Pesticides dioxin and

Aquaplant is not suitable for the remediation of aromatic hydrocarbons benzene, toluene, ethylene, and xylene (BTEX), polychlorinated biphenyls, volatile chlorinated hydrocarbons, pesticides, dioxins, and furans. 

Application of several analytical methods is often necessary because the analytes are numerous, inorganic, and organic. Pollutants include heavy metals, anions, amines, phenols, pesticides, dioxins, and many other classes, requiring different sampling, extraction, and measurement techniques. 

Method 3545A can be applied to the extraction of base/neutrals and acids (BNAs), chlorinated pesticides and herbicides, PCBs, organophosphorus pesticides, dioxins and furans and total petroleum hydrocarbons (TPHs). 

Applicabdity Limitations Photolysis is appropriate for difficult-to-treat chemicals (e.g., pesticides, dioxins, chlorinated organics), nitrated wastes, and those chemicals in media which permits photolyzing the waste. The waste matrix can often shield chemicals from the light (e.g., ultraviolet light absorbers, suspended solids, solid wastes). The photolysis process typically requires pretreatment to remove suspended materials, and the by-products formed may be more toxic than the parent molecules. 

Baird is the 20-acre site of a former chemical mixing and batching company. Poor waste disposal practices resulted in the contamination of groundwater, soil, the municipal water supply, and a brook adjacent to the site. Over one hundred contaminants, including chlorinated and nonchlorinated volatile organics, heavy metals, pesticides, herbicides, and dioxins, had been identified in site soil and groundwater. Remediation activities included soil excavation and incineration, and groundwater treatment (the audit focused on the soil excavation and incineration... 

Chlorinated dibenzo ip-dioxins are contaminants of phenol-based pesticides and may enter the environment where they are subject to the action of sunlight. Rate measurements showed that 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) is more rapidly photolyzed in methanol than octachlorodi-benzo-p-dioxin. Initially TCDD yields 2,3,7-trichlorodiben-zo-p-dioxin, and subsequent reductive dechlorination is accompanied by ring fission. Pure dibenzo-p-dioxin gave polymeric material and some 2,2 -dihydroxybiphenyl on irradiation. Riboflavin-sensitized photolysis of the potential precursors of dioxins, 2,4-dichlorophenol and 2,4,5-trichloro-phenol, in water gave no detectable dioxins. The products identified were chlorinated phenoxyphenols and dihydroxy-biphenyls. In contrast, aqueous alkaline solutions of purified pentachlorophenol gave traces of octachlorodibenzo-p-dioxin on irradiation. 

The biological activity of several halogenated herbicides in water is destroyed by ultraviolet irradiation (18). Irradiation seems to be a promising method for decontaminating small quantities of pesticides. The chemical similarity between the chlorinated dioxins and other chlo-rinted aromatic compounds suggested that if there were parallels in their photochemical behavior, sunlight might destroy dioxins in the environment. 

Plant uptake is one of several routes by which an organic contaminant can enter man s food chain. The amount of uptake depends on plant species, concentration, depth of placement, soil type, temperature, moisture, and many other parameters. Translocation of the absorbed material into various plant parts will determine the degree of man s exposure—i.e., whether the material moves to an edible portion of the plant. Past experience with nonpolar chlorinated pesticides suggested optimal uptake conditions are achieved when the chemical is placed in a soil with low adsorptive capacity e.g., a sand), evenly distributed throughout the soil profile, and with oil producing plants. Plant experiments were conducted with one set of parameters that would be optimal for uptake and translocation. The uptake of two dioxins and one phenol (2,4-dichlorophenol (DCP)) from one soil was measured in soybean and oats (7). The application rates were DCP = 0.07 ppm, DCDD 0.10 ppm, and TCDD = 0.06 ppm. The specific activity of the com-... 

Many dioxins were, and still are, introduced into the environment together with phenoxyherbicides - derivatives of 2,4,5-T and 2,4-D. Therefore, the general toxic background created by these herbicides may be much higher than expected, since they can contain many other dioxins as additives along with 2,3,7,8-TCDD. Moreover, these compounds can evolve dioxins when transformed in natural conditions. Thus, the danger of all such pesticides must be measured in two ways by the content of highly toxic dioxins, and by the dioxin precursors [38]. 

In addition to the chemicals included on the other lists, the CDC also included heavy metals such as arsenic, lead, and mercury volatile solvents such as benzene, chloroform, and bromoform decomposition products such as dioxins and furans polychlorinated biphenyls (PCBs) flammable industrial gases and liquids such as gasoline and propane explosives and oxidizers and all persistent and nonpersistent pesticides. Agents included in this volume are limited to those that are most likely to pose an acute toxicity hazard. 

A part from the general monitoring studies, other studies have been performed focusing the hotspots areas of the Ebro river basin, mainly the Ebro delta [30, 31] and the Vero-Cinca tributaries [98-100], and specific groups of compounds like semi-polar pesticides, DDTs and dioxin-like compounds. 

Muir, D.C.G., C.A. Ford, B. Rosenberg, R.J. Norstrom, M. Simon, and P. Beland. 1996. Persistent organochlo-rines in beluga whales (Delphinapterus leucas) from the St Lawrence River estuary. I. Concentrations and patterns of specific PCBs, chlorinated pesticides and polychlorinated dibenzo-p-dioxins and dibenzofurans. Environ. Pollut. 93 219-234. 

Endocrine disruptors apparently affect all nuclear receptors. Thus, a notable increment in impotence, alterations of the libido and of oligospermia in workers exposed to pesticides has been described. These alterations are due to the action of some compounds with estrogen-mimetic action and to their interaction with the androgen receptor. Additionally, alterations of thyroid function have been detected in rats exposed to dioxin and other toxic agents,... 

Von Bavel et al. [55] used a solid phase carbon trap in conjunction with supercritical fluid chromatography for the simultaneous determination of polychlorobiphenyls, pesticides, polychlorodibenzo-p-dioxins and polychlorodibenzofurans in soils. 

Namiesnik et al. [33] have reviewed the analysis of soils and sediments for organic contaminants. They discuss methods of sample preparation and isolation-preconcentration prior to instrumental determination. Compound classes discussed include volatile organic compounds, polychlorobiphenyls, polyaromatic compounds, pesticides and polychlorodibenzo-p-dioxins and polychlorodibenzofurans. 

POPS currently regulated under the Convention include pesticides such as aldrin, chlorodane, DDT, dieldrin, endrin, heptachlor, mirex and toxaphene chemicals with industrial applications such as polychlorinated biphenyls (PCBs)2 and chemical byproducts such as dioxins and furans and hexachlorodbenzene, which fits in all three categories.3... 

Tetrachlorobenzene Pesticide - insecticide and intermediate in herbicide production - related to dioxin (TCDD)... 

Until recently most people and nearly all corporations accepted the release of at least some level of hazardous wastes into the environment as an unpleasant, but necessary, consequence of the huge success of modern chemical technology. Certainly no one is happy about the presence of dioxins (and PCBs and PAHs and other hazardous chemicals) in the environment. They undoubtedly result in some number of health problems and deaths around the world each year. But that is a small price to pay, some would argue, for having such a diverse and rich supply of pesticides, drugs, perfumes, synthetic foods, medicines, and other chemical products. 

This technology can remove oily sludges, pesticides, herbicides, pentachlorophenol, polychlorinated biphenyls (PCBs), coal by-products, wood treating compounds, dioxins, and furans. It is often used in conjunction with the company s base-catalyzed decomposition (BCD) process. The BCD process is designed to treat chlorinated compounds. 

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