Switching from coal to natural gas in power plants can reduce how much sulfur dioxide, a gas that smells like a freshly struck match, is emitted into the atmosphere and ultimately how much sulfate pollution enters waterways, according to a Penn State-led research team that has developed a model to detect if the recent switch from coal to gas is affecting streams.
“The number of power plants switching from coal to natural gas is increasing, and sulfur dioxide emissions in Pennsylvania and across the United States are decreasing dramatically,” said Xianzeng Niu, assistant research professor in Penn State’s Earth and Environmental Systems Institute (EESI). “Both technology and the shift of fuels have contributed to this trend. We wanted to look at how this trend has affected water quality.”
Coal- and natural gas-burning power plants emit sulfur dioxide into the atmosphere, but coal has a much higher sulfur content than natural gas and releases more sulfur dioxide when burned. The sulfur particles eventually fall back down to earth and can acidify streams. Too much sulfur, which enters waterways in the form of sulfate, can cause water chemistry to become harmful to ecosystems.