On average, seawater in the world’s oceans has a salinity of approximately 3.5%, or 35 parts per thousand.

This means that for every 1 litre (1000 mL) of seawater there are 35 grams of salts (mostly, but not entirely, sodium chloride) dissolved in it.

Although a vast majority of seawater is found in oceans with salinity around 3.5%, seawater is not uniformly saline throughout the world.

The planet’s freshest (least saline) sea water is in the eastern parts of Gulf of Finland and in the northern end of Gulf of Bothnia, both part of the Baltic Sea. Read more

Some liquid crystals form monolayers on water surface. When compressed from sides, such films of monomolecular thickness can wrinkle like fabric on a flat, smooth table, pulled together with palms simultaneously from both sides. With increasing surface pressure, the wrinkles of the monolayer fold up and form subsequent layers. The research on new compounds at the Institute of Physical Chemistry of the Polish Academy of Sciences in Warsaw has resulted in the discovery of new mechanisms of multilayer formation that are responsible for creation of liquid crystal films with a structure that has never been observed before.

Jan Paczesny

After pouring on a water surface, liquid crystals can form ordered layers of monomolecular thickness. When such layers are compressed in their plane, they can form, under appropriate conditions, a film composed of three layers — a trilayer. It was supposed that from time to time even 5-layers may be formed. “The existence of 5-layers has not, however, been well documented. We managed to confirm their presence with high precision. Moreover, we observed 9-layers that until now were considered exclusively as research suggestions,” says Dr Andrzej Żywociński from the Institute of Physical Chemistry of the Polish Academy of Sciences (IPC PAS) in Warsaw. The research findings have been published in Chemistry — A European Journal. Read more

A simple method to convert waste glass into a material which can be used to remove pollutants from contaminated water has been developed by Dr Nichola Coleman from the University of Greenwich’s School of Science.

From left: Dr Nichola Coleman and Cameron Abercrombie, final year Chemistry student from the University of Greenwich. (Credit: Image courtesy of University of Greenwich)

Nichola Coleman, a Senior Lecturer in Materials Chemistry at the university’s Medway campus says: “The novelty of the research is that the glass can be recycled into something useful — nobody has previously thought to use waste glass in this way.” Read more

Water is a valuable resource. New technologies are making it easier to handle drinking water responsibly, purify wastewater effectively and even recover biogas and fertilizer.

Clean drinking water and basic sanitation are human rights. Yet almost 780 million of the world’s population still have no access to drinking water and some 2.6 billion people live without sanitary facilities. Water, though, is also an important economic factor: Today, agricultural and manufacturing businesses already use up more than four fifths of this precious commodity. And the demand for water continues to rise. The Organization for Economic Cooperation and Development (OECD) is expecting that by 2050, global water consumption will have risen by more than half. Some 40 percent of the world’s population will then be living in regions with extreme water shortages — 2.3 billion people more than today. Read more

New research by scientists at the University of Bristol has challenged one of the key beliefs in chemistry: that proteins are dependent on water to survive and function. The team’s findings, published this month in Chemical Science, could eventually lead to the development of new industrial enzymes.

Proteins are large organic molecules that are vital to every living thing, allowing us to convert food into energy, supply oxygen to our blood and muscles, and drive our immune systems. Since proteins evolved in a water-rich environment, it is generally thought that they are dependent on water to survive and function. Read more