Detoxification of water by semiconductor photocatalysis

An overview of the use of semiconductor photocatalysis for water purification is given. The basic principles of semiconductor photocatalysis are described along with the current understanding of the underlying reaction mechanism(s) and how it fits in with the major features of the observed Langmuir-Hinshelwood-type kinetics of pollutant destruction. These features are illustrated based on literature on the destruction of aqueous solutions of 4-chlorophenol as a pollutant, using titanium dioxide as the photocatalyst. The range of organic and inorganic pollutants that can be destroyed by semiconductor photocatalysis are reported and discussed. The basic considerations that need to be made when designing a reactor for semiconductor photocatalysis are considered. These include: the nature of the reactor glass, the type of illumination source, and the nature and type of semiconductor photocatalyst. The key basic photoreactor designs are reported and discussed, including external illumination, annular, and circular photoreactors. Actual designs that have been used for fixed and thin falling film semiconductor photocatalyst reactors are illustrated and their different features discussed. Basic non-concentrating and concentrating solar photoreactors for semiconductor photocatalysis are also reported. The design features of the major commercial photocatalytic reactor systems for water purification are reported and illustrated. Several case studies involving commercial photocatalytic reactors for water purification are reported. An attempt is made briefly to compare the efficacy of semiconductor photocatalysis for water purification with that of other, more popular and prevalent water purification processes. The future of semiconductor photocatalysis as a method of purifying water is considered

Iodine generator for reclaimed water purification

The system disclosed is for controlling the iodine level in a water supply in a spacecraft. It includes an iodine accumulator which stores crystalline iodine, an electrochemical valve to control the input of iodine to the drinking water and an iodine dispenser. A pump dispenses fluid through the iodine dispenser and an iodine sensor to a potable water tank storage. The iodine sensor electronically detects the iodine level in the water, and through electronic means, produces a correction current control. The correction current control operates the electro-chemical iodine valve to release iodine from the iodine accumulator into the iodine dispenser

Water management system and an electrolytic cell therefor Patent

Description of electrical equipment and system for purification of waste water by producing silver ions for bacterial contro

Reverse osmosis water purification system

A reverse osmosis water purification system, which uses a programmable controller (PC) as the control system, was designed and built to maintain the cleanliness and level of water for various systems of a 64-m antenna. The installation operates with other equipment of the antenna at the Goldstone Deep Space Communication Complex. The reverse osmosis system was designed to be fully automatic; with the PC, many complex sequential and timed logic networks were easily implemented and are modified. The PC monitors water levels, pressures, flows, control panel requests, and set points on analog meters; with this information various processes are initiated, monitored, modified, halted, or eliminated as required by the equipment being supplied pure water

Method of preparing water purification membranes

Allyl amine and chemically related compounds are polymerized as thin films in the presence of a plasma discharge. The monomer compound can be polymerized by itself or in the presence of an additive gas to promote polymerization and act as a carrier. The polymerized films thus produced show outstanding advantages when used as reverse osmosis membranes

Awareness and the demand for environmental quality: Drinking water in urban India

The demand for environmental quality is often presumed to be low in developingcountries due to poverty. Less attention has been paid to the possibility that lack of awareness about the adverse health effects of environmental pollution could also keep the demand low. We use a household survey from urban India to estimate the effects of awareness and wealth on home water purification. Average costs of different home purification methods are used to derive get estimates of lower bounds on willingness to pay for better drinking water water quality in Delhi. We find that measures of awareness such as schooling and exposure to mass media have statistically significant effects on adoption of different home purification methods and therefore, on willingness to pay. These effects are similar in magnitude to the wealth effects.Environmental awareness, drinking water quality, health risks

Quick appraisal of "Sistema de suministro desde el embalse del Cenajo a la Mancomunidad de Canales del Taibilla"

The project under assessment concerns the construction of an aqueduct in order to divert water from Tajo-Segura Channel onto the Cenajo reservoir and to the water purification plants of Sierra de la Espada and of Campotéjar. The main objective is to improve water quality rather than quantit

Awareness and the Demand of Safe Drinking Water Practices

The demand for environmental goods is often low in developing countries. The major causes are awareness regarding the contamination of water and poverty, but less attention has been paid to the former reason. We use a household survey from Hyderabad city and estimate the contribution of awareness and income on households’ water purification behaviour. The study finds out that measures of awareness such as different level of schooling of decision-makers and household heads and their exposure to mass media have statistically significant effects on home purification methods for drinking water, while other members of households can effect this behaviour only when they get higher levels of schooling.Demand, Awareness, Safe Drinking Water, Logit Model, Probit Model

Analytical methods for bacterial kinetics studies

Methods utilize mathematical equations and models and specialized computer techniques. Techniques apply to food production, complex chemicals production, and polluted water purification

Hydrogen eliminator

Vented hydrogen is converted into water by mixing hydrogen with sufficient air to ensure that a flame cannot be maintained and then passing it through a reactor containing palladium catalyst; reaction takes place at relatively low temperature. Device may have wide range of applications for air purification