scholarly journals Comprehensive diagnosis of PCDD/F emission from three hazardous waste incinerators

2018 ◽  
Vol 5 (7) ◽  
pp. 172056 ◽  
Author(s):  
Xuan Cao ◽  
Longjie Ji ◽  
Xiaoqing Lin ◽  
William R. Stevens ◽  
Minghui Tang ◽  
...  
Keyword(s):  
Gas Phase ◽  
Hazardous Waste ◽  
De Novo ◽  
Solid Phase ◽  
Bag Filter ◽  
Start Up ◽  
Equivalent Quantity ◽  
Comprehensive Diagnosis ◽  
Wet Scrubber ◽  
Waste Incinerators

Comprehensive diagnosis of polychlorinated dibenzo- p -dioxin and dibenzofuran (PCDD/F) emissions was systematically conducted on three hazardous waste incinerators (HWIs). Results indicated that PCDD/F mainly existed in the solid phase before the bag filter. This was especially true for higher chlorinated dioxin and furan congeners (hexa-, hepta- and octa-). The aged bag filters tended to increase the gas-phase PCDD/F. Emissions also increased due to PCDD/F desorption from circulated scrubbing solution and plastic packing media used in the wet scrubber. The PCDD/F concentrations were elevated during the start-up process, reaching up to 5.4 times higher than those measured during the normal operating period. The ratios of PCDFs/PCDDs revealed that the surface-catalysed de novo synthesis was the dominant pathway of PCDD/F formation. Installation of more efficient fabric filters, intermittent replacement of circulated scrubbing solution will result in reduced PCDD/F emission. Additionally, 2,3,4,7,8-PeCDF correlated well with the international toxic equivalent quantity (I-TEQ) value, which suggests that 2,3,4,7,8-PeCDF could act as an I-TEQ indicator.

scholarly journals Measurement of Dioxin Emissions from a Small-Scale Waste Incinerator in the Absence of Air Pollution Controls

2019 ◽  
Vol 16 (7) ◽  
pp. 1267 ◽  
Author(s):  
Gang Zhang ◽  
Xiangxuan Huang ◽  
Wenbo Liao ◽  
Shimin Kang ◽  
Mingzhong Ren ◽  
...  
Keyword(s):  
Air Pollution ◽  
Solid Waste ◽  
De Novo ◽  
Dominant Role ◽  
Small Scale ◽  
Waste Incinerator ◽  
Bag Filter ◽  
Mean Values ◽  
Carbon Injection ◽  
Waste Incinerators

Polychlorinated dibenzo-p-dioxin and dibenzofuran (PCDD/Fs) emissions from basic small-scale waste incinerators (SWI) may cause health risks in nearby people and are thus subject to stringent regulations. The aim of this study was to evaluate PCDD/F emission and reduction of a basic SWI in the absence of air pollution controls (APCs). The results indicated that the stack gas and fly ash presented average PCDD/F levels and emission factors of 3.6 ng international toxic equivalent (I-TEQ)/Nm3 and 189.31µg I-TEQ/t and 6.89 ng I-TEQ/g and 137.85µg I-TEQ/t, respectively, much higher than those from large municipal solid waste incinerators (MSWI). PCDD/Fs congener fingerprints indicated that de novo synthesis played a dominant role in the low-temperature post-combustion zone and increased the presence of high-chlorine substituted congeners. On the basis of the emission factor 327.24 µg I-TEQ/t-waste, approximately 3000 g I-TEQ dioxins might be generated in total through basic SWIs and open burning. After refitting an SWI by adding activated carbon injection with a bag filter (ACI+BG), the PCDD/F emissions decreased to mean values of 0.042 ng I-TEQ/Nm3, far below the standard of 0.1 ng I-TEQ/Nm3, and the removal efficiency reached 99.13% in terms of I-TEQ. Therefore, it is entirely feasible to considerably reduce PCDD/F emissions by refitting basic SWI, which is positive for the future development of rural solid waste (RSW (RSW) disposal by SWI.

scholarly journals Volatile Terpenes and Terpenoids from Workers and Queens of Monomorium chinense (Hymenoptera: Formicidae)

Molecules ◽  
2018 ◽  
Vol 23 (11) ◽  
pp. 2838 ◽  
Author(s):  
Rui Zhao ◽  
Lihua Lu ◽  
Qingxing Shi ◽  
Jian Chen ◽  
Yurong He
Keyword(s):  
Mass Spectrometry ◽  
Gas Phase ◽  
Solid Phase Microextraction ◽  
De Novo ◽  
Solid Phase ◽  
Mandibular Glands ◽  
Headspace Solid Phase Microextraction ◽  
Unknown Structure ◽  
Volatile Terpenes

Twenty-one volatile terpenes and terpenoids were found in Monomorium chinense Santschi (Hymenoptera: Formicidae), a native Chinese ant, by using headspace solid-phase microextraction (HS-SPME) coupled with gas-phase chromatography and mass spectrometry (GC-MS), which makes this ant one of the most prolific terpene producers in insect. A sesquiterpene with unknown structure (terpene 1) was the main terpene in workers and neocembrene in queens. Terpenes and terpenoids were detected in poison, Dufour’s and mandibular glands of both workers and queens. Worker ants raised on a terpene-free diet showed the same terpene profile as ants collected in the field, indicating that de novo terpene and terpenoid synthesis occurs in M. chinense.

scholarly journals Release of Trace Elements from Bottom Ash from Hazardous Waste Incinerators

Recycling ◽  
2018 ◽  
Vol 3 (3) ◽  
pp. 36 ◽  
Author(s):  
Tran Dung ◽  
Elvira Vassilieva ◽  
Rudy Swennen ◽  
Valérie Cappuyns
Keyword(s):  
Trace Elements ◽  
Hazardous Waste ◽  
Ethylenediaminetetraacetic Acid ◽  
Solid Phase ◽  
Bottom Ash ◽  
Treatment Strategies ◽  
Waste Incineration ◽  
Leaching Tests ◽  
Waste Incinerators ◽  
Hazardous Waste Incineration

Bottom ash is the major by-product of waste incineration and can contain trace elements (As, Cd, Co, Cu, Cr, Mo, Ni, Pb, and Zn) with concentrations up to thousands of mg·k−1. In this study, a combination of different extractions and leaching tests (i.e., CH3COOH and ammonium-EDTA (Ethylenediaminetetraacetic acid) extractions and pHstat leaching tests) was used to investigate the potential release of trace elements from bottom ash samples derived from hazardous waste incineration plants. Although large variations have been found in the release of trace elements by different extractions, in general, the highest concentrations of most trace elements (except As and Mo) were released with the CH3COOH extraction, whereas the release of As and Mo was highest with the ammonium-EDTA extraction. Kinetics of element release upon acidification based on a pHstat leaching test at pH 4 could be related to the solid-phase speciation of some selected trace elements. The relatively high-potential mobility and elevated total concentrations of some trace elements imply a threat to the environment if these bottom ashes are not treated properly. Results of the present study may be useful to develop potential treatment strategies to remove contaminants and eventually recover metals from bottom ash.

scholarly journals Pengaruh Ukuran Partikulat Hasil Gasifikasi Batubara Terhadap Efisiensi Wet Scrubber

2020 ◽  
Vol 13 (3) ◽  
pp. 249-256
Author(s):  
Derina Paramitasari ◽  
Erbert Ferdy Destian ◽  
Mochammad Ismail
Keyword(s):  
Particle Size ◽  
Gas Phase ◽  
Flow Rate ◽  
Solid Phase ◽  
Two Phase ◽  
Venturi Scrubber ◽  
Particle Size Analyzer ◽  
Particulate Size ◽  
Wet Scrubber ◽  
Wet Esp

Syngas dari gasifikasi batubara mengandung komponen pengotor seperti tar, char, H2O,  ash, NH3, H2S dan COS. Zat-zat pengotor tersebut dibagi mejadi dua fase, yaitu fase gas (uap) dan fase padatan (partikulat). Selanjutnya, syngas akan dibersihkan dari pengotornya menggunakan cyclone, wet scrubber dan wet ESP. Dalam penelitian ini, jenis wet scrubber yang digunakan adalah venturi scrubber. Efisiensi dari venturi scubber ini ditentukan oleh ukuran partikulat pengotor dalam syngas. Syngas dari cyclone dianalisa ukuran partikulatnya menggunakan Particle Size Analyzer dan didapatkan grup ukuran partikulat dalam mikrometer (%vol), yaitu 0 – 1 (8,81%), 1 – 2 (12,51%), 2 – 4 (27,33%), 4 – 6 (15,94%), 6 – 8 (10,25%), 8 – 10 (6,7%), 10 – 20 (10,66%), 20 – 40 (4,96%), 40 – 60 (2,6%), dan 60 – 80 (0,17%). Lalu, data tersebut dianalisa dengan debit (flow rate) dan fraksi massa umpan venturi scrubber, maka didapatkan hasil efisiensi venturi scrubber sebesar 97,48%.Syngas from coal gasifiation consist of various impurities such as tar, char, H2O, ash, NH3, H2S and COS. Those impurities can be classified into two phase groups, which are gas phase (includes vapor) and solid phase (particulates). After gasification, syngas will be purified or cleaned from its impurities with some equipments such as cyclone, wet scrubber and wet ESP. The wet scrubber type that is used in this research is venturi scrubber. The scrubber efficiency is determined by the amount of particulate in syngas. Particulate size in syngas from cyclone is analyzed using Particle Size Analyzer, to obtain data of particulate sizes in micrometer (%vol), which are yaitu 0 – 1 (8,81%), 1 – 2 (12,51%), 2 – 4 (27,33%), 4 – 6 (15,94%), 6 – 8 (10,25%), 8 – 10 (6,7%), 10 – 20 (10,66%), 20 – 40 (4,96%), 40 – 60 (2,6%), dan 60 – 80 (0,17%). Then, those data are calculated together with the flow rate and mass fraction of scrubber feed, to get venturi scrubber effficiency 97,48%.

Reduction of organochlorine emissions from municipal and hazardous waste incinerators

1987 ◽  
Vol 21 (6) ◽  
pp. 602-604 ◽  
Author(s):  
Ralph C. Dougherty ◽  
Humberto. Collazo-Lopez
Keyword(s):  
Hazardous Waste ◽  
Waste Incinerators

Scheduling Hazardous Waste Incinerators Using a Simulated Annealing Linear Programming Heuristic

2010 ◽  
Vol 27 (7) ◽  
pp. 569-575 ◽  
Author(s):  
Carol Schulte ◽  
James Curry ◽  
Victor Zaloom ◽  
Weihang Zhu ◽  
Helen Lou ◽  
...  
Keyword(s):  
Linear Programming ◽  
Simulated Annealing ◽  
Hazardous Waste ◽  
Waste Incinerators

Validating Soot Models in LES of Turbulent Flames: The Contribution of Soot Subgrid Intermittency Model to The Prediction of Soot Production in an Aero-Engine Model Combustor

2021 ◽  
Author(s):  
Lívia Pereira Tardelli ◽  
Nasser Darabiha ◽  
Denis Veynante ◽  
Benedetta Franzelli
Keyword(s):  
Gas Phase ◽  
Reference Model ◽  
Solid Phase ◽  
Phase Evolution ◽  
Turbulent Flames ◽  
Engine Model ◽  
Aero Engine ◽  
New Strategy ◽  
Parametric Studies ◽  
Soot Model

Abstract Predicting soot production in industrial systems using an LES approach represents a great challenge. Besides the complexity in modeling the multi-scale physicochemical soot processes and their interaction with turbulence, the validation of newly developed models is critical under turbulent conditions. This work illustrates the difficulties in evaluating model performances specific to soot prediction in turbulent flames by considering soot production in an aero-engine combustor. It is proven that soot production occurs only for scarce local gaseous conditions. Therefore, to obtain a statistical representation of such rare soot events, massive CPU resources would be required. For this reason, evaluating soot model performances based on parametric studies, i.e., multiple simulations, as classically done for purely gaseous flames, is CPU high-demanding for sooting flames. Then, a new strategy to investigate modeling impact on the solid phase is proposed. It is based on a unique simulation, where the set of equations describing the solid phase are duplicated. One set accounts for the reference model, while the other set is treated with the model under the scope. Assuming neglected solid phase retro-coupling on the gas phase, the soot scalars from both sets experience the same unique temporal and spatial gas phase evolution isolating the soot model effects from the uncertainties on gaseous models and numerical sensitivities. Finally, the strategy capability is proven by investigating the contribution of the soot subgrid intermittency model to the prediction of soot production in the DLR burner.

Determination of the Force Constants of Non-linear XY2 Molecules in the Gas-Phase by the GF Matrix Method

2004 ◽  
Vol 59 (9) ◽  
pp. 621-622 ◽  
Author(s):  
Fatih Ucun ◽  
Vesile Gūçlü
Keyword(s):  
Gas Phase ◽  
Condensed Phase ◽  
Matrix Method ◽  
Solid Phase ◽  
Force Constants ◽  
Matrix Solution ◽  
The Matrix ◽  
Newton Raphson ◽  
Raphson Method

The force constants of the internal coordinates of nonlinear XY2 molecules in the gas-phase were calculated by using the GF matrix method. The matrix solution was carried out by means a computer program built relative to the Newton-Raphson method and the calculations were listed in a table. The force constants of some molecules in the liquidand solid- phase were also found and compared with these ones, and it was seen that the force constants for more condensed phase are lower as in an agreement with having its lower frequency.

scholarly journals PCDD/F and PCBz Emissions during Start-up and Normal Operation of a Hazardous Waste Incinerator in China

2014 ◽  
Vol 14 (4) ◽  
pp. 1142-1151 ◽  
Author(s):  
Xiaoqing Lin ◽  
Qunxing Huang ◽  
Tong Chen ◽  
Xiaodong Li ◽  
Shengyong Lu ◽  
...  
Keyword(s):  
Hazardous Waste ◽  
Normal Operation ◽  
Waste Incinerator ◽  
Hazardous Waste Incinerator ◽  
Start Up
Sign in / Sign up

Export Citation Format

Share Document