Heavy metals landfill leachates

Beccaloni E, Borrello P, Mesmeci L, Stacul E. Arsenic and heavy metals in leachate from a real landfill and a laboratory landfill. Ann Chi 2000 90(11 12) 629 36. 

Corrective Action Application In Massachusetts, a municipal wastewater treatment plant receives a number of wastestreams containing heavy metals from local industries. When tested, the dewatered sludge failed the EP toxicity test. In order to permit landfill disposal of the sludge, solidification processes were examined. A soluble, silicate-based system, developed by Chemfix, was ultimately selected which produced a product whose leachate passed the EP toxicity test (Sullivan, 1984). 

Pohland, F.G. and Gould, J.P., Containment of Heavy Metals in Landfills with Leachate Recycle, Proc. 7th Annual Symposium Disposal of Hazardous Waste, EPA 600/g-81-002a, pp. 171-189, 1981. 

Heavy metals have the potential to enter the water supply from the leachate or runoff from landfills. It is estimated that nonrecycled lead-acid batteries produce about 65% of the lead in the municipal waste stream. When burned, some heavy metals such as mercury may vaporize and escape into the air, and cadmium and lead may end up in the ash, making the ash a hazardous material for disposal. 

The evaluation of risk has underlined the possible adverse effects both on human health after the exposure to drinking water contaminated by landfill leachate and on small rodents and aquatic species at the hypothesized condition for humans, the estimated toxic effects of the raw leachate are mainly due to the levels of ammonia and cadmium and carcinogenic effects are induced by arsenic first and then by PCBs and PCDD/Fs while ecological potential risk is mainly attributable to the concentration of inorganic compounds, in particular ammonia for small rodents, cadmium, ammonia, and heavy metals for fishes. 

Landfill leachate is an important point pollution source to water body, which contains DOM with a large number of unknown molecules that actively involve in biogeochemical and environmental processes (Chin et al. 1997). DOM not only plays an important role in freshwater systems for the mobility of toxic heavy metals and other pollutants but also may itself be a groundwater contaminant (Christensen etal. 1998). 

Many old landfills were located on permeable ground, where leachates were allowed to percolate and attenuate through the porous material. Table 16.1 shows that the leachates percolating out of landfill sites contain significant concentrations of nutrients, heavy metals and organics this uncontrolled means of landfilling has resulted in the contamination of aquifers at many landfill sites around the world [45]. 

In Switzerland, where direct landfill of MSW is prohibited, all MSW has to be burned in incinerators and the bottom ash has to be stored in special controlled landfill sites (so called reactor deposits ). Re-use of today s BA is no longer practised because such BA is a heterogeneous random product (Lichtensteiger 1996) and elevated heavy metal concentrations in future leachates cannot be excluded (e.g., Staubli 1992). 

Traditional landfill presents several disadvantages since the space available for landfill has become scarce. In addition, municipal waste has to be transported over increasing distances with associated wastage of energy [3]. Leachates from unprepared landfills may contain hazardous levels of substances such as ammonium salts, heavy metals and organic chemical waste that may contaminate the air, soil and ground water [4] and thus may affect crops and secondary animals and man [3, 4, 5, 6, 7]. 

Other applications of the MetPLATE test include the assessment of heavy metal toxicity in aquatic environments (Gupta and Karuppiah, 1996), soils (Bitton et ah, 1996 Brohon and Gourdon, 2000 Kong et ah, 2003), sediments (Bitton et ah, 1992a de Vevey et ah, 1993 Kong et ah, 1998), leachates from wood treated with CCA and other wood preservatives (Stook et ah, 2001), municipal solid waste (MSW) landfill leachates (Ward et ah, 2002), teapots (Boularbah et ah, 1999) and metal accumulation in plants (Boularbah et ah, 2000). 

Calace, N., Liberatori, A., Petronio, B.M. and Pietroletti, M. (2001) Characteristics of different molecular weight fractions of organic matter in landfill leachates and their role in soil sorption of heavy metals, Environmental Pollution 113, 331-339. 

Micro-foam, or colloidal gas aphrons have also been reportedly used for soil flushing in contaminated-site remediation [494—498], These also have been adapted from processes developed for enhanced oil recovery (see Section 11.2.2.2). A recent review of surfactant-enhanced soil remediation [530] lists various classes of biosurfactants, some of which have been used in enhanced oil recovery, and discusses their performance on removing different type of hydrocarbons, as well as the removal of metal contaminants such as copper and zinc. In the latter area, the application of heavy metal ion complexing surfactants to remediation of landfill and mine leachate, is showing promise [541]. 

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. 

OVERVIEW OF PROCESSES CONTROLLING FATE OF LANDFILL LEACHATE COMPOUNDS. 5.1 Dissolved Organic Matter, Inorganic Macrocomponents, and Heavy Metals. 5.2 Xenobiotic Organic Compounds NORMAN LANDFILL (USA)... 

In summary, leachates contain a variety of compounds (dissolved organic matter, inorganic compounds, heavy metals, and XOCs), due to the mixed nature of the waste in landfills. The spatial variability of the leachate quality is significant, and this can affect the leaching pattern from the landfill and the resulting plumes. A landfill should be seen as a complex source, which is expected to last for decades or even centuries. 

Heavy metals. The behavior of heavy metals in a landfill leachate plume is simultaneously controlled by sorption, precipitation, and complexation, and proper evaluations of metal attenuation must account for this complex system. Generally, heavy metals do not constitute a groundwater pollution problem at landfills (Arneth et al., 1989), because landfill leachates usually contain only modest heavy metal concentrations, and the metals are subject to strong attenuation by sorption and precipitation in the landfill itself (Kjeldsen et al., 2002). Sulfide-producing conditions result in extremely low solubility of... 

Urase, X. et al.. Effect of high concentration of organic and inorganic matter in landfill leachate on the treatment of heavy metals in very low concentration level. Water Sci. Technol, 36(12, Water Quality Conservation in Asia), 349, 1997. 

A. Mdller, A. Grahn, and U. Welander, Precipitation of Heavy Metals from Landfill Leachates by Microbially Produced Sulphide, Environmental Technology, 25(1), 69-77 (2004). 

Griffin, R.A., Frost, R.R., Au, A.K., Robinson, G. and Shimp, N.F., 1977. Attenuation of pollutants in municipal landfill leachate by clay minerals. Part 2. Heavy metal adsorption. Ill. State Geol, Surv, Environ, Geol. Note 79. 47 pp,... 

Such natural services may be interrupted in other ways. If the chemical or sewage plant upstream puts something toxic into the stream that the water treatment plant of the city downstream cannot remove by standard treatments, a new water supply or a new treatment method will have to be found at increased cost. In earlier years before the toxicity of the polychlorinated biphenyls was fully appreciated, General Electric released enough of them into the Hudson River north of Albany, New York that the whole Hudson River from Hudson Falls to New York City is now a Superfund site.7 Fishermen are advised not to eat the fish that they catch. It is not always easy to calculate the cost of a fishery lost to toxic heavy metal ions or acids draining out of a mine site.8 One settlement, involving a salmon fishery in a river in Idaho, was for 60 million dollars. The Exxon Valdez oil spill in Alaska cost Exxon 3 billion dollars. The persons whose wells become contaminated by leachate from the nearby landfill will face the costs of bringing water from a distance. This was a cost that was not included when the landfill was built. The U. S. National Research Council has recommended that the U. S. Department of Commerce resume development of a method to better measure environmental costs.9... 

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