kinds of cell density of algalladen
water and water quality was analyzed with cell density of 1.0×106 cells·L-1 as comparison
sample. The results show that the produced DMTS concentration during the courses of dying and
decomposing of algal mats shows significant correlation with the density of algae. The
relationship between DMTS concentration and the density of algae fits linear and quadratic model.
When the algae density is 1.0×107 cells·L-1, the concentration of DMTS reaches a maximum of
891.8 ng·L-1, about 90 times more than the odor threshold concentration with emitting
appreciable odor. When the algae density is 1.0×108 cells·L-1, the concentration of organic
matter increases gradually with the concentration of dissolved oxygen reduced to 0. The level of
oxidationreduction potential drops to -300 to -400 mV with strong reduction characteristic,
which can generate black sediment of ferrous sulfide and turn the water into black.