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Heptachlor, chemical formula C10H5Cl7, is an organochlorine compound that was used as an insecticide. It is one of the cyclodiene insecticides. [1] Heptachlor is a white to light tan waxy solid with a camphor-like odour. It is insoluble in water and soluble in xylene, hexane, and alcohol. [2] Heptachlor was used extensively in the past for killing insects in homes, buildings, and on food crops. These uses stopped in 1988. [3] Due to its highly stable structure, heptachlor can persist in the environment for decades. [1] It is readily converted to more potent heptachlor epoxide once it enters the environment or the body. [4]
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The carbon dioxide (CO2) produced when fossil fuels are burned is normally released into the atmosphere. Researchers working on synthetic fuels — also known as carbon-neutral fuels — are exploring ways to capture and recycle that CO2. At EPFL, this research is spearheaded by a team led by Professor Xile Hu at the Laboratory of Inorganic Synthesis and Catalysis (LSCI). The chemists have recently made a landmark discovery, successfully developing a high-efficiency catalyst that converts dissolved CO2 into carbon monoxide (CO) — an essential ingredient of all synthetic fuels, as well as plastics and other materials. The researchers published their findings in Science on 14 June. Replacing gold with iron The new process is just as efficient as previous technologies, but with one major benefit. “To date, most catalysts have used atoms of precious metals such as gold,” explains Professor Hu. “But we’ve used iron atoms instead. At extremely low currents, our process achieves conversion rates of around 90%, meaning it performs on a par with precious-metal catalysts.” “Our catalyst converts such a high percentage of CO2 into CO because we successfully stabilised iron atoms to achieve efficient CO2 activation,” adds Jun Gu, a PhD student and lead author of the paper. To help them understand why their catalyst was so highly active, the researchers called on a team led by Professor Hao Ming Chen at National Taiwan University, who conducted a key measurement of the catalyst under operating conditions using synchrotron X-rays. Closing the carbon cycle Although the team’s work is still very much experimental, the research paves the way for new applications. At present, most of the carbon monoxide needed to make synthetic materials is obtained from petroleum. Recycling the carbon dioxide produced by burning fossil fuels would help preserve precious resources, as well as limit the amount of CO2 — a major greenhouse gas — released into the atmosphere. The process could also be combined with storage batteries and hydrogen-production technologies to convert surplus renewable power into products that could fill the gap when demand outstrips supply.
On 26 June 2019, China Ministry of Environment and Ecology (MEE) released the Comprehensive Management Plan for Volatile Organic Compounds in Key Industries to strengthen the guidance on governance of VOCs. Recently, China issued several national standards to complete the management of VOCs. In particular, they provide more detailed regulations on VOCs emissions in some key industries. According to the MEE research, the emission of VOCs has become a major source of atmospheric and environmental pollution. VOCs are important precursors in the formation of PM2.5 particulates and ozone (O3). The new comprehensive management plan is expected to improve pollution control of VOCs in key industries and in key regions. Five major problems in the management of VOCs are pointed out in the plan, they are:
To deal with these problems, the plan provides the targeted control methods and requirements for major governance industries such as petrochemical, coating, packaging and printing, oil storage and gas station. The improvement of the overall treatment of VOCs in industrial parks is also mentioned in the plan, as well as the supervisory responsibilities of the relevant government departments in this operation. The five annexes of the program introduce the major monitoring areas, focused VOCs substances, as well as the requirements for record keeping, industrial enterprises governance points and the petroleum products storage, transportation and sales governance points. The main focuses of the entire process of VOCs emission from the source to the disposal are reflected in the last three annexes. Further information is available at: MEE Notice
