Most odor control systems can be classified into one of four categories. These categories include Chemical Adsorption, Biological Oxidation, Chemical Scrubbing, and Combined Technologies. Below is a brief description of each category. Further explanation on each type can be found in their corresponding individual FAQs. Adsorption: Adsorption is the adherence of ions/molecules, gas, liquid, or dissolved material to the surface of a solid. It is also the adherence of ions from an aqueous solution to a solid mineral surface. Adsorption is not to be confused with absorption. Some companies providing adsorption odor control include: Megtec, APC Technologies Inc. Biological Oxidization: Biological oxidations is a process where bacteria and other micro-organisms consume dissolved oxygen and organics substances using the energy released to change organic carbon into carbon dioxide and cellular material. There are two main categories of Biological oxidation. These are bio-oxidation using inorganic media (bio-scrubbers/bio-trickling filters) and bio-oxidation using organic media (bio-filters). Some companies providing bio-oxidation odor control include: Megtec, APC Technologies Inc, Zabocs Biological Odor Control. Chemical Scrubbing: This is also known as chemical absorption. It is defined as the “taking of one substance directly into another substance”. Absorption can be a physical or chemical process. Some companies providing bio-oxidation odor control include: Pacific Service & Supply Co., Inc., Lantec, ERG Air Pollution Control. Combination Technologies: This is combining the technologies of the types of odor control technologies above.