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1.
In Japan the volume of municipal solid waste is reduced by incineration, with fly ash and bottom ash disposed in controlled landfills. The leachability of anions and heavy metal cations, Zn, Cu and Pb, from MSW fly ash and bottom ash at different pHs was examined using batch- and column-leaching tests. The MSW ashes had a high capacity for neutralizing acids. Behaviour during leaching depended on the pH of the solution. For the volumes applied, the leachabilities of MSW fly ash were very similar at pHs from 3 to 6. Due to its amphoteric nature, Pb is leachable at pHs of approximately 10 or more, with leachate concentrations of about 3 and 3-10mg/L for the fly ash and bottom ash, respectively, much higher than for Zn and Cu. Pb concentrations for most leaching solutions were 1 and 3mg/L for the fly ash and bottom ash, respectively. Zn, and Cu leached at low concentrations for solutions of pH 3-6. Na and K ions leached at high concentrations of approximately 5000 mg/L in the first batch leaching test, decreasing to 10mg/L by the fourth leach. Ca and Mg ions leached more gradually than Na and K. Cl(-) and SO(4)(2+) ions were the major anions in the MSW ash. The high pH and cation leaching are expected to have negative impacts on the performance of clay liners.  相似文献   

2.
Due to the prohibition of food waste landfilling in Korea from 2005 and the subsequent ban on the marine disposal of organic sludge, including leachate generated from food waste recycling facilities from 2012, it is urgent to develop an innovative and sustainable disposal strategy that is eco-friendly, yet economically beneficial. In this study, methane production from food waste leachate (FWL) in landfill sites with landfill gas recovery facilities was evaluated in simulated landfill reactors (lysimeters) for a period of 90 d with four different inoculum–substrate ratios (ISRs) on volatile solid (VS) basis. Simultaneous biochemical methane potential batch experiments were also conducted at the same ISRs for 30 d to compare CH4 yield obtained from lysimeter studies. Under the experimental conditions, a maximum CH4 yield of 0.272 and 0.294 L/g VS was obtained in the batch and lysimeter studies, respectively, at ISR of 1:1. The biodegradability of FWL in batch and lysimeter experiments at ISR of 1:1 was 64% and 69%, respectively. The calculated data using the modified Gompertz equation for the cumulative CH4 production showed good agreement with the experimental result obtained from lysimeter study. Based on the results obtained from this study, field-scale pilot test is required to re-evaluate the existing sanitary landfills with efficient leachate collection and gas recovery facilities as engineered bioreactors to treat non-hazardous liquid organic wastes for energy recovery with optimum utilization of facilities.  相似文献   

3.
针对利用原有生活垃圾填埋场改扩建飞灰固化物填埋场,从勘查设计和建设角度,通过与常规生活垃圾填埋的安全和环保各相关因素对比,分析扩建前后填埋场稳定性、防渗及导排系统等勘察设计要点,研讨扩建工程新老填埋堆体基础层、防渗及导排系统等安全环保关键技术及扩建的适宜性,为扩建的可行性研究提出较为系统的技术论证思路.  相似文献   

4.
Limited space for accommodating the ever increasing mounds of municipal solid waste (MSW) demands the capacity of MSW landfill be maximized by building landfills to greater heights with steeper slopes. This situation has raised concerns regarding the stability of high MSW landfills. A hybrid method for quasi-three-dimensional slope stability analysis based on the finite element stress analysis was applied in a case study at a MSW landfill in north-east Spain. Potential slides can be assumed to be located within the waste mass due to the lack of weak foundation soils and geosynthetic membranes at the landfill base. The only triggering factor of deep-seated slope failure is the higher leachate level and the relatively high and steep slope in the front. The valley-shaped geometry and layered construction procedure at the site make three-dimensional slope stability analyses necessary for this landfill. In the finite element stress analysis, variations of leachate level during construction and continuous settlement of the landfill were taken into account. The "equivalent" three-dimensional factor of safety (FoS) was computed from the individual result of the two-dimensional analysis for a series of evenly spaced cross sections within the potential sliding body. Results indicate that the hybrid method for quasi-three-dimensional slope stability analysis adopted in this paper is capable of locating roughly the spatial position of the potential sliding mass. This easy to manipulate method can serve as an engineering tool in the preliminary estimate of the FoS as well as the approximate position and extent of the potential sliding mass. The result that FoS obtained from three-dimensional analysis increases as much as 50% compared to that from two-dimensional analysis implies the significance of the three-dimensional effect for this study-case. Influences of shear parameters, time elapse after landfill closure, leachate level as well as unit weight of waste on FoS were also investigated in this paper. These sensitivity analyses serve as the guidelines of construction practices and operating procedures for the MSW landfill under study.  相似文献   

5.
In recent history the volume of electronic products purchased by consumers has dramatically escalated. As a result this has produced an ever-increasing electronic waste (E-waste) stream, which has generated concerns regarding the E-waste’s potential for adversely impacting the environment. The leaching of toxic substances from obsolete personal computers (PCs) and cathode ray tubes (CRTs) of televisions and monitors, which are the most significant components in E-waste stream, was studied using landfill simulation in columns. Five columns were employed. One column served as a control which was filled with municipal solid waste (MSW), two columns were filled with a mixture of MSW and CRTs, and the other two were filled with MSW and computer components including printed wire boards, hard disc drives, floppy disc drives, CD/DVD drives, and power supply units. The leachate generated from the columns was monitored for toxic materials throughout the two-year duration of the study. Results indicate that lead (Pb) and various other heavy metals that were of environmental and health concern were not detected in the leachate from the simulators. When the samples of the solids were collected from underneath the E-waste in the columns and were analyzed, significant amount of Pb was detected. This indicates that Pb could readily leach from the E-waste, but was absorbed by the solids around the E-waste materials. While Pb was not observed in the leachate in this study, it is likely that the Pb would eventually enter the leachate after a long term transport.  相似文献   

6.
Recently, roofed landfills have been gaining popularity in Japan. Roofed landfills have several advantages over non-roofed landfills such as eliminating the visibility of waste and reducing the spread of offensive odours. This study examined the moisture balance and aeration conditions, which promote waste stabilisation, in a roofed landfill that included organic waste such as food waste. Moisture balance was estimated using waste characterization and the total amount of landfilled waste. Internal conditions were estimated based on the composition, flux, and temperature of the landfill gas. Finally, in situ aeration was performed to determine the integrity of the semi-aerobic structure of the landfill.With the effects of rainfall excluded, only 15% of the moisture held by the waste was discharged as leachate. The majority of the moisture remained in the waste layer, but was less than the optimal moisture level for biodegradation, indicating that an appropriate water spray should be administered. To assess waste degradation in this semi-aerobic landfill, the concentration and flow rate of landfill gas were measured and an in situ aeration test was performed. The results revealed that aerobic biodegradation had not occurred because of the unsatisfactory design and operation of the landfill.  相似文献   

7.
Fresh municipal solid waste incineration residues (MSWIR) and a drilling core of 2-10 years old landfilled MSWIR were investigated to determine the alterations due to weathering in a landfill. Physical and geochemical properties and transformations of major components and heavy metals were analyzed for fresh and landfilled residues. Carbonates and hydroxides (10-12vol%) as major mineralogical compositions in the 8-10 years weathered MSWIR were observed by modal analysis of thin sections. Three step sequential extractions indicated that reducible phases, mainly the Fe, Al and Mn hydroxides increased with depth in the landfill. A pH controlled leaching test (including availability test and pH dependent leaching test) was then conducted. Results indicated lower concentrations of leachable contents at pH values from 6 to 10 for the four elements (Pb, Zn, Al and Fe) in the 8-10 years landfilled residues than in the fresh and 1-2 years landfilled residues. This means that 8-10 years weathered MSWIR became more stable than fresh landfilled residues. The reasons for the stabilization of these elements might be the hydration of Al and Fe during weathering in the landfill, which then results in the heavy metals adsorptions of these minerals.  相似文献   

8.
建立了针对生活垃圾填埋场地下水污染问题的数学预测模型,以丹阳北庄生活垃圾填埋场工程为例,预测和分析了北庄生活垃圾填埋场渗滤液对地下水的污染。  相似文献   

9.
The rate and extent of deterioration of starch-plastic composites were determined over a 2-year period for samples buried in a municipal solid waste landfill. The deterioration of the starch-plastic composites following exposure was determined by measuring changes in tensile properties, weight loss, and starch content of samples retrieved from the landfill. Elongation decreases of 92 and 44% were measured for starch-plastic composite LDPE and LLDPE films, respectively, while elongation decreases of 54 and 21% were measured for their corresponding control films following 2 years of burial. Starch loss of 25% for LLDPE and 33% for LDPE starch-plastic composite films was measured following 2 years of landfill burial. Starch-plastic composites did not fragment or lose mass during the 2-year landfill burial. The limited degradation observed for the starch-plastic composites was attributed to the ineffectiveness of the prooxidant additive to catalyze the thermal oxidation of the polyethylene or polypropylene component of the starch-plastic composite under the environmental conditions present within the landfill.  相似文献   

10.
This research concentrates the design, construction and evaluation of simulated pilot scale landfill lysimeter at KUET campus, Khulna, Bangladesh. Both the aerobic and anaerobic conditions having a base liner and two different types of cap liner were simulated. After the design of a reference cell, the construction of landfill lysimeter was started in January 2008 and completed in July 2008. In all construction process locally available civil construction materials were used. The municipal solid waste (MSW) of 2800–2985 kg having the total volume of 2.80 m3 (height 1.6 m) and moisture content of 65% was deposited in each lysimeter by applying required compaction energy. In contrast, both the composition in terms of methane (CH4), carbon dioxide (CO2) and oxygen (O2) as well as the flow rate of landfill gas (LFG) generated from MSW in landfill lysimeter were measured and varied significantly in relation to the variation of lysimeter operational condition. Moreover, anaerobic lysimeter-C shows the highest composition of LFG in compare to the anaerobic lysimeter-B due to the providing of lower compaction of cap liner in anaerobic lysimeter-C. Here, it is interesting to note that in absence of compacted clay liner (CCL) and hence percolation of rainwater that facilitates rapid degradation of MSW in aerobic lysimeter-A has resulted in the highest settlement than that of anaerobic landfill lysimeter-B and C. Moreover, in case of anaerobic lysimeter-B and C, the leachate generation was lower than that of aerobic lysimeter-A due to the providing of cap liner in anaerobic lysimeter-B and C, played an important role to reduce the percolation of rainwater. The study also reveals that the leachate pollution index (LPI) has decreased in relation to the increasing of elapsed period as well as the LPI for collection system of aerobic lysimeter-A was higher than that of the collection system of anaerobic lysimeter-B and C. Finally, it can be depicted that LPI for lysimeter was significantly high and proper treatment will be necessary before discharging the lysimeter leachate into the water bodies.  相似文献   

11.
Journal of Material Cycles and Waste Management - Owing to Minamata Convention on mercury, the final disposal of mercury in environmentally safe manners will be required. Mercury disposal in...  相似文献   

12.
This study was conducted to evaluate the possibility of applying the stoichiometric methane potential using elemental analysis, to landfill gas modeling at the Sudokwon 2nd Landfill Site in South Korea, where most of the household and demolition waste from more than twenty million citizens is disposed. The used model structure is based on the first order decay equation. The theoretical stoichiometric methane potential was corrected by multiplying the ratio of decomposable carbon which was obtained by biochemical decomposable carbon test. Then the optimum reaction constant k was found by sensitivity analysis and the Monte Carlo method. Under these input conditions, the modeling results showed that the discrepancies between the measured and modeled values of total quantity of methane and the mean deviation were 1.6 and 3.2%, respectively. Thus, it can be established that the application of stoichiometric method using elemental analysis data could be a useful methods to apply to landfill gas modeling.  相似文献   

13.
Journal of Material Cycles and Waste Management - As resident awareness of environmental issues has grown, waste disposal has become an important part of urban environmental governance. Most...  相似文献   

14.
Municipal solid waste disposal sites in arid countries such as Kuwait receive various types of waste materials like sewage sludge, chemical waste and other debris. Large amounts of leachate are expected to be generated due to the improper disposal of industrial wastewater, sewage sludge and chemical wastes with municipal solid waste at landfill sites even though the rainwater is scarce. Almost 95% of all solid waste generated in Kuwait during the last 10 years was dumped in five unlined landfills. The sites accepting liquid waste consist of old sand quarries that do not follow any specific engineering guidelines. With the current practice, contamination of the ground water table is possible due to the close location of the water table beneath the bottom of the waste disposal sites. This study determined the percentage of industrial liquid waste and sludge of the total waste dumped at the landfill sites, analyzed the chemical characteristics of liquid waste stream and contaminated water at disposal sites, and finally evaluated the possible risk posed by the continuous dumping of such wastes at the unlined landfills. Statistical analysis has been performed on the disposal and characterization of industrial wastewater and sludge at five active landfill sites. The chemical analysis shows that all the industrial wastes and sludge have high concentrations of COD, suspended solids, and heavy metals. Results show that from 1993 to 2000, 5.14+/-1.13 million t of total wastes were disposed per year in all active landfill sites in Kuwait. The share of industrial liquid and sludge waste was 1.85+/-0.19 million t representing 37.22+/-6.85% of total waste disposed in all landfill sites. Such wastes contribute to landfill leachate which pollutes groundwater and may enter the food chain causing adverse health effects. Lined evaporation ponds are suggested as an economical and safe solution for industrial wastewater and sludge disposal in the arid climate of Kuwait.  相似文献   

15.
The biodrying process of solid waste is a pre-treatment for the bio-stabilisation of the municipal solid waste. This study aims to investigate the fate of the municipal solid waste fine fraction (MSWFF) resulting from a biodrying treatment when disposed in landfills that are operated as bioreactors. Biodried MSWFF was apparently stable due to its low moisture content that slows down the microbial activity. The lab-scale anaerobic bioreactors demonstrated that a proper moisture content leads to a complete biodegradation of the organic matter contained in the biodried MSWFF. Using a pilot-scale landfill bioreactor (LBR), MSWFF stabilisation was achieved, suggesting that the leachate recirculation could be an effective approach to accomplish the anaerobic biodegradation and biostabilisation of biodried MSWFF after landfilling. The biostabilisation of the material resulting from the LBR treatment was confirmed using anaerobic and aerobic stability indices. All anaerobic and aerobic indices showed a stability increase of approximately 80% of the MSWFF after treatment in the LBR. The similar values of OD7 and BMP stability indices well agree with the relationship between the aerobic and anaerobic indices reported in literature.  相似文献   

16.
The evaluation of a hazardous waste disposal site is a complicated process because it requires data from diverse social and environmental fields. These data often involve processing of a significant amount of spatial information which can be used by GIS as an important tool for land use suitability analysis. This paper presents a multi-criteria decision analysis alongside with a geospatial analysis for the selection of hazardous waste landfill sites in Kurdistan Province, western Iran. The study employs a two-stage analysis to provide a spatial decision support system for hazardous waste management in a typically under developed region. The purpose of GIS was to perform an initial screening process to eliminate unsuitable land followed by utilization of a multi-criteria decision analysis (MCDA) to identify the most suitable sites using the information provided by the regional experts with reference to new chosen criteria. Using 21 exclusionary criteria, as input layers, masked maps were prepared. Creating various intermediate or analysis map layers a final overlay map was obtained representing areas for hazardous waste landfill sites. In order to evaluate different landfill sites produced by the overlaying a landfill suitability index system was developed representing cumulative effects of relative importance (weights) and suitability values of 14 non-exclusionary criteria including several criteria resulting from field observation. Using this suitability index 15 different sites were visited and based on the numerical evaluation provided by MCDA most suitable sites were determined.  相似文献   

17.
GIS-based approach for optimized siting of municipal solid waste landfill   总被引:4,自引:1,他引:3  
The exponential rise in the urban population of the developing countries in the past few decades and the resulting accelerated urbanization phenomenon has brought to the fore the necessity to develop environmentally sustainable and efficient waste management systems. Sanitary landfill constitutes one of the primary methods of municipal solid waste disposal. Optimized siting decisions have gained considerable importance in order to ensure minimum damage to the various environmental sub-components as well as reduce the stigma associated with the residents living in its vicinity, thereby enhancing the overall sustainability associated with the life cycle of a landfill. This paper addresses the siting of a new landfill using a multi-criteria decision analysis (MCDA) and overlay analysis using a geographic information system (GIS). The proposed system can accommodate new information on the landfill site selection by updating its knowledge base. Several factors are considered in the siting process including geology, water supply resources, land use, sensitive sites, air quality and groundwater quality. Weightings were assigned to each criterion depending upon their relative importance and ratings in accordance with the relative magnitude of impact. The results from testing the system using different sites show the effectiveness of the system in the selection process.  相似文献   

18.
Long-term biodegradation of MSW in an aerobic landfill bioreactor was monitored as a function of time during 510 days of operation. Operational characteristics such as air importation, temperature and leachate recirculation were monitored. The oxygen utilization rates and biodegradation of organic matter rates showed that aerobic biodegradation was feasible and appropriate to proceed in aerobic landfill bioreactor. Leachate analyses showed that the aerobic bioreactor could remove above 90% of chemical oxygen demand (COD) and close to 100% of biochemical oxygen demand (BOD5) from leachate. Ammonium (NH4+), nitrate (NO3-) and sulphate (SO4(2-)) concentrations of leachate samples were regularly measured. Results suggest that nitrification and denitrification occurred simultaneously, and the increase in nitrate did not reach the levels predicted stoichiometrically, suggesting that other processes were occurring. Leachate recirculation reduced the concentrations of heavy metals because of the effect of the high pH of the leachate, causing heavy metals to be retained by processes such as sorption on MSW, carbonate precipitation, and hydroxide precipitation. Furthermore, the compost derived from the aerobic biodegradation of the organic matter of MSW may be considered as soil improvement in the agricultural plant production. Bio-essays indicated that the ecotoxicity of leachate from the aerobic bioreactor was not toxic at the end of the experiment. Finally, after 510 days of degradation, waste settlement reached 26% mainly due to the compost of the organic matter.  相似文献   

19.
In order to investigate the effect of raw leachate on anaerobic digestion of food waste, co-digestions of food waste with raw leachate were carried out. A series of single-phase batch mesophilic (35 ± 1 °C) anaerobic digestions were performed at a food waste concentration of 41.8 g VS/L. The results showed that inhibition of biogas production by volatile fatty acids (VFA) occurred without raw leachate addition. A certain amount of raw leachate in the reactors effectively relieved acidic inhibition caused by VFA accumulation, and the system maintained stable with methane yield of 369–466 mL/g VS. Total ammonia nitrogen introduced into the digestion systems with initial 2000–3000 mgNH4–N/L not only replenished nitrogen for bacterial growth, but also formed a buffer system with VFA to maintain a delicate biochemical balance between the acidogenic and methanogenic microorganisms. UV spectroscopy and fluorescence excitation–emission matrix spectroscopy data showed that food waste was completely degraded.We concluded that using raw leachate for supplement water addition and pH modifier on anaerobic digestion of food waste was effective. An appropriate fraction of leachate could stimulate methanogenic activity and enhance biogas production.  相似文献   

20.
Journal of Material Cycles and Waste Management - Minamata convention on mercury requests mercury wastes landfilling in environmentally safe manners. Owing to great difficulties to form public...  相似文献   

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