Wastewater treatment entails removing and treating many different types of pollutants or contaminants found in wastewater. There are, of course, many different types of processes that are aimed at treating wastewater to remove such contaminants and pollutants. Generally, the basic approaches revolve around biological and/or chemical treatment processes. While there has been significant progress made in developing new technology for treating wastewater, there still remains one serious concern that is especially felt by small towns and local governments all over the world. The thrust of the technology that has been developed today for treating wastewater is principally aimed at very large wastewater anaerobic and aerobic treatment facilities that require tremendous capital investment and space for retention compounds to facilitate digestion. These wastewater treatment systems and processes fall outside of the economic reach for many small local government bodies or small businesses that need or require their own wastewater treatment facilities. Therefore, there has been and continues to be a need for a cost effective wastewater treatment system that is affordable by small governmental bodies and others who have a need to treat and process wastewater. It is further recognized that some individuals need a system of a capacity or scale that is substantially below the size of the typical treatment plants normally designed for large municipalities.
Further, another deficiency of conventional wastewater treatment processes is that they often rely solely on aerobic or anaerobic digestion to remove contaminants and are not particularly designed to deal with a wide range of contaminants and pollutants typically found in wastewater streams. Therefore, there is also a need for a practical and cost-effective wastewater treatment process wherein the process effectively removes a wide range of pollutants and contaminants from the wastewater.
In addition, it is widely known that hydrocarbon based toxic and hazardous wastes are commonly produced as a consequence of numerous commercial and industrial processes. In some cases, this waste material may be difficult to contain at the point of generation, and as a result, this material may ultimately escape to the environment as a contaminant. Such contamination often poses serious environmental and health concerns, and consequently there arises the need to remove or neutralize this contamination.
One commonly employed process being used for treating low levels of hydrocarbon contamination is in situ bioaugmentation. In this process, genetically altered microorganisms are applied directly to the affected material where they proceed to digest the hydrocarbon contaminants. In the case of ground contamination, the effected soil is seeded with the micro-organisms and their digestion progress is continuously monitored. Although effective, treatments using this approach tend to be prolonged and may require extended treatment and monitoring periods, possibly lasting five to ten years before satisfactory results are obtained. Capital and operational costs for this process can be excessive.
Another common method of treating soil contaminated with hazardous hydrocarbon compounds involves the removal and off-site processing of the soil. The off-site processing typically includes baking the contaminated soil in a high temperature furnace or kiln so as to burn or combust the hydrocarbon contaminants and hence effectively remove them. This treatment approach, while not as slow as in situ bioaugmentation, tends to be extremely expensive as a consequence of the high transport and fuel costs associated with such processing. Soils treated via this process are often void of nutrients and beneficial bacteria, which negatively impacts soils reuse.
Still other equally expensive processes, which have been successfully employed to treat hydrocarbon-contaminated soil, involves in-situ exposure to highly oxidative reactants, such as hydrogen peroxide, in conjunction with lead and zinc bearing solutions. While effective in reducing the overall toxic hydrocarbon content of the contaminated soil, this type of treatment tends to attack or neutralize non-toxic organics which may also happen to be present in the soil. The use of strong oxidants can mobilize heavy metals if present in the soils and actually increase the danger to the public from them. In general, neutralization of non-toxic organics is undesirable and hence this approach is less than ideal in most instances.
Therefore, there is and continues to be a need for a practical and efficient technique for eliminating or neutralizing toxic hydrocarbon contaminants typically found in the environment which is fast acting, cost effective and which targets only the specific toxic hydrocarbons of concern.
USPTO Backgrounds
USPTO Backgrounds