Phytoremediation technologies use living plants to capture contaminants throughout the environment. But the phytoremediation of contaminated soil as a way to recover land previously damaged by human activities is proving especially promising. Many plant species—from poplar trees to native perennials—have proven remarkably effective at capturing specific metals, pesticides, oils, or other harmful chemicals in the soil. In doing so, they reduce or prevent those harmful substances from entering groundwater or otherwise dispersing, and causing further harm.

True, there are many industrial processes that can capture toxins in the soil. These include liming, leaching, deep plowing, and “washing.” But all of these are extremely expensive and energy-intensive approaches. By contrast, phytoremediation of contaminated soil can be extremely cost effective. Over the last few years, researchers have seen promising results using native plant species to capture toxic metals concentrated in tailings from mining operations, and cannabis and hemp plants to remediate soil contaminated with PFAS. In both cases, the plants work with remarkable efficiency and very little human oversight or intervention.

But this isn’t simply a cost effective approach. Phytoremediation also has the added benefit of protecting or enriching the soil in addition to removing toxins. You can’t say that about industrial processes like deep plowing and leaching. These disrupt the soil and contribute to poor soil quality and erosion. With phytoremediation of contaminated soils, there’s even the opportunity to recover and reuse valuable metals captured by plants (so-called “phytomining“).

But before a phytoremediation project makes it out into the field, it needs to get piloted in the lab. 

Reliable, Steam-Based Soil Sterilization for Phytoremediation

Reliable soil sterilization is a vital first step in many phytoremediation pilots. But sterilizing soil is extremely challenging. Soil samples vary wildly in terms of composition and density, microbial loads, nutrient concentrations, and chemical profiles. Regardless of their differences, every soil load poses clear sterilization challenges:

Soil loads are heavy, hard to penetrate, and hard to validate.

As such, every lab needs to develop its own soil sterilization protocol (if not several, for the various substrates they are using) and validate it using a quality biological indicator. 

At Priorclave, we’ve made it our business to support labs and researchers in any field, including those doing soil studies for agriculture, remediation, landscape recolonization, and species preservation. While labs have several options for sterilizing samples for agricultural and soil research, we’ve found that many prefer steam-based sterilization in an autoclave. Need help getting started with your soil sterilization “recipe?” Check out this quick guide to soil sterilization for labs.