Water treatment without unwanted by-products

AROUND the world, ozone is still the disinfection method of choice for many producers of bottled waters, including spring water, despite concerns about ozonation by-products such as bromate. Bromide ions occur naturally in many spring waters and on their own pose no problem. However, the presence of ozone can cause conversion of bromide into bromate, with the consequent potential for consumer health problems. The World Health Organisation (WHO) lists bromate as a carcinogenic substance and recommends its maximum limit in mineral water be set at 0.01mg/l (10ppb). As an alternative to ozonation, UV has many advantages. It is already widely used across a wide spectrum of the food and beverage industries, and also in industries where water of the highest purity is required, such as pharmaceutical manufacturing. UV kills all known spoilage microorganisms, including bacteria, viruses, yeasts and moulds (and their spores) without producing any disinfection by-products. It is a low maintenance, environmentally friendly technology that eliminates the need for chemical treatment whilst ensuring very high levels of disinfection. In fact Hanovia, one of the leading suppliers of UV disinfection technology, has noticed that more and more bottled water and soft drinks producers are now looking for ozone alternatives, and enquires about UV are on the increase. "Around the world many bottled water and soft drinks companies already use our UV technology to disinfect their products safely, avoiding the problems associated with ozonation and other chemical disinfection methods," notes managing director John Ryans. UV disinfection has many advantages over alternative methods. Unlike chemical biocides, it does not introduce toxins, residues or by-products into the process and does not alter the taste, odour or pH of the water. How UV disinfection works UV is the part of the electromagnetic spectrum between visible light and X-rays. The specific portion of the UV spectrum between 185-400nm (also known as UV-C) has a strong germicidal effect, with peak effectiveness at 265nm. At these wavelengths UV kills micro-organisms by penetrating their cell membranes and damaging the DNA, making them unable to reproduce and effectively killing them. A typical UV disinfection system consists of a UV lamp housed in a protective quartz sleeve, which is mounted within a cylindrical stainless steel chamber. The water to be treated enters at one end and passes along the entire length of the chamber before exiting at the other end. Virtually any liquid can be effectively treated with UV, including spring, surface or municipal water, filtered process water, viscous sugar syrups and effluent. There are two main types of UV technology, based on the type of UV lamps used: low pressure and medium pressure. Low-pressure lamps have a monochromatic UV output (limited to a single wavelength at 254nm), whereas medium pressure lamps have a polychromatic UV output (with an output between 185-400nm). Generally speaking, low-pressure systems are best suited for small, intermittent flow applications, whilst medium pressure technology is better suited to higher flow rates. Applications in the bottled water industry UV treatment can be used for primary water disinfection or as a backup for other water purification methods such as carbon filtration, reverse osmosis or pasteurisation. As UV has no residual effect, the best position for a treatment system is immediately prior to the point of use. This ensures incoming microbiological contaminants are destroyed and there is a minimal chance of post-treatment contamination. Incoming water supplies Although natural springs and municipal water supplies are normally free from harmful or pathogenic micro-organisms, this should not be assumed. Surface water from wells, rivCheap Nike Air Max 2017 For Online Sale