Limitations in processes to detect chemicals in oilfield wastewater
Chemical detection processes commonly used by the oil industry are not designed to work with fresh water, researchers at the Colorado School of Mines have found. In order to manage wastewater's high salt content, chemists have to dilute the sample. But by doing so, they may also be diluting chemicals. It's therefore difficult to understand the impact of harmful chemical byproducts from wastewater, such as benezene, on source waters. The researchers propose using several "under-utilised approaches" to manage the complexity of analysing flowback and produced waters.
By Sara Jerome,

@sarmje

Methods to assess chemicals in oilfield wastewater may not be sufficient, researchers say.

A new study from researchers at the Colorado School of Mines highlights limitations in chemical detection processes used in the oil sector. Published in Trends in Environmental Analytical Chemistry, this area of study is significant to drinking water utilities, advocates, and regulators who seek to understand the ways that energy industry activity may pose a threat to drinking water.

“We assessed current trends and emerging technologies in analytical chemistry and reviewed their applicability to flowback and produced waters. In addition, we propose under-utilized approaches that may serve as potential solutions to address the issues created by the complex matrices inherent to flowback and produced waters,” the study said.

The Environmental Defense Fund explained the meaning of the findings in a blog post.

“Oilfield wastewater is extremely salty and can contain multiple combinations of many potentially harmful chemicals (approximately 1,600 on a national basis). However, most standard or approved analytical methods available to regulators were designed to work with fresh water. Because oil and gas wastewater is so salty — sometimes 10 times saltier than seawater or more — chemists often have to dilute wastewater samples to manage the high salt content,” the blog said.

Diluting the samples may also be diluting chemicals, the blog explained.

Benzene, a cancer-causing petroleum byproduct, is one example.

“It has a drinking water standard of 5 parts per billion — that’s 5 cents in 10 million dollars. It really doesn’t take much dilution of a sample to lose that level of precision,” the blog said.

The upshot is that flawed methods for analyzing chemicals in oilfield wastewater make it difficult to understand what impact it may have on source waters.

The United States Energy Association, in its materials, notes that the oil and gas industry plays a major role in the global energy sector. Advocates point out that the industry is a major employer.

For similar stories visit Water Online’s Produced Water Treatment Solutions Center.