Collection Pipe Research Articles

METHOD OF COLLECTING DOMESTIC SOLID WASTE IN THE URBANIZATION PROCESS IN NAM TU LIEM DISTRICT, HANOI CITY

Nam Tu Liem district is a newly established district of Hanoi city, the urbanization process is taking place rapidly, and urban facilities and infrastructure are being developed, on the other hand, it also creates pressure on the environment, increasing the amount of solid waste. This study aims to understand the changes in the management and collection methods of domestic solid waste in residential areas, during the urbanization process. The study uses the field survey method, collects information from residents and management agencies, conducts analysis, and evaluates the effectiveness of waste collection methods currently being implemented in this district. The study results calculated that there are about 330.34 tons of domestic solid waste generated every day, domestic solid waste is collected at fixed locations and times in residential areas. For old apartment buildings, waste is collected at no fixed time, by collection pipes along the height of the building and then led to the ground floor. The collection model has changed in new apartment buildings, solid waste is collected at the garbage collection room on each separate floor, then the garbage collectors will transport it to the garbage collection point. The study found that 70 % of respondents did not classify solid waste at source, 29 % did classify solid waste to extract some recyclable waste components to sell to scrap collectors, and a few people classified organic waste to compost for growing plants at home. Most people understood or had heard of waste classification at source, but only 34 % of respondents were willing to change their habits or spend money to classify waste at source.

A novel stereoscopic mode of planting and breeding shed

A novel stereoscopic mode of planting and breeding shed has been designed. The shed body comprises of a steel frame structure inserted with 4 transverse beams along the length direction of the shed through the middle part of the shed body. The transverse beams are covered with a partition. The top of the shed body is covered with 300 and 80 solar panels, while the lower and upper sides are covered with the first and second transparent materials. The partition is provided with 200 and 40 breeding cages, where the 200 and 40 manure drains connected to the breeding cages (each manure drain connected to one breeding cage) are vertically arranged under the partition. The 2 manure collection pipes are connected to the manure drains at a slope of 60?. The transverse beams have 80 adjustable hammocks, which serve as space-saving hanging pots to grow plants. The lower side of the partition is provided with eighty spray heads through the pipes. The inner side of the shed body is provided with twenty heating devices. The novel planting and breeding shed can effectively utilize space, achieving the recycling of resources and waste, maximizing economic benefits and realizing the concept of low-carbon and green environmental protection.

Numerical investigation and optimal design of capillary barrier cover with passive gas collection pipes on the performance at limiting landfill gas emissions

Relying solely on soil properties may not fully ensure the performance of capillary barrier covers at limiting landfill gas (LFG) emissions. This study proposed to install passive gas collection pipes in the coarse-grained soil layers of capillary barrier covers to enhance their performance at limiting LFG emissions. First, the LFG generation rate of municipal solid waste and its influencing factors were analyzed based on empirical formulas. This information provided necessary bottom boundary conditions for the analyses of LFG transport through capillary barrier covers with passive gas collection pipes (CBCPPs). Then, numerical simulations were conducted to investigate the LFG transport properties through CBCPPs and reveal relevant influencing factors. Finally, practical suggestions were proposed to optimize the design of CBCPPs. The results indicated that the maximum whole-site LFG generation rate occurred at the end of landfilling operation. The gas collection efficiency (E) of CBCPPs was mainly controlled by the ratio of the intrinsic permeability between the coarse- and fine-grained soil (K2/K1) and the laying spacing between gas collection pipes (D). E increased as K2/K1 increased but decreased as D increased. An empirical expression for estimating E based on K2/K1 and D was proposed. In practice, CBCPPs were supposed to be constructed once the landfilling operation finished. It is best to select the fine- and coarse-grained soils with K2/K1 exceeding 10,000 to construct CBCPPs.

Efficient hydraulic and thermal simulation model of the multi-phase natural gas production system with variable speed compressors

The natural gas production system is a very complex system, involving pipelines, compressors and valves with different structures and calculation parameters. It can be divided into two different parts: gas production and collection pipe networks. Fluid flow in the gas production pipe network is multi-phase flow. Fluid flow in the gas collection pipe network is single-phase flow. It is imperative to consider gas production and collection pipe networks in conjunction to ensure accurate operation simulation. The complexity of the network structures and flow statuses can cause computational instability or even divergence problems in simulations when coupling these two types of pipe networks. To address this issue, an automatic and practical node numbering method is proposed for the large-scale pipe network, which can ensure the full rank of the solution matrix and computational stability. On the other hand, due to the need for frequent adjustments of the pipe networks to satisfy the production demand, computational boundary treatments of constant inlet/outlet pressure, constant flow rate or constant pressure ratio for the compressor stations are not suitable. To address this issue, the characteristic curves of compressors are coupled into the simulation of pipe networks to represent the variable-speed centrifugal and reciprocating compressors.The accuracy and robustness of the proposed models and numerical methods are validated through comparisons with software results and field data. The simulation time is only within 0.5 s for the natural gas production system with 210 nodes and 176 pipelines. Our model has relative deviations within 3% in both pressure and flow rate compared to field data and within 10% compared to software.

Prediction of drought in lake mead

Lake Mead is a reservoir on the Colorado River on the border of Nevada and Arizona. It is the largest reservoir in the United States. Due to the drought caused by climate change and the increasing water demand of the population served by Lake Mead, the capacity of this reservoir has been greatly reduced. The continuous water shortage has had a huge impact on the surrounding cities, and people are preparing to adopt wastewater recycling. To alleviate the shortage of water sources. this paper uses the water level data of the past years to establish a grey forecast Grey Model (1,1) model to predict the changes in the water level of Lake Mead in the next 30 years and compares them based on the prediction of short-term and long-term drought data. based on the previous survey of wastewater sources and collection methods, it is believed that the wastewater recovery system is mainly affected by four factors: financial support, collection pipe network coverage, treatment technology, and wastewater classification capabilities.

Sanitary installations and wastewater plumbing as reservoir for the long-term circulation and transmission of carbapenemase producing Citrobacter freundii clones in a hospital setting

BackgroundAccumulating evidence shows a role of the hospital wastewater system in the spread of multidrug-resistant organisms, such as carbapenemase producing Enterobacterales (CPE). Several sequential outbreaks of CPE on the geriatric ward of the Ghent University hospital have led to an outbreak investigation. Focusing on OXA-48 producing Citrobacter freundii, the most prevalent species, we aimed to track clonal relatedness using whole genome sequencing (WGS). By exploring transmission routes we wanted to improve understanding and (re)introduce targeted preventive measures.MethodsEnvironmental screening (toilet water, sink and shower drains) was performed between 2017 and 2021. A retrospective selection was made of 53 Citrobacter freundii screening isolates (30 patients and 23 environmental samples). DNA from frozen bacterial isolates was extracted and prepped for shotgun WGS. Core genome multilocus sequence typing was performed with an in-house developed scheme using 3,004 loci.ResultsThe CPE positivity rate of environmental screening samples was 19.0% (73/385). Highest percentages were found in the shower drain samples (38.2%) and the toilet water samples (25.0%). Sink drain samples showed least CPE positivity (3.3%). The WGS data revealed long-term co-existence of three patient sample derived C. freundii clusters. The biggest cluster (ST22) connects 12 patients and 8 environmental isolates taken between 2018 and 2021 spread across the ward. In an overlapping period, another cluster (ST170) links eight patients and four toilet water isolates connected to the same room. The third C. freundii cluster (ST421) connects two patients hospitalised in the same room but over a period of one and a half year. Additional sampling in 2022 revealed clonal isolates linked to the two largest clusters (ST22, ST170) in the wastewater collection pipes connecting the rooms.ConclusionsOur findings suggest long-term circulation and transmission of carbapenemase producing C. freundii clones in hospital sanitary installations despite surveillance, daily cleaning and intermittent disinfection protocols. We propose a role for the wastewater drainage system in the spread within and between rooms and for the sanitary installations in the indirect transmission via bioaerosol plumes. To tackle this problem, a multidisciplinary approach is necessary including careful design and maintenance of the plumbing system.

Performance evaluation of solid waste landfilled gas collection with HDPE pipe material characteristics analysis

The landfill gas collection pipe system for municipal solid waste is essential to be applied in different areas to maitain the people’s health, environment and as well as utilization of naturally generated land fill gas from MSW. The design of high density polyethylene pipe in solid waste dumpyard can be utilized in the suitable zones after proper treatment of MSW.This system provides material testing and design to fulfill the requirement of an LFG system. It consists LFG collector, piping system blower, compression system and gas engine to use the landfill gas for using the generating the energy.LFG abstraction at various pressure for an effective collection of gas system is beneficial for the environmental due to greenhouse gas emissions, smell control, minimizing fugitive emissions and fire catching in MSW dumpyards.Collection efficiency depends on suitable pipe system such as reducing hazardous,minimum lekage, maximum pressure bearing capacity with long life above 70 °C.This paper analyses the various testing parameters like hydraulic, tensile compressive, impact and bending properties of HDPE pipe.

Effect of landfill in-situ aeration with novel air amplifier: A case study

Landfill aeration may cause economic problems due to the amount of power consumed by blowers. Thus, this study proposes the use of an air amplifier to reduce the power consumption of air injection into landfills. The developed air amplifier is an aerodynamic device that induces a large amount of airflow using a small quantity of compressed air caused by the Coanda effect. Field experiment results demonstrated that the use of the air amplifier reduced power consumption by at least 90% and showed an air amplification effect of approximately 3.5 times compared with existing in-situ aeration systems. After aeration, the methane (CH<sub>4</sub>) reduction efficiency was 90.3%. The CH<sub>4</sub>/CO<sub>2</sub> ratio was 0.12 (0.06–0.25) on average, and the CH<sub>4</sub>/CO<sub>2</sub> ratio decreased as the oxygen concentration increased. Thus, the air amplifier is a low-cost solution for landfill aeration systems. In addition, aeration using existing leachate collection and drainage pipes was found to be more economical than air injection using air injection wells. However, despite the air injection, approximately 20% of organic carbon was decomposed anaerobically. The CH<sub>4</sub>/CO<sub>2</sub> ratio range of 0.56–0.90 was presented as a criterion for categorizing a landfill as semi-aerobic.

Tratamiento de lixiviados mezclados tipo I y tipo III mediante filtración y oxidación química

In Riobamba city from Ecuador, for more than thirty years solid urban waste was placed in an open dump, without gas and leachate control. In 2016, the landfill was technically closed and an emerging cell with the characteristics of a sanitary landfill was built nearby. The Environmental Health and Hygiene Management Department of the Riobamba Municipal Decentralized Autonomous Government monitors leachate generation, recording 19.24 m3/day of young leachate (Type I) from the emerging cell and 5.78 m3/day of mature leachate (Type III) from the old landfill. The two types of leachates are mixed in the main collection pipe that reaches a storage pool that receives 25.02 m3/day. The results of the physical-chemical analysis determine that the values of the parameters are outside the permissible limits. Turbidity is >1000 NTU (Nephelometric Turbidity Unit), and the concentration of suspended solids is 1200 mg. L-1 and iron 135.85 mg. L-1. Calcium (1223 mg. L-1) and manganese (356.15 mg. L-1) were also evaluated, as these minerals are related to the 16,000 mg. L-1 of hardness. For the treatment of the mixed leachate, two phases are proposed: a) physical treatment by downward filtration in a granular bed to reduce the concentrations of suspended solids, and b) chemical treatment by oxidation using sodium hypochlorite. Laboratory results showed a 96.40% decrease in the concentration of suspended solids. Turbidity stabilized at 65 UTN. Iron, calcium, and manganese concentrations decreased by 95.60%, 96.28%, and 50.60%, respectively.

Investigating the Deformation Characteristics of Buried High-Density Polyethylene Pipes: Considering the Effect of Sequentially Applying Pressure and Elevating Temperature.

High-density polyethylene (HDPE) materials have many applications in the municipal solid waste (MSW) landfills. HDPE gravity drainage pipes are commonly utilized in MSW landfills because of the polymer’s resistance to harsh chemical conditions. When landfill wastes are freshly filled, the weight acting on the leachate collection pipe increases. The temperature of the leachate collection pipe increases as a result of the heat produced by the decomposition of organic components after waste filling. In this paper, the effects of sequentially applying pressure and elevating temperature on the deformation characteristics (such as deformations and strains) of HDPE pipes are investigated. Measurements of pipe deformations and circumferential strains from model experiments in which 110 mm HDPE pipes were backfilled with sand and subjected to 300 kPa of maximum vertical pressure at temperatures of 20, 60 and 80 °C showed the following results: (1) a classification of pipe behavior relative to the surrounding soil stiffness is advantageous for HDPE pipe design; (2) when temperature increases to 60 °C and 80 °C, the strain distribution around the pipe changes from V-shaped to U-shaped, and the pipe deformation profile changes from elliptical to rectangular; (3) when temperature increases from 20 °C to 60 °C, the vertical and horizontal pipe deflections increase by a factor of 1.08~1.19; (4) when temperature increases from 60 °C to 80 °C, the vertical and horizontal pipe deflections increase by a factor of 1.15~1.31; and (5) the existing analytical method that considers two extreme interfaces can capture the deformations measured in the model test well. In addition, preliminary recommendations for the design of leachate collection pipes are provided based on the analysis of differences in pipe profile versus temperature.

Effects of saltwater intrusion and sea level rise on aging and corrosion rates of iron pipes in water distribution and wastewater collection systems in coastal areas

Failure of water distribution and wastewater collection pipes can impact human health and environment due to potential contamination of water and soil in the surrounding areas, as well as service interruptions and road closures. This paper provides a quantitative assessment of projected shifts in failure rates of iron pipes due to saltwater intrusion and sea level rise in coastal areas. Probability of pipe failure depends on pipe characteristics, environmental parameters, and systems conditions. Analyses showed that saltwater intrusion and sea level rise can significantly affect the integrity of water and wastewater collection pipes due to potential changes in soil and groundwater characteristics that increase corrosion rates. Corrosion rate is intensified by increased conductivity of groundwater due to salinity. Coastal areas with subtropical climate have higher corrosion rates. The estimated lifetimes of ductile iron pipes are between 80 and 100 years. However, the actual service lifetimes can be significantly shorter. Pipes in subtropical areas corrode significantly faster than those in temperate climates. Presence of dissolved oxygen and chloride ion can significantly intensify the corrosion rates, shortening service times of iron pipes. Projections for pipe corrosion can help development of effective asset management strategies and for infrastructure maintenance planning in coastal areas that are vulnerable to sea level rise.

Efficiency of gas collection systems at Danish landfills and implications for regulations

Globally, landfills are an important source of anthropogenic methane emissions. Regulations require landfill gas be managed to reduce emissions, and some landfills have therefore installed gas collection systems to recover energy and mitigate methane emissions. However, the efficiency of such systems is seldom evaluated. This paper presents the gas collection efficiencies of 23 Danish landfills and suggests how these values could be used to regulate landfill methane emissions in Denmark. Methane emissions from all sites were measured using the tracer gas dispersion method, and gas collection efficiencies were calculated using the ratio of the methane collection rate to the sum of the collection and emission (and oxidation) rates. Gas collection efficiencies ranged between 13 and 86% with an average of 50% – a value lower than for Swedish (58%), UK (64%) and US (63%) landfills. Possible reasons for the inefficiency of gas collection systems in Denmark include shallow gas collection pipes, leakage from installations (e.g. leachate wells, gas engines), low gas recovery due to minimal gas production or a lack of gas collection in active waste cells. It is suggested to use gas collection efficiency to regulate landfills and help them reach a particular methane mitigation goal. Gas collection efficiency that falls below the target mitigation rate would in turn trigger actions to reduce landfill methane emissions. At sites where the quality of the collected gas is too low to operate a gas engine, the installed gas collection system could be retrofitted to a biocover system designed for methane oxidation.

Thermal energy transfer around buried pipe infrastructure

Decarbonisation of heating is essential to meet national and international greenhouse gas emissions targets. This will require adoption of a range of solutions including ground source heat pump and district heating technologies. A novel route to these solutions includes dual use of buried infrastructure for heat transfer and storage in addition to its primary function. Water supply and wastewater collection pipes may be well suited for thermal energy applications being present in all urban areas in networks already in proximity to heat users. However, greater understanding of their potential interactions with surrounding heat sources and sinks is required before full assessment of the energy potential of such buried pipe networks can be obtained. This paper presents an investigation into the thermal interactions associated with shallow, buried water filled pipes. Using the results of large scale experiments and numerical simulation it is shown that soil surface ambient conditions and adjacent pipes can both act as sources or sinks of heat. While conduction is the main mechanism of heat transfer in the soil directly surrounding any pipe, any adjacent water filled pipes may lead to convection becoming important locally. In the test case, the thermal sphere of influence of the water filled pipe was also shown to be large, at in excess of 4 m over a timescale of 4 months. Taken together, these points suggest that design and analysis approaches when using water supply and wastewater collection networks for heat exchange and storage need careful consideration of environmental interactions, heat losses and gains to adjacent pipes or other infrastructure, and in ground conditions for a number of pipe diameters from any buried pipe.

Optimal Design and Performance Analysis of Thermoelectric Power Generation Device Based on Multi‐Objective Genetic Algorithm

AbstractThe combined use of flue gas waste heat resources and thermoelectric generators (TEGs) is considered to be a relatively reliable method to generate electricity. The focus of this study is on the optimization and improvement of the hot‐end heat collection pipe. This paper aims to increase the temperature difference between hot and cold ends of TEG and enhance uniformity of temperature distribution, thereby improving the output power of the TEG system. To balance the temperature difference between the cold and hot ends of the TEG, the pressure drop from the inlet to the outlet and the mass of TEG hot end pipes, a finite element simulation model is constructed. Meanwhile, a multi‐objective genetic algorithm is applied to optimize the structure of four dimensions: fin bottom length, fin height, fin thickness, and outlet diameter. Three optimization objectives, namely, average temperature difference, total pressure drop from inlet to outlet, and pipeline mass are globally optimized to determine the best size, based on which the accuracy of the simulation model is verified by conducting experiments.

Conjugate depths in partially filled sewers and pipes

Partially filled pipes have many applications in hydraulic and environmental engineering; such as sewer and storm water collection pipes and circular culverts. Hydraulic jump can lead to scouring at hydraulic structures and thus excess energy should be dissipated to prevent scour and erosion. Calculation of conjugate depths in circular pipes and culverts is important in hydraulic engineering. The conjugate flow depths are commonly used to estimate the length of the hydraulic jump and the energy loss in the jump. Available relationships to estimate the conjugate depths in circular pipes are not accurate and wide application range. In comparison to easily available numerical solutions, a closed-form solution is a function of all input independent variables; and thus the dependence of the conjugate depth on each input independent variable can be easily interpreted. This study presents explicit solutions for the conjugate depths (pre- and post-jump depths) in partially filled pipes. The proposed solutions are examined over a wide range of the Froude number and geometric conditions, providing satisfactory estimations when compared with the exact solution obtained from the specific force relation. If the prejump flow depth of the hydraulic jump is known, the postjump flow depth can be determined using the proposed solution with a maximum relative error less than 1.4%. Inversely, if postjump flow depth is known, the prejump flow depth can be determined with a maximum relative error less than 2.3%. The proposed direct solutions are general, accurate, simple, and useful for studying the partially filled circular open channels.

In-Situ Testing of Methane Emissions from Landfills Using Laser Absorption Spectroscopy

Field monitoring of methane emissions from landfills is of great importance for both environmental concern and economic benefit. This study presents a highly effective method to measure methane emissions from landfills based on tunable diode laser absorption spectroscopy (TDLAS). Methane concentration is obtained by analyzing the absorption spectrum of the laser after passing through the landfill gas. The relationship between methane concentration and the optical signal was calibrated in the laboratory. As the methane concentration increased from 400 ppm to 5000 ppm, the absorption spectrum amplitude increased linearly from 0.0005 to 0.0046. In situ testing of methane emissions at a large-scale landfill in China demonstrated the accuracy of the TDLAS method. The methane concentrations in the well-covered areas were generally below 100 ppm. In the working area or the coverage area with holes, the methane concentration was about 700 ppm. The methane concentration was up to 1900 ppm, where the gas collection pipe is disconnected. Due to to the accuracy and simplicity, the TDLAS method is suitable to detect methane emissions on a large-scale from landfills.

Impact of internal conditions on the gas flow path in semi-aerobic landfill reactors

Despite the continuous development of waste disposal technology, landfill remains a significant means of municipal solid waste disposal around the world. Accelerating the process of waste stabilisation has become a pressing problem. In this study, four indoor landfill reactors were set up. Reactors A and C were semi-aerobic landfills, and in reactors B and D the gas vents were disconnected from the leachate collection pipes. Kitchen waste was the main ingredient of the sample waste (55.46%). The void fractions of reactors C and D were decreased by adding extra gravel. The void fractions were 32.82% and 33.27% in reactors A and B, respectively, whereas those in reactors C and D were about 6% lower. The temperatures of reactors A and B were higher than those of reactors C and D. The temperature peak in reactor A occurred earlier than that in Reactor B. The temperature and gas concentration measurements confirmed that not all the air was discharged directly through the gas vent, and some air passed horizontally through the waste layer of the reactor. It was finally showed that the void fraction and connections in the pipelines inside the landfill reactor affected the gas flow path.

Optimization design method for urban sewage collection pipe networks.

In this study, a secondary subsystem mathematical model is established under the condition that the layout of the sewage collection branch, trunk, and main pipe network projects is fixed. The sewage collection branch and trunk pipe network projects are treated as the research objective by taking the minimum annual cost of the sewage collection pipe network projects as the objective function, the longitudinal slope of the pipe section and the economic flow rate of the pipe section as constraints, and the diameter of the pipe section as the decision variable. A first-level subsystem mathematical model is established by taking the sewage collection branch, trunk, and main pipe network project as the research object. A large system mathematical model is established in the same manner. This model can be solved using the large system secondary decomposition-dynamic programming aggregation method, and the optimal diameter for each pipe section can be obtained. A regional sewage collection pipe network project in Taizhou city was considered as an example for comparative analysis before and after optimization, and the results verified that the optimization method proposed in this study can solve this complex large system optimization problem.

Evaluation of the Removal of Cod and Bod in Wastewater from Bus Washing Using Coagulation, Flocculation and Aerobic Biological Treatment

Wastewater treatment is a complex task, especially when it is understood that it is used for multiple uses; one of the uses in which a large number of pollutants are used is for washing cars, especially buses and trucks use a large amount of solvents, detergents and soaps of different compositions, which are difficult to remove from water , especially because they act as emulsifiers between substances not soluble in water and the water that dissolves and eliminates them together with the internal and external dirt of buses and trucks. In Colombia, the implementation of a standard that has made the amount of contamination, that residual water can carry is more restrictive, before being poured into a sewer collection pipe, this is evaluated in terms of chemical oxygen demand (DQO) and biological oxygen demand (BOD5), these parameters define the quality of the water to be collected. The University of Santander provides scientific and technical consultancy services to the community of companies in the Santander region and the company PARBER is a local consultant, which is in search of solutions for the environmental problems of the wastewater from the laundries of cars, for this study agreements were made between the parties to search for wastewater treatment systems, which can be used by car wash industrialists and to be able to comply with the standards established in the new legislation; For this purpose, a sampling methodology for wastewater, jar tests and a water aeration device were developed that simulate the processes consecutively and also independently, to determine the capacity of removal of COD and BOD5 from wastewater. ; the scenario used was a car wash, which is a client of Industrias PARBER, which facilitated the tributary water for all the tests and also provided its facilities for the assembly of a prototype of aeration, to perform the aerobic biological treatment test ; composite samples of 4 hours of laundry were taken, which has a 24-hour service, with higher flow rates in the morning hours, in which the analyzed samples were taken; the analyzes were carried out in the water laboratory of the University of Santander, to determine the degree of contamination, also jars tests were performed, to simulate the operations of coagulation, flocculation and sedimentation, as part of the possible treatment to be applied to the waters residuals of the laundry of cars..

Influence of the void fraction and vertical gas vents on the waste decomposition in semi-aerobic landfill: Lab-scale tests

The waste classification has not been carried out worldwide, especially in developing countries. The high content of water in the kitchen waste will definitely affect the amount of air flowing into waste layer from leachate collection pipe. In this experiment, three lab-scale landfill simulation reactors were established. Reactor A and B are semi-aerobic landfill modes, while reactor C has no vertical gas vent. The void fraction in the waste of reactor B was increased by adding gravel serve as part of the waste. The waste sample used in landfill reactor mainly included kitchen waste (58%). The waste decomposition conditions in the landfill were investigated using temperature sensors embedded in the waste, by determining the velocity and gas flow direction and by measuring the volume and composition of leachate produced. The results showed that the void fraction of waste in reactor A and C was 29.79% and 30.86% respectively, and that of waste in reactor B 34.96%. Compared with reactor A, reactor B had its temperature increase earlier. In addition, the temperature distribution in vertical gas vent of the reactor A and B is higher than in the leachate collection pipe. The gas flux of vertical gas vent increased with the temperature of gas vent. Reactor A and B had significantly lower concentration of chemical oxygen demand (COD) and ammonia nitrogen (NH3+-N) than that of reactor C. It was concluded that landfill decomposition can be accelerated by increasing the void fraction in the waste and keeping a vertical gas vent open.