Municipal Waste Landfill Research Articles

Method of evaluating the impact of landfill leachate on groundwater quality

Closed municipal and industrial waste landfill sites create potential hazard of ground water pollution. Pollutants that occur in leachate infiltrate to the soil substratum, where they are carried to in underground water. A municipal waste landfill substratum can be used for elimination of pollutants contained in leachates. Model research was performed with the use of a sand bed and artificially prepared leachates. Efficiency of filtration in a bed of defined thickness was assessed based on change of COD value. Results of the model tests have indicated that the mass of pollutants contained in leachate filtered through porous ground layer depends on the mass of supplied pollutants, intensity of supplied leachate, and layer thickness. Increase of the mass of pollutants supplied to a unit area of ground layer causes reduction of the relative value of COD mass. The method of evaluation of quality of water seeping through the aeration layer presented in this paper allows for estimation of the flowing out pollutants mass. Based on the test results obtained, efficiency of purification in the aeration zone can be assessed; likewise, safe thickness of the filtration layer under the landfill site can be designed.

Seasonal characterization and quantification of municipal solid waste: Energy content and statistical analysis

Determining the seasonal and annual quantities and compositions of the municipal solid waste and assessing the present management conditions of three urban communities in the northwest of Iran were the core objectives of this study. Our findings revealed that the average daily per capita of municipal waste generation was 0.489–0.841 kg/cap-day. Organic and food waste comprised the largest part (56.46%) of the total generated waste in the studied cities, whereas paper and cardboard, plastics, metals, rubber, textiles, glass, woods, and other waste constituted 5.99, 12.62, 1.05, 0.95, 7.71, 1.63, 1.23, and 12.36%, respectively. More than 21% of the total generated waste was directly recyclable. Bulk density of the waste was determined as 182.53 kg/m3. In addition, the moisture content and the chemical characteristics (food and organic fraction) of the generated waste including the amounts of carbon, nitrogen, phosphorous, ash, and C/N ratio were 67.44, 50.86, 1.67, 0.41, 34.91, and 30.61%, respectively. Waste composition in different seasons followed a variable pattern. In the present conditions, all the three studied cities were sending their waste to the municipal waste landfill sites that were actually used as a dump for waste. Hence, great concerns were raised from the public health and environmental viewpoints such as ground water, soil, and air pollution at the final disposal sites in the area. Implementation of source reduction, separation and recycling program, closing dump sites, and investing for new landfill sites according to the scientific and environmental approaches, were proposed.

Heavy metals contamination and human health risk assessment in soils of an industrial area, Bandar Abbas – South Central Iran

ABSTRACTThe purpose of this study was to determine the contamination level, distribution, health risk and potential sources of Cr, Cd, Pb, Zn, Cu, Ni and As in 66 topsoil samples from industrial areas in Bandar Abbas County. The geoaccumulation index, pollution index and pollution load index were calculated to assess the pollution level in the industrial soils. The hazard index and carcinogenic risk were used to assess human health risk of heavy metals. Results showed that the contamination levels of heavy metals were in the descending order of Cu> Cd> Pb> Zn> As> Ni> Cr. Moreover, based on principal component analysis, Cd, Zn, Cu, and Pb originated mainly from anthropogenic sources, including power plants, oil and gas refinery, steel and zinc production factories and municipal waste landfills. For non-carcinogenic effects, hazard index of studied metals decreased in the order of Cr> As> Cd> Pb> Ni > Cu> Zn. Arsenic, chromium and cadmium were regarded as the priority pollutants. Carcinogenic risks due to Cd and As in suburban soils were within tolerable risk to human health; however, children faced more health risk in their daily life than adults via their unconscious ingestion and dermal contact pathway.

Performance evaluation of a biological landfill leachate treatment plant and effluent treatment by electrocoagulation

A major problem in municipal waste landfills is generation of leachate, a dark black colored liquid with high concentrations of pollutants. The objectives of this study were to evaluate the efficiency of available leachate treatment methods at a biological treatment plant and the electrocoagulation (EC) process using aluminum and iron electrodes for treatment of effluent from the biological treatment plant. In this experimental study, leachate from the AqQala landfill in Gorgan was examined. Equipment for electrochemical unit included a power supply as well as iron and aluminum electrodes. The EC process was operated under different reaction times (20, 40, 60 min), pH values (3, 7, 9) and current densities (1.66, 3.33, 5A/m2 ). The results showed that the effluent from the biological treatment plant has high concentrations of organic matter similar to wastewater, and should therefore be treated before discharge to the environment. According to the results, increasing the reaction time or the current density in the EC process increases the removal efficiency. The EC process is suggested as an alternative treatment process with high efficiency for the removal of organic matter, nitrate, phosphorous and turbidity in sewage treatment, which could prevent water and soil pollution.

Numerical simulation of benzene seepage through cracked compacted mineral liner of municipal waste landfill

Numerical simulation of benzene seepage through cracked compacted mineral liner of municipal waste landfill

Development of Proposals for Solid Municipal Waste Landfill Placing by Example of Regions of the Far North

The sustainable development of each region, the quality of its environment depends to a great extent on the provision of environmental safety, especially in the field of waste management. The growth of industrial production in the Tyumen region and the improvement of the population social base contributes to a significant increase in production and consumption waste. The article is devoted to the problem of the emergence, recycling and utilization of an increasing amount of solid municipal waste every year. The author considers the unresolved issues of the location, processing and disposal of waste in the Nefteyugansk District, the Khanty-Mansi Autonomous Okrug - Yugra, leading to increase in their volumes, the size of the territory they occupy, increase in the number of unauthorized landfills, intensive pollution of soils, surface and groundwaters and atmospheric air. Proposals for the placement of a comprehensive inter-municipal TKO testing ground have been developed. The most favorable territory for the location of the TKO enterprise was determined.

Effects of the silica nanoparticles (NPSiO2) on the stabilization and transport of hazardous nanoparticle suspensions into landfill soil columns

Abstract This study evaluates the stability and transport behaviors of hazardous nanoparticles into soil landfills using experimental procedures to simulate the effects of natural silica nanoparticle suspensions during their percolation into the soil layers of municipal waste landfills. For this, we prepared stabilized suspensions of nanoparticle oxides containing silicon (NPSiO2), titanium (NPTiO2), copper (NPCuO) and zinc (NPZnO), which are recognized as hazardous to the environment, and we conducted leaching experiments within the soil column by simulating landfills layers and simulating the capture and attenuation of nanomaterials into municipal waste landfills. The results demonstrated that the presence of NPSiO2 in suspensions increases the stable concentrations of copper, zinc and titanium oxides and strongly decreases soil layer effectiveness. In contrast, NPZnO improves effectiveness due to its ability to promote agglomeration and setting conditions, allowing further complexation.

Determination of biomass content in combusted municipal waste and associated CO2 emissions in Estonia

Incineration of mixed municipal waste is gaining increasing importance in many European countries. This is also the case in several European Union member states such as Estonia, where waste-to-energy technology provides a relatively fast option to meet the demanding EU waste management targets regarding municipal waste recovery and landfilling. Furthermore, the biomass fraction of municipal solid waste, when used as a fuel for energy production, is recognised as a renewable energy source and is therefore eligible for government subsidy under Estonian legislation. Also CO2 emissions are accounted for according to their source, either as biogenic (resulting from the biomass fraction of the waste), and thus climate neutral, or as fossil, and thus liable for CO2 charges. Therefore, it is crucial that operators of waste incineration plants are able to determine the ratio of biogenic and fossil carbon in combustible waste. This paper summarises the results of the research conducted in the first waste incineration plant in Estonia and the Baltic States to determine the material composition (incl. biomass content) and the proportion of fossil CO2 emission from combusted mixed municipal solid waste. The results of a one year long manual waste sorting study and laboratory analysis show that the share of the biomass fraction is approximately 52 % in the combusted municipal solid waste (on a dry weight basis) and that fossil carbon accounts for about 40 % of the total carbon (on a wet weight bases). The associated annual average fossil CO2 emissions are about 429 kg per ton of combusted municipal waste.

Effect of salt concentration on desiccation cracking behavior of GMZ bentonite

Bentonite has been proposed for use as an engineering barrier and buffer in nuclear waste repositories and has been used frequently in municipal waste landfills. The cracking behavior and deformation properties of this material can be influenced by the chemistry of pore water. In the present work, the influence of salt concentration on the desiccation cracking behavior of GMZ bentonite was investigated with laboratory experiments. Image processing techniques and SEM tests were performed on the specimens which had undergone the desiccation testing in order to analyze the cracking mechanisms. Results show that the water evaporation process can be identified by a steady rate stage, a falling rate stage and a residual stage. The water evaporation rate is strongly affected by the salt concentration of the pore water; higher salt concentrations result in lower evaporation rates; the final water content is strongly impacted by a high initial salinity; otherwise the water contents are very similar for the residual stage. During desiccating, most of cracks appeared at the steady evaporation stage. The cracking morphology and patterns were greatly affected by the salt concentration of the pore water; and larger crack lengths and lower crack densities were obtained as the initial salinity was increased.

Refuse Derived Fuel from Municipal Solid Waste rejected fractions- a Case Study

Portuguese legislation enforces adequate alternatives to municipal waste landfilling of organic wastes as well as others susceptible of valorisation. In the present work, the energetic valorisation of final municipal solid wastes rejected fractions is studied through the production of Refuse Derived Fuel (RDF). To accomplish this purpose several sampling campaigns were performed. Physical, chemical and energetic characterization of the rejected streams was done. Preliminary data allows us to conclude that studied materials have interesting potential to be used as RDF, particularly if blended with higher heating value materials in order to obtain RDF pellets with good combustion behavior, consistency and storage characteristics.

Elimination of ethanethiol released from municipal wastes by absorption sequencing electrochemical oxidation

ABSTRACTAs a typical municipal waste landfill gas, ethanethiol can become an air pollutant because of its low odor threshold concentration and toxicity to human beings. A hybrid process of absorption combined with electrochemical oxidation to degrade ethanethiol was investigated. The ionic liquid 1-butyl-3-methylimidazolium tetrafluoroborate ([BMIM]BF4) was employed as an absorbent to capture ethanethiol from the air stream. Electrochemical oxidation demonstrated that ethanethiol could be oxidized on a β-PbO2 anode modified with fluoride, while [BMIM]BF4 was used as an electrolyte. After a reaction time of 90 min under a current density of 50 mA/cm2, ethanethiol could be thoroughly destructed by the successive attack of hydroxyl radicals (·OH) electrogenerated on the surface of the β-PbO2 anode, while the sulfur atoms in ethanethiol were ultimately converted to sulfate ions . The reaction mechanism is proposed, and the operating condition is also estimated with a kinetic model. This hybrid process could be a promising way to remove thiol compounds from municipal waste landfill gases.

Application of Electrical Resistivity Data Sets for the Evaluation of the Pollution Concentration Level within Landfill Subsoil

The paper presents complex analyses of geophysical site investigation results. The electrical resistivity method was used to investigate the potential pollutant migration pathways within areas of existing and former landfill sites. For the purpose of the present study, there were four municipal waste landfills and one industrial landfill chosen for further comprehensive analyses. The landfill bottom was isolated using geomembrane liner. However, ground water monitoring results revealed that the base was not leakage-free. Another two landfills were established in the past, when no containment systems were legally required. The geoelectrical investigation was the final part of an overall analytical assessment of the contaminated sites. The study was aimed at pollution spatial migration analyses and the interpretation of results, for further design of the reclamation and restoration plans. A clear correlation between pollution indicators such as salt compounds and electrical resistivity, allow aerial analyses and the precise determination of contaminated zones. The research results presented in the paper have been recently obtained and concern a period from 2010 to 2015.

Bio-recalcitrant pollutants removal from wastewater with combination of the Fenton treatment and biological oxidation

The implementation of the Fenton treatment as an intermediate step in combined technological scheme for the removal of bio-recalcitrant organic pollutants from industrial effluents is proposed in this study. The treatment schemes for the purification of three heavily polluted wastewaters originated from a municipal non-hazardous waste landfill, industrial hazardous waste landfill and plywood manufacturing factory were developed. Accordingly, the wastewaters were subjected to aerobic biological treatment (BIO) combined with the Fenton process with the final aim of establishing universally applicable treatment scheme.The study demonstrated that the Fenton oxidation can be successfully included in the high-strength wastewater treatment scheme as an intermediate treatment step for the removal of bio-recalcitrant organics fraction. The elaborated BIO-Fenton-BIO approach was found to be cost-effective for the total organic load reduction and for the selected specific pollutants removal from the studied high-strength wastewaters. Consequently, it could be considered suitable for broader practical implementation.

Instability Phenomena in Municipal Waste Landfill. Numerical Modeling in Saturated and Unsaturated Conditions

Instability phenomena in waste landfills are not rare and the consequences are more severe than ones for typical landslide, having also environmental impact. Old waste dumps are often located in dried (or partially dried) valleys, natural gulches or ravines, therefore waste is often placed on sloped ground. Their mechanical characteristics are often very poor and, due to lack of drainage systems, are in saturated state. Therefore, instability can appear at every stage of the operation, during the closure or post-closing. The paper presents some aspects related to specific instability phenomena in waste landfills and dumps and to stability analysis in saturated and unsaturated state using numerical methods. As well, it presents a case study of an old dumpsite in Romania where a landslide occurred during the closing works and for which a consolidation solution was proposed, based on drainage and mechanical consolidation. Numerical modeling has been used for simulating the effect of the drainage and for evaluating the gain in stability, considering the unsaturated final state of the drained waste.

Options and limitations for bromate control during ozonation of wastewater

Wastewater treatment plants (WWTPs) are important point sources for micropollutants, which are harmful to freshwater organisms. Ozonation of wastewater is a powerful option to abate micropollutants, but may result in the formation of the potentially toxic oxidation by-product bromate in bromide-containing wastewaters. This study investigates options to reduce bromate formation during wastewater ozonation by (i) reducing the bromide concentration of the wastewater, (ii) lowering the ozone dose during wastewater treatment and (iii) adding hydrogen peroxide to limit the lifetime of ozone and quench the intermediates of the bromate formation pathway. Two examples demonstrate that a high share of bromide in wastewater can originate from single point sources (e.g., municipal waste incinerators or landfills). The identification of major point sources requires laborious sampling campaigns, but may facilitate the reduction of the bromide load significantly. To reduce the bromate formation by lowering the ozone dose interferes with the aim to abate micropollutants. Therefore, an additional treatment is necessary to ensure the elimination of micropollutants. Experiments at a pilot-plant illustrate that a combined treatment (ozone/powdered activated carbon) allows to eliminate micropollutants with low bromate yields. Furthermore, the addition of hydrogen peroxide was investigated at bench-scale. The bromate yields could be reduced by ∼50% and 65% for a hydrogen peroxide dose of 5 and 10 mg L−1, respectively. In conclusion, there are options to reduce the bromate formation during wastewater ozonation, however, they are not simple with sometimes limited efficiency.

Removal of organic materials and hexavalent chromium from landfill leachate using a combination of electrochemical and photocatalytic processes

Leachate is one of the major problems of municipal waste landfills. Landfills produce a dark black colored liquid with high levels of chemical oxygen demand (COD) and heavy metals and low biochemical oxygen demand (BOD)/COD ratio. The objectives of this study were to evaluate the effectiveness of an electrochemical process using graphite and platinum electrodes and photocatalytic properties of titanium dioxide nanoparticles stabilized on bentonite at different reaction times for removal of chromium and organic materials from leachate. Equipment used in the electrochemical reactor included an anode electrode plate, a commercial platinum electrode and a graphite cathode. We also evaluated the impact of electrical current density (1-4 A/m(2)), reaction time (1-8 h), concentration of catalyst (1-4 g/L) and UV radiation intensity (3-8 UV lamps). The results showed that the removal efficiency increased with increasing reaction time, current density, intensity of UV radiation and dose of catalyst. Moreover, biodegradability (BOD/COD ratio) was improved. Based on the results, this electrochemical pretreatment process can remove organics materials, heavy metals, reduce organic load and increase wastewater biodegradability. Thus, it can be used as an efficient option for treating sewage and preventing environment pollution. Keywords Author Keywords:Leachate; Organic matter; Chromium; Electrochemical; Photocatalytic processes KeyWords Plus:WASTE-WATER; ALUMINUM ELECTRODES; ELECTROCOAGULATION; OXIDATION; IRRADIATION; WASTEWATERS; DEGRADATION; REACTOR; CR(VI); IRON

ЭКОЛОГО-ГЕОЛОГИЧЕСКАЯ ХАРАКТЕРИСТИКА ПОЛИГОНОВ ТВЕРДЫХ КОММУНАЛЬНЫХ ОТХОДОВ (ТКО) КАК СОВРЕМЕННЫХ ПРИРОДНО-ГЕОЛОГИЧЕСКИХ ОБЪЕКТОВ

ЭКОЛОГО-ГЕОЛОГИЧЕСКАЯ ХАРАКТЕРИСТИКА ПОЛИГОНОВ ТВЕРДЫХ КОММУНАЛЬНЫХ ОТХОДОВ (ТКО) КАК СОВРЕМЕННЫХ ПРИРОДНО-ГЕОЛОГИЧЕСКИХ ОБЪЕКТОВ

Bromide Sources and Loads in Swiss Surface Waters and Their Relevance for Bromate Formation during Wastewater Ozonation.

Bromide measurements and mass balances in the catchments of major Swiss rivers revealed that chemical industry and municipal waste incinerators are the most important bromide sources and account for ∼50% and ∼20%, respectively, of the ∼2000 tons of bromide discharged in the Rhine river in 2014 in Switzerland. About 100 wastewater treatment plants (WWTPs) will upgrade their treatment for micropollutant abatement in the future to comply with Swiss regulations. An upgrade with ozonation may lead to unintended bromate formation in bromide-containing wastewaters. Measured bromide concentrations were <0.05 mg L(-1) in ∼75% of 69 WWTPs, while they ranged from 0.4 to ∼50 mg L(-1) in WWTPs with specific bromide sources (e.g., municipal waste incinerators, landfill leachate, and chemical industry). Wastewater ozonation formed little bromate at specific ozone doses of ≤0.4 mg O3/mg DOC, while the bromate yields were almost linearly correlated to the specific ozone dose for higher ozone doses. Molar bromate yields for typical specific ozone doses in wastewater treatment (0.4-0.6 mg O3/mg DOC) are ≤3%. In a modeled extreme scenario (in which all upgraded WWTPs release 10 μg L(-1) of bromate), bromate concentrations increased by <0.4 μg L(-1) in major Swiss rivers and by several micrograms per liter in receiving water bodies with a high fraction of municipal wastewater.

Leachate from Municipal Waste Landfill and Its Natural Degradation-A Case Study of Zubří, Zlín Region.

This work deals with the natural degradation of leachate from an old reclaimed landfill by means of a biological pond. Hamra is a municipal waste landfill with a limited formation of leachate, which has already been reclaimed. Leachate in this location is disposed of using natural biogeochemical method, and it is subsequently discharged into a surface stream. The main issue dealt with here is the long-term effectiveness of natural degradation of leachate and the limits of its use. The solutions of these fundamental questions took advantage of a database of analytical assessments collected during a long-term monitoring of the landfill site. The primary degradation trends and the long-term development have been revealed and described on the basis of these assessments. The main benefit of the biological pond is the dilution of the dominant contaminants, especially of inorganic character. In the case of ammonium ions, they show nitrification caused by their transition from the reduction into oxidizing environment. From a long term point of view, the disadvantage of natural degradation of leachate can be seen in the gradual reduction in efficiency due to the concentration of the substances or an undesired growth of water plants, which can be successfully eliminated, for example, by means of targeted aeration and by maintaining vegetation in the pond and its surroundings. The biological potential of the locality is very favorable and, despite its anthropogenic load, it creates a location with suitable living conditions for many water animals and plants. That is why it can be concluded that the efficiency of the natural biochemical cleaning elements can be considered as sufficient, taking into account the nature of the deposited waste, the quantity and quality of leachate, as well as the climate character of the locality.

Migration of pollutants in porous soil environment

Abstract Landfill leachate makes a potential source of ground water pollution. Municipal waste landfill substratum can be used for removal of pollutants from leachate. Model research was performed with use of a sand bed and artificially prepared leachates. Effectiveness of filtration in a bed of specific thickness was assessed based on the total solids content. Result of the model research indicated that the mass of pollutants contained in leachate filtered by a layer of porous soil (mf) depends on the mass of pollutants supplied (md). Determined regression functions indicate agreement with empirical values of variable m′f. The determined regression functions allow for qualitative and quantitative assessment of influence of the analysed independent variables (m′d, l, ω) on values of mass of pollutants flowing from the medium sand layer. Results of this research can be used to forecast the level of pollution of soil and underground waters lying in the zone of potential impact of municipal waste landfill.