1 . Chinese scientists say they have developed a robotic fish that can remove microplastic particles from water environments. Researchers working on the project say the robots could help to clean up plastic pollution in oceans around the world.

The robotic swimmers are about 1.3 centimeters long. They are made of a soft chemical Compound. The robots are designed to absorb microplastics while moving through the water. The project was launched by a team at Sichuan University in southwestern China. The researchers said the robots have already performed well in shallow water and they plan to carry out more tests in deeper waters. The scientists reported their findings in a new study in Nano Letters. The publication comes from the American Chemical Society, a nonprofit organization supported by the U.S. Congress. The robotic fish were built to target microplastic particles, which are smaller than five millimeters. Studies have confirmed that microplastic pollution has been discovered in many natural environments. The material comes from the breakdown of manufactured plastic products and industrial waste.

The team said the robots can be controlled by light. Turning “a near-infrared light laser” on and off causes the fish’s tail to move back and forth, the American Chemical Society said. The robotic fish can swim up to 2.76 body lengths per second. The researchers said this is faster than most similar soft robots. Wang Yuyan was a member of Sichuan University’s research team. She told Reuters news agency that the small, lightweight robot is currently being used to collect microplastics for research purposes. But Wang added that the team plans to expand that use so the robot fish can remove larger amounts of microplastic waste from deep ocean areas. The fish can take in different kinds of microplastics and even repair itself when damaged, the researchers said. And if a robot fish is accidentally eaten by a real fish, it could safely digest the material, the team added. Wang said similar robots could be developed to be placed inside the human body to remove unwanted materials or disease.

3 . In the United Kingdom, coffee consumption is on the rise. But beyond just fueling Londoners as they make their ways to work, coffee is also fueling their buses while fighting climate change.

It is reported that London’s buses will soon be powered in part by a newly developed biofuel, one that mixes diesel (柴油) with oils removed from spent coffee grounds, to reduce carbon dioxide emissions (排放) from its bus transport system. Recycling technology firm Bio-Bean collects used coffee grounds from major coffee producers across the UK, and removes the oils from them. Then it’s mixed into B20 biodiesel, with 20% biofuel and 80% conventional diesel.

With B20, the buses don’t require any adaptions to run on it. Bio-Bean founder said that, if the UK could use all of the 500,000 tons of coffee waste it produced each year, it could power the city of Manchester for a year. London uses other biofuels to support its effort to cut emissions from its bus system. Coffee is just the latest source, joining used cooking oil and animal fat from meat processing plants, but those old coffee grounds have to go somewhere, and fueling the city’s labor force is preferable to sending them to a waste yard. Bio-Bean’s B20 is an easy way to save businesses money on waste removal, and using the biodiesel in buses cut carbon emissions by 80%.

Coffee waste is becoming an almost unlimited resource, considering London’s citizens alone create 200,000 tons of coffee grounds every year. As more and more Britons switch from tea to coffee, that number will only elevate. The use of coffee grounds as a biofuel source has the added benefit of improving air quality in the city but sadly, it does not give off the pleasant coffee smell one might expect.

4 . Erhai Lake in Dali city is the second largest freshwater lake of Yunnan province. It’s a famous attraction, as well as Dali’s main source of drinking water.

The lake used to be seriously polluted due to the rapid development of tourism and the local economy. Since 2018, local authorities have been building an environmental protection system for the lake, the Erhai Lake Ecological Corridor (生态廊道), to protect it from being polluted and to improve local ecosystem. The project contains five parts: a 129-km road around the entire lake, a pipe system to stop waste water flowing into the like, the removal of 1,806 families who lived within the protection area, the protection of the lake’s wetlands and ecosystem, and the construction of experimental fields for wetland research.

By the end of 2020, the road around the lake had been basically completed. A 12-km part of the Corridor has been open to the public for free since September 2020 for a test operation. The Corridor is described as a “pearl necklace” surrounding the lake, with the villages located along the shore of Erhai Lake being the “pearls”. These villages benefit from the project financially, as they are linked and gain access to transportation and tourism around the lake.

According to staff members of the project, the lake’s water quality has already improved a lot during the construction of the Corridor. More wild birds fly to the lake and there is less unwanted plants in the water. It is also providing a good sight-seeing place for both the city’s residents and foreign tourists.

6 . The government of Singapore has created a highly developed system that turns wastewater into drinking water. The system involves a network of tunnels and high-technology treatment centers.

Reused wastewater can now meet 40 percent of Singapore's water demand. The country's water agency says it expects to meet 55 percent of Singapore's water demand by the year 2060. Most of the water is used for microchip manufacturing centers and cooling systems in buildings. But some of it is added to the country's drinking water supplies. The system helps reduce ocean pollution, as only a small amount of the treated water is sent into the sea.

The United Nations estimates that 80 percent of the world's wastewater flows back into the oceans without being treated or reused. Singapore has few natural water sources. The island nation has long had to depend mostly on supplies from neighboring Malaysia.

Low Pei Chin is chief engineer of the water reclamation department of the Public Utilities Board. She told reporters with Agence France-Press, "Singapore lacks natural resources, and it is limited in space, which is why we are always looking for ways to explore water sources and stretch our water supply." One major plan is to "collect every drop" and "reuse endlessly," she added.

The Changi Water Reclamation Plant on Singapore's eastern coast is the main part of the country's recycling system. Parts of the water treatment center are underground. Wastewater enters the center through a 48-kilometer tunnel that is linked to sewers. The center contains a large system of steel pipes, tubes, tanks, cleaning systems and other machinery. It can treat up to 900 million liters of wastewater a day. In one building, a network of air flow systems has been put in place to keep the air smelling as fresh as possible. Waste that arrives at the plant goes through a cleaning process before powerful pumps send it flowing to areas above ground for more treatment.

There, the treated water receives additional cleaning. Bacteria and viruses are removed through highly developed cleaning processes and disinfected with ultraviolet radiation.

Singapore is also in the process of expanding its recycling system. The country will add another underground tunnel and a major water treatment center to serve the western half of the island. Officials expect work on the center to be completed by 2025. By the time the expansion is finished, Singapore will have spent about $7.4 billion on its water treatment systems.

Global warming is pushing the population on polar bears to     1     (it) limit. According to a new study, they could have     2     (few) than 100 years left before extinction.

Polar bears live by hunting seals in the Arctic Ocean, but as more and more ice     3     (melt) in that region, their habitat continues to shrink. Since amounts began to be     4     (precise) measured at the end of the 1970s, sea ice that lasts for more than a year in the Arctic has decreased at a rate of 13% per decade.

Studies show that     5     (decline) sea ice will lead to a reduction in polar bears. They will be unable to bear the effects of climate change over the next several decades, the scientists believe, and will be wiped out by 2100.

“What we’ve shown is that, first, we’ll lose the       6     (survive) of bear cubs. Although cubs will be born, the female bears won’t have enough body fat to produce milk     7     (bring) them along through the ice-free season,” said Dr. Steven Amstrup, chief scientist of Polar Bears International, to the BBC.

The study comes     8       a conclusion that, even in a situation     9     countries achieve a moderate reduction in greenhouse gases, several populations of polar bears will disappear. But Amstrup said, “The animal can still continue to survive if we have     10     urge to keep climate change little.”

8 . Margot doesn’t have a garbage can. It doesn’t need one because Margot simply doesn’t cause anything to get thrown away. The restaurant doesn’t allow any type of single use plastic. Margot, which opened last year, is one of the small but growing restaurants around the world aiming to avoid not only food leftovers, but also any garbage.

“Food waste has been increasing as an issue for restaurants over the last 10 years,” says Calvin Brown. He runs the Sustainable Restaurant Association. Based in the United Kingdom, the organization helps food business become more environmentally responsible. He says that food waste contributes to releasing the greenhouse gas, so there is strong motivation to reduce waste and help the environment.

In the USA, food waste and packing account for nearly half of the material sent to landfills. Restaurants from McDonald’s to Starbucks are addressing this issue with “no straw Mondays” and limits on single-serving plastic, but a handful of restaurateurs are trying to get rid of rubbish entirely. There’s also economic case to be made for waste reduction. One study shows that restaurants save seven dollars for every dollar invested in anti- waste methods.

Avoiding food waste is the first and perhaps most obvious challenge for sustainable restaurants. Doug McMaster, chef at Silo in London, only serves a set menu. This removes the worry that one particular item won’t sell well, and will spoil in the refrigerator. Compost (堆肥) is a necessity as well. Nolla (meaning “zero” in Finnish) in Helsinki, Finland is giving compost to its suppliers as well as its diners. Nolla also has food- tracking software more commonly used among corporate food service companies to keep track of what sells and what rots.

Sometimes restaurants call themselves environmentally friendly, but they might just be using the label. Calvin offers some pointers on what to look for to make sure a restaurant is truly committed to sustainability.