Reverse Osmosis Membrane Biocides & Disinfectants

Reverse Osmosis Biocides  - Non-oxidizing, non-ionic biocides can be used either online or as part of a cleaning program to control biofouling in reverse osmosis (RO) membranes. When used as an online treatment, the biocide should be dosed prior to the RO system to control bio-growth in the membranes.

Application frequency of any selected biocide will normally depend on biological loading and biofilm growth rate. The program should be used to control differential pressures in the RO plant to reduce cleaning frequency. Application rates and frequency of application (biocide program costs vs. effectiveness)  vs. reduction in cleaning frequency, downtime, membrane life (operating costs without biocide program) should be balanced to determine the most cost-effective biocide dosing frequency.

Dosing biocide further back in the pre-treatment will help control bio-growth but will also greatly increase demand and application costs. The main goal of an effective biocide program is to control biofouling in the membranes to an acceptable and cost-effective level compared to cleaning program costs (and other associated costs).

The two ROC products widely used are 2,2-dibromo-3-nitrilopropionamide (DBNPA) and isothiazolinone. These products are fully compatible with polyamide (PA) and cellulose acetate (CA) membranes. We also offer two high-performance alternatives, chlorine dioxide and a hydrogen peroxide solution synergized with colloidal silver.

DBNPA

DBNPA is fast-acting and readily decomposes to harmless by-products on discharge. On-line, it is dosed just prior to the RO system to control biofouling in the membranes. The dose rate is typically 100 ppm for 1 hour. The frequency of application depends on the degree of biological contamination in the feed water and the rate of biofilm growth in the membranes. Typically frequency of application can vary from every other day to once a month. The half-life of DBNPA is reduced with the increase of pH. In high pH feed waters (> 8.5) the dose rate and contact time should be doubled.

DBNPA biocide should not be dosed with stainless steel injection quills as corrosion of the injection assembly will occur.

ROCbio DBNPA -  fast-acting, non-oxidizing, antimicrobial reverse osmosis bio-control formulation with a broad spectrum of activity developed to control the planktonic and sessile microorganisms that may form as biofilms on membrane surfaces and in pre-treatment vessels and pipework ... DBNPA based biocide >>

Isothiazolone

Isothiazolone has a longer contact time than DBNPA. The dose rate is typically 50 – 100ppm for 4 hours of contact. Isothiazolone is more effective than DBNPA in waters with high organic loading. Isothiazolone can also be used at low dose rates on a continuous basis (10 – 20ppm).

ROCbio 50 - non-oxidizing, non-ionic antimicrobial reverse osmosis disinfectant formulation based on 0.5% isothiazalone for use in membranes and pre-treatment plant ... isothiazalone based biocide >>

ROCbio 150 - non-oxidizing, non-ionic antimicrobial reverse osmosis biocide formulation based on 1.5% isothiazolinone for use in membranes and pre-treatment plant ... isothiazolinone based biocide >>

ROCbio 300 - non-oxidizing, non-ionic antimicrobial RO disinfectant formulation based on 3.0% isothiazalone for use in membranes and pre-treatment plants. It has a broad spectrum of activity ... isothiazolinone based biocide >>

Hydrogen peroxide silver

ROCbio Silver, an innovative blend of hydrogen peroxide and silver, is an eco-friendly, multi-component oxidizing biocide utilizing a stable combination of hydrogen peroxide (H2O2) and silver(Ag) ions to form a powerful sanitizing solution. This synergistic combination is so effective it creates a biocide twenty times more powerful than that of hydrogen peroxide alone.

ROCbio Silver - eco-friendly, multi-component oxidizing biocide utilising a stable combination of hydrogen peroxide and silver (H2O2/Ag) ions to form a highly effective sanitizing solution ... hydrogen peroxide silver biocide >> 

Chlorine dioxide

ROC produces a range of chlorine dioxide products that are ideal for use in reverse osmosis systems. Chlorine dioxide is a highly effective biocide that carries a number of important regulatory approvals including US EPA, FDA and UK Government for many of its uses. It is effective at concentrations as low as 0.1 ppm and will eliminate both planktonic and sessile bacteria.

         ROC Chlorine dioxide - Reverse Osmosis Chemicals International offer several alternative products that will deliver               varying amounts of high purity chlorine dioxide suitable for reverse osmosis applications ... chlorine dioxide >> 


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