Leachate Treatment Facilities Research Articles

Co-digestion performance of organic fraction of municipal solid waste with leachate: Preliminary studies

The main aim of the study was to evaluate the co-digestion performance of OFMSW with different wastes. Leachate, reverse osmosis (RO) concentrate collected from a leachate treatment facility and dewatered sewage sludge taken from a wastewater treatment plant (WWTP) were used for co-digestion in this paper. An extra effort was made to observe the effect of leachate inclusion in the co-digestion. In the study, the mono-digestion of OFMSW, leachate, RO concentrate and sewage sludge as well as digestion of 7 different waste mixtures were carried out for this objective. The experiments were carried out for approximately 50days under mesophilic conditions. The highest methane yield was 785L CH4/kg VSadded in the reactor, which had only OFMSW. While the methane yield derived from OFMSW was found higher than previous studies, methane yield of leachate was found to be 110L CH4/kg VSadded, which was lower than findings in the literature. The mono-substrate of OFMSW was followed by the reactor of having waste mixture of leachate+sewage sludge+OFMSW+water (C7) with 391L CH4/kg VSadded, which was the only combination included water. In order to understand the effect of leachate and water inclusions on co-digestion, two separate waste combinations; leachate+sewage sludge+OFMSW+water (C7) and leachate+sewage sludge+OFMSW (C1) were prepared that had different amounts of leachate but same amounts of other wastes. The methane yield of leachate+sewage sludge+OFMSW+water (C7) indicated that addition of some water instead of leachate could stimulate biogas production. Methane yield of this reactor was found to be 71% higher than the waste combination of leachate+sewage sludge+OFMSW (C1). It could be thought that the high amount of non-biodegradable matters in leachate could be responsible for lower methane yield in leachate+sewage sludge+OFMSW (C1) reactor. Methane yields of the reactors showed that co-digestion of OFMSW and leachate could be a solution not only for treatment of leachate and but also increasing the biogas potential of leachate. Leachate addition could also adjust optimum total solids (TS) content in anaerobic digestion. It was also understood that RO concentrate did not affect the methane yield in a negative way. The similar characterization of leachate and RO concentrate in this study could offer the utilization of RO concentrate instead of leachate. The findings showed that volatile solids (VS) removals were changed from 32% to 61% in the reactors. While the reactor of leachate+RO concentrate+OFMSW (C6) had the highest VS removal, the reactor of the sole substrate leachate had the lowest VS removal.

Optimization of photocatalytic post-treatment of composting leachate using UV/TiO2

In this study, optimization of photocatalytic process via UV light and TiO2 nanoparticles immobilized on concrete surface in post-treatment of composting leachate was investigated. This investigation was conducted in laboratory scale and batch mode. Biological pretreated leachate samples were collected from the effluent of Gorgan composting leachate treatment facility in the north of Iran. Optimization of the simultaneous COD and color removal were carried out through experiments designed by response surface method and central composite design with six replications in central point. Based on the results of experiments, after 21.5 h of radiation with 7.5 mW Cm−2 light intensity in pH 5.7 and in the presence of 48.8g m−2 immobilized TiO2, maximum simultaneous COD and color removal were achieved to be 58 and 36%, respectively. GC/MS analysis revealed that the composting leachate contained various groups of refractory organic compounds, most of which could be degraded into simpler and more biodegradable by products, using photocatalytic process.

매립지내 환경에너지단지의 무방류 시스템 구축방안

A research was performed for zero discharge system of waste water which is produced from energy recovery process of waste and biomass. Leachate and all kinds of waste water should be separated and integrated into three categories in addition to converting existing leachate treatment facility into waste water treatment facility as well as introducing a management system of reverse osmosis membrane facility and bioreactor landfill. Following these conditions to better water treatment process, it was likely to produce over 3,000 tons of low-grade recycling water and 2,000 tons of high-grade recycling water per day when zero discharge system of waste water is applied starting from 2016. Economical efficiency was also surveyed in total treatment fee. Present system costs 18,129 million won per year, and suggested zero discharge system would cost 15,789 million won per year.

Toward Safe Treatment of Municipal Solid Wastes in China’s Urban Areas

M solid waste management (MSWM) in China warrants particular attention as China has become the largest municipal solid waste (MSW) generator in the world. Until the end of 2010, total amount of MSW reached 221 million tons in Chinese urban areas, in which 63.5% had been safely treated and disposed. Urbanization, population growth, and industrialization are three key reasons behind the large magnitude of China’s increase in total waste generation. In order to achieve sustainable MSWM, the Chinese government released a national plan within its 12th five-year plan (2011− 2015) on April 19th 2012, targeting safe treatment of MSW in Chinese urban areas. The main objective of this plan is to construct necessary infrastructure for safe treatment of MSW. Several missions will be completed during 2011−2015. First of all, many new waste treatment and final disposal facilities will be constructed (with a budget of 173 billion RMB), particularly incinerators and landfills, so that the increased daily treatment capacity can reach 0.58 million tons. Due to different geographical and economic situations, while incinerators will be encouraged in the more populated east China, landfills will be encouraged in the less populated west China. Second, MSW transfer systems (with a budget of 35.1 billion RMB) will be constructed in all urban areas (urban population more than 30 000) with an increased daily capacity of 0.457 million tons. All the MSW will be delivered and transferred by using trucks with closed containers and compressors so that secondary pollution can be avoided. Advanced technologies on Internet of things will be developed in order to optimize the route of MSW deliveries. Third, existing MSW facilities will be updated (with a budget of 21.1 billion RMB for 1882 projects), such as constructing new leachate treatment facilities in existing landfills, recovering methane from existing landfills for power generation, and safely closing those landfills that have reached their designed life cycles. For those areas where land values are higher or incinerators are available, local governments are encouraged to redevelop the existing landfills so that metals can be collected and reused/recycled, wastes with higher caloric values can be burned and composting matters from organic wastes can be used for landscape purpose. Fourth, source separation for all the MSWs will be fully promoted (with a budget of 21 billion RMB). Each province should select at least one city within its territory to initiate source separation project so that related experiences can be shared by other cities. Based upon community waste collection stations, a regional waste collection network and waste market should be established so that those valuable wastes can be collected and traded, rather than flowing into landfills or incinerators. Related facilities will be constructed, such as preparing different garbage bags, trash bins, garbage separation centers, and garbage trucks for different wastes. Capacity building programs will also be promoted so that best practices can be implemented by the general public. In addition, special hazardous and toxic waste (HTW) treatment facilities will be constructed so that those HTWs can be safely handled, such as used batteries, discarded fluorescent tubes, mercury-based thermometers, and paints. Fifth, kitchen wastes will be asked to be separated from other wastes in all units (including households) at source sites and then be delivered to special sites by specially designed trucks for resourcification (with a budget of 10.9 billion RMB). All the collected kitchen wastes are required to be registered by local governments in order to avoid illegal collection and treatment. Resourcification options include composting, making biofuels, recovering methane, and mixed treatment with other degradable organic wastes. Finally, monitoring system for MSW will be established (with a budget of 2.5 billion RMB), such as online monitoring facilities in all the incinerators and landfills so as to avoid illegal emissions. In order to realize these missions, both policies and evaluation indicators have been prepared. While preferable policies are raised to encourage the successful implementation of this plan, such as improved MSWM regulations, the

Landfill Leachate Treatment: A Case Study for Istanbul City

AbstractOne of the most important problems arising from landfilling solid wastes is the leachate which contains high amount of pollution. Discharge of leachate without treatment causes negative effects on environmental and public health. In this study, parameters of chemical oxygen demand (COD), total nitrogen (TN), ammonia nitrogen (NH4‐N), and total phosphorus (TP) were examined in the samples taken from the influent and effluent of leachate treatment plant, where Odayeri landfill leachate is treated. Obtained results showed that the treatment plant, which consisted of preanoxic biological treatment system, ultrafiltration (UF) and nanofiltration (NF) units were operating with high efficiency. Among the examined parameters during study, COD, TN, NH4‐N, and TP were found to be treated at the rate of 99, 94.5, 99, and 93.8%, respectively. Landfilling is increasing rapidly in the world and this consequently brings the need of leachate treatment facilities. Therefore, this study is considered to be a guide for construction and operation stages of proposed new treatment plants.

Monitoring of leachate quality stored in gas ventilation pipes for evaluating the degree of landfill stabilization

Monitoring of leachate quality is the essential measure in aftercare for evaluating landfill stabilization. Generally, the most common way of leachate monitoring is executed at the inlet of the leachate treatment facility. However, it does not necessarily reflect the actual state of the site. Thus, methodologies which focus on both the discharge, in order to determine when the post-closure care of the facility should terminate, and on the degree of waste stabilization in the landfill are required. In the present study, monitoring of leachate quality stored in 68 gas ventilation pipes was conducted and the degree of waste stabilization at each location in the landfill was estimated by a statistical approach using the results obtained by monitoring. Leachate characteristics varied significantly for each pipe but seemed to reflect the waste condition of the nearby location. Correlation among the analysed items was quite high. Namely, the difference of leachate quality seemed to be categorized only by the level of concentration but not by the specific characteristics. To confirm this, Euclidean distances of dissimilarity were calculated by multidimensional scaling using six items of leachate quality and temperature. Two factors (thickness of leachate and concentration of total organic carbon (TOC) and electric conductivity (EC)) that distinguish leachate characteristics appeared. To indicate the degree of stabilization by location, the spatial distribution of TOC, total nitrogen (TN), inorganic carbon (IC), and chloride ion were estimated by using the ordinary Kriging methodology. As the result, it was estimated that the concentration of leachate existing within the landfill, especially TN, was higher than the completion criteria for leachate in most parts of the investigated area.

Numerical model for a watering plan to wash out organic matter from the municipal solid waste incinerator bottom ash layer in closed system disposal facilities

Bottom ash from municipal solid waste incineration (MSWI) is a main type of waste that is landfilled in Japan. The long-term elution of organic matter from the MSWI bottom ash layers is a concern because maintenance and operational costs of leachate treatment facilities are high. In closed system disposal facilities (CSDFs), which have a roof to prevent rainfall from infiltrating into the waste layers, water must be supplied artificially and its quantity can be controlled. However, the quantity of water needed and how to apply it (the intensity, period and frequency) have not been clearly defined. In order to discuss an effective watering plan, this study proposes a new washout model to clarify a fundamental mechanism of total organic carbon (TOC) elution behavior from MSWI bottom ash layers. The washout model considers three phases: solid, immobile water and mobile water. The parameters, including two mass transfer coefficients of the solid-immobile water phases and immobile-mobile water phases, were determined by one-dimensional column experiments for about 2 years. The intensity, period and frequency of watering and other factors were discussed based on a numerical analysis using the above parameters. As a result, our washout model explained adequately the elution behavior of TOC from the MSWI bottom ash layer before carbonation occurred (pH approximately 8.3). The determined parameters and numerical analysis suggested that there is a possibility that the minimum amount of water needed for washing out TOC per unit weight of MSWI bottom ash layer could be determined, which depends on the two mass transfer coefficients and the depth of the MSWI bottom ash layer. Knowledge about the fundamental mechanism of the elution behavior of TOC from the MSWI bottom ash layer before carbonation occurs, clarified by this study, will help an effective watering plan in CSDFs.

Inorganic nitrogen transformations in the treatment of landfill leachate with a high ammonium load: A case study

The inorganic nitrogen transformations occurring at a municipal waste leachate treatment facility were investigated. The treatment facility consisted of a collection well and an artificial wetland between two aeration ponds. The first aeration pond showed a decrease in ammonium (from 3480 (+/- 120) to 630(+/- 90) mg x L(-1)), a reduction in inorganic nitrogen load (3480 to 1680 mg N x L(-1)), and an accumulation of nitrite (< 1.3 mg-N x L(-1) in the collection well, to 1030 mg-N x L(-1)). Incomplete ammonium oxidation was presumably the result of the low concentration of carbonate alkalinity (approximately 2 mg x L(-1)), which may cause a limitation in the ammonium oxidation rate of nitrifiers. Low carbonate alkalinity levels may have been the result of stripping of CO(2) from the first aeration pond at the high aeration rates and low pH. Various chemodenitrification mechanisms are discussed as the reason for the reduction in the inorganic nitrogen load, including; the reduction of nitrite by iron (II) (producing various forms of gaseous nitrogen); and reactions involving nitrous acid. It is suggested that the accumulation of nitrite may be the result of inhibition of nitrite oxidizers by nitrous acid and low temperatures. Relative to the first aeration pond, the speciation and concentration of inorganic nitrogen was stable in the wetlands and 2nd aeration pond. The limited denitrification in the wetlands most probably occurred due to low concentrations of organic carbon, and short retention times.

DISTRIBUTION OF TRITIUM IN THE LEACHATES AND METHANE GAS CONDENSATES FROM MUNICIPAL WASTE LANDFILLS IN KOREA

In this paper, the tritium levels in the leachates and methane gas condensates which have occurred at 13 sanitary landfills of municipal solid wastes (MSW) are investigated and reported. During the 6 months investigation period, the mean tritium concentrations of the raw leachates were distributed from 17 to 1,196 TU. They corresponded to several scores or hundreds higher tritium levels than that of the normal environmental level except for two cases. High tritium levels were also detected in the effluents of the leachate treatment facilities. Generally, the tritium existed in the dissolving fraction of the leachate but for some cases about 10% of the total tritium content was present as colloidal particles of over 0.45 μm in size. In general, the relationship between the tritium and other contaminants in the raw leachate was low, but it was relatively high between the tritium and TOC. Thus, it is predicted that the dissolving state of the tritium in the leachates would be affected by the tritium sources of the tipped wastes in a MSW.

Behavior of endocrine-disrupting chemicals in leachate from MSW landfill sites in Japan

Endocrine-disrupting chemicals (EDCs) in landfill leachates and the effluent from leachate treatment facilities have been analyzed by many researchers. However, seasonal and yearly variations and the influence of landfill age are still not clear. In this study, leachate was sampled on four occasions each, at different seasons, from two MSW landfills which receive different waste material. Then, the quantities of alkylphenols (APs), bisphenol A (BPA), phthalic acid esters (PAEs) and organotin compounds (OTs) in leachate were determined. By sampling leachate from landfill cells of different age, the long-term behavior of EDCs was studied. Furthermore, leachate was also sampled at different points in the process of a leachate treatment system, and then the behavior of EDCs in the facility was studied. The concentrations of APs were as low as in surface waters, and OTs were not detected (detection limit was 0.01 μg/l), while BPA and DEHP, which were the most abundant of the four substances measured as PAEs, were found in all the leachates that were measured. Concentrations of BPA and DEHP were almost constant regardless of season, except for a couple of low concentrations observed for BPA. The varying composition of landfilled waste did not influence BPA and DEHP in leachate. Concentration of BPA in raw leachate tends to decrease as the years go by, but the concentration of DEHP was observed to remain at a constant level. BPA was considerably degraded by aeration for leachates from the two landfills, except when the leachate temperature was low. Aeration, coagulation/sedimentation, and biological treatment could not remove DEHP.

Landfill evolution and treatability assessment of high‐strength leachate from msw with high organic and moisture content

The generation of contaminated leachate remains an inevitable consequence of the practice of solid waste disposal in landfills. The collection and treatment of leachate have become common practice in order to prevent environmental pollution. Leachate treatment is highly dependent on the quality of leachate, which in turn is influenced by various factors including waste composition and operational procedures. This paper investigates the treatability of high‐strength leachate from pre‐sorted and baled municipal solid waste characterized by high organic and moisture content. For this purpose, waste disposal and leachate generation rates were monitored. Leachate samples were collected and analysed for selected indicators including BOD, COD, pH, and NH4‐N and a pilot scale treatment plant with coagulation, precipitation and sequential batch biological reactors was constructed to evaluate the feasibility of leachate treatment. Concentration levels were related to biological activity within the landfill and the results indicated that (1) pre‐sorting and baling of the waste did not hinder waste stabilization; and (2) the high organic and moisture contents resulted in an extremely strong leachate, particularly at the onset of biodegradation processes, which can affect the leachate treatment facility. The effectiveness of the pilot plant in treating the leachate exceeded 90% using COD and NH4‐N as indicators.

Long-term characterization, lagoon treatment and migration potential of landfill leachate: a case study in an active Italian landfill

The elaboration of 10 years of monitoring of leachate quality and quantity, leachate treatment and degree of contamination of soil and surface waters at the Tre Monti site––an active, 4-million-m 3 landfill in Northern Italy––is presented in this study. A hydrological model of leachate production is applied, with a good match of the experimental data. The concentrations of all leachate components except sulfate are characterized by fluctuations over a constant or increasing value. Different ways of interpreting leachate quality data are discussed; the elaboration indicates that the pollutant load on the leachate treatment facility will remain basically constant as long as waste will be added to the landfill. The analysis of the data relative to 10 years of leachate pre-treatment in the adjoining, non-aerated lagoon system indicates that a significant removal is achieved for most leachate components; the operational conditions of the plant are described, and the removal mechanisms are discussed. Finally, the potential for contamination of soil and surface waters is examined by analyzing long-term quality trends of the sub-superficial waters sampled near the lagoons and by means of an analytical campaign conducted on clay cores sampled near and underneath the treatment ponds. The experimental values indicate that the clay layer located under the entire site offers an effective barrier to the migration of leachate contaminants.

Temporal variation of leachate quality from pre-sorted and baled municipal solid waste with high organic and moisture content

Landfill leachate characterization is a critical factor in establishing a corresponding effective management strategy or treatment process. However, it is often difficult to forecast leachate quality because of a variety of influencing factors such as waste composition and landfill operations. This paper describes leachate formation mechanisms, summarizes leachate quality indicators, and investigates the temporal variation of leachate quality from pre-sorted and baled municipal solid waste characterized with high organic and moisture content. The purpose of the study is to evaluate the potential effects of waste composition and site-specific operational procedures on biodegradation processes and leachate quality at a field-scale landfill that receives in excess of 1800 tonnes per day of refuse. For this purpose, waste disposal and leachate generation rates were monitored and leachate samples were collected for a period of 18 months during the early stages of refuse deposition. Chemical analysis was performed on the samples and the temporal variation of several parameters were monitored including pH, COD, TOC, TDS, chlorides, sulfates, orthophosphates, nitrates, ammonia nitrogen, hardness, and heavy metals. Chemical concentration levels were related to biological activity within the landfill and the results indicated that: (1) pre-sorting and baling of the waste did not hinder waste stabilization; and (2) the high organic and moisture contents resulted in an extremely strong leachate, particularly at the onset of biodegradation processes, which can affect the leachate treatment facility.

２１世紀の廃棄物管理と資源

Laws of waste recycle have been established in recent years. As the result, waste recycle is on the considerable increase. However, there is a limit to recycle of waste, because even the recycled products become wastes at the end of their lives.In our country, the life span of the industrial waste's disposal site was 3.7 years, and the life span of general waste's disposal site was 12.3 years at 1999.Industrial waste was about 400 million tons, and general waste was about 54 million tons in fiscal 1999. Then, the final disposal amount of industrial waste was about 50 million tons, and that of general waste was about 11 million tons.Nowadays, plastics and incinerated residue are major wastes, which are dumped at the final disposal site. These wastes do not contribute to the stabilization of final disposal sites. These wastes eternally occupy the final disposal sites, and prevent the utilization of these areas. Moreover, leachate treatment facilities are essential for the final disposal sites, and the treatment of the leachate is required throughout the long term.However, the waste plastics are available as an urban energy source, and the incinerated residue has potential value as urban metal resources.If these wastes are reproduced,it will contribute to prolonging life of the final disposal site, and also contribute to mining quantity control of natural resources.The point of waste management in the 21st century is to reduce final disposal waste and to convert it to resources.

Colloidal and dissolved metals in leachates from four Danish landfills

Landfill leachate samples were collected at four Danish landfills. The samples were collected anaerobically for characterization of the leachate in terms of pH, total alkalinity, total solids, total organic carbon, cations, anions and heavy metals. The sample procedure was designed to accurately reflect the in situ mobile colloid and associated contaminant concentrations. The leachate samples were separated into size fractions in order to obtain information about size distribution of colloids and associated heavy metals using filters with the pore sizes: 1.2, 0.40 and 0.001 μm. The general characterization of the four leachate samples showed large variation in the leachate quality for the investigated landfills ranging a factor of 2–60 among the four landfills for individual parameters. The dominant part of the colloidal material was in the smallest colloidal size fraction (0.001–0.40 μm) with total organic carbon (TOC) as one of the major components of the colloidal mass. Also Si, Al, Ca, Fe and S were found in the colloidal fractions. This indicated that both clay type particles, organic matter and precipitates (most likely sulfides) were present in the leachate samples. The distribution of the investigated elements varied from Cl being primarily in the dissolved fraction to Fe which mostly was found in the colloidal fractions. The concentrations of heavy metals in the leachate samples were 0.2–3.6 μg Cd/L, 28–84 μg Ni/L, 85–5310 μg Zn/L, 2–34 μg Cu/L, 0–188 μg Cr/L and 0–16 μg Pb/L with a considerable but highly varying part of the heavy metals associated with the colloidal fractions. However, when the heavy metal content in leachates is low, it is probably not of major environmental concern that part of the heavy metal is associated with the colloids. However, if the metal content is high and, as was the case for Zn in one of the leachate samples, nearly exclusively associated with the colloidal fractions, the behavior of the heavy metal in the leachate treatment facilities and in the environment may differ from the behavior expected for truly dissolved heavy metal.

韓国におけるオープンダンピング型陸上廃棄物埋立地浸出水の特性

A method for prediction of leachate amount and analysis of leachate characteristics at an open-dumping landfill site, Nanji-do, Seoul, Korea were studied to help designing of leachate treatment facility and planning for adequate utilization of produced land. Water content capable of maintaining by wastes was introduced to water balance equations for prediction of leachate amount, resulted that 4, 339 m3/day in average was computed. Despite HELP model gave more leachate amount, similar value was obtained by using Stegmann model applicable for condition of unfavorable soil covering at sanitary landfills. Cl-concentration profile in leachate suggested that behavior of leachate production at an open-dumping site was likely to those of at semiaerobic landfill sites and sea-based waste disposal sites. Air could penetrate into inner layer, if dumping height was 95 m. Rate of oraganics decomposition could be slower than that of sanitary landfill, was understandable from analysis of BOD and nitrogen concentrations in leachate. Heavy metals detected were mainly form of suspended solids and values of leachate effluent are higher than those of internal leachate. Cadmium, mercury, and lead were seldom detected in leachate. It was found that sulfate-reducing bacteria were widely distributed in leachates and more number of sulfate-reducing bacteria showed lower values of heavy metals in leachate, besides, number of sulfate-reducing bacteria were highly correlated (r=0.523, n=36) with TBOD values of leachate.

Genotoxicity assay of landfill leachates

Environmental burden with genotoxic chemicals is increasingly becoming a serious problem mainly due to hazardous waste dumping and industrial effluents. The Mutatox® mutagenicity assay was validated with known mutagen for its efficacy in the detection of direct mutagens and S-9 activated promutagens and applied to the complex environmental samples of landfill leachates from the Al-Sulaibiyah solid waste disposal site in Kuwait. The leachate samples from borehole 3 collected between December 1994 and May 1995 (cold and rainy months) showed genotoxic response in direct assay, indicating the presence of direct acting mutagens, whereas the samples collected between June and September 1995 (hot and dry months) were active in both direct and S-9 activated assay, also showing the presence of promutagens. Thus the leachate from the landfill, which is not equipped with a leachate collection and treatment facility, was found capable of exerting genotoxic effects that may influence the biota of the receiving system. © 1998 John Wiley & Sons, Inc. Environ Toxicol Water Qual 13: 127–131, 1998

Genotoxicity assay of landfill leachates

Environmental burden with genotoxic chemicals is increasingly becoming a serious problem mainly due to hazardous waste dumping and industrial effluents. The Mutatox® mutagenicity assay was validated with known mutagen for its efficacy in the detection of direct mutagens and S-9 activated promutagens and applied to the complex environmental samples of landfill leachates from the Al-Sulaibiyah solid waste disposal site in Kuwait. The leachate samples from borehole 3 collected between December 1994 and May 1995 (cold and rainy months) showed genotoxic response in direct assay, indicating the presence of direct acting mutagens, whereas the samples collected between June and September 1995 (hot and dry months) were active in both direct and S-9 activated assay, also showing the presence of promutagens. Thus the leachate from the landfill, which is not equipped with a leachate collection and treatment facility, was found capable of exerting genotoxic effects that may influence the biota of the receiving system. © 1998 John Wiley & Sons, Inc. Environ Toxicol Water Qual 13: 127–131, 1998

A Review Of Recent Studies On The Sources Of Hazardous Compounds Emitted From Solid Waste Landfills: A U.S. Experience

Municipal solid waste landfills operating in the United States receive a large variety of materials generated by an industrialized, "throwaway" society. As a result, liquid and gas emissions (produced during the normal decomposition processes occurring within the landfill) are often contaminated with hazardous compounds. The presence of hazardous pollutants in liquid and gaseous emissions is well documented, however, the source of these pollutants is not always apparent. Potential sources of these hazardous contaminants in municipal solid waste landfills may include small quantity generators of hazardous wastes, household hazardous wastes, wastes disposed prior to the 1980 enactment of U.S. hazardous waste disposal legislation, and biological and chemical transformation products of buried refuse. Source identification will facilitate characterization and quantification of emissions necessary for the design and operation of leachate gas collection and treatment facilities.

A Review of Recent Studies On the Sources of Hazardous Compounds Emitted From Solid Waste Landfills: a U.S. Experience

Municipal solid waste landfills operating in the United States receive a large variety of materials generated by an industrialized, "throwaway" society. As a result, liquid and gas emissions (produced during the normal decomposition processes occurring within the landfill) are often contaminated with hazardous compounds. The presence of hazardous pollutants in liquid and gaseous emissions is well documented, however, the source of these pollutants is not always apparent. Potential sources of these hazardous contaminants in municipal solid waste landfills may include small quantity generators of hazardous wastes, household hazardous wastes, wastes disposed prior to the 1980 enactment of U.S. hazardous waste disposal legislation, and biological and chemical transformation products of buried refuse. Source identification will facilitate characterization and quantification of emissions necessary for the design and operation of leachate gas collection and treatment facilities.