contaminated

Decontaminating Drinking Water | Earth Wise

July 24, 2023 By EarthWise Leave a Comment

At least two billion people around the world often drink water that is contaminated with disease-causing microbes. Waterborne diseases are responsible for two million deaths each year, mostly among children under the age of five.

There are various ways to decontaminate water, including chemicals that can themselves produce toxic byproducts as well as using ultraviolet light, which takes fairly long to disinfect the water and requires a source of electricity.

Scientists at Stanford University and the SLAC National Accelerator Laboratory have recently invented a low-cost, recyclable powder that kills thousands of waterborne bacteria every second when the water containing it is exposed to ordinary sunlight. The discovery of this ultrafast disinfectant could be a tremendous benefit to the nearly 30% of the world’s population with no reliable access to safe drinking water.

The new disinfectant is a harmless metallic powder that works by absorbing both ultraviolet and high-energy visible light from the sun. It consists of nano-sized flakes of aluminum oxide, molybdenum sulfide, copper, and iron oxide. The key innovation is that when these four metallic ingredients are immersed in water, they all function together by reacting with the surrounding water and generating chemicals that quickly kill bacteria. The chemicals themselves don’t last long. They quickly break down in the water leaving completely safe drinking water.

The nontoxic powder is recyclable. It can be removed from water with a magnet. It can also be reused at least 30 times. Apart from its uses in less developed parts of the world, it could be valuable for hikers and backpackers who want to drink water from natural sources of unknown quality.

**********

Web Links

New nontoxic powder uses sunlight to quickly disinfect contaminated drinking water

Photo, posted February 27, 2013, courtesy of Petras Gagilas via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

More Plastic Pollution From The United States | Earth Wise

December 7, 2020 By EarthWise Leave a Comment

A new study published in the journal Science Advances has revealed that the United States is contributing far more to coastal plastic pollution than was previously believed. A previous study using 2010 data ranked the US 20th globally, in its contribution to ocean plastic pollution from mismanaged waste. The new study ranks the U.S. third among the world’s countries.

The largest contributor to the discrepancy is that the earlier study did not account for plastic scrap exports. Using plastic waste generation data from 2016 – which is the most recent global data available – the study’s authors calculated that more than half of all plastics collected for recycling in the US were shipped abroad. This amounts to over 2 million tons. Of this amount, some 88% went to countries struggling to effectively manage, recycle, or dispose of plastics, and between 15-25% was, in fact, low-value or contaminated, meaning that it was effectively unrecyclable. When all of these factors were taken into account, the researchers estimated that a million tons of US-generated plastic waste ended up polluting the environment. It just occurred beyond our own borders.

Overall, 2-3% of all plastic waste generated in the US – about a million tons – is either littered or illegally dumped into the domestic environment. When this is combined with the exported waste, the US is responsible for more than 2 million tons of plastic waste being dumped into the environment. About two-thirds of that ends up in coastal environments, where it is likely to enter the ocean by wind or through waterways.

The United States generates the most plastic waste of any country in the world. Unfortunately, we have been operating under the illusion that we were doing a pretty good job of dealing with it.

*********

Web Links

New Study Reveals United States a Top Source of Plastic Pollution in Coastal Environments

Photo, posted April 3, 2015, courtesy of Vaidehi Shah via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Pesticides And Food Insecurity

April 19, 2017 By EarthWise

A newly released report by the United Nations takes a strong stance against the use of industrial agrochemicals, saying that they are not necessary for feeding the world. The continued use of pesticides at the rate the world currently does in fact can have very detrimental consequences.