Ultraviolet (UV) light is a natural part of sunlight; the short wavelengths are absorbed by the protecting ozone layer. UV lamps designed for water disinfection use a gas mixture containing the element mercury (Hg) vapour to produce ultraviolet light.
Mercury is an advantageous gas for UV disinfection applications because it emits light in the germicidal (‘germs killing’) wavelength range (UVC and UVB). The light output depends on the concentration of mercury atoms, which is directly related to the mercury vapor pressure.
Mercury at low vapour pressure produces essentially monochromatic (single wavelength) UV light at 253,7 nm, so-called low-pressure UV lamps.
At higher vapour pressures, the frequency of collisions between mercury atoms increases, producing UV light over a broad spectrum. These so-called polychromatic (more wavelengths) medium-pressure lamps have an overall higher intensity.
Exposure to UV light in the wavelength spectrum of 200 – 400 nm damages the genetic (DNA and RNA) and other molecules inside a micro-organism. The damage ‘kills’ the specific micro-organism.
Bacteria, protozoa, viruses, fungi, algae are all sensitive to UV light. Because of differences in their shape, they are sensitive to different wavelengths.
Applying UV light does not leave residuals in the water, which is an advantage over chemical disinfection methods. UV is proven to be very effective in inactivation of Giardia and Cryptosporidium with a very low dose.
The use of chlorine as a disinfectant is commonly accepted worldwide. People are becoming more concerned about the by-products of chlorine as it reacts with other organic compounds producing various compounds like e.g. trihalomethanes (THMs). THMs are documented as probable or possible human carcinogens.
Other disadvantages of chlorination are how it changes of taste and odours, the need for additional equipment such as tanks to guarantee proper contact time, and necessary monitoring to ensure proper concentration levels.
Chlorination is known to provide poor disinfection performance against viruses such as enterovirus and hepatitis A and microorganims such as Giardia and Cryptosporidium .
Ozone, one of the strongest oxidants known, is effective as an oxidising agent in reducing bacteria with a relatively short exposure time. Ozone generators are used to produce ozone gas on-site since the gas is unstable and has a very short life.
These systems must be carefully installed and monitored because high levels of ozone will oxidise and deteriorate all downstream piping and components. High levels of ozone are extremely harmful, especially in enclosed or low ventilation areas.
Furthermore ozone forms highly carcinogenic by-products at high bromide levels such as bromate, bromoform, dibromeacetic acid etc. This is becoming an even bigger concern with drinking water disinfection.
As a result of by-product formation some countries have already banned ozone for drinking water treatment.For more information contact Instek Control +27 12 998 6326 or email firstname.lastname@example.org
From the left: Sandro Marino – Interfusao, Brasilië; Raymond Karsten – Instek Control, South Africa; Joachim Felber – Centec, Germany; Bill Hancock - Zeroday LLC, North America
Low-pressure (LP) UV lamp
Low-pressure (LP) UV lamps have some important differences compared to medium-pressure (MP) UV lamps:
Some applications use of low-pressure UV lamps, mainly because of:
Two other important reasons to use low-pressure UV lamp technology are:
The UV spectrum is divided in 4 ranges:
This range extends from wavelengths between 315 – 400 nm (nanometer). Light in this range is absorbed by the skin and leads largely to “sun tanning”.
Application for these wavelengths:
This range extends from wavelengths between 280 – 315 nm. Light in this range is also absorbed by the skin but leads largely to “sun burning”.
Applications for these wavelengths:
This range extends from wavelengths between 200 – 280 nm. This range is absorbed by DNA and RNA (genetic molecules) in micro-organisms and leads to their inactivation (‘killing’) by inhibiting their ability to replicate.
Applications for these wavelengths:
This range extends wavelengths from 100 – 200 nm. It is called “vacuum UV” since UV light in this range is strongly absorbed by water or oxygen in air and can thus only exist in vacuum.
Applications for these wavelengths:
Contact the ‘experts in ultraviolet light’ to fully optimize your new or existing water treatment system with bestUV technology.
OLAS (Optical Light Absorption Sensor) Absorptiometry and density measurement. This Sensor (OLAS), fabricated by Werne&Thiel GbR sends light into the material of interest (medium) and makes use of the accurately measured absorption of light to determine the composition of medium.
With this method not only the composition of water slurries, suspensions and composite materials of all kinds (e.g. cement slurry, chemical pulp, etc.) can be determined, but also the thickness of foils and coatings and much else. Whatever in production, manufacturing or processing results in a change of absorption of light of medium can be measured, monitored and controlled by the OLAS .
Density measurement in concrete residual water. The development of the OLAS measuring system, an online measuring system, that determines the solid content of concrete recycling water, was initiated years ago. It has been established into a reliable and economic measuring system reaching product maturity. OLAS, named after its functionality namely:
Optical Light Absorption Sensor, makes use of a sophisticated and modernized infrared absorption measuring method, in which the measurement of light is introduced into the medium through optical fibres.
When desired, OLAS can be supplemented by the OLASTPC (OLAS Touch Panel Controller), an optimal evaluation that functions as a display and control unit that forms a complete measurement system.
Visit https://www.instek.co.za/aggregate-instrumentation for more information on this exciting product or contact Raymond at 012 998 6326 / email@example.com
Giovanni Battista Venturi “discovered” the venturi effect in 1797, and ever since the Venturi effect have been in use in fluid and airflow mechanics over a range of disciplines ranging from Aeronautics to Farming, and everything in-between.
For the Food and Beverage Industry, Centec GmbH developed the Vortex Injector using the same principle to create arguably the best mixing system for carbonation and mixing of liquids to date.
The working principle is straight forward. Fluid moves through the inlet chamber where it is accelerated and pressurized.
Moving through the mixing chamber there is an immediate pressure drop that opens the liquid and creates a vacuum. This creates conditions for a near perfect fusion of liquids and or gases. The gas or liquid is injected into the product through multiple nozzles around the circumference of the mixing chamber. The homogenous mixing of the products take place instantaneously.
The Centec Vortex Injector is especially designed for the homogeneous mixing of liquids and Gas, e.g. CO2, O2 or N2, with beer, wine, or other beverages.
Because this system is so effective the dissolving times are greatly reduced and the dosing can be done precisely and accurately. It is a proven system implemented in major Breweries, Wineries, and Soft Drink concerns.
The Centec Vortex mixer is a hydrodynamic fitting for the mixing and dispersion of multiple liquids and further applications include additive dosing of liquid ingredients (e.g. flavors, sweeteners, vitamins, colors) to a main stream.
The benefits of the Venturi Vortex Injector are numerous and includes:
· Instant, homogenous Mixing and additive dosing of liquids and gasses.
· Designed for each specific application with the unique characteristics of each product and process incorporated.
· Full CIP Capability
· Outstanding Price-to-Performance ratio
· Smaller holding loops and dissolving times resulting in more compact plant designs
· More accurate dosing ability resulting in material and time savings.
For more information visit VORTEX or contact Raymond +27 12 998 6326 / firstname.lastname@example.org.
Bacteria settle among any structure (pipelines, tanks, machinery) in contact with the water in a very short time, if appropriate preventative measurements are not applied. The ALVIM real-time, on line, Biofilm Monitoring System is able to detect bacterial settlement since its first phases (down to 1% of surface covered by micro-organisms such as Legionella pneumophila) and, based on these data, manually or automatically adjust and optimize cleaning treatments / biocide treatments. This way keeping biofilm growth under control.What is biofilm?
Important advantages of the ALVIM technology compared to other sensors in the market
Operating conditions for the NEW ALVIM SENSOR - AX03S3
Temperature: -10<T<+150°C (to monitor biofilm growth: +2<T<+40°C)
Pressure: <10 bar
Conductivity: >30 µs/cm
Data Communication Wiring: 4-20mA and RS485/MODBUS RTU
Alcohol Measurement Sensors for the Brewery Industry:
Measurement of conductivity of liquid media for