Avista Technologies produces water treatment chemicals for reverse osmosis systems and their pretreatments.
These chemicals are pre-tested, tested and are subject to continuous testing to ensure that the unique challenges of various water treatment processes and changing raw waters are always met.
The following chemicals/treatments are available:
Colloid and silt pollution are the main causes of a loss of performance in membrane separation systems. Therefore, many system designs include as pre-processing a wide variety of mechanisms to ensure particle removal. These include multimedia filters, fine filters and ultrafiltration systems. The RoQuest® coagulants neutralize the negative electrostatic charges of the particles and filter media surfaces. The elimination of these charges allows collisions and attachments between particles and media grain surface.
Due to the high yields of a reverse osmosis plant, the solubility limits of the salts are exceeded in the concentrate. The salts precipitate and form deposits on the membrane surface, the scaling. Frequent scaling deposits are calcium carbonate CaCO3, calcium sulphate CaSO4, barium sulphate BaSO4 and strontium sulphate SrSO4. Less frequent but equally problematic are deposits of silicon dioxide SiO2 and calcium fluoride CaF.
Vitec® offers a range of products that pushes the solubility limits upwards and thus prevents premature scaling. These antiscalants have been developed for a variety of waters, e.g. for the treatment of spring, surface, town and well waters, seawater and process and waste water.
The biocides are used to suppress bacteria, micro-organisms and algae indifferently. This can be done by continuous dosing, shock dosing or by a CIP cleaning system. We provide support for the optimization of the most suitable disinfection regimes for the membrane system.
Biological fouling of membrane systems is a major challenge in the operation of such plants. The reason for this is above all the use of effective biocides, which have no oxidizing effect, in order to rule out irreversible damage to the polyamide membrane layer.
RoCide® offers two types of biocides for use in membrane systems: RoCide®DB and RoCide®IS2. Both formulations are non-oxidizing and EPA-registered. They can be safely used in both polyamide and cellulose acetate membranes. However, they are not suitable for in-line feeding in drinking water production or treatment systems. Both have excellent environmental properties and are quickly decomposed in a natural way. Therefore, these chemicals are particularly suitable for systems that are operated in accordance with strict environmental and waste water regulation
RoClean® Technologies offers an extensive range of specially developed membrane cleaners to eliminate virtually all membrane blockages. Details can be found in the product data sheets.
All supplied membrane cleaners are concentrated and must be diluted with permeate (or drinking water). The mixing and solution behaviour of all AVISTA membrane cleaners is very high. Warming up the cleaning solution and adjusting good cleaning hydraulics have an enhancing effect on the membrane cleaners.
AntiChlor is a modified, odorless liquid sodium bisulfite formulation used to remove free and combined chlorine from reverse osmosis (RO) feedwaters.