NEW METHOD TO REMOVE TOXIC MERCURY FROM WATER
Scientists have developed a method(technique with electrochemical alloying) to efficiently clean water contaminated with toxic mercury.The method, described in the journal Nature Communications, works via extracting the heavy metal ions from water by encouraging them to form an alloy with another metal.The new method involves a metal plate — an electrode — that binds specific heavy metals to it. The electrode is made of the noble metal platinum, and through an electrochemical process it draws the toxic mercury out of the water to form an alloy of the two. In this way, the water is cleaned of the mercury contamination. The alloy formed by the two metals is very stable, so there is no risk of the mercury re-entering the water.One strength of the new cleaning technique is that the electrode has a very high capacity. Each platinum atom can bond with four mercury atoms.
The filtering works using electrochemistry — chemical interactions where electricity is used to move electrons from one atoms or molecule to another. Much like the positive and negative electrodes in a battery, a platinum electrode is dipped into the contaminated water as electricity is run through the electrode.
Platinum, which is a noble, unreactive metal under normal circumstances, forms an alloy with mercury atoms when electricity is involved in the process. The contaminated water gets progressively cleaner as more mercury from the water is taken up with the platinum to form an alloy. The alloy, being very stable, doesn’t allow mercury to re-enter the water.
LEARNING WITH TIMES
Mercury is a metallic element that occurs naturally in the environment.Mercury is one of the major causes of environmental damage and health problems worldwide. Mercury spreads very easily through nature, and can enter the food chain. Freshwater fish, for example, often contain high levels of mercury. According to the World Health Organization (WHO), mercury is one the most harmful substances for human health. It can influence the nervous system, the development of the brain, and more. It is particularly harmful for children and can also be transmitted from a mother to a child during pregnancy.it can also be quickly absorbed by the skin or lungs if inhaled. No amount of boiling can remove Mercury from water,Mercury can find its way into our water supply quite easily. The largest source of mercury in water supply is from discarded devices that contain the heavy metal being throw away without taking extra safety measures. Heavy metals can trickle into water bodies and spread over larger areas very quickly.
Elemental mercury is typically released from industrial processes, agricultural processes, household, commercial and medical products containing mercury, sewage discharge and sediment. Elemental mercury vapor may cause nervous system damage when exposed at high concentrations.
Inorganic mercury is found in batteries and is used in the chemical industry and it is produced from elemental mercury through the process of oxidation. Inorganic mercury is the most common form that is present in drinking water but is not considered to be very harmful to human health, in terms of the levels found in drinking water. However, kidney damage may result from exposure to inorganic mercury through other sources.
Organic mercury (primarily methyl mercury) is produced by specific bacterial organisms in surface waters that convert inorganic mercury into organic mercury, which is the form of mercury that poses a significant threat to human health. Methyl mercury is ingested typically by fish and bioaccumulates both in the tissues of fish and the humans that eat these fish. Large predatory fish can contain as much as 100,000 times more methyl mercury than the surrounding water medium. This form is rarely present in drinking water but is a very common contaminant in the tissues of fish and causes damage to the nervous system as well as teratogenesis. Both inorganic and organic mercury are considered to have a more detrimental effect on children due to the fact that both forms are more easily absorbed into their system.The international Minamata Convention is a global treaty to protect human health and the environment from the adverse effects of mercury.