Biological oxygen demand is the technique used to measure the concentration of biodegradable organic matter present in the water and other materials. Some of the techniques patented in USPTO are mentioned below.
Patent no: 6,114,172 titled ‘Process and device for determining the biological oxygen demand of sewage’ with the abstract: In order to determine the biological oxygen demand of sewage, a sample of sewage is taken into a reaction vessel in which there is a biological bath which is kept moving turbulently by an agitator. An oxygen probe measure the oxygen consumption per unit time. After each measuring cycle the reaction vessel is rinsed with diluting water and is then ready for another measuring cycle. The reaction vessel penetrates into the sewage to be tested. The sewage sample enters the reaction vessel via an aperture.
Patent no: 5,976,377 titled ‘System and method for the reduction of the biological oxygen demand level of a flowable waste water’ with the abstract: A system for the treatment of waste water including hydrocarbons and of a high biological oxygen demand. Preferably, the system includes a portable platform suitable for transport from site to site. A reaction vessel defining a substantially vertically oriented flow path therethrough for flowable waste water is mounted with its lower portion within and surrounded by a collection basin which receives waste water for treatment and recycling via trickling down through a biomass disposed on packing material within the reaction vessel. Simultaneously with the trickle down of the waste water, ambient air is forced upwardly countercurrent to the flow of the waste water to provide oxygen to the biomass, to enhance the flow of waste water over the biomass, and to sweep gaseous products from the reaction vessel. Optionally, oxygen is introduced into the collection basin to enhance biodegradation reactions within the collection basin. The system may be operated in either batch mode or continuously. A method is disclosed.
Patent no: 5,275,734 titled ‘Chemical pre-treatment and biological destruction of propylene carbonate waste streams effluent streams to reduce the biological oxygen demand thereof’ with the abstract: Disclosed is a method of treating a process stream from a process producing a non-biodegradable alkylene carbonate stream. The alkylene carbonate is hydrolyzed in a strong, aqueous, alkaline solution to form an aqueous alkaline solution of the corresponding alkylene glycol. This solution is then acidified to a pH of about 8 to 8.5. The acidified solution is aerated in activated sludge to reduce the biological oxugen demand (BOD) of the solution.
Patent no: 4,241,227 titled ‘Process for reducing biological oxygen demand of gas condensate’ with the abstract: Gas condensates formed from the gases obtained from coal gasification, cokefication, or carbonization are extracted with an acid- and alkali-resistant solvent, e.g. organic esters or ethers, and phenols are thereby removed. The extract is separated into solvent and phenolic phases and the solvent is recycled to the extraction process. The same solvent is used in a greater quantity for a second stage treatment of the gas condensate to preferentially remove tar bases and again the solvent and tar base phases are separated with recycling of the solvent. Residual solvent, acid gases and other volatile components are removed from the gas condensate by distillation and/or stripping with the ammonia and acid gases being separately recovered. The gas condensate is thereafter subjected to biological cleaning, e.g. by a biological oxidation.