Along the banks of a nine-kilometer stretch of the Rio Doce in Brazil are bright orange barriers similar to ones deployed at sea to help contain oil spills. The barriers were erected to protect plants and animals along the banks from toxic mud that has traveled more than 500 km from a collapsed dam that was holding wastewater produced by mining activities. The 2.2 billion cubic feet of toxic mud has now reached the Atlantic Ocean. On its way to the Ocean, the mud destroyed villages close to the dam and leveled approximately nine square kilometers of vegetation.
While the company responsible claims the mud is harmless; environmentalists are concerned that it will cause severe pollution. The mouth of the Rio Doce is a feeding and breeding ground for a variety of marine life such as leather back turtles, dolphins and whales. Brazilian water management authorities tested the waste, and they found toxic levels of mercury, arsenic, chromium and manganese. In larger amounts, these elements can poison ecosystems and are harmful to plants, wildlife and the people who consume them. Given the high concentrate of iron ore and silica in the mud, researchers also fear that it could turn into concrete as it dries out.
According to Andres Ruchi, director of the Marine Biology school in Santa Cruz in Espirito Santo state, said, "The flow of nutrients in the whole food chain in a third of the south-eastern region of Brazil and half of the Southern Atlantic will be compromised for a minimum of a 100 years."[i]
While the company is working to remove sand banks and dredge at the river’s mouth to facilitate the dilution of the wastewater, there is concern that two other dams used by Samarco could collapse. Work is being performed to reinforce the dams and prevent additional wastewater from impacting local communities. The company has provided six 1,000-liter tanks to store fish from the river, and is digging wells along the river to source water for the hundreds of thousands of people who rely on the river.
Environmentalists have call the dam break “Brazil’s worst environmental disaster ever” and biologists estimate that it will take at least 30 years to clean up the Rio Doce basin.
CETAC offers sample introduction accessories that improve the transport efficiency of a liquid sample to an ICP-AES, leading to enhanced analyte sensitivity (such as for arsenic) by the host detection system (the ICP-AES).
The two CETAC accessories that improve sample transport efficiency to an ICP-AES are:
- The U5000AT+ Ultrasonic Nebulizer
- The HGX-200 Hydride Generator
With the U5000AT+ Ultrasonic Nebulizer, detection limits for arsenic with ICP-AES are in the range of 0.1 to 1.0 ppb, with 0.5ppb a typical limit.
With the HGX-200, detection limits for arsenic with ICP-AES are usually lower, with detection limits of 0.1ppb or less.
For more information on these products, please contact us.
[i] http://www.bbc.com/news/world-latin-america-34892237
