scholarly journals SURFACE-ALTERED ZEOLITES AS PERMEABLE BARRIERS FOR IN SITU TREATMENT OF CONTAMINATED GROUNDWATER

2002 ◽  
Author(s):  
Robert S. Bowman ◽  
Pengfei Zhang ◽  
Xian Tao
1999 ◽  
Author(s):  
Robert S. Bowman ◽  
Zhaohui Li ◽  
Stephen J. Roy ◽  
Todd Burt ◽  
Timothy L. Johnson ◽  
...  

2002 ◽  
Author(s):  
Robert S Bowman ◽  
Pengfei Zhang ◽  
Xian Tao ◽  
Richard L Johnson ◽  
Douglas Wolf

2000 ◽  
Vol 42 (5-6) ◽  
pp. 371-376 ◽  
Author(s):  
J.A. Puhakka ◽  
K.T. Järvinen ◽  
J.H. Langwaldt ◽  
E.S. Melin ◽  
M.K. Männistö ◽  
...  

This paper reviews ten years of research on on-site and in situ bioremediation of chlorophenol contaminated groundwater. Laboratory experiments on the development of a high-rate, fluidized-bed process resulted in a full-scale, pump-and-treat application which has operated for several years. The system operates at ambient groundwater temperature of 7 to 9°C at 2.7 d hydraulic retention time and chlorophenol removal efficiencies of 98.5 to 99.9%. The microbial ecology studies of the contaminated aquifer revealed a diverse chlorophenol-degrading community. In situ biodegradation of chlorophenols is controlled by oxygen availability, only. Laboratory and pilot-scale experiments showed the potential for in situ aquifer bioremediation with iron oxidation and precipitation as a potential problem.


2015 ◽  
Vol 15 (3) ◽  
pp. 632-641 ◽  
Author(s):  
Franklin Obiri-Nyarko ◽  
Jolanta Kwiatkowska-Malina ◽  
Tomasz Kasela

Laboratory batch experiments were performed to: (i) select two individual and two mixtures of potential reactive materials for permeable barriers to treat groundwater contaminated with benzene and soluble lead (Pb2+); (ii) investigate the involved contaminant removal mechanisms; and (iii) determine the permeability and assess the environmental compatibility of the selected materials. Five individual reactive materials (zeolite, diatomaceous earth, brown coal, compost, and zero-valent iron as control) and four mixtures (compost:brown coal, compost:zeolite, compost:mulch, and mulch:diatomaceous earth) in different ratios were investigated. Benzene and Pb2+ were investigated separately using Pb2+/benzene spiked deionized water. Zeolite and brown coal were selected as individual materials for Pb and benzene based on their removal efficiencies. For the material mixtures, compost:brown coal (1:3) and compost:zeolite mixtures (1:3) were selected for Pb, whereas compost:zeolite (1:1) and compost:brown coal (1:5) were selected for benzene. The sequential extraction of Pb from these selected reactive materials showed that Pb was held mainly in the exchangeable fraction (52%–76%). Benzene was removed by biodegradation and sorption, with the latter contributing most to its removal (60%–99%). The selected materials were compatible with the environment considering the amounts of toxic metals leached from them, and their permeabilities were in the range of 4.2 × 10−5–2.14 × 10−3 m s−1.


2017 ◽  
Author(s):  
Dawn E Holmes ◽  
Roberto Orelana ◽  
Ludovic Giloteaux ◽  
Li-Ying Wang ◽  
Pravin Shrestha ◽  
...  

AbstractPrevious studies ofin situbioremediation of uranium-contaminated groundwater with acetate injections have focused on the role ofGeobacterspecies in U(VI) reduction because of a lack of other abundant known U(VI)-reducing microorganisms. Monitoring the levels of methyl CoM reductase subunit A (mcrA) transcripts during an acetate-injection field experiment demonstrated that acetoclastic methanogens from the genusMethanosarcinawere enriched after 40 days of acetate amendment. The increased abundance ofMethanosarcinacorresponded with an accumulation of methane in the groundwater. An enrichment culture dominated by aMethanosarcinaspecies with the sameMethanosarcina mcrAsequence that predominated in the field experiment could effectively convert acetate to methane. In order to determine whetherMethanosarcinaspecies could be participating in U(VI) reduction in the subsurface, cell suspensions ofM. barkeriwere incubated in the presence of U(VI) with acetate provided as the electron donor. U(VI) was reduced by metabolically activeM. barkericells, however, no U(VI) reduction was observed in inactive controls. These results demonstrate thatMethanosarcinaspecies could play an important role in the long-term bioremediation of uranium-contaminated aquifers after depletion of Fe(III) oxides limits the growth ofGeobacterspecies. The results also suggest thatMethanosarcinahave the potential to influence uranium geochemistry in a diversity of anaerobic sedimentary environments.


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