SurfactantSurfactants are chemical compounds that decrease the surface tension or interfacial tension between two liquids, a liquid and a gas, or a liquid and a solid. Surfactants may function as emulsifiers, wetting agents, detergents, foaming agents, or dispersants. The word "surfactant" is a blend of surface-active agent, coined 1950. Surfactants are usually organic compounds that are akin to amphiphilic, which means that this molecule, being as double-agent, each contains a hydrophilic "water-seeking" group (the head), and a hydrophobic "water-avoiding" group (the tail).
Aquatic ecosystemAn aquatic ecosystem is an ecosystem found in and around a body of water, in contrast to land-based terrestrial ecosystems. Aquatic ecosystems contain communities of organisms—aquatic life—that are dependent on each other and on their environment. The two main types of aquatic ecosystems are marine ecosystems and freshwater ecosystems. Freshwater ecosystems may be lentic (slow moving water, including pools, ponds, and lakes); lotic (faster moving water, for example streams and rivers); and wetlands (areas where the soil is saturated or inundated for at least part of the time).
Aquatic plantAquatic plants are plants that have adapted to living in aquatic environments (saltwater or freshwater). They are also referred to as hydrophytes or macrophytes to distinguish them from algae and other microphytes. A macrophyte is a plant that grows in or near water and is either emergent, submergent, or floating. In lakes and rivers macrophytes provide cover for fish, substrate for aquatic invertebrates, produce oxygen, and act as food for some fish and wildlife.
MicelleA micelle (maɪˈsɛl) or micella (maɪˈsɛlə) (plural micelles or micellae, respectively) is an aggregate (or supramolecular assembly) of surfactant amphipathic lipid molecules dispersed in a liquid, forming a colloidal suspension (also known as associated colloidal system). A typical micelle in water forms an aggregate with the hydrophilic "head" regions in contact with surrounding solvent, sequestering the hydrophobic single-tail regions in the micelle centre. This phase is caused by the packing behavior of single-tail lipids in a bilayer.
Aquatic animalAn aquatic animal is any animal, whether vertebrate or invertebrate, that lives in water for all or most of its lifetime. Many insects such as mosquitoes, mayflies, dragonflies and caddisflies have aquatic larvae, with winged adults. Aquatic animals may breathe air or extract oxygen from water through specialised organs called gills, or directly through the skin. Natural environments and the animals that live in them can be categorized as aquatic (water) or terrestrial (land). This designation is polyphyletic.
Particulate organic matterParticulate organic matter (POM) is a fraction of total organic matter operationally defined as that which does not pass through a filter pore size that typically ranges in size from 0.053 millimeters (53 μm) to 2 millimeters. Particulate organic carbon (POC) is a closely related term often used interchangeably with POM. POC refers specifically to the mass of carbon in the particulate organic material, while POM refers to the total mass of the particulate organic matter.
Critical micelle concentrationIn colloidal and surface chemistry, the critical micelle concentration (CMC) is defined as the concentration of surfactants above which micelles form and all additional surfactants added to the system will form micelles. The CMC is an important characteristic of a surfactant. Before reaching the CMC, the surface tension changes strongly with the concentration of the surfactant. After reaching the CMC, the surface tension remains relatively constant or changes with a lower slope.
DetergentA detergent is a surfactant or a mixture of surfactants with cleansing properties when in dilute solutions. There are a large variety of detergents, a common family being the alkylbenzene sulfonates, which are soap-like compounds that are more soluble in hard water, because the polar sulfonate (of detergents) is less likely than the polar carboxylate (of soap) to bind to calcium and other ions found in hard water. The word detergent is derived from the Latin adjective detergens, from the verb detergere, meaning to wipe or polish off.
Colored dissolved organic matterColored dissolved organic matter (CDOM) is the optically measurable component of dissolved organic matter in water. Also known as chromophoric dissolved organic matter, yellow substance, and gelbstoff, CDOM occurs naturally in aquatic environments and is a complex mixture of many hundreds to thousands of individual, unique organic matter molecules, which are primarily leached from decaying detritus and organic matter. CDOM most strongly absorbs short wavelength light ranging from blue to ultraviolet, whereas pure water absorbs longer wavelength red light.
Organic horticultureOrganic horticulture is the science and art of growing fruits, vegetables, flowers, or ornamental plants by following the essential principles of organic agriculture in soil building and conservation, pest management, and heirloom variety preservation. The Latin words hortus (garden plant) and cultura (culture) together form horticulture, classically defined as the culture or growing of garden plants. Horticulture is also sometimes defined simply as "agriculture minus the plough".
