Consolidation effect of dredged soil by siphon method focusing on the porous filter material

Abstract A new Fe-C porous filter material was prepared with dredged sediment of river as raw material. The orthogonal test L9(34) and component ratio experiment of raw material were conducted to investigate the optimum technological condition. Further, the filter obtained was characterized by Brunauer-Emmett-Teller (BET), scanning electron microscopy (SEM), energy dispersive X-ray spectroscope (EDS), and X-ray diffraction (XRD). Results showed that the optimal technological condition was sludge: straw: starch: iron powder: foam: iron powder 74.5∶10∶7.5∶3∶5, preheating temperature 280 ℃, preheating 15 min, sintering temperature 1080 ℃, and sintering 11 min. The BET surface area of the filter was 3.32 m2 g− 1, and average pore size was 10.05 nm. Phase composition mainly included SiO2, Fe3O4, Fe2O3 and muscovite (KAl2(Si3Al)O10(OH)2). Average effluent concentrations of total phosphorus (TP), total organic carbon (TOC), and total nitrogen (TN) of the biofilter system filled with the filter obtained were decreased to 0.08, 3.43, and 3.76 mg L− 1, separately, at hydraulic retention time 4 h. Thus, the filter prepared with dredged sediment of rive as raw material is an alternative material for polluted river water purification.

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Effect of sintering temperature on the structure of of a porous filter material

Soviet Powder Metallurgy and Metal Ceramics ◽

10.1007/bf00791804 ◽

1984 ◽

Vol 23 (3) ◽

pp. 211-214

Author(s):

L. E. Lunin ◽

V. T. Bondar' ◽

V. S. Pugin ◽

P. A. Kornienko ◽

N. P. Pavlenko

Keyword(s):

Sintering Temperature ◽

Filter Material ◽

Porous Filter

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LARGE-SIZED EXPERIMENT FOR SLOPE STABILITY MANAGEMENT OF DREDGED SOIL IMPROVED WITH CONVERTER SLAG

Journal of Japan Society of Civil Engineers Ser B3 (Ocean Engineering) ◽

10.2208/jscejoe.75.i_893 ◽

2019 ◽

Vol 75 (2) ◽

pp. I_893-I_898

Author(s):

Yuzo AKASHI ◽

Takashi NEGI ◽

Akira HIGUCHI ◽

Yasuo KASUGAI ◽

Masaaki KATAGIRI ◽

...

Keyword(s):

Slope Stability ◽

Converter Slag ◽

Dredged Soil

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Unravelling the process of petroleum hydrocarbon biodegradation in different filter materials of constructed wetlands by stable isotope fractionation and labelling studies

Biodegradation ◽

10.1007/s10532-021-09942-1 ◽

2021 ◽

Author(s):

Andrea Watzinger ◽

Melanie Hager ◽

Thomas Reichenauer ◽

Gerhard Soja ◽

Paul Kinner

Keyword(s):

Stable Isotope ◽

Constructed Wetlands ◽

Hydrogen Isotope ◽

Petroleum Hydrocarbon ◽

Isotope Fractionation ◽

Isotope Effects ◽

Filter Material ◽

Hydrocarbon Biodegradation ◽

Stable Isotope Fractionation ◽

Filter Materials

AbstractMaintaining and supporting complete biodegradation during remediation of petroleum hydrocarbon contaminated groundwater in constructed wetlands is vital for the final destruction and removal of contaminants. We aimed to compare and gain insight into biodegradation and explore possible limitations in different filter materials (sand, sand amended with biochar, expanded clay). These filters were collected from constructed wetlands after two years of operation and batch experiments were conducted using two stable isotope techniques; (i) carbon isotope labelling of hexadecane and (ii) hydrogen isotope fractionation of decane. Both hydrocarbon compounds hexadecane and decane were biodegraded. The mineralization rate of hexadecane was higher in the sandy filter material (3.6 µg CO2 g−1 day−1) than in the expanded clay (1.0 µg CO2 g−1 day−1). The microbial community of the constructed wetland microcosms was dominated by Gram negative bacteria and fungi and was specific for the different filter materials while hexadecane was primarily anabolized by bacteria. Adsorption / desorption of petroleum hydrocarbons in expanded clay was observed, which might not hinder but delay biodegradation. Very few cases of hydrogen isotope fractionation were recorded in expanded clay and sand & biochar filters during decane biodegradation. In sand filters, decane was biodegraded more slowly and hydrogen isotope fractionation was visible. Still, the range of observed apparent kinetic hydrogen isotope effects (AKIEH = 1.072–1.500) and apparent decane biodegradation rates (k = − 0.017 to − 0.067 day−1) of the sand filter were low. To conclude, low biodegradation rates, small hydrogen isotope fractionation, zero order mineralization kinetics and lack of microbial biomass growth indicated that mass transfer controlled biodegradation.

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Shear Friction Characteristics and Modification Factor of Concrete Prepared Using Expanded Bottom Ash and Dredged Soil Granules

International Journal of Concrete Structures and Materials ◽

10.1186/s40069-019-0364-x ◽

2019 ◽

Vol 13 (1) ◽

Author(s):

Keun-Hyeok Yang ◽

Kyung-Ho Lee

Keyword(s):

Shear Crack ◽

Bottom Ash ◽

Lightweight Aggregate Concrete ◽

Maximum Aggregate Size ◽

Crack Plane ◽

Upper Bound Theorem ◽

Friction Characteristics ◽

Dredged Soil ◽

Shear Friction ◽

Modification Factor

Abstract The objective of this study is to assess the shear friction characteristics of lightweight aggregate concrete (LWAC) prepared using artificially expanded bottom ash and dredged soil granules. A total of 37 concrete mixtures were prepared under the classification of three series. In the first and second series, the natural sand content for replacing lightweight fine aggregates and the water-to-cement ratio varied to obtain different densities and compressive strengths of concrete. The third series was designed to estimate the effect of the maximum aggregate size on the friction resistance along the shear crack plane of the monolithic interfaces. The frictional angle of the LWAC tested was formulated as a function of the ratio of the effective tensile and compressive strengths of concrete through the expansion of the integrated mathematical models proposed by Kwon et al., based on the upper-bound theorem of concrete plasticity. When predicting the shear friction strength of LWAC, the present mathematical model exhibits relatively good accuracy, yielding the mean and standard deviation of the ratios between experiments and predictions of 1.06 and 0.14, respectively, whereas the empirical equations proposed by the AASHTO provision and Mattock underestimated the results. Ultimately, an advanced modification factor for shear design of LWAC is proposed as a function of the density and compressive strength of concrete and the maximum size of aggregates.

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Stability of porous filter cleaning by vertical flow

10.1063/5.0059551 ◽

2021 ◽

Author(s):

Boris S. Maryshev ◽

Lyudmila S. Klimenko

Keyword(s):

Vertical Flow ◽

Porous Filter

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Determination of Free Solanesol Levels in Cigarette Filters by Liquid Chromatography–Mass Spectrometry

Journal of Analytical Toxicology ◽

10.1093/jat/bkab041 ◽

2021 ◽

Author(s):

Roberto Bravo Cardenas ◽

Phuong Ngac ◽

Clifford Watson ◽

Liza Valentin-Blasini

Keyword(s):

Liquid Chromatography ◽

Sample Preparation ◽

Tobacco Smoke ◽

Limit Of Detection ◽

Internal Standard ◽

Filter Material ◽

Previous Method ◽

Tobacco Smoke Exposure ◽

Triple Quadrupole Mass Spectrometer ◽

Cigarette Butts

Abstract Solanesol, a naturally occurring constituent of tobacco, has been utilized as a good marker for environmental tobacco smoke particulate and as a noninvasive predictor of mainstream cigarette smoke tar and nicotine intake under naturalistic smoking conditions. A fast and accurate method for measuring free solanesol to assess tobacco smoke exposure is highly desirable. We have developed and validated a new environmentally friendly, high-throughput method for measuring solanesol content in discarded cigarette filter butts. The solanesol deposited in the used filters can be correlated with mainstream smoke deliveries of nicotine and total particle matter to estimate constituent delivery to smokers. A portion of filter material is removed from cigarette butts after machine smoking, spiked with internal standard solution, extracted and quantitatively analyzed using reverse-phase liquid chromatography coupled to a triple-quadrupole mass spectrometer. The new method incorporates a 48-well plate format for automated sample preparation that reduces sample preparation time and solvent use and increases sample throughput 10-fold compared to our previous method. Accuracy and precision were evaluated by spiking known amounts of solanesol on both clean and smoked cigarette butts. Recoveries exceeded 93% at both low and high spiking levels. Linear solanesol calibration curves ranged from 1.9 to 367 µg/butt with a 0.05 µg/butt limit of detection.

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