LA - Study on Cultural Carbon in the Mississippi River

LSU researchers are conducting a first-of-its-kind study exploring carbon transport in the Mississippi River that may lead to global applications.

For the past 10 years, LSU hydrologist Yi-Jun Xu has been studying dissolved carbon transport along the Mississippi River system to the Gulf of Mexico, as well as the emission of carbon into the atmosphere.

Dissolved carbon, both organic and inorganic, is carried in river systems. While the carbon cycle happens naturally in waterbodies, additional carbon can be added through decomposing materials like trees or, in this case, humans.

In the Mississippi River system, the carbon can either be carried into the Gulf of Mexico as an important food source for aquatic organisms or be returned to the atmosphere as carbon dioxide, the primary greenhouse gas emitted by humans.

Carbon introduction

Xu and graduate students Anamika Dristi and Lee Potter are now starting to determine how much carbon is introduced to natural water systems from wastewater treatment plants, an important source of cultural carbon.

Wastewater treatment plants collect household wastewater from residences, treat it through several processes, and release it back into the river.

"Wastewater treatment plants do not monitor and treat dissolved carbon. Right now, they try to remove silt and nitrogen, and they try to kill bacteria in water, but they do not have a process to remove carbon," Xu said. "If our study proves that the human contribution is very high, then that means it may be necessary to treat water also by reducing that released carbon content from the wastewater treatment plant."