Leading environmental issue

Rapid industrial development and the diversified character of the world economy today have led to large volumes of different types of wastewaters. Also, hazardous waste disposal has become a leading environmental issue. Many industrial processes generate polluted wastewater that require necessary treatment to meet environmental regulations prior to discharge into receiving waters. 

The presence of the so-called heavy metals, eg, lead, cadmium, and antimony, iu traditional solders has become an important environmental issue owiag to concerns for health and safety. As a result, solders containing no lead and antimony such as tin—silver are finding a growing number of apphcations (Table 2). 

Vapor pressure. The vapor pressure at working conditions should preferably be low if an organic solvent is to be used. High vapor pressure for an organic solvent will lead to the emission of volatile organic compounds (VOCs) from the process, potentially leading to environmental problems. VOCs will be discussed in more depth later when environmental issues are considered. 

Vimpani GV, Wigg NR, Robertson EF, et al. 1985. The Port Pirie cohort study Blood lead concentration and childhood developmental assessment. Presented at Lead Environmental Health Current Issues, May, Duke University, Durham NC. 

Coke does not offer the same potential environmental issues as other petroleum products (Chapter 10 and above). It is used predominantly as a refinery fuel unless other uses for the production of a high-grade coke or carbon are desired. In the former case, the constituents of the coke that will release environmentally harmful gases such as nitrogen oxides, sulfur oxides, and particulate matter should be known. In addition, stockpiling coke on a site where it awaits use or transportation can lead to leachates as a result of rainfall (or acid rainfall) which are highly detrimental. In such a case, application of the toxicity characteristic leaching procedure... 

Antibiotic revolution has provided long and healthy life to people. The life expectancy has almost doubled. The increased population has caused many social problems in terms of food resources, environmental issues, employment, etc. To control these problems, population is required to be controlled. This has lead to the concept of family planning. Antifertility drugs are of use in this direction. Birth control pills essentially contain a mixture of S)mthetic estrogen and progesterone derivatives. Both of these compounds are hormones. It is known that progesterone suppresses ovulation. Synthetic progesterone derivatives are more potent than... 

The dehnition makes clear that development of new technologies, social structures, or whatever has to take into account economic and social issues (present generations) and long-term and large-scale environmental issues (future generations). Thus developments that have to lead to sustainability are limited and have to consider the idea that every human being must be able to fulfill his or her needs in a more or less equal way. 

The lack of a robust set of economic metrics to value hydrogen is another barrier that was mentioned. The measures used to value hydrogen (and other forms of energy) are rooted in a petroleum-based economy that does not necessarily reflect the actual costs of energy. The decisions that will lead to the incorporation of hydrogen into the energy mix will likely derive from dealing with security and environmental issues, none of which are adequately valued today. 

Photovoltaics also require significant research activity in the chemical sciences. Low-cost methods are required for producing solar-grade silicon for photovoltaic cells. Better solar cell materials are needed than the presently utilized amorphous silicon. These materials must be more efficient without the use of heavy metals such as cadmium, tellurium, indium, and lead, which present significant environmental issues. An understanding of the degradation process of photovoltaic cells is needed, as is an answer to why these materials lose their effectiveness after prolonged exposure to the sun. Finally, there is a need to develop catalysts for the efficient photochemical conversion of water. 

---