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绿色化学 Green Chemistry. 重庆师范大学 Chongqing Normal University. Chapter one Introduction. Exploit and effectively utilize natural resources: Explore the natural world, and find useful chemical substances not known before.
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绿色化学 Green Chemistry 重庆师范大学 Chongqing Normal University
Chapter one Introduction • Exploit and effectively utilize natural resources: • Explore the natural world, and find useful • chemical substances not known before. • Examine the chemicals found in plants and animals on land, in the sea. • Determine their structure and explore their function.
Chapter one Introduction Chapter one Introduction • 1.1Typical environmental problems • 1.2Indoor Pollutions • 1.3Health concerns • 1.4Towards Sustainable Development
Typical environmental problems • Global warming • Depletion of Ozone Layer • Air pollution • Acid rain • Siege Garbage • Water Pollution • Rapid reduction of living things manifoldness • Forest Destruction • Marine Pollution
Global warming is when the earth heats up (the temperature rises). It happens when greenhouse gases trap heat and light from the sun in the earth’s atmosphere, which increases the temperature. This hurts many people, animals, and plants. Many cannot take the change, so they die. Global Warming
Main Green House Gases • CO2, NOx, CH4, Halogenides, • methane, water vapor. Greenhouse gasses are gasses are in the earth’s atmosphere that collect heat and light from the sun. With too many greenhouse gasses in the air, the earth’s atmosphere will trap too much heat and the earth will get too hot. As a result people, animals, and plants would die because the heat would be too strong.
Global Warming • Human Activities are the origin of these effects: • Cooking, • Lighting, • Warming, • Transportation, • Industry.
Temperature changes • According to the 2007 Fourth Assessment Report by the Intergovernmental Panel on Climate Change (IPCC), global surface temperature increased 0.74 ± 0.18 ºC during the 20th century. Climate model projections summarized in the latest IPCC report indicate that the global surface temperature is likely to rise a further 1.1 to 6.4 ºC during the 21st century.
An increase in global temperature will cause sea levels to rise and will change the amount and pattern of precipitation, probably including expansion of subtropical deserts. Warming is expected to be strongest in the Arctic and would be associated with continuing retreat of glaciers, permafrost and sea ice.
Depletion of ozone layer • The ozone layer is located between 10 and 50 km above the Earth's surface and contains 90% of all stratospheric ozone. Under normal conditions, stratospheric ozone is formed by a photochemical reaction between oxygen molecules, oxygen atoms and solar radiation. • The ozone layer protects the Earth from the ultraviolet rays sent down by the sun.
Depletion of ozone layer • The main cause of ozone layer depletion is the increased stratospheric concentration of chlorine from industrially produced CFCs , halons and selected solvents. Once in the stratosphere, every chlorine atom can destroy up to 100 000 ozone molecules. The amount of damage that an agent can do to the ozone layer is expressed relative to that of CFC-11 and is called the Ozone Depletion Potential (ODP), where the ODP of CFC-11 is 1.
Depletion of ozone layer • The use of ozone consuming agents (ODS) • The developed countries used • 1986, 975.8 thousand ts • 1992, 424.1 thousand ts • decreasing amounts are used • Our country • 1986, 47.5 thousand ts • 1992, 102.7 thousand ts • 1993, 117.1 thousand ts • Several measures have been taken, and a decreasing amounts are expected
Depletion of ozone layer Consequences • increase in UV-B radiation at ground level: a one percent loss of ozone leads to a two percent increase in UV radiation. Continuous exposure to UV radiation affects humans, animals and plants, and can lead to skin problems (ageing, cancer), depression of the immune system, and corneal cataracts (an eye disease that often leads to blindness). Increased UV radiation may also lead to a massive die-off of photoplancton (a CO2 "sink") and therefore to increased global warming. • disturbance of the thermal structure of the atmosphere, probably resulting in changes in atmospheric circulation; • reduction of the ozone greenhouse effect: ozone is considered to be a greenhouse gas. A depleted ozone layer may partially dampen the greenhouse effect. Therefore efforts to tackle ozone depletion may result in increased global warming. • changes in the tropospheric ozone and in the oxidising capacity of the troposphere.
Air pollution is the introduction of chemicals, particulate matter, or biological materials that cause harm or discomfort to humans or other living organisms, or cause damage to the natural environment or built environment, into the atmosphere. Air pollution
Pollutants can be classified as primary or secondary: Primary pollutants are directly emitted from a process, such as ash from a volcanic eruption, the gas from a motor vehicle exhaust or sulfur dioxide released from factories. Secondary pollutants are not emitted directly. Rather, they form in the air when primary pollutants react or interact. About 4 percent of deaths in the United States can be attributed to air pollution.
Sulfur oxides (SOx) - SO2 is produced by volcanoes and in various industrial processes. Since coal and petroleum often contain sulfur compounds, their combustion generates sulfur dioxide. Further oxidation of SO2, usually in the presence of a catalyst such as NO2, forms H2SO4, and thus acid rain. Nitrogen oxides (NOx) - Nitrogen dioxide is the chemical compound with the formula NO2. This reddish-brown toxic gas has a characteristic sharp, biting odor. NO2 is one of the most prominent air pollutants. Carbon monoxide - is a colorless, odorless, non-irritating but very poisonous gas. It is a product by incomplete combustion of fuel such as natural gas, coal or wood. Carbon dioxide (CO2) - a colorless, odorless, non-toxic greenhouse gas associated with ocean acidification, emitted from sources such as combustion, cement production, and respiration.
Volatile organic compounds - In this field they are often divided into the separate categories of methane (CH4) and non-methane (NMVOCs). Particulate matter - Particulates, alternatively referred to as particulate matter (PM) or fine particles, are tiny particles of solid or liquid suspended in a gas. Persistent free radicals connected to airborne fine particles could cause cardiopulmonary disease. Toxic metals, such as lead, cadmium and copper. Chlorofluorocarbons (CFCs) - harmful to the ozone layer emitted from products currently banned from use.
Acid rainAcid rain is a rain or any other form of precipitation that is unusually acidic, i.e. elevated levels of hydrogen ions (low pH). It can have harmful effects on plants, aquatic animals, and infrastructure through the process of wet deposition. Acid rain is caused by emissions of sulfur dioxide and nitrogen oxides which react with the water molecules in the atmosphere to produce acids.
Garbage Siege Garbage siege is a more important problem for our Chinese people in current development stage. Beijing is already surrounded by garbage.
Water Pollution • Water pollution is the contamination of water bodies (e.g. lakes, rivers, oceans and groundwater). Water pollution occurs when pollutants are discharged directly or indirectly into water bodies without adequate treatment to remove harmful compounds.
Water pollution is a major global problem. It has been suggested that it is the leading worldwide cause of deaths and diseases, and that it accounts for the deaths of more than 14,000 people daily. An estimated 700 million Indians have no access to a proper toilet. Some 90% of China's cities suffer from some degree of water pollution, and nearly 500 million people lack access to safe drinking water. In addition to the acute problems of water pollution in developing countries, industrialized countries continue to struggle with pollution problems as well.
Living things manifoldness refers to the ensemble of all living creatures including plant, animals, micro-organism and other things. One kind of plant disappears every 27 year, and nearly 90 kinds of vertebrates (脊椎动物)become extinct. Rapid reduction of living things manifoldness
Rapid reduction of living things manifoldness • The speed of these reduction accelerates quite a few kinds of living things disappear before they are named. • Large amounts of genes lose. • No effective measure taken, human beings risk the challenge of being living in the used manner.
Forest Destruction • Forest • The lung of living things on the earth Have important ecological and economic values
Forest Destruction • 1 hectare of forest adsorbs 1t of CO2, and releases 0.73ts of O2, the later is sufficient for the breath of 1000 persons. • 10 m2 forest ⇨ one person
Forest Destruction • It is obvious that forest could: • conserve water resource, • keep water and soil, • prevent and fix the sand blown by the wind, • regulate the climate, • fix carbon and provide oxygen, • prevent pollution, purify the air, • Improve the environment, • protect species, • provide wood, etc..
Marine Pollution Marine pollution occurs when harmful effects, or potentially harmful effects, can result from the entry into the ocean of chemicals, particles, industrial, agricultural and residential waste, noise, or the spread of invasive organisms. Most sources of marine pollution are land based. The pollution often comes from nonpoint sources such as agricultural runoff and wind blown debris.
Red tide is a common name for a phenomenon more correctly known as an algal bloom (large concentrations of microorganisms), an event in which estuarine, marine, or fresh water algae accumulate rapidly in the water column and results in discoloration of the surface water. It is usually found in coastal areas.
Chapter one Introduction • 1.1 Typical environmental problems • 1.2 Indoor Pollutions • 1.3 Health concerns • 1.4 Towards Sustainable Development
Indoor pollutions • Indoor pollution • Indoor pollution is defined as "the presence of physical, chemical or biological contaminants in the air of confined environments, which are not naturally present in high quantities in the external air of the ecological systems." (Italian ministry for the Environment, 1991) • In the last thirty years much attention has been paid to reducing the outdoor pollution, but only recently has the international scientific community worried about reducing the contamination of the air of closed environments. If we consider the amount of time a person spends in a closed environment (90%) we will understand that the issue of indoor pollution is of primary importance.
Indoor pollutions • The main sources of indoor pollutants are: • construction materials • heating, air-conditioning devices, and cooking apparatuses etc. • furniture • coatings (wall paint, varnish, floors etc.) • maintenance and cleaning products (detergents, pesticides etc.)
Indoor Pollutions Ammonia (NH3): emitted from agricultural processes. Ammonia is a compound with the formula NH3. It is normally encountered as a gas with a characteristic pungent odor. Ammonia contributes significantly to the nutritional needs of terrestrial organisms by serving as a precursor to foodstuffs and fertilizers. Ammonia, either directly or indirectly, is also a building block for the synthesis of many pharmaceuticals. Although in wide use, ammonia is both caustic and hazardous.
Odors: such as from garbage, sewage, and industrial processes. Radioactive pollutants: produced by nuclear explosions, war explosives, and natural processes such as the radioactive decay of radon.
Chapter one Introduction • 1.1 Typical environmental problems • 1.2 Indoor Pollutions • 1.3Health concerns • 1.4 Towards Sustainable Development
Ancient Ways for a Long Life Not Feasible Meditation, Austerity, etc Pray for Supernatural Being Make pills of Immorality Seek for Special Medicine
Anti-senility prolong life New Medication For incurable diseases Modern Medical Science & Pharmacy Reduce side effect Avoid Residence Increase Curative effect Let’s see examples 医治不治之症 抗衰老 防残留, 升疗效 降低副作用
Chapter one Introduction • 1.1 Typical environmental problems • 1.2 Indoor Pollutions • 1.3 Health concerns • 1.4Sustainable Development
Sustainable Development Sustainable development (SD) is a pattern of resource use that aims to meet human needs while preserving the environment so that these needs can be met not only in the present, but also for generations to come (sometimes taught as ELF-Environment, Local people, Future). The term was used by the Brundtland Commission which coined what has become the most often-quoted definition of sustainable development as development that "meets the needs of the present without compromising the ability of future generations to meet their own needs."
Sustainable Development • In early 80, theory of sustainable development has been proposed. • In 1992, “Agenda of 21th Century” has been formulated. • The view point of sustainable development comes out from the traditional one. • 2004 • The view point of scientific development • The development of recyclable economy
Sustainable Development • A view point of industrial realization: • The symbol of development is the increment in industry. • The mark of modernization is industrialization and industrial civilization. • The goal and driven forces for development are GNP(GDP). • Irrespective of the protection and development of resources and environment. • The criteria marking development is unjust.
The field of sustainable development can be conceptually broken into three constituent parts: environmentalsustainability, economic sustainability and sociopolitical sustainability. A representation of sustainability showing how both economic and societal values are constrained by environmental limits. Scheme of sustainable development: at the confluence of three constituent parts.