Drained effects of geotextile filter materials in extremely soft soils

Author(s):  
Yuan Zhou ◽  
Di Wang ◽  
Lingyun Zhang ◽  
Yufeng Gao ◽  
Zhihao Lu
2014 ◽  
Vol 4 (3) ◽  
pp. 15-24 ◽  
Author(s):  
O. Eswara Reddy ◽  
◽  
Madhav. M.R ◽  
Saibaba Reddy.E ◽  
Vidyaranya Bandi ◽  
...  
Keyword(s):  

2021 ◽  
Author(s):  
Andrea Watzinger ◽  
Melanie Hager ◽  
Thomas Reichenauer ◽  
Gerhard Soja ◽  
Paul Kinner

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.


2021 ◽  
Vol 6 (2) ◽  
Author(s):  
Tarek N. Salem ◽  
Nagwa R. El-Sakhawy ◽  
Ahmed A. El-Latief
Keyword(s):  

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Subin Kim ◽  
Jinhyo Chung ◽  
Sang Hyun Lee ◽  
Jeong Hyeon Yoon ◽  
Dae-Hyuk Kweon ◽  
...  

AbstractInfluenza, one of the most contagious and infectious diseases, is predominantly transmitted through aerosols, leading to the development of filter-based protective equipment. Though the currently available filters are effective at removing submicron-sized particulates, filter materials with enhanced virus-capture efficiency are still in demand. Coating or chemically modifying filters with molecules capable of binding influenza viruses has received attention as a promising approach for the production of virus-capturing filters. For this purpose, tannic acid (TA), a plant-derived polyphenol, is a promising molecule for filter functionalization because of its antiviral activities and ability to serve as a cost-efficient adhesive for various materials. This study demonstrates the facile preparation of TA-functionalized high-efficiency particulate air (HEPA) filter materials and their efficiency in influenza virus capture. Polypropylene HEPA filter fabrics were coated with TA via a dipping/washing process. The TA-functionalized HEPA filter (TA-HF) exhibits a high in-solution virus capture efficiency of up to 2,723 pfu/mm2 within 10 min, which is almost two orders of magnitude higher than that of non-functionalized filters. This result suggests that the TA-HF is a potent anti-influenza filter that can be used in protective equipment to prevent the spread of pathogenic viruses.


2021 ◽  
Vol 710 (1) ◽  
pp. 012057
Author(s):  
M R Lodahl ◽  
A E Riis ◽  
K T Brødbæk ◽  
C T Leth
Keyword(s):  

2019 ◽  
Vol 50 (5) ◽  
pp. 671-688
Author(s):  
C. J. Sainea-Vargas ◽  
M. C. Torres-Suárez

Author(s):  
Amar Amavasai ◽  
Jean-Philippe Gras ◽  
Nallathamby Sivasithamparam ◽  
Minna Karstunen ◽  
Jelke Dijkstra

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