Academic literature on the topic 'Pollution dissoute'

The aquatic sciences have their share of scientific controversies. In some cases the controversy is the classic situation of economic benefit versus environmental protection; in other cases it involves “genuine” scientific debate over uncertainties of the science or debate over what management option is optimal. This chapter discusses two pollution cases that pit scientists from universities or government agencies against those supported by the industry responsible for the pollution. Additional controversies that are also discussed are a disagreement over management options for shoreline protection, and a scientific disagreement over uncertainties in data on fish populations, which is usually the reason for controversies over fisheries. Controversies over effects of pollution often focus on how much (what concentration) of a chemical is needed to produce a certain harmful effect. Chemical companies tend to argue that levels of a chemical found in the environment are too low to cause problems, while environmentalists typically contend that lower levels can be harmful. One chemical about which there is sometimes controversy is oil. In the case of oil spills, debate commonly centers on how long the effects of pollution last. Oil degrades over time, resulting in less oil in the environment. The critical issue here is: When does this degradation reach a point where spilled oil is no longer harmful? Oil is a complex combination of various hydrocarbons that generally floats on water, although some lighter-weight components (the water-soluble fraction) dissolve. Weathering is a process that takes place in the air and water, in which the lightweight components evaporate, thus leaving the heavier components (e.g., tar), which have traditionally been viewed as less toxic. When oil comes into shallow water and marshes, it can coat and smother resident communities. It can sink below the surface of beaches and marshes and remain there for many years. Oil in marsh sediments undergoes some microbial breakdown but very slowly. Effects of a small oil spill (190,000 gallons of number 2 fuel oil) in Falmouth, Massachusetts, in the late 1960s lasted for over a decade, according to Sanders et al. (1980).

This chapter examines how an ideal of monogamy helps sustain intersecting gendered and racial hierarchies. Woman of color feminism has long censured the association of female sexual respectability with whiteness and social privilege, but this work generally dates the advent of that association to the establishment of modern slavery and colonialism. William Shakespeare’s sonnets, however, register the development of a fiction of somatic, heritable whiteness as a correlate of respectable sexuality, one disseminated in classical discourses celebrating male friendship and in imperial allegories of sexual conquest. Yet in their depiction of a three-way affair between the poet, a “fair” young man, and a “black” mistress, the sonnets conspicuously fail to cordon off rational and mutual “fair” male friendship from the humiliating enslavement of “black” female appetite. Instead, drawing on the Pauline theory of sin and grace that influenced thinkers from Martin Luther and John Calvin to Sigmund Freud and Jacques Lacan, the sonnets dissolve the oppositions ostensibly embodied by the poet’s “two loves”—agency and passivity, mastery and submission, fidelity and promiscuity, purity and pollution—to imagine intimacies beyond the couple.

Few people today lead home-centred lives, and perhaps that’s how it should be. For earlier generations the home was all important: it was a place of comfort after a hard day’s work, a place to be proud of, a place of love and security for young children—and possibly a place of drudgery, boredom, quarrels and abuse. But whatever a home was, it was a place which chemistry was to transform, so that today it is cleaner, healthier, safer to live in, and with some remarkable labour-saving gadgets and entertainment facilities. It is cleaner because of detergents, healthier because of disinfectants and safer because the chemicals we use may be protected by other chemicals, as we shall see. Throughout the 19605, 708 and 8os the use of detergents was portrayed by some as almost wanton pollution of rivers and lakes. The chemicals that lift grease and dirt from dishes, clothes and even our own bodies were accused of causing ‘eutrophication’: the imbalance in rivers, lakes or inland seas that produces an excess of slimy algae or weeds. The main culprit was said to be phosphate in detergents, but even the surfactants they relied on for their cleaning ability were under a cloud, because these were produced from oil. Such was the odium under which detergents laboured that companies strove to produce ‘green’ alternatives that were phosphate-free. Unfortunately many consumers did not like them, but their rejection in the end hardly mattered because it turned out that phosphates were not so environmentally damaging after all. Detergents are made up of many components, but two are worth a closer look: surfactants, which dissolve grease, and phosphates, which soften the water. It is not difficult to find something good to say about them both of them. During the Gulf War of 1991, millions of barrels of crude oil were deliberately released by the Iraqi invaders into the waters of the Persian Gulf. As usually happens, it was the local birds who bore the brunt of this ecological vandalism.

The process of cleaning one item invariably involves making something else dirty. Whether that something else is an organic or halogenated solvent, soapy water, or a rag, we seldom address the dirtying that accompanies any cleaning process. If we are to achieve environmentally benign cleaning, we must look at the life cycle of solvents employed for cleaning, including the potential for recycling, reuse, or release into the environment. Truly “green” cleaning processes not only minimize the amount of waste generated; but also they prevent the dispersal of that waste into large amounts of solvent, water, soil, or air. Dense-phase carbon dioxide is a great cleaning solvent from a pollution-prevention viewpoint. By-product CO2 generated by other industrial processes can be captured, so it is not necessary to generate CO2 specifically for cleaning. Spills of CO2 will not contaminate groundwater or create a need for soil remediation. Carbon dioxide even has advantages for the work environment, since no chronic, harmful effects are known from repeated inhalation of low concentrations of CO2. The barriers to using CO2 as a cleaning solvent have centered around two issues: the expense of high-pressure equipment and the poor solubility of many contaminants in CO2. Micell Technologies, Inc., based in Raleigh, NC, has addressed the equipment issue by using liquid CO2 just below ambient temperature (∼18–22 °C) and vapor pressure (∼50 bar). The equipment needed to contain this pressure is considerably less expensive than that needed for supercritical CO2 processes. As for the second barrier, Micell has surfactant packages that enhance the ability of CO2 to dissolve many contaminants commonly found on clothes or on metal parts. Micell is in the process of designing and bringing to market integrated CO2 solutions, including equipment and appropriate chemistries, to replace the organic solvents or water traditionally used in garment dry cleaning, metal degreasing, and textile processing. Dry cleaning is a bit of a misnomer, in that clothes are cleaned in a liquid solvent. “Dry” simply means that exposure of a garment, such as a wool suit or silk blouse, to water is minimized to prevent damage to hydrophilic fibers.