Water

Water - History of water treatment

In ancient Greek and Sanskrit (India) writings dating back to 2000 BC, water treatment methods were recommended. People back than knew that heating water might purify it, and they were also educated in sand and gravel filtration, boiling, and straining. The major motive for water purification was better tasting drinking water, because people could not yet distinguish between foul and clean water. Turbidity was the main driving force between the earliest water treatments. Not much was known about micro organisms, or chemical contaminants.

After 1500 BC, the Egyptians first discovered the principle of coagulation. They applied the chemical alum for suspended particle settlement. Pictures of this purification technique were found on the wall of the tomb of Amenophis II and Ramses II.

After 500 BC, Hippocrates discovered the healing powers of water. He invented the practice of sieving water, and obtained the first bag filter, which was called the ‘Hippocratic sleeve’. The main purpose of the bag was to trap sediments that caused bad tastes or odours.

In 300-200 BC, Rome built its first aqueducts. Archimedes invented his water screw.

Water - Aqueducts

The Assyrians built the first structure that could carry water from one place to another in the 7th century BC. It was 10 meters high and 300 meters long, and carried the water 80 kilometres across a valley to Nineveh. Later, the Romans started building many of these structures. They named them aqueducts. In Latin, aqua means ‘water’, and ducere means ‘to lead’. Roman aqueducts were very sophisticated pieces of engineering that were powered entirely by gravity, and carried water over extremely large distances. They were applied specifically to supply water to the big cities and industrial areas of the Roman Empire. In the city of Rome alone more than 400 km of aqueduct were present, and it took over 500 years to complete all eleven of them. Most of the aqueducts were underground structures, to protect them in times of was and to prevent pollution. Together, they supplied Rome with over one million cubic meters of water on a daily basis. Today, aqueducts can still be found on some locations in France, Germany, Spain and Turkey. The United States have even taken up building aqueducts to supply the big cities with water again. Many of the techniques the Romans used in their aqueducts can be seen in modern-day sewers and water transport systems.