Comparative
Toxicity of Chlorinated Saline and Freshwater
Wastewater Effluents to Marine Organisms
- Publication date
- Publisher
Abstract
Toilet
flushing with seawater results in saline wastewater, which
may contain approximately 33–50% seawater. Halogenated disinfection
byproducts (DBPs), especially brominated and iodinated DBPs, have
recently been found in chlorinated saline wastewater effluents. With
the occurrence of brominated and iodinated DBPs, the adverse effects
of chlorinated saline wastewater effluents to marine ecology have
been uncertain. By evaluating the developmental effects in the marine
polychaete <i>Platynereis dumerilii</i> directly exposed
to chlorinated saline/freshwater wastewater effluents, we found surprisingly
that chlorinated saline wastewater effluents were less toxic than
a chlorinated freshwater wastewater effluent. This was also witnessed
by the marine alga <i>Tetraselmis marina</i>. The toxicity
of a chlorinated wastewater effluent to the marine species was dominated
by its relatively low salinity compared to the salinity in seawater.
The organic matter content in a chlorinated wastewater effluent might
be partially responsible for the toxicity. The adverse effects of
halogenated DBPs on the marine species were observed pronouncedly
only in the “concentrated” chlorinated wastewater effluents.
pH and ammonia content in a wastewater effluent caused no adverse
effects on the marine species. The results suggest that using seawater
to replace freshwater for toilet flushing might mitigate the “direct”
acute detrimental effect of wastewater to the marine organisms