For the requirements of manufacturers and industrial norms, maintaining excellent water quality is crucial. The ability of water-borne microorganisms to survive and thrive in many conditions is widespread and diversified.
As a result, an uncontrolled water system runs the risk of harming patients or tampering with medication. Water must be purified to prevent interactions with other product components or pharmaceutical substances. Water must also be monitored and controlled microbiologically.
Let's look more closely at the microbiological problems in water and their reduction techniques.
Physico-chemical methods of water treatment
Chemical and physical water purification techniques supported by trustworthy technology, may often reduce contaminants to less than one part per million or more. These methods have assay sensitivity in the parts per billion range.
Since, the reverse osmosis (RO) system and pre-treatment equipment are particularly prone to contamination, thus, regular testing, cleaning, and maintenance are required to prevent bacterial accumulation.
What microbiological concerns exist in water?
Potable water from private water companies or municipalities is screened for germs, including Escherichia coli, enterococci, bacteria aeruginosa, and faecal coliforms, in addition to being monitored to make sure that levels of chemical contaminants stay within defined safety criteria.
If the bacteria in the water are not removed, they begin to collect, adhere to things, and form biofilms.
What are biofilms?
These are multispecies structures which are encased in an extracellular polysaccharide matrix. If left unchecked, biofilms can release bacterial populations into the water, resulting in protracted microbial colonisation. They also provide the bacteria with physical resistance and adhesion.
How are biofilms produced?
When bacteria adhere to a surface, they form microbial colonies called biofilms, which resemble slime. After joining together, bacterial cells release a polysaccharide called glycocalyx, which results in the formation of a biofilm (hydrated polymeric slimy matrices). The glycocalyx allows each bacterium to encase itself on the surface; as these organisms assemble, a biofilm forms.
Methods of biofilm formation
The methods by which biofilms are created are:
· Individual cells cover the surface (initial attachment).
· Permanent affixation.
· The link is established permanently and extrapolymeric materials are produced.
· Individual cells or clusters of cells are gradually released from the biofilm over time.
How to reduce microbiological contamination in water?
Commercial and industrial water filtration systems are susceptible to malfunctions, downtime, and production issues brought on by bacteria. Thankfully, there are many techniques to keep bacteria out of the water. They all require careful system oversight and meticulous preparation.
· Testing frequently
To ascertain whether or not there are any bacteria present, microbiologists might run an oxidase test. It investigates whether any CO2 gas generation is being caused by glucose. If the CO2 levels are lower than anticipated, bacterial contamination is highly likely.
· Thoroughly cleaning the water system's plumbing
A regular part of keeping a water treatment plant or a wastewater treatment plant functioning is disinfection. By employing a team, your industrial water filtration system may be thoroughly cleaned.
· Membrane toughness
Routine membrane cleaning in reverse osmosis purification systems can prolong membrane life, and assist prevent bacterial infection.
· Upkeep
To ensure that the water is going at the appropriate speed, check the water pump. In a water supply that moves slowly and lacks the required turbulence, bacteria can grow.
· Upkeep of the equipment
Upkeep of Pre-treatment Equipment
1: Input filters
The purpose of the backwash operation is to ensure that all debris, pollutants, and blocked slime are removed from the system, before they contaminate microorganisms.
2: Resin Tank
Due to the fact that direct sunlight encourages bacterial growth, the resin tank should be placed away from the sun.
3: Security Filter
The filter element of the security filter needs to be changed, if the difference in water pressure between the intake and output exceeds 0.06 MPA. The element filter should be changed every two to three months, depending on the water quality.
4: Ultrafiltration (UF) System Maintenance
To keep the sensitive membranes in the UF system free of bacteria, they must be cleaned periodically. However, the sterilizing process depends on whether the system is made to eliminate organic or inorganic contaminants, or a combination of both.
Cleaning UF Systems
The tubular membranes should be cleaned with a low and a high alkaline cleaning agent, at concentrations of 0.06 percent and 1 percent, respectively. The procedure, called clean in place (CIP), takes 40 to 60 minutes.
Chemical cleaning agents that can be used on membranes include caustics, chelating, and surfactant compounds.
Inorganic UF System Cleaning
The best cleaning solution for inorganic UF systems is citric acid at a concentration of 3%. Additionally, you can use nitric, hydrochloric, sulphuric, oxalic, and nitric acids.To remove any inorganic impurities, the cleaning process should take one to three hours.
5: Reverse osmosis system maintenance
The need for antibacterial cleaning of RO membranes will depend on the source of the pollution. Your RO membranes need cleaning or replacement if your water recovery rate is less than 70%.
The following steps are taken to prevent microorganisms from entering a RO Plant:
Concrete Flushing: Particles that have stuck to the membranes but not the feed side of the system, can be removed by flushing water out at very high rates.
Chemical cleaning:The membranes are immersed in chemicals when using this approach. The remaining bacteria are then flushed from the membranes to remove them.
Reverse Flushing:Reverse filtering is utilized to remove any germs that may have found a home in the membrane pores.
Design Principles for the Design of Pipe and Tanks
If pipes and tanks are poorly constructed or maintained, contamination can develop in them more easily, than in any other part of the water system.
The following general specifications apply to well-designed pipes:
1: Smooth internal surfaces are more conducive to the growth of microorganisms
It's important to fend off corrosion and avoid rouging (the development of iron oxide). Pipe joints and welds have the potential to disrupt smoothness as well.
2: Constant tank water flow and rapid piping flow
Speeds between one and two metres per second have been shown to be adequate. There are consequently fewer opportunities for germs to adhere to surfaces and form biofilms. In shear strains, microorganisms attach to surfaces ineffectively.
3: Avoid standing water by avoiding specific areas
Branch pipes should always be kept as brief as possible. The likelihood of contamination can also be reduced by using the proper drainage slope.
4: Prevent leaks
To prevent the ingress of airborne microorganisms, filters should be fitted on the air vents of storage tanks. It is even possible to hold them underneath a "blanket" of an inert gas, like nitrogen.
5: Distribution and storage in hot environments
Most manufacturers insist that the temperature of storage and delivery be kept above 65°C, since endotoxin-shedding biofilms are thought to pose substantial risks.
However, it should be kept in mind that for the majority of pharmaceutical formulation applications, 65 °C is too high a temperature. This means that user points often have some sort of cooling device.
Conclusion
In water-distribution systems, microbial adhesion will lead to the production of biofilms, which will aggravate water pollution, reduce potable water's visual quality, speed up pipe corrosion, and reduce microbiological safety because pathogen survival is improved.Therefore, microbial control is a priority for engineers, factory employees, and microbiologists.
At Netsol Water, we not only assist you in choosing the best water and wastewater treatment system for your needs, but also provide routine maintenance. If you have any questions regarding our services, or how to prevent bacteria in purification systems, please don't hesitate to contact our design head or send us an email.
