Examination on Influence Caused by Air Injection Manners Changing in Aerobic-Anaerobic Landfill Method

2015 ◽  
Vol 768 ◽  
pp. 310-317
Author(s):  
Gang Zhen Jiao ◽  
Lei Zhang ◽  
Xiong Shi ◽  
Gui Fu
Keyword(s):  
Numerical Simulation ◽  
Mathematical Model ◽  
Organic Carbon ◽  
Simulation Model ◽  
Solid Phase ◽  
Landfill Gas ◽  
Air Injection ◽  
Carbon And Nitrogen ◽  
Speed Up ◽  
Leachate Quality

In this study, aerobic-anaerobic landfill method (AANM) is focused on as a new way to speed up landfill stabilization, inhibit landfill gas flux, and ameliorate on leachate quality. Numerical simulation model is developed to guide the air injection craftwork and study its effect on achieving above goals. On basis of work finished in last period (0~310 days), air was injected into Lysimeters A (Lys.A) at 0.5 m, and at 2.5 m in Lys.B with the same rate of 1 L/min. In Lys.C there is no air injected. In order to interview the influence by air injection manners changing, from 310 days till 360 days, air injection manners are changed from Mono-site into Double-site in Lys.A and in Lys. B it will be changed from bottom-site (2.5m) into middle-site (1.5m). In Lys.C there will be no changing. By interviewing the comparisons on simulated results in 50 days with and without air injection manners changing, it was found that air injection manners changing in Lys.A causes TOC discharging amount increase more than 6 times, but T-N and GHE resulted from landfill gas decrease 24.1% and 71 % respectively. Air injection manners changing in Lys.B resulted in discharged TOC and T-N increase 108.1 % and 53.5 % respectively, while T-N decreases 3.7 %. On basis of mechanism assumption, mathematical model was developed and according to the simulated results for 5 years, air injected at 2.5 m achieved improvements on stabilization of solid phase organic carbon and nitrogen for 34 % and 13 %, amelioration on leachate quality for 35 % and 62 % of TOC and T-N, and the restraint of GHE for 14 times compared with no air injection case.

Optimum Position of Air Injection in Aerobic and Anaerobic Refuse Lysimeters

2015 ◽  
Vol 768 ◽  
pp. 318-329 ◽  
Author(s):  
Gang Zhen Jiao ◽  
Lei Zhang ◽  
You Cai Zhao ◽  
Jian Li Ma
Keyword(s):  
Organic Carbon ◽  
Solid Phase ◽  
Bottom Layer ◽  
Pilot Scale ◽  
Air Injection ◽  
Carbon And Nitrogen ◽  
Optimum Position ◽  
Lower Temperature ◽  
Leachate Quality ◽  
Aerobic And Anaerobic

In order to determine the optimum air injection craftwork for the aerobic-anaerobic landfill method, three pilot-scale lysimeters were constructed. Through experiment in the lysimeters, it was concluded that air injection at bottom layer (in this research it’s 2.5 m) is the optimum position in terms of improving on the solid organic matters stabilization, amelioration on leachate quality, the restraint of GHE (Green House Effect) by CH4. For instance, air injected at bottom layer may get more TOC minimization in leachate under lower temperature (-4-10°C) and high temperature (20-35°C) compared with other conditions. NH4+-N content expressed similar advantages with air injected at bottom layer case. Meanwhile, accompanied with the high dissolved oxygen (DO) and higher TOC consumption in leachate, aerobic fermentation was activated in this case, and most organic carbon was transformed in term of CO2, in which the goal of restraint on GHE was realized. On basis of mechanism assumption, mathematical model was developed and according to the simulated results for 5 years, air injected at 2.5 m achieved improvements on stabilization of solid phase organic carbon and nitrogen for 34 % and 13 %, amelioration on leachate quality for 35 % and 62 % of TOC and T-N, and the restraint of GHE for 14 times compared with no air injection case.

scholarly journals Mathematical Model and Simulator of Rotor With Vibrating Blades Model / Matematyczny I Symulator Stopnia Wirnikowego Z Drgającymi Łopatkami

2014 ◽  
Vol 29 (1) ◽  
pp. 93-102
Author(s):  
Michał Wachłaczenko ◽  
Radosław Przysowa ◽  
Mariusz Żokowski
Keyword(s):  
Numerical Simulation ◽  
Mathematical Model ◽  
Simulation Model ◽  
Rotational Speed ◽  
Operating Conditions ◽  
Bladed Disk ◽  
Input Force ◽  
Turbojet Engine ◽  
Timing Data

Abstract The paper presents description of rotating bladed disk mathematical model. Correctly defined mathematical model of rotor allows creation of numerical simulation model which can be used to generate tip-timing data. First of all, the model is necessary to conduct a research on blade response due to input force in form of changing rotational speed. This enables the possibility to determine turbojet engine terminal operating conditions causing its failure

Landfill Gas Detection in Leachate Pipe: A Consideration for Design Improvement of Leachate Piping and Gas Venting Systems

2014 ◽  
Vol 699 ◽  
pp. 607-612
Author(s):  
Mohd Amir Zaid bin Ghazali ◽  
Nasiman bin Sapari ◽  
Emmanuel Olisa ◽  
Hisyam Jusoh
Keyword(s):  
Landfill Gas ◽  
Degradation Process ◽  
Solid Waste Disposal ◽  
Displacement Method ◽  
Water Displacement ◽  
Negative Effects ◽  
Current Trends ◽  
Speed Up ◽  
Leachate Quality

Landfill provides simple and economic means of solid waste disposal. However, it causes negative effects to the environment due to leachate generation and greenhouse gas emissions. Current trends in landfill design allow aerobic or semi aerobic processes to take place inside the landfill to speed up degradation process and reduce odour. In Malaysia, the semi aerobic system of landfill design is adopted. This paper presents the study of the gas venting system and leachate quality of the semi aerobic landfill. The gas samples were collected from the end of the leachate pipe and the gas vent of a sanitary landfill by the water displacement method. Raw leachate samples from the landfill leachate ponds were collected and the COD of the samples were measured. The concentration of methane gas escaping from the leachate pipe was found to be around 13%. The COD content of the raw leachate was found to be more than 15000 mg/l. The improvement of landfill gas collection in Malaysia is recommended.

Fundamental Examination of Numerical Simulation Model for Pressure Rise due to Underwater Arc

2014 ◽  
Vol 134 (7) ◽  
pp. 604-613 ◽  
Author(s):  
Toshiya Ohtaka ◽  
Tomo Tadokoro ◽  
Masashi Kotari ◽  
Tadashi Amakawa
Keyword(s):  
Numerical Simulation ◽  
Simulation Model ◽  
Pressure Rise

The Effect of Using Ramps with Trench Cylindrical Holes on Film Cooling Effectiveness

2015 ◽  
Vol 3 (2) ◽  
pp. 15-27
Author(s):  
Ahmed A. Imram ◽  
Humam K. Jalghef ◽  
Falah F. Hatem
Keyword(s):  
Numerical Simulation ◽  
Film Cooling ◽  
Air Injection ◽  
Baseline Model ◽  
Cooling Effectiveness ◽  
Film Cooling Effectiveness ◽  
Blowing Ratio ◽  
Hot Air ◽  
Test Study ◽  
Cylindrical Holes

     The effect of introducing ramp with a cylindrical slot hole on the film cooling effectiveness has been investigated experimentally and numerically. The film cooling effectiveness measurements are obtained experimentally. A test study was performed at a single mainstream with Reynolds number 76600 at three different coolant to mainstream blowing ratios 1.5, 2, and 3. Numerical simulation is introduced to primarily estimate the best ramp configurations and to predict the behavior of the transport phenomena in the region linked closely to the interaction between the coolant air injection and the hot air mainstram flow. The results showed that using ramps with trench cylindrical holes would enhanced the overall film cooling effectiveness by 83.33% compared with baseline model at blowing ratio of 1.5, also  the best overall flim cooling effectevness was obtained at blowing ratio of 2 while it is reduced at blowing ratio of 3.

Stabilization of Organic Carbon and Nitrogen in Consolidating Benthal Deposits

1985 ◽  
Vol 17 (6-7) ◽  
pp. 929-940 ◽  
Author(s):  
C. W. Bryant ◽  
L. G. Rich
Keyword(s):  
Organic Carbon ◽  
Model Verification ◽  
Volatile Acid ◽  
Free Energies ◽  
Organic Loading ◽  
Carbon And Nitrogen ◽  
Loading Rates ◽  
Degradation Reactions ◽  
The Individual ◽  
Organic Deposits

The objective of this research was to develop and validate a predictive model of the benthal stabilization of organic carbon and nitrogen in deposits of waste activated sludge solids formed at the bottom of an aerated water column, under conditions of continual deposition. A benthal model was developed from a one-dimensional, generalized transport equation and a set of first-order biological reactions. For model verification, depth profiles of the major interstitial carbon and nitrogen components were measured from a set of deposits formed in the laboratory at 20°C and a controlled loading rate. The observed sequence of volatile acid utilization in each benthal deposit was that which would be predicted by the Gibbs free energies of the individual degradation reactions and would be controlled by the reduction in interstitial hydrogen partial pressure with time. Biodegradable solids were solubilized rapidly during the first three weeks of benthal retention, but subsequent solubilization occurred much more slowly. The benthal simulation effectively predicted the dynamics of consolidating, organic deposits. Simulation of organic loading rates up to 250 g BVSS/(m2 day) indicated that the stabilization capacity of benthal deposits was far above the range of organic loading rates currently used in lagoon design.

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