What Techniques Are Used to Remediate Polluted Water?
Pollution isn’t just the clouds of carbon dioxide you see emitted from engine exhausts or plastic in the ocean. In fact, much of the water we use in farming, ecosystems or consumption originally comes from groundwater – water under the ground’s surface.
The trouble is that this groundwater is often impure and highly toxic, meaning it can cause harm to crops, animals or humans. To understand how this toxic water becomes usable, we’ve put together this brief article to show you the ropes.
What Is Remediation?
Simply put, the process of remediation involves removing pollutants from groundwater or rendering the pollutants harmless. Groundwater is found below the ground’s surface, often beneath layers of rock and materials known as aquifers.
Through remediation, the goal is to make groundwater safe for consumption by people as well as reduce the environmental impacts that pollutants may have.
Alongside water, soil is also commonly remediated when it has been in contact with contaminated groundwater, which has all sorts of uses for agriculture, environmentalism and restoring ecosystems, among other things. There is plenty of online information, as well as services, you can find for soil remediation, such as Soilfix.
Methods
As time has gone on, new innovations have been made in remediation, but that doesn’t mean traditional methods have died out. The main two methods to consider are in situ and ex situ – or, in-site and off-site. In-situ methods treat the water where it is; ex-situ methods transfer and then treat.
The most common tried-and-tested method for water remediation is called ‘pump and treat’, where groundwater is pumped out of the ground via a vacuum pump before being purified by absorbing contaminants.
Today the most common techniques consist of: bioremediation, which uses bacteria, fungi, and algae to break down pollutants; chemical remediation, which neutralises or breaks down pollutants through chemicals; and physical remediation, where filtration, sedimentation or aeration are utilised to gradually remove contaminants.
Each method is best suited to the specific location and pollutants, and each stage of remediation requires adherence to strict safety criteria, ensuring the water is up to government standards.