As posted to CleanTechBlog.com
Unlike some other environmental issues, there is virtually no controversy or skepticism about the perils of mercury in the environment. Not only has mercury been known for centuries to be highly poisonous, it’s also increasingly linked to other physiological ills, including some speculation in recent years that it’s related to certain neurological disorders.
Despite the breadth of constituencies concerned about mercury pollution, it’s evident we have a long way to go. A report just issued by the U.S. Environmental Protection Agency (EPA) found that mercury concentrations exceeded safe levels at 49 percent of U.S. lakes and reservoirs sampled from 2000 to 2003.
From where does all this mercury in our water come? Sources can be classified into two groups: One is legacy industrial facilities from days of yore, in which mercury was either used in or generated as a byproduct of the core production process. Although many of these facilities are now shut down, the mercury often lingers at these sites, even after remediation approaches have been pursued. Over time, the mercury finds its way into aquifers underground or nearby rivers and streams.
Other sources are related to coal use. Mercury is a trace element in most hydrocarbons, but especially in coal. Thus, where it is mined or stored in a pile, rainfall leaches mercury from the coal on the ground. And when it is burned – mainly at powerplants – mercury emissions come out of the smokestack into the air, only to fall somewhere else downwind in a future rainstorm. Inevitably, the mercury ends up in the water – somewhere, someway, somehow.
Related to coal burning, the EPA is cracking down, via its upcoming Clean Air Mercury Rule, which aims to drive a 70 percent reduction in mercury air emissions from large-point sources. Several mercury emission control technologies are under development, including those by companies such as Albemarle and Amended Silicates.
But there’s a problem: Much of the rest of the world won’t be subject to strict mercury emissions limits, so U.S. water supplies will still be fed by new sources of mercury from elsewhere (such as China, which is adding new coal powerplants weekly absent any mercury control technologies), since mercury emissions can stay airborne for a long time. In any event, we’re still exposed to mercury run-off from coal mines and coal piles, plus all of those legacy industrial sites.
Historically, the main approach for dealing with mercury in water streams has not actually involved taking mercury out of the water, but rather introducing large volumes of clean water to reduce overall concentration levels. To employ an old adage from the water industry, “The solution to pollution is dilution.”
In mathematical terms, instead of reducing the numerator, dilution involves massively increasing the denominator. But that approach can only go so far. For example, current EPA limits stipulate that all natural or manmade water streams feeding into the Great Lakes can have mercury concentration levels no higher than 1.3 parts per trillion (ppt). Given some of the nasty sources in the old industrial heartland, enormous volumes of clean water would need to be introduced to reduce concentrations of some of the polluted sources to permitted levels. So let’s just say that something less than 100 percent of the water streams flowing into the Great Lakes are in mercury compliance.
Why not just extract the mercury from water? Until recently, only activated carbon has been known to be effective as an agent for removing mercury, but it leeches, too, so once the carbon has adsorbed the mercury it must be dealt with as a hazardous waste, implying expensive disposal procedures. And carbon quickly saturates with mercury, so lots of carbon is required. All told, a very expensive process.
Because mercury remediation in water has generally been unsatisfactory from an economic (and sometimes also from an environmental) perspective, regulators have often been rather lenient in addressing water streams where mercury levels are above desirable (or even required) levels. Regulators rarely seek to be “bad guys,” so they tend to refrain from forcing corporations to undertake compliance actions that risk putting industrial facilities out of business, thereby eliminating major employers and tax bases – often in poor rural areas. Instead, variances and waivers are often issued, allowing non-compliance to continue.
A good solution for cost-effective removal of mercury from water may now finally be at hand. A Cleveland-area company named MAR Systems has developed a proprietary material of abundant and low-cost supply to use in lieu of activated carbon. It almost instantaneously achieves very high (95-plus percent) mercury capture and binds the mercury so that it can be disposed as ordinary waste. The fundamental intellectual property of MAR Systems is based on research undertaken by the EPA itself.
(Full disclosure: Early Stage Partners, the venture capital firm with which I work, was sufficiently impressed with the MAR Systems technology that it recently made an equity investment in the company, and I represent ESP on the board of MAR Systems.)
Perhaps now the rising concern about mercury can be matched by a corresponding increase of remedial action, driving toward full compliance with the rules and regulations that are already on the books.
