How can we control biofilm growth in drinking water pipeline without increasing disinfectant dosing as WQ standards and not to end up with disinfectant byproducts due to excess disinfectant?
Disinfectants obviously controls biofilm growth. But increasing dosing pose health problems as well. In addition, unpleasant taste and odour are results of increased dosing. Are there any other methods to control biofilm growth. Some studies say biofilm growth improves the efficiency of systems by reducing pipe roughness initially, however it increases when pipes are old. What is the better cheaper method to clean biofilms from older pipes?
Once every year we do what we call a "free burn." We switch off our chloramine solution and inject 100% free cholorine. This drastically reduces the nitrification within our system, which in turn reduces the disinfection byproducts. It has worked wonders for our pipe scaling and biofilm growth. This in combination with a heavily monitored flushing schedule has resolved our dbp and biofilm issues.
A chemical-free technology for controling biofilm in water lines of any reasonable size is with HydroFlow, which emits a sustained 150 kHz frequency that neutralizes bacteria (sessile and free floating), algae and scale accumulation. HydroFlow operates on low energy consumption (AC current) and attaches to the outside of any pipe material. https://www.youtube.com/watch?v=uwe2RCDt76Y
Biogy is unavoidable we need to accept that we should get good water and as well maintain clean pipelines just flush the pipe every once a while and maintain it time to time.
It may be possible to add our bio-catalyst formulations at very high dilutions to remediate this problem. It works in other biofilm growth situations and can be used in conjunction with disinfectants. Would need to be tested for your requirements.
To avoid Biofilming in especially public water supply pipe lines, change the disinfectants quite often, and change the dosage percentage. have a cycle of disinfectants in order to avoid the mircro organisims getting immune to the disinfectant systems.
SanEcoTec's AVIVE Water Treatment Process is unique. In Ontario Canada, know to be a very tightly regulatated drinking water due to Wakerton in 2003, we are replacing chlorine as secondary disinfectant with a New Generation of Hydrogen Peroxide. We have demonstrated better biofilm control, reduced DBPs, and can keep an H2O2 residual in the hot water as well. This H2O2 is NSFStd60 listed for continuous dosing (8ppm active H2O2) and doesn't need to be followed by Chlorine, as it keeps a better, more effective and long lasting residual without the zero taste and odour issues.
I hope this helps support you in finding the solution to your problem as you do not make this clear -
One is biofilm in a potable water main is a natural thing and you must accept that you cannot control it and if you remove it from the pipe wall it will come back - usually within 28 days. We have been working alongside University of Sheffield in the UK on this subject over the last 7 years. Check out their website and articles on the internet - http://www.podds.co.uk/. I would ask why you need to control it? Are you having water quality issues that you are attributing to the biofilm? we have found our issue is not the film but the metal oxides -usually of Mn and Fe that are present in most potable systems sticking to the film and then remobilising when we exceed the energy equilibrium between the film and the pipewall - usually when we change flows in the main. You need to learn to manage this 'accumulation' over time as cleaning mains is not cost beneficial in the long term.
we combine our pipeline management approach, based on PODDS principles to successfully manage water quality risks in old and dirty mains quite successfully. we also do mains cleaning as part of our discolouration reduction strategy including ice pigging. NWG were the first company to successfully use ice pigging on a large scale in the UK. Whilst it is more cost beneficial per meter cleaned than jetting/relining I refer you back to my earlier point - unless you change the constituents of your water it all comes back!
Hi Muthukrishna, I've asked one of our specialist about your problem, his reply :
This exercise is rather straightforward; the system need to be flushed out completely with ECA water to remove all bacteria / algae colonies. Thereafter, depending on project specifics a very basic dosing system (e.g. 1:500 - 1:1000) can be installed to deal with any originating / entered organics in the piping. The key is to utilise Electro Chemically Activated (ECA) water products, that is in a dis-equilibrium state, carrying a micro-charge of ±850 - 1200mV. This electrification component is the double-dose effective part over and above the chemical composition of ions in the ECA water (HOCl-, ClO2-, O3, etc). The effect is so dramatic on the mitochondrial DNA of the organism, that it is completely destroyed without any chance of building up any resistance to the chemical components.
The beauty of this solution is that once the contaminants have been dealt with, the ECA water relaxes back into an inert saline solution without any sort of chemical residue. Should any ions still be active in the water when consumed, it carries no health risk like other conventional poisonous chemicals do. Please see Material Data Safety Sheet attached.
To move forward; please send us a water analysis of the water in question - specifically identifying organics. We will then be able to calculate ECA volumes to address the severity of the case. If no analysis exists, we can assist. Please take care that the 2L+ sealed sample reaches us within 24hrs of sampling and that it is kept out of direct sunlight. Qualified SANS analysis takes a week and costs in the region of R6,000 depending on actual tests conducted. Our typical ECA system costs in the region of R95,000 + auxiliary equipment, if so required, and can effectively treat up to 20,000 litres per hour. Larger units are available. It is important to look at a holistic solution, as the contaminants need to be prevented (e.g restructured water system) in addition to being treated with the ECA dosing solution.
Please see attached Files and contact details for francois.
Published
by Matt Van Aardt, Live Project Development Trading - Owner
1 Comment
We are interested in going forward with ECA. Please do let us know the way forward and what test results are required to calculate ECA Volumes.
Dear Muthukrishna I have no practical experience of ice pigging. It was developed at the University of Bristol. An internet search will lead you to a Wiki entry where you can download their paper. YouTube also have a number of demonstration videos. Good Luck.
Published
by Robert Pitchers, WRc plc - Technical Consultant
Dear Muthukrishna In the absence of an effective chemical treatment, biofilms can only be prevented by removing nutrients that support their growth or having a low water temperature. The first approach is used in some European countries where drinking water is distributed without a residual. This concept is referred to as biostability and the availability of nutrients was expressed in terms of the assimilable organic carbon (AOC) or biodegradable dissolved organic carbon (BDOC). I had experience of AOC and it was generally accepted that an AOC of 10 microgrammes per L was necessary for biostability. It would be equivalent to a very good quality groundwater that is not under any direct influence from a surface water. The success of biostability depends on having very extensive treatment process capable of achieving significant nutrient removal and maintaining an intact distribution system. It would require significant upgrading to the capacity of an existing treatment works. Using temperature to prevent biofilms is not a practical option. A number of options are available to limit biofilm growth. Generally, smooth surfaces support less biofilm compared to the rough surfaces of corroded metal pipes; the latter have cracks and crevices that can provide a nice location for growth and protect organisms from potentially adverse conditions. The shorter the residence time of water the more likely is it possible to maintain an effective residual. Also, the higher the velocity, the greater the surface shear stress and the thinner the biofilm. Don’t ignore the contribution of sediments. They can offer a good surface for biofilms. Where they are found, sediment can be removed by flushing (water mains) and draining and cleaning treated water storage reservoirs). Devices (called "pigs") are sometimes used to mechanically scrape biofilms from pipe surfaces, although their success is open to question. Using crushed ice is viewed as a desirable option. Including a disinfectant will make cleaning more effective. Effective control of water treatment can help to reduce the amount of particles entering the network and so reducing the amount of sediment accumulation.
Published
by Robert Pitchers, WRc plc - Technical Consultant
1 Comment
Hi Robert, Thanks for your answer. How will crushed ice be useful in removing or controlling biofilm?
We have a product called Bio-Purge, produced in Québec, that is very effective to remove biofilm in Municipal distribution network, cooling towers, wells etc. Here is a brief description of it:
BD-2000 is biopenetrant specifically formulated to control the biofilm and reduce other biologic related problems in water systems. BD-2000 is a product approved by Health Canada and the Minister of the Environment of Quebec. It is made up of items Generally Recognized As Safe (GRAS) under the provisions of Title 21, Code of Federal Regulations (USA), Section 182, and is certified to meet the requirements of ANSI/NSF Standard 60-Drinking Water Chemicals-Health Effects. As such, it is accepted for potable use when administered within the guidelines of federal, state and local health and environmental agencies.
For more info's like case study, brochure, spec's & MSDS sheets, please, contact me at beauregardclaude@hotmail.com
Dear Sir, We have this unique product CDD5000 for 99% bio film removal, prevention and line sanitization with nominal operational cost. kindly contact me for more details. Regards, Swapnil Gujar. Marketing@SVS Aqua.com +91-9168012051
Interesting answers and comments. Working since 8 years on biofilm-related issues, scientific research and industrial approaches, I'm quite sure there is no universal solution for this problem. I can just underline the need of checking the effectiveness of the treatment you apply (you can trust your supplier, but checking is always a good choice!). For more info about biofilm growth monitoring and check of sanitation effectiveness: http://www.alvim.it
Magnetic polarization treatments reduces biofilm in pipes
Hello,
We have experienced very good results with our magnetic polarization treatment in pipes, primarly in internal networks like hospitals, but more recently in drinking water pipeline.
Our treatement is originally designed for reducing scaling via cristalization changes from calcite to aragonite (like talcum powder). But as we use the most powerful materials available (rare earth), we also noticed :
* permanent bacteria abatement in the device * biofilm destabilization in distributed water. This is due to a slight change of water surface tension which makes conditions unfavorable to biofilm The time scale is 3-4 months to measure biofilm decrease, which we do with ATP-Metry. We have installed devices on 'small to medium' drinking water networks, i.e. several tens of km / linear distribution (non looped) Don't hesistate to contact me if this seems relevant to you Florent PERRIN ARIONIC France
there are so many options are available for reducing the biogrowth in drinking water. cleanliness is the first step to control the biogrowth in drinking water. water source ,water distribution,water storage,water filteration should be clean as per drinking water guideline. i am sure disinfectants will be reduce.
Dear Muthkrishna - have you considered a low ozone dose. I was involved with developing the BiofoulControl project http://biofoulcontrol.com initially developed for off shore work but suitable for pipelines and similar projects.
Published
by Philip Page, Statiflo International Ltd - Director Business Development
Hello. Depending on the length of pipeline, you can use ultrasounds: no chemical, very low electric al consumption, easy installation, 0 maintenance... I can help you. Thanks