Hong Kong’s air quality getting worse

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Air pollution levels in Hong Kong were the worst ever last year, the South China Morning Post reported on January 10, a finding that may further undermine the city’s role as an Asian financial center as business executives relocate because of health concerns.

Worsening air quality in Hong Kong caused by vehicle emissions and industrial pollution from the neighboring Pearl River Delta is already forcing many in the financial community to move to Singapore.

Readings at three roadside monitoring stations in Hong Kong’s Central, Causeway Bay and Mong Kok commercial districts showed that pollution levels were above the 100 mark more than 20 per cent of the time, the newspaper said, citing the city’s Environmental Protection Department.

This was 10 times worse than in 2005, when very high readings were recorded only two per cent of the time, it said. The station in Central business district, home to the Asia head- quarters of global banks such as HSBC Holdings Plc and Goldman Sachs Group Inc, showed the worst figures, with excessive readings a quarter of the time, the report said. Hourly readings are taken at the roadside stations throughout the year on major pollutants such as respirable suspended particles and nitrogen oxides. A reading above 100 means at least one pollutant fails air quality objectives.        hongkong-air-pollution

Environmentalists renewed their calls for the immediate introduction of new air quality objectives, claiming that the government had deliberately delayed their introduction to ease the way for major infrastructure projects, the newspaper said.

The department blamed the figures on unfavorable weather conditions, worsening background, pollution and the number of aging vehicles on streets. The newspaper quoted the government as saying a number of measures were being considered to help improve air quality, and new air quality objectives would be discussed by Hong Kong’s legislature soon.

CO2 sucker could just clean the air

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Researchers in California have produced a cheap plastic capable of removing large amounts of carbon dioxide (CO2) from the air. Down the road, the new material could enable the development of large-scale batteries and even form the basis of “artificial trees” that lower atmospheric concentrations of CO2 in an effort to stave off catastrophic climate change.

These long-term goals attracted the researchers, led by George Olah, a chemist at the University of Southern California (USC) in Los Angeles. Olah, who won the 1994 Nobel Prize in chemistry, has long envisioned future society relying primarily on fuel made from methanol, a simple liquid alcohol. As easily recoverable fossil fuels become scarce in the decades to come, he suggests that society could harvest atmospheric CO2 and combine it with hydrogen stripped from water to generate a methanol fuel for myriad uses.

Olah and his colleagues also work on making cheap, iron-based batteries that can store excess power generated by renewable energy sources and feed it into the electrical grid during times of peak demand. To function, the iron batteries grab oxygen from the air. But if even tiny amounts of CO2 get into the reaction, it kills the battery. In recent years, researchers have come up with good CO2 absorbers made from porous solids called zeolites and metal organic frameworks. But they’re expensive. So Olah and his colleagues set out to find a cheaper alternative.

They turned to polyethylenimine (PEI), a cheap polymer that is a decent CO2 absorber. But it only grabs CO2 at its surface. To boost PEI’s surface area, the USC team dissolved the polymer in a methanol solvent and spread it atop a batch of fumed silica, industrially produced porous solid made from microscopic droplets of glass fused together. When solvent evaporated, it left solid PEI with a high surface area.

When the researchers tested the new material’s CO2-grabbing abilities, they found that in humid air each gram of the material sopped up an average of 1.72 nanomoles of CO2. That’s above the 1.44 nanomoles per gram absorbed by a recent rival made from aminosilica and among the highest levels of CO2 absorption from air ever tested, the team reported in the Journal of the American Chemical Society. Once saturated with CO2, the PEI-silica combo is easy to regenerate. The CO2 floats away after polymer is heated to 85 degree Celsius. Other solid CO2 absorbers must be heated to over 800 degree Celsius to drive off the CO2.