IISER Current Affairs - 2019
Category Wise PDF Compilations available at This Link
Indian Institute of Science Education and Research (IISER) in collaboration with private company has developed a new device-Arsenic Sensor and Removal Media to detect and remove arsenic content from water and make it safe and usable by households.
Arsenic Sensor and Removal Media
The device is very easy to use, very cost effective and anyone can use it to detect arsenic easily. It uses very simple and household detection sensing methodology. It is capable of sensing soluble arsenic (3) which cannot be easily detected and removed.
It can show immediate change in colour in arsenic contaminated water. It provides holistic approach in immediate detection of arsenic contamination levels from available water resources and thereafter produces arsenic-free potable water. It has high sensitivity as it can sense up to parts per billion (ppb) level compared to many currently available techniques which sense parts per million (ppm).
Arsenic is a natural component in the earth’s crust. It is widely distributed throughout the environment in the air, water and land. It is highly toxic in its inorganic form. Intake of soluble inorganic arsenic over long period can lead to chronic arsenic poisoning (arsenicosis), diabetes, cardiovascular diseases and cancer. WHO permissible limit of arsenic in groundwater is 0.1 mg per litre. . In India, it was revised recently by Bureau of Indian Standards from 0.05 mg/l to 0.01 mg/l. In India, Arsenic pollution big problem in Bengal and neighbouring states. In Bengal, there are 83 blocks in eight districts where groundwater is arsenic contaminated. Malda, Murshidabad and Nadia districts have higher levels of arsenic concentration.
Scientists from the Indian Institute of Science, Education and Research (IISER), Thiruvananthapuram have developed gelator that can suck up oil and congeal it.
The gelator is hydrophobic material that has property of oleilophilic (oil-loving) and takes up oil when it comes in contact with it. It can be used to recover marine oil spills with a simple, efficient and cost-effective method.
The gelator is developed using a cheap raw material mannitol and cellulose pulp through a one-step process. In this process the mannitol gets adsorbed on the cellulose fibre through hydrogen bonding. The adsorption process changes the cellulose matrix from being very hydrophilic (water-loving) to hydrophobic (water repelling).
The property of gelator to self-assemble to form micro fibres makes congealing of oil possible and the oil loses its fluidity and gets trapped within the entangled fibrous network to form a rigid gel. Gelation essentially turns the liquid oil into semi-solid and this allows congealed oil to be simply scooped out using a scoop or a sieve.
During the studies, it was found that the gelator was able to absorb and congeal 16 times its own weight of oil. Even, the absorbed oil can be recovered by applying pressure or fractionated by a simple distillation process.
Applications: Gelator can also serve as a more efficient, quick and cost-effective way for absorption of crude oil from the sea following marine spill. Unlike other alternatives, the gelator can be easily applied over oil-water mixture and no solvent is needed for spraying it thus making it environment friendly.