Environmental issues

Comments on environmental issues appear regularly in the media. Often these quote arguments in favour of or against some theory concerning the environment. First, what is the environment A popular definition is everything around me plus me. Apart from natural catastrophes such as earthquakes and asteroids hitting Earth, the major long-term problems with our environment can be traced to human activities. 

Following the industrial revolution and towards the middle of the 20th century after the Second World War, it became apparent that the lifestyle of the human race could not continue in the same way indefinitely. The planet could not take the prevailing rate of resource consumption and pollution. Politicians worldwide had to take some action. Either that or the human race would need to find another planet to inhabit and pollute. 

The environment is effectively a balance between the three media of atmosphere, soil and water. They co-exist and sustain our lives. Improvements designed to protect one can actually make matters worse for another. The underlying principle of the Design for the Environment with its environmental impact indices is to achieve a proper balance between sustainable development and economic growth. 

Carbon dioxide 1 Fossil fuels, deforestation, road vehicles, forest fires 

Methane 10 Agriculture, natural decay of vegetation, landfill 

At the risk of excluding many key environmental issues, the following are singled out as being closely related to the design and operation of chemical processes. 

Burning of Fossil Fuels for Power Generation and Transportation 

Another point to keep in mind is that public consciousness and concern about environmental issues tends to wax and wane. Superimposed on this cyclic pattern, however, is a general trend towards increasing expectations for cleanliness of air and water, and maintenance of natural resources. The revived interest in sustainable development, fueled by increasing petrochemical prices (until recently) and increasingly by concerns about global climate change, is very much part of this overall trend. 

We will first discuss solid waste-related environmental concerns, including recycling, and then turn briefly to other environmental concerns with impacts on plastics packaging. 

Since 1980 the nitrogen industry has made major improvements in environmental controls to reduce the release of atmospheric emissions and liquid effluents. Some of the environment issues for specific nitrogen products are summarized below. Other environmental issues will be discussed in the chapters devoted to the specific nitrogen products. 

The primary pollution problem in nitric add manufacture is the abatement of nitrogen oxides (NOx) in tail gases. In the United States in 1998, gaseous emissions from newly constructed nitric add plants must be limited to 1.5 kilograms of NOx per tonne of nitric add (100% basis) produced, with a maximum stack opacity of 10%. Modern add towers, with extended sections, can reduce NOx emissions to less than 200 parts per million35. Production of ammonia also involves the combustion of hydrocarbons so NOx abatement must also be addressed for this product as well. 

So what are nitrogen oxides Where does they come from And why is there a concern about the amount that enters the atmosphere Nitrogen dioxide (NO2) is a brownish, highly reactive gas that is present in all urban atmospheres. N02 can irritate the lungs, cause bronchitis and pneumonia, and lower resistance to respiratory infections. Nitrogen oxides are an important precursor both to ozone (Oj) and acid rain, and may affect both terrestrial and aquatic ecosystems. The major mechanism for the formation of NO2 in the atmosphere is the oxidation of the primary air pollutant, nitric oxide (NO). NOx plays a major role, together with VOCs (Volatile Organic Compounds), in the atmospheric 

In September, 1998 the United States Environmental Protection Agency (EPA) issued a rale (known as the NOx SIP Call) that required 22 states and the District of Columbia to submit State Implementation Plans (SIP s). These SIP s would reduce emissions of nitrogen oxides (NOx) - compounds that react with other chemicals in the atmosphere to form ozone (or smog). EPA required these reductions after determining that NOx and ozone are transported by the wind to downwind states, which results in unhealthy air quality in the downwind states156. 

The original EPA rule required that NOx reductions be in place by May, 

The chemical industry manufactures a very large number (-30,000) of products through a variety of processes using fossil fuel as the source of carbon. The future of the chemical industry will be greatly influenced by three main environment-related issues. First, many chemicals and commonly used organic solvents are toxic and hazardous and may have a long-term detrimental effect on the environment. Consequently, minimum use or total avoidance of such chemicals is desirable. The use of volatile organic chemicals (VOCs) as solvents, for example, must be minimized or avoided wherever possible. 

Second, in the manufacture of many chemicals, unwanted side products are generated. As an example, consider reaction 1.6.1, a common method for making a carboxylic acid. 

In an industrial process, the ammonia generated in this reaction is neutralized with an acid such as H SO. The net result is the generation of a large amount of ammonium sulfate and bisulfate, which are unwanted solid wastes. 

Nitrous oxide and chlorinated fluorocarbons (CFCs) are also ozone depleters. As the ozone layer in the earth s atmosphere screens out the harmful part of ultraviolet radiation in sunlight, ozone depletion is a matter of serious concern. The chemical industry must therefore look 

The strategy for resolving the environmental issues mentioned earlier has been outlined in detail, in what is known as the 12 principles of green chemistry. In the context of homogeneous catalysis, these principles emphasize the need for the use of catalysts rather than stoichiometric reagents for the minimization of waste. They also underline the importance of biodegradable products, renewable raw materials, and the use of innocuous solvents rather than VOCs. 

Ever since Rachel Carson drew attention to the adverse environmental effects of some pesticides in her book Silent Spring in 1962, there has been a growing concern and awareness of environmental issues. The environmental movement has grown very rapidly in recent years and this is evident from the establishment and rapid growth of the Green political parties in countries like Germany and the U.K. It is therefore appropriate to examine the position of the chemical industry with regard to the environment since a number of the problems have been laid at the former s doorstep. 

Let us now briefly look into several major environmental problems/ disasters which clearly are associated with the chemical industry. 

In principle, a significant reduction in the energy related impact on the environment is being achieved, if non-fossil hydrogen be substituting conventional fuels. There are no emissions of carbon oxides, hydrocarbons, dust or ash, heavy metals, lead compounds, or SO2. Some environmental risks are left concerning, e.g., gas emission during combustion or the establishment of the infrastructure. 

An antimicrobial class comprises compounds with a related molecular structure and generally with similar modes of action. Variations in the properties of antimicrobials within a class often arise as a result of the presence of different sidechains of the molecule, which confer different patterns of PK and PD behavior on the molecule. The major classes of antimicrobial drugs are discussed below. 

Everywhere the production, application, and disposal of lubricants has to cover the requirements of the best possible protection of our nature and environment in general and of the living beings in special. 

Intervention of man in groundwater regimes is intensive in densely populated areas, and quality deterioration is manifold examples being 

Marcel Dekker, Inc. 270 Madison Avenue, New York, New York 10016 

The common thread in these water deterioration processes is their being cases of intermixing of natural waters of different qualities or mixing of uncontaminated water with contaminated effluents. Hence the need (1) to be familiar with the methodology of mixing identification and reconstruction of the properties of the involved end members (section 6.7) and (2) the establishment of initial databases (section 18.3). 

Exercise 1.1 All the rivers flow into the sea... is written in Ecclesiastes. This remarkable observation was made more than 2000 years ago. What is remarkable about it Which basic concepts of hydrology is it describing  

Exercise 1.2 ... and the sea does not fill up continues Ecclesiastes. The ancient observer raises a fundamental research problem—he draws attention to what seems to be a violation of a universal law, which he must have known. Which law is it  

Alternatively, extensive hooding and a high level of ventilation is necessary to capture blows in most situations, but carries the cost of a high volume of gas to be moved and filtered. 

Apart from the furnace top there are a number of points of fume emission such as from tapping operations as well as high lead dust from raw materials handling operations, which aU require extensive ventilation to capture such emissions. 

As indicated in Chapter 4, sinter contains between 1.0 and 2.0 per cent sulfur and typically 1.7 per cent for a lead content of around 45 per cent. This is the major input of sulfur to the blast furnace, although coke can contribute of the order of five per cent of the total sulfur supply. 

The sulfur content of blast furnace bullion is around 0.5 per cent and slag around 1.5 per cent. The remaining sulfur reports to furnace off-gases. Some may be captured as a basic lead sulfate in fume, which is recycled to the sinter plant, otherwise the remainder reports as SO2 in filtered off-gases and is normally discharged to attnosphere. 

Equilibrium conditions at the base of the furnace would suggest that the SO2 partial pressure should be of the order of 10 to 10 atmospheres. Consequently the sulfur content of the gas stream from the base of the furnace should be negligible and sulfur will be captured in the bullion and in slag. It follows that the presence of SO2 in furnace exit gas results from reaction higher in the shaft, probably the decomposition of sulfate according to Equation 5.10 and the reaction between volatilised PbS and PbO according to Equation 5.11. 

The federal government s passage of the Clean Air Act in 1970 set national limits on industrial emissions to reduce air pollution and acid rain. Since 1970, the Clean Air Act has been amended and some states, such as California, have set even stricter limits on several of these emissions. Therefore, a major point of emphasis when designing a hydrogen plant is the reduction of plant emissions. A typical hydrogen plant has three sources of emissions 1) Flue gas from the combustion chamber of the reformer 2) Condensate from the process and 3) Wastewater from the steam generation system. 

It is difficult to describe a detailed degradation pathway for lignosulfonates for several reasons. Firstly, the chemical structure of lignosulfonates is complex, which complicates a mechanistic understanding of the degradation process. Secondly, lignin and 

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The operations group will develop general operating and maintenance objectives for the facilities which will address product quality, costs, safety and environmental issues. At a more detailed level, the mode of operations and maintenance tor a particular project will be specified in the field development plan. Both specifications will be discussed in this section, which will focus on the input of the production operations and maintenance departments to a field development plan. The management of the field during the producing period is discussed in Section 14.0. 

Accurate, precise isotope ratio measurements are used in a variety of applications including dating of artifacts or rocks, studies on drug metabolism, and investigations of environmental issues. Special mass spectrometers are needed for such accuracy and precision. 

Rayon is unique among the mass produced man-made fibers because it is the only one to use a natural polymer (cellulose) directly. Polyesters, nylons, polyolefins, and acryflcs all come indirectly from vegetation they come from the polymerization of monomers obtained from reserves of fossil fuels, which in turn were formed by the incomplete biodegradation of vegetation that grew millions of years ago. The extraction of these nonrenewable reserves and the resulting return to the atmosphere of the carbon dioxide from which they were made is one of the most important environmental issues of current times. CeUulosic fibers therefore have much to recommend them provided that the processes used to make them have minimal environmental impact. 

In the area of municipal and iadustrial wastewater treatment, the principal environmental issue is the toxicity of residual flocculating agents ia the effluent. Laboratory studies have shown that cationic polymers are toxic to fish because of the iateraction of these polymers with giU. membranes. Nonionic and anionic polymers show no toxicity (82,83). Other studies have shown that ia natural systems the suspended inorganic matter and humic substances substantially reduce the toxicity of added cationic polymer, and the polymers have been used successfully ia fish hatcheries (84—86). Based on these results, the EPA has added a protocol for testing these polymers for toxicity toward fish ia the presence of humic acids (87). The addition of anionic polymers to effluent streams containing cationic polymers to reduce their toxicity has been mentioned ia the patent Hterature (83). 

Eoams play important roles in environmental issues, both beneficial and detrimental. 

Evaluations of fuel resources or total fuel supply focus on critical economic and environmental issues as well as existence. These issues include avadabihty, utilisation patterns, environmental consequences, and related economic considerations. 

Shale Oil. In the United States, shale oil, or oil derivable from oil shale, represents the largest potential source of Hquid hydrocarbons that can be readily processed to fuel Hquids similar to those derived from natural petroleum. Some countries produce Hquid fuels from oil shale. There is no such industry in the United States although more than 50 companies were producing oil from coal and shale in the United States in 1860 (152,153), and after the oil embargo of 1973 several companies reactivated shale-oil process development programs (154,155). Petroleum supply and price stabiHty has since severely curtailed shale oil development. In addition, complex environmental issues (156) further prohibit demonstration of commercial designs. 

Although ASTM specifies certain quaUty levels, there are a number of factors that contribute to other quaUty levels in the marketplace. At times, government regulations are more restrictive than ASTM specifications, especiaHy with respect to environmental issues. Secondly, competitive forces may encourage companies to provide fuel quaUty that is better than that defined by ASTM. Thirdly, ASTM specifications do not have the force of law, and certain companies may decide to exceed or not meet their recommended values. In response to this last factor, some states have adopted ASTM fuel quahty specifications as state regulations, thus forcing a minimum quaUty level in the field. 

Environmental Issues. Hydrothermal energy, recognized as one of the clean power sources for the twenty-first century, is not entirely free of environmental problems. 

California land-use regulations and growth control Latin American environmental initiatives environmental issues, acid rain, recycling, greenhouse effect... 

California environmental law pesticides, chemicals, biotechnology chemicals, pesticides, ha2ardous wastes state international environmental issues chemistry, pesticides, environment environmental poHcy pollution, waste management U.S. environmental regulations... 

New plant constmction will bring iacreased capacity to a level which will depend on real growth to keep sales abreast with production. It is anticipated that consoHdation of ownership will continue and that the trend to specialized busiaesses supporting a plant faciUty will also continue. Pressures from environmental issues could change the cost of final products as well as mandate the use of post-consumer waste resia as feedstock for production. 

Gas purification processes fall into three categories the removal of gaseous impurities, the removal of particulate impurities, and ultrafine cleaning. The extra expense of the last process is only justified by the nature of the subsequent operations or the need to produce a pure gas stream. Because there are many variables in gas treating, several factors must be considered (/) the types and concentrations of contaminants in the gas (2) the degree of contaminant removal desired (J) the selectivity of acid gas removal required (4) the temperature, pressure, volume, and composition of the gas to be processed (5) the carbon dioxide-to-hydrogen sulfide ratio in the gas and (6) the desirabiUty of sulfur recovery on account of process economics or environmental issues. 

Larger environmental issues are associated with the manufacture of wet-process acid and elemental phosphoms, than with the manufacture of technical- or food-grade acids and salts from these raw materials. In the manufacture of both wet acid and phosphoms, the 2 5 recovered may... 

Over time, finish components tend to separate and migrate within the fiber and throughout the yam package. With nylon, the ionic emulsifiers and antistats tend toward the core of the fiber whereas the hydrocarbon lubricants remain on the surface. It is, therefore, essential to scour yams and fabrics at neutral to basic pH to reemulsify the lubricant and remove the finish emulsifier prior to dyeiag. In formulating any new finish, environmental issues such as biodegradabihty, water and air pollution must be considered (137). 

Because of their initial commercial success and the industry s growing awareness of environmental issues, soHd acid catalysts are expected to ultimately replace Hquid acid catalysts. Several pubHcations describe the use of soHd acid catalysts for the production of cumene and detergent alkylates (62,85-87,109). 

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