Ultraviolet water treatment for industrial water treatment - Water and Wastewater - Water Treatment
Water is used at some point in almost every manufacturing process worldwide. In many industrial applications, the use of chemicals such as chlorine or biocides is restricted for process reasons. UV provides a highly effective, chemical-free disinfection solution for a vast range of industrial applications. Our flexible industrial water treatment solutions suit the needs of a vast number of manufacturing processes.
atg UV Technology has recently developed a chemical-free Advanced Oxidation Process (AOP) known as Keratox for the treatment and removal of organic and chemical contaminants from municipal drinking water and wastewater.
Utilising atg UV Technology’s UV treatment systems, in combination with a unique and patented Titanium Dioxide (TiO2) catalyst, the Keratox advanced oxidation solution can be used to target and remove contaminantsin order to meet regulations such as the EU Priority Substances Directive (2013/39/EC), a new ‘daughter directive’ of the widely established Water Framework Directive (2000/60/EC) that will affect all European member states.
The Priority Substances Directive, and other associated watch lists for chemicals of priority concern will require up to 45 micro-pollutants such as Polycyclic Aromatic Hydrocarbons (PAH’s), Endocrine Disruptor Compounds (EDC’s), Alkylphenol’s and trace pesticides and pharmaceuticals to be removed from effluent wastewater streams before discharge into the environment. In addition, some municipal drinking water suppliers are also looking at implementing Advanced Oxidation Processes for contamination removal before potable drinking water enters their municipal water network.
atg UV Technology’s advanced disinfection systems will safely and effectively eradicate bacteria and parasites, such as legionella from a range of industrial applications without the need for hazardous chemicals or extreme temperatures, thereby minimising the risk of scalding and removing the necessity for mixer devices. Additionally, UV can be used on all types of pipework, especially in older systems where it is not possible to obtain temperatures required for thermal disinfection.
Ultraviolet disinfection is ideally suited for the following industrial applications:
- Cooling and heating
- Water features and pools
- Drinking water and water supplies
- Rainwater harvesting
With a number of units specially designed and developed for hydroponics and agriculture, atg UV’s treatment systems eliminate all types of water-borne micro-organisms.
Our leading Ultraviolet treatment systems are used in a number of key areas to vastly reduce the risk of product rejection, crop failure and the spread of disease. With a number of “emerging” pathogens now displaying increased resistance to traditional methods of disinfection, Ultraviolet treatment is now the preferred and accepted method of disinfection over traditional chemical methods.
- Process water
- Water reuse
- Storage tanks
Specially designed and developed for the pharmaceutical industry, atg UV’s breakthrough chamber design eliminates all crevices and unnecessary fittings, maintaining the integrity of the system.
Our leading UV technology is used in a number of key areas, including ultra-pure water generation, the treatment of process water and disinfection of contaminated effluent water discharges.
Treatment with the appropriate dose of UV energy will inactivate all types of micro-organisms. A UV dose greater than a log-4 reduction (99.99%) can be easily achieved. With a wide range of Ultraviolet systems, atg UV can provide treatment for applications, such as:
- TOC Reduction
- Toxic discharges
- Effluent discharges
The purpose of de-chlorination is the removal of free chlorine and combined chlorine compounds from potable water, as supplied by municipal water supplies. Chlorine will oxidize the surface of thin film composite polyamide membranes, causing the membrane to lose its ability to repel or reject salts. As a result, the membranes used in Reverse Osmosis (RO) or Electro-deionisation (EDI) systems will exhibit shorter lifetimes when exposed to chlorine in the water they are treating and membrane manufacturers will usually specify an upper limit to ensure a suitable life of the membrane. As a result, it is usual to use a method of de-chlorination upstream of the RO or EDI system.
De-chlorination by treatment with Medium Pressure UV avoids all the pitfalls associated with both sodium meta-bisulphite and Granulated Activated Carbon. At high doses, UV is very effective at removing free chlorine from water.
Other benefits of using UV for this purpose are: the water receives a high UV disinfection dose; there is a degree of TOC destruction; it eliminates labour and the safety hazard of mixing sodium metabisulphite; it eliminates the risk of introducing micro-organisms onto reverse osmosis membranes (via sodium metabisulphite injection); there is an overall improved water quality at point-of-use.
In ‘clean’ processes or ultrapure water applications, ozone is mainly used for CIP sanitization purposes in the process water loops. However, residual ozone represents a potential health hazard and it can be damaging to finished goods, as well as to processing and fabrication equipment. Breakdown of residual ozone is therefore essential in these and other applications before the ozonated water can be used. The process of de-ozonation has been performed in the past by passing through a filter bed of Granulated Activated Carbon (GAC). However, the same porous structure of GAC that enables GAC to remove ozone, allows GAC filters to become prime incubators for micro-organisms. Other methods used are dosing with hydrogen peroxide H2O2 (ozone quenching) or aeration by cascade, in a packed column or by air diffusion.
In purified water systems, strategic placement of properly designed and sized medium or low pressure UV systems simply and effectively reduces residual ozone to below detectable levels with the additional benefit of TOC destruction. Positioning a UV system directly before the water treatment components requiring protection from ozone (e.g. DI polishing) maximizes the sanitizing benefits provided by residual ozone up to that point. When loop sanitizing is required, the UV is simply turned off and any sensitive process step is by-passed for a brief period of time. Using UV to remove ozone has an advantage because UV does not require additives that may leave behind residuals. In addition, dissociation of ozone with UV may also help to oxidize Total Organic Carbon (TOC).
Total Organic Carbon (TOC) is found in all water supplies as naturally occurring organic matter. Over many years of experience, medium or low pressure UV treatment has become recognised as an effective process step in the breakdown and reduction of TOC in water intended for use in pharmaceutical, health care, power generation and micro-electronics applications. In the latter case, ultra-pure water is used to wash silicon wafers on which even small deposits of carbon compounds on the wafers can severely affect their performance.
UV treatment is often just one part of the process of TOC reduction; it may be used in line with additional processes such as activated carbon, ultrafiltration, reverse osmosis and de-ionisation
The short wavelengths required for the production of hydroxyl radicals are absorbed very strongly by water (this absorption is the reason why the radicals are produced) and the effective path lengths within a UV chamber are short. UV systems designed for TOC reduction therefore require special geometries and high purity quartz materials that are partially transparent to short UV wavelengths. The UV doses that are required are considerably higher than those used for disinfection applications.