Each glass of tap water contains 10mn 'good bacteria' from water pipes

When you drink a glass of tap water, you're ingesting around 10 million bacteria found in water pipes and purification plants. But don't worry – while it may seem utterly disgusting, the bacteria are actually good for you, according to a new study.

Researchers from Lund University in Sweden have discovered that bacteria and other microbes are found in the form of a thin, sticky coating in drinking water treatment plants and on the inside of water pipes.

Known as a 'biofilm,' the coating is inescapable because every surface involved in the process of getting drinking water to your tap is covered in it.

But according to the researchers, there's absolutely no need to worry. In fact, you should be happy – because they suspect a large part of water purification happens inside the pipes, and not only in purification plants.

"We suspect there are 'good' bacteria that help purify the water and keep it safe – similar to what happens in our bodies. Our intestines are full of bacteria, and most of the time when we are healthy, they help us digest our food and fight illness,” researcher Catherine Paul said.

Sedimentation Process

In Water Treatment Process Sedimentation is the process of removal of suspended particles that are heavier than water by gravitational settling. Most raw water will contain mineral and organic particles. The density of mineral particles is usually between 2000 to 3000 kg/m3 and can easily settle out by gravity. Organic particles, on the other hand, have densities ranging from 1010 to 1100 kg/m3and take a long time to settle by gravity. In conventional water treatment, coagulants are used to destabilize particle to form larger and settlable solids. The relevant terms with respect to sedimentation are:



Plain Sedimentation

refers to the separation of suspended particles from liquid by gravitation and natural aggregation of settling particles. Examples are settling of sand in filtration and the settling of grits, and sandy and silty particles in pre-sedimentationtreatment. Such particles  are usually greater than 10 μm in size.

WHO technical notes on drinking-water, sanitation and hygiene in emergencies

water treatment process
2011. World Health Organization / Water Engineering Development Centre

These four-page illustrated notes have been prepared to assist those working immediately or shortly after an emergency to plan appropriate responses to the urgent and medium-term water and sanitation needs of affected populations.
The notes are relevant to a wide range or emergency situations, including both natural and conflict-induced disasters. They are suitable for field technicians, engineers and hygiene promotors, as well as staff from agency headquarters.

from Water Sanitation and Health (WSH)

Download technical notes

• 1. Cleaning and disinfecting wells
  pdf, 943kb
• 2. Cleaning and disinfecting boreholes
  pdf, 899kb

Coagulation, flocculation & settling

Coagulation Process

in water treatment process Coagulation is the process that involves the addition of chemical coagulant(s) to reduce the repulsion forces between particles or the neutralization of the charges on the particles. Traditionally, metal salts such as aluminum sulfate or alum, ferric sulfate, ferric chloride, and ferrous sulfate have been utilized as coagulants. In recent years, polymers have been used in conjunction with, or in lieu of, metal salts to enhance the coagulation process.

Reverse Osmosis

water treatment process

Reverse Osmosis

in water treatment process,  RO ( Reverse Osmosis)  is one among Technic to produce pure water from certain quality source water.  Reverse Osmosis  is a modern process technology to purify water for a wide range of applications, including semiconductors, food processing, biotechnology, pharmaceuticals, power generation, seawater desalting, and municipal drinking water.

Historical development of reverse Osmosis

Research on Reverse Osmosis began in the 1950’s at the University of Florida where Reid and Breton were able to demonstrate desalination properties of cellulose acetate membrane. Loeb and Sourirajan continued the development of the RO technology with the creation of the first asymmetric cellulose acetate membrane.