Hotel Service Unit 14 Q4

Water, especially untreated or inadequately treated water, can harbor a diverse range of microorganisms, including:

1. Bacteria:

• Coliform Bacteria: A group of bacteria commonly found in the intestines of humans and animals, indicating fecal contamination. Some strains, like E. coli, can cause serious illness.
• Pathogenic Bacteria: These bacteria are capable of causing diseases. Examples include:
  • Salmonella: Causes food poisoning.
  • Shigella: Causes dysentery.
  • Vibrio cholerae: Causes cholera.
  • Legionella: Causes Legionnaires’ disease, a severe form of pneumonia.

2. Viruses:

• Enteric Viruses: These viruses infect the gastrointestinal tract and are transmitted through contaminated water or food. Examples include:
  • Norovirus: Causes gastroenteritis (stomach flu).
  • Rotavirus: A common cause of diarrhea in infants and young children.
  • Hepatitis A virus: Causes liver inflammation.

3. Protozoa:

• Parasitic Protozoa: These single-celled organisms can cause various illnesses. Examples include:
  • Giardia lamblia: Causes giardiasis, a diarrheal illness.
  • Cryptosporidium: Causes cryptosporidiosis, another diarrheal illness.
  • Entamoeba histolytica: Causes amoebiasis, a potentially serious intestinal infection.

4. Fungi and Algae:

• While not typically pathogenic, certain fungi and algae can cause problems in water systems:
  • Mold and Mildew: Can grow in damp environments and cause aesthetic issues, odors, and potential health concerns for people with allergies or sensitivities.
  • Algae: Can bloom in nutrient-rich water, causing discoloration, taste and odor problems, and potential toxin production.

Additional Points:

• Biofilms: Microorganisms can form biofilms, which are slimy layers attached to surfaces. Biofilms can harbor various types of microorganisms, including pathogens, and protect them from disinfectants.
• Water Source: The types of microorganisms present in water depend on the source. Surface water (rivers, lakes) is more likely to contain a variety of microbes, while groundwater may have lower levels of contamination.
• Treatment Effectiveness: The presence and concentration of microorganisms in treated water depend on the effectiveness of the treatment process. Filtration, disinfection, and other treatment methods are employed to remove or inactivate harmful microbes.

It’s important to note that not all microorganisms in water are harmful. Many are harmless or even beneficial, playing roles in natural ecosystems. However, the presence of pathogenic microorganisms poses a significant risk to human health and necessitates proper water treatment and disinfection to ensure safe drinking water and prevent the spread of waterborne diseases.

A Silver Ion Sterilizer operates on the principle of oligodynamic effect, which is the biocidal effect of certain metals, especially silver, in low concentrations. It releases silver ions (Ag+) into the water, which disrupt the cellular functions of microorganisms, leading to their inactivation or death.  

1. Oligodynamic effect – Wiki

2. Silver Ion (Ag+) Technology: What Is It and How It Stops Bacteria and – The Kare Lab

Here’s a breakdown of its operation:

1. Silver Electrodes:

• The sterilizer consists of two silver electrodes (usually made of high-purity silver, 99.99%) housed in an electrode chamber.   1. Silver Ion Sterilizer – Separator Spares & Equipment Llc separatorequipment.com
• The water to be sterilized flows through this chamber, passing between the two silver plates.   1. Silver Ion Sterilizer – Separator Spares & Equipment Llc separatorequipment.com

2. Electrolysis:

• A controlled direct current (DC) is applied to the silver electrodes.   1. Silver Ion Sterilizer – Separator Spares & Equipment Llc separatorequipment.com
• This causes the silver atoms to lose electrons and become positively charged silver ions (Ag+).   1. Passing direct current through silver and copper electrodes that are… – ResearchGate www.researchgate.net
• These silver ions are released into the flowing water.   1. Silver Ion Water Treatment | UV Guard uvguard.com

3. Antimicrobial Action:

• The silver ions interact with the cell membranes and internal structures of microorganisms like bacteria, viruses, and fungi.   1. Silver. A powerful weapon against microbes – Corporate – Coloplast www.coloplast.com
• Multiple mechanisms are believed to contribute to the antimicrobial action:
  • Disruption of Cell Membranes: Silver ions can bind to and damage the cell membranes, causing leakage of cellular contents and eventually cell death.   1. Microampere electric currents caused bacterial membrane damage and two-way leakage in short time | bioRxiv www.biorxiv.org
  • Interference with DNA Replication: Silver ions can interact with bacterial DNA, inhibiting its replication and preventing cell division.   1. Silver. A powerful weapon against microbes – Corporate – Coloplast www.coloplast.com
  • Inhibition of Enzyme Activity: Silver ions can bind to and inactivate crucial enzymes involved in microbial metabolism, disrupting cellular processes.   1. 2 Silver is a bifunctional molecule. At lower concentration the enzyme… – ResearchGate www.researchgate.net

4. Residual Disinfection:

• A key advantage of silver ion sterilization is its residual effect.   1. What are the Problems with Silver as a Disinfectant? – Oxyl-Pro www.oxylpro.com
• Silver ions remain active in the water for a certain period, providing ongoing disinfection and preventing the regrowth of microorganisms within the system.   1. Silver Ionisation Disinfection System – UV Guard uvguard.com

Control and Monitoring:

• Flow Rate Control: A flow switch or flow meter may be integrated to ensure the water passes through the sterilizer at the appropriate rate for effective disinfection.   1. Silver Ion Sterilizer – Separator Spares & Equipment Llc separatorequipment.com
• Current and Time Control: The amount of silver ions released depends on the applied current and the contact time with the water. The sterilizer may have controls to adjust these parameters based on water flow rate and desired silver concentration.   1. Silver Ion Sterilizer – Separator Spares & Equipment Llc separatorequipment.com2. JOWA Ag-S – Silver Ion Steriliser jowa.com
• Silver Ion Concentration Monitoring: Some advanced sterilizers may have sensors to monitor the silver ion concentration in the treated water, ensuring it remains within the effective and safe range.

Advantages:

• Effective against a wide range of microorganisms.
• Long-lasting residual disinfection.
• Tasteless and odorless.
• No harmful disinfection byproducts.
• Relatively simple and low-maintenance technology.

Disadvantages:

• Slower disinfection rate compared to chlorine.
• Limited effectiveness against certain microorganisms (some protozoa and spores).
• Potential for silver accumulation in the environment if not properly managed.

In summary, a Silver Ion Sterilizer offers a chemical-free alternative to chlorine for water disinfection on ships. By releasing silver ions into the water through electrolysis, it effectively kills or inactivates microorganisms, providing long-lasting protection against contamination.  

1. Silver Ion Sterilizer – Separator Spares & Equipment Llc

2. Silver Ion Water Treatment – UV Guard – Water Disinfection and Chemical Free Water Treatment