Environmental issues, laboratory

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). 

High school students should have a greater understanding of global environmental issues. This can be accomplished by using environmentally-relevant examples to teach high school chemistry. Appropriate demonstrations and laboratory experiments that illustrate these topics are suggested. To incorporate additional environmental chemistry in die secondary curriculum, help from environmental scientists will be needed. 

Welch et al. evaluated analytical procedures and environmental issues. They investigated methods for the extraction and detection of cocaine, some of its metabolites, morphine, and codeine from hair. They concluded from a round-robin study that extractions with 0.1 ATHCL are as efficient to remove the target compounds from hair as enzymatic digestion that dissolve the hair. GC/MS with either El or Cl provides accurate determinations of the targeted compounds. External contamination by powdered or vapor-deposited cocaine was incompletely removed by all approaches tested, making it difficult to differentiate incorporated drug from external contamination. This was also proved in extensive laboratory experiments by Wang and Cone. ... 

The oxidative-reductive transmetallation can be carried out with organometallic reagents that have a reduction potential more positive than magnesium ( — 2.375 V). Since these reactions are typically carried out with organomercury derivatives, there is a major environmental issue with formation of Hg , resulting in this method rarely being used, even in the laboratory. 

The 1970s had opened with the first oil crisis. This geopolitical event made political leaders seek alternative energy sources. The chemical profession followed the money. Since grants were awarded for work on alternative energy sources and environmental issues, chemists started work in such areas. They became environmentally conscious (Baird 1995) and started cleaning-up their operation, whether in industrial plants or in academic laboratories. Everybody became safety-conscious, and pollution of the environment became drastically curtailed (Ember 1991, Rodrick 1992, McGinn 2000). 

Radionuclide analysis methods are published in analytical chemistry and radiochemistry journals, and in methods manuals issued by nuclear facilities such as government laboratories. For example, the Environmental Measurements Laboratory Procedures manual, HASL-300 (Chieco 1997), is an excellent source. Standard methods for radionuclide analysis (see Section 6.7) are available, and should be used whenever appropriate. If conditions differ from those to which published methods have been applied, radionuclide recovery and decontamination must be tested and additional process steps may have to be inserted. 

The cornerstone of a sound program for prudent laboratory practices is a process designed to comprehensively review the operations and potential hazards associated with each experiment over its life cycle. This review should take place before any work is conducted. The diverse nature of research and development activities makes it advisable to have such a process in place as part of the scientific method of experimentation. In laboratories where this preliminary survey is routinely practiced, it has proved to be useful in both the maintenance of safe laboratory operations and the minimization of chemical exposure and waste generation. Because of the diversity of types of researchers and laboratory work, such processes— both formal and informal—can help individuals associated with new, modified, or unfamiliar experiments or procedures to plan and work safely, responsibly, and productively. By first evaluating the work area, materials, equipment, and procedures in depth, hidden hazards may be identified and addressed. The pre-experiment review process can also help to ensure that every experiment and laboratory operation complies with all applicable laws, regulations, and other policies. Moreover, by addressing all relevant health, safety, and environmental issues when an experiment is first conceived, further research, scale-up, or development based on it can be made safer and more effective. 

The matrices and elements that are studied target international trade, health, environmental issues, or politics that are associated with between country issues, and where possible are drawn from real-life samples. Laboratories are given the freedom to choose the method, measurands, or components that are relevant to their interests, and are encouraged to use their routine measurement methods. Usually, each laboratory is asked to report, as well as the value of the measurand, an expanded measurement uncertainty within which the value of the quantity being measured is claimed to be with a stated probability. The laboratories are also asked to indicate the method used, whether or not they consider themselves to be expert in the analysis, and to what guides or standards they may be accredited. As with any interlaboratory proficiency study full anonymity of the laboratories is guaranteed. 

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