Degradation in the Environment

In a battery of tests, which determine the tendency of chemicals to inhibit aquatic organisms, accumulate in such organisms, and degrade in the environment, 2-hydroxy-2-nitro-l,3-propanediol was found to have low potential for harm in the environment (7). 

Sewer Disposal. Photoprocessing and printing wastes tend to be aqueous solutions that ate combined with other plant effluents and sent to the local sewer plant for treatment. The parameters of concern include silver, pH, and biological oxygen demand (BOD). BOD is a measure of how well a waste material degrades in the environment. Lower values ate preferred. Silver-bearing waste streams ate typically treated on-site, and the treated effluent is released to the drain. The printer usually receives a small cash credit for silver recovered. 

The highly reactive hexachlorocyclopentadiene is rapidly degraded in the environment and is not routinely detected as an environmental pollutant... 

In contrast to the ester bond the P-C-bond of the phosphonic acid is hardly biologically degradable. The P-C bond will be principally but slowly degraded in the environment by the actinic sector of the sun s rays. 

It may, therefore, be concluded that, within a generally consistent pattern of behavior, organotins are degraded in the environment to afford nontoxic, inorganic tin species. A generalized, environmental-breakdown scheme for the commercially used tributyl- and triphenyltin derivatives (516), that is probably applicable to other triorganotins, is illustrated in Scheme 1. 

By definition, any pesticide has toxic effects on organisms. Listed pesticides are those that combine high toxicity with resistance to degradation in the environment. Moore and Ramamoorthy109 review the behavior of chlorinated pesticides in natural waters. 

Compounds highly brominated attach strongly to sediments. They are slowly degraded in the environment [53,54]... 

A variety of molecular indicators of the freshness (and perhaps nutritional quality) of organic matter exists. For example, certain labile phytoplankton constituents, such as polyunsaturated fatty acids, are readily degraded in the environment or in herbivore guts, and are thus depleted in more degraded particles (de Baar et ak, 1983 Wakeham and Canuel, 1988). Preferential loss of labile algal fatty acids resulting in the enrichment of more stable components in the products of heterotrophic metabolism has been observed in both field studies and laboratory feeding experiments (Prahl et ak, 1985 Wakeham and Canuel, 1988 Harvey et ak,... 

Many synthetic polymers, including most plastics, do not degrade in the environment. What can be done with plastic and other polymer waste ... 

It is obtained by the copolymerisation of 3-hydroxybutanoic acid and 3 - hydroxypentanoic acid. PHBV Is used in speclaUly packaging, orthopaedic devices and in controlled release of drugs. PHBV undergoes bacterial degradation in the environment. 

Chlorination of benzene gives an addition product that is a mixture of stereoisomers known collectively as hexachlorocyclohexane (HCH). At one time, this was incorrectly termed benzene hexachloride. The mixtnre has insecticidal activity, though activity was found to reside in only one isomer, the so-called gamma isomer, y-HCH. y-HCH, sometimes under its generic name lindane, has been a mainstay insecticide for many years, and is about the only example of the chlorinated hydrocarbons that has not been banned and is still available for general use. Although chlorinated hydrocarbons have proved very effective insecticides, they are not readily degraded in the environment, they accumulate and persist in animal tissues, and have proved toxic to many bird and animal species. 

Disposal of the remnants after the product has passed its useful life should be done safely, perhaps to be reused or recycled, or broken down and returned to its origin. A product such as Freon may contain components designed to be safe and inert, and thereby would not degrade in the environment and persist and accumulate to cause long-term problems. 

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