Leachate analyses

The behaviour of poly(vinyl chloride) products in landfill sites longterm and their leachate products and gas evolution have been monitored. Over the period of the study no degradation of the poly(vinyl chloride) was observed. The leachate analysis determined that there was no significant contribution to the level of heavy metals in landfills, and that the presence of phthalates and organotin compounds presented no risk to the aquatic environment. 14 refs. 

Edmonds M., Oppenheimer C., Pyle D. M., and Herd R. A. (2003a) Rainwater and ash leachate analysis as a proxy for plume chemistry at Soufriere Hills Volcano, Montserrat. In Volcanic Degassing, Geological Society of London Special Publication 213. (eds. C. Oppenheimer, D. M. Pyle, and J. Barclay). Geological Society of London, pp. 203-218. 

Mg of chemicals calculated. Average concentration in leachate analyses multiplied by total weight except for Cerro Negro which is a weighted average using leachate analysis for each size fraction and location. 

Regarding leachate analysis, UV spectrophotometry can be useful for a fast characterisation or the study of landfill evolution. Depending on the nature of organic components, aqueous solutions can limit the interest of the approach. In this case, an extraction step of the solid matrix with an organic solution can be necessary in order to have more specific information. 

The results of the experiments with bentonite and leachate reported in the literature have helped our understanding of the properties of bentonite, and its attenuating potential of some pollutants. However, it is very difficult to reproduce environmental conditions in the laboratory so that some of the results obtained cannot be readily extrapolated to real situations. It is difficult to compare data obtained with different experimental settings and to take into account the possible artefacts that may be caused by leachate handling, storage conditions and sample preparation techniques before analysis. Griven the interferences and leachate matrix effects commonly observed during leachate analysis, the reliability of the data obtained must also be carefully considered (DeWalle et al. 1981 Daly Farooq 1982 Lund et al. 1992). 

DeWalle, F, B., Zeisig, T., Sung, J. F. C. etal. 1981. Analytical methods evaluation for applicability in leachate analysis. Municipal Environmental Research Laboratory Office of Research and Development. US Environmental Protection Agency, Cincinnati, Ohio, 1-12. 

Headspace analysis has also been used to determine trichloroethylene in water samples. High accuracy and excellent precision were reported when GC/ECD was used to analyze headspace gases over water (Dietz and Singley 1979). Direct injection of water into a portable GC suitable for field use employed an ultraviolet detector (Motwani et al. 1986). While detection was comparable to the more common methods (low ppb), recovery was very low. Solid waste leachates from sanitary landfills have been analyzed for trichloroethylene and other volatile organic compounds (Schultz and Kjeldsen 1986). Detection limits for the procedure, which involves extraction with pentane followed by GC/MS analysis, are in the low-ppb and low-ppm ranges for concentrated and unconcentrated samples, respectively. Accuracy and precision data were not reported. 

The bacterial aerobic degradation of pyrene is initiated by the formation of cfi-pyrene-4,5-dihydrodiol. Analysis for this metabolite was used to demonstrate the biodegradability of pyrene in an environment in which there was continuous input of the substrate, when it was not possible to use any diminution in its concentration as evidence for biodegradation (Li et al. 1996). The corresponding metabolite from naphthalene—cfi-naphthalene-1,2-dihydrodiol—has been used to demonstrate biodegradation of naphthalene both in site-derived enrichment cultures and in leachate from the contaminated site (Wilson and Madsen 1996). 

An example of the effects of waste settlement can be illustrated by a recent incident at a hazardous waste landfill facility in California.5 At this facility, waste settlement led to sliding of the waste, causing the standpipes (used to monitor secondary leachate collection sumps) to move 60-90 ft downslope in 1 day. Because there was a very low coefficient of friction between the primary liner and the geonet, the waste (which was deposited in a canyon) slid down the canyon. There was also a failure zone between the secondary liner and the clay. A two-dimensional slope stability analysis at the site indicated a factor of safety (FS) greater than 1. A three-dimensional slope stability analysis, however, showed that the safety factor had dropped below one. Three-dimensional slope stability analyses should therefore be considered with canyon and trench landfills. 

Regarding POCs, eight compounds (see Table 1) were selected as indicators from the qualitative analysis of leachate due to their frequent detection, to their abundance, and to their absence in groundwater wells monitored upstream the landfill. The selected compounds include plasticizers or their degradation products, insect repellent and natural compounds resulting from anthropogenic pollution. 

Another peculiarity of the study is that the use of a biological system has allowed the authors to hypothesize a possible mechanism of action of the leachate as a mixture, hypothesis that could have been drafted on the basis of the only knowledge derived by chemical analysis. Researchers suggest that leachate inhibits cell proliferation at low doses probably inducing a reversible cell cycle arrest that becomes irreversible at high doses, probably due to leachate-induced oxidative stress. This activity is mainly due to the chemical compounds extracted in the aqueous phase. Similar effects were noticed by previous investigations on other human cells (human peripheral blood lymphocytes and a human breast cancer cell line, MCF-7) [31, 32], supporting the hypothesis that cells that survive the initial insult from leachate constituents maintains the potential to proliferate until the effects on cell metabolism lead to death. 

In this barrel, air is expected to come naturally. Temperature and leachate volume were measured twice a week. Once a week, waste was taken out to mix with air and then put back into the barrel. At the same time, sample was taken to measure water content. Stabilization step ended when waste body stopped generating water, varied from 18 to 51 days, due to waste input characteristic and environmental temperature. After this time, raw RDF was collected and stored for further analysis. Stabilization time of El > E3 and R1 > R3 was compared with that of other study (Table 8). 

Multivariate curve resolution, 6 54—56 Multivariate linear regression, 6 32—35 Multivariate optical elements (MOE), 6 68 Multiwalled carbon nanotubes (MWCNTs), 77 48, 49 22 720 26 737. See also Carbon nanotubes (CNTs) Multiwall nanotubes (MWNTs) synthesis of, 26 806 Multiwall fullerenes, 12 231 Multiwall nanotubes (MWNTs), 12 232 Multiwall paper bags, 78 11 Multiway analysis, 6 57-63 Multiyear profitability analysis, 9 535-537 Multiyear venture analysis, 0 537-544 sample, 9 542-S44 Mummification, 5 749 Mumps vaccine, 25 490 491 Mumps virus, 3 137 Municipal biosolids, as biomass, 3 684 Municipal distribution, potential for saline water use in, 26 55-56 Municipal effluents, disposal of, 26 54 Municipal landfill leachate, chemicals found in, 25 876t... 

Municipal solid waste (MSW), 25 864 as biomass, 3 684 cadmium in, 4 489-490 characteristics of leachates in, 25 867t characterizing, 25 866-869 collection of, 25 869-870 composition analysis for, 27 365t ferrous scrap in, 27 411 incineration of, 25 872-873 mixed, 27 367-369 preparation of, 27 367-369 processing, 27 364-371 quantity and composition of, 27 362-364 recovery rates for, 27 364, 366-367t recycled, 27 360, 362-371 toxic chemicals in, 25 875-876 Municipal waste sludge, as biomass, 3 684 Municipal water, for aquaculture, 3 198 Municipal water softening methods,... 

If the response of the organism is produced by a combination of the two compounds, then they are said to exert joint action. This joint action can be further classified into simply additive, more than additive (i.e., synergistic), and less than additive (i.e., antagonistic). When this scheme is applied to multicomponent mixtures present in leachates of solid wastes, the analysis becomes more complex because the joint actions of different compound pairs may fall into different types of joint action. In the next section, three different modeling schemes are presented. 

Availability Adequacy and Comparability of Testing Procedures for the Analysis of Pollutants Established under Section 304(h) of the Federal Water Pollution Control Act Report to Congress 600284101 Characterization of Soil Disposal System Leachates 503289001 Compendium of Methods for Marine and Estuarine Environmental Studies... 

Methods for the analysis of soils, soil material and other materials Eluates and leachates (Tables 5, 6 and 8)... 

Solutions and leachates for analysis must be particle free, and should therefore be centrifuged in polypropylene tubes and nof filtered unless this is specified in the methodology. 

Relatively small amounts of carbon tetrachloride are released to water. The total in 1978 was estimated to be 2.5 metric tons, due almost entirely to discharges from carbon tetrachloride production facilities (Rams et al. 1979). Analysis of data from ERA S Storage and Retrieval (STORET) database for the early 1980s indicate that carbon tetrachloride was detectable in 5.5% of 1,343 industrial effluent samples (Staples et al. 1985). The median concentration of all samples was <5 og/L. Carbon tetrachloride was also detected in leachates from industrial landfills at concentrations ranging from <10 to 92 pg/L (Brown and Donnelly 1988). 

Two different approaches have been taken by researchers to determine the secondary mineralogy of CCBs (1) direct observation, which is accomplished via analysis of weathered ash materials, and (2) prediction, based on chemical equilibrium solubility calculations for ash pore-waters and/or experimental ash leachate or extractant solutions. Because the secondary phases are typically present in very low abundance, their characterization by direct analysis is difficult. On the other hand, predictions based on chemical equilibrium modelling or laboratory leaching experiments may not be reliable indicators of element leachability or accurately indicate the secondary phases that will form under field conditions (Eighmy et al. 1994 Janssen-Jurkovicova et al. 1994). 

The leachate was changed according to the International Atomic Energy Association (IAEA) procedure, which calls for sampling daily for four days, weekly for eight weeks, monthly for six months, and semi-annually from then on. On leachatechanging day, a 10 m aliquot was removed from the container and acidified to a pH of 1 with concentrated nitric acid. This acid was added to prevent adherence of isotopes on the sample container walls. Analysis of the sample consisted of ... 

Recall Problem 3.1. You are the boss of an analytical laboratory and, this time, you check the numbers from the analysis of chlorobenzene in water samples of very different origins, namely (a) moderately contaminated groundwater, (b) seawater ([salt]tot 0.5 M), (c) water from a brine ([salt]tot = 5.0 M), and (d) leachate of a hazardous-waste site containing 40% (v v) methanol. For all samples, your laboratory reports the same chlorobenzene concentration of 10 ng IT1. Again the sample flasks were unfortunately not completely filled. This time, the 1 L flasks were filled with 400 mL liquid, and stored at 25°C before analysis. What were the original concentrations (in /J,g-L l) of chlorobenzene in the four samples ... 

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