Issue 14

Particle Size Optimisation of Sand to Improve Water Treatment Efficiency

More efficient treatment methods must be developed for ensuring the future availability of drinking water. The purpose of this project was to determine how particle size composition can be optimized to improve the performance of sand as a natural, inexpensive, sustainable water filtration media.
Calibrated sieves were used to selectively remove specific particle size fractions from all-purpose sand. Permeation times, together with pH and calcium concentrations of filtered water samples were used to prove that the water filtration rate of sand can be increased by 65% by removing the <150 micron particle size fraction (11.3% by weight), while maintaining pH buffering performance.

A Sense of Scale

From sub-atomic to Universal, the range of scale tends towards infinity – in both directions. It could be argued that the small can be imagined as our minds can attempt to grapple with the concept of nothing and then it is only a case of imagining something getting infinitesimally closer to that limit. Yet with large scale we become stuck – viewing from or within a constricted radius of planet Earth it is difficult to put scale into perspective. We quickly lose our ability to compare the large with the larger which soon appear to be both insignificantly small in comparison to the larger still. This article helps rebalance scale. What you once thought big, you\’ll think big no longer.

Uses of Hydrogen Peroxide

The human immune system largely depends on hydrogen peroxide to function – Lymphocytes located in the blood produce H2O2 and utilise its anti-bacterial properties to eradicate malicious bacteria in the blood stream. The body also produces it organically as a by-product of particular chemical processes, and it predominantly originates from the thyroid gland, lungs, and intestines.

The Aurorae

The Aurora Borealis and Aurora Australis are one of the world’s seven natural wonders and have left men in awe for generations. This article investigates the causes of The Aurorae, the causes of the different colours and investigates Auroras on other planets such as the Jovian Aurora on Jupiter.