Soil Vapor Extraction (SVE)

Bioremediation is a process that uses microorganisms, fungi, green plants, or their enzymes to return a contaminated environment to its original condition. It can be employed to attack specific soil contaminants, such as chlorinated pesticides, or to treat a wider range of pollutants. Bioremediation can occur naturally (natural attenuation) or be spurred on by adding fertilizers (biostimulation) or specific microorganisms (bioaugmentation).

Many mid-ocean (mesopelagic) animals use bioluminescence for camouflage through a strategy called counter-illumination: they possess light-producing organs (photophores) on their undersides that generate light matching the intensity and color of the downwelling sunlight or moonlight. This effectively eliminates their silhouette when viewed from below, hiding them from predators hunting from the depths.

An approach to land management and philosophy that adopts arrangements observed in flourishing natural ecosystems. It includes a set of design principles derived from systems thinking, and it aims to create sustainable human settlements and agricultural systems by modeling them on natural patterns. Core tenets include care for the Earth, care for people, and fair share (returning surplus).

A Volatile Organic Compound (VOC) is an organic chemical that has a high vapor pressure at room temperature, leading to significant evaporation. This property is due to a low boiling point. The European Union defines a VOC as any organic compound having an initial boiling point less than or equal to 250°C measured at a standard pressure of 101.3 kPa.

The South Atlantic Anomaly (SAA) is a large area over the South Atlantic and South America where the Earth's inner Van Allen radiation belt comes closest to the planet's surface. In this region, the magnetic field intensity is significantly weaker, about one-third of the global average. This weakness allows charged particles to penetrate to lower altitudes.

Phytoremediation is a bioremediation process that uses various types of plants to remove, transfer, stabilize, or destroy contaminants in soil and groundwater. This low-cost, solar energy-driven technique is effective for cleaning up sites with low to moderate levels of contamination. Different mechanisms are involved, including phytoextraction (uptake into harvestable plant tissues), phytodegradation (breakdown of contaminants), and phytostabilization (reducing mobility).

Biogenic Volatile Organic Compounds (BVOCs) are VOCs produced and emitted by living organisms, predominantly plants. Isoprene (\(C_5H_8\)) and terpenes are the most abundant BVOCs. While natural, their emissions are vast, exceeding anthropogenic VOCs globally. They play critical roles in plant defense, signaling, and are major precursors for atmospheric ozone and secondary organic aerosols, influencing air quality and climate.

In-Situ Chemical Oxidation (ISCO) is an aggressive remediation technology that involves injecting strong chemical oxidants directly into the contaminated subsurface to destroy pollutants. Common oxidants include permanganate, persulfate, hydrogen peroxide (Fenton's reagent), and ozone. These chemicals react with contaminants, converting them into less toxic substances like carbon dioxide, water, and inorganic salts, without requiring excavation of the contaminated material.

Secondary Organic Aerosols (SOAs) are fine airborne particles formed from the atmospheric oxidation of VOCs. Gaseous VOCs react with oxidants like \(O_3\), \(\bullet OH\), or \(NO_3\bullet\) to produce low-volatility products. These products can then undergo gas-to-particle conversion, either by forming new particles (nucleation) or condensing onto pre-existing aerosols. SOAs are a major component of PM2.5, impacting climate and human health.