Discussion: Washing of Zinc(II) from Contaminated Soil Column

An in situ measuring system of respiration rate was applied for monitoring biodegradation of diesel fuel in a bioventing process for bioremediation of diesel contaminated soil. Two laboratory-scale soil columns were packed with 5 kg of soil that was artificially contaminated by diesel fuel as final TPH (total petroleum hydrocarbon) concentration of 8,000 mg/kg soil. Nutrient was added to make a relative concentration of C:N:P = 100:10:1. One soil column was operated with continuous venting mode, and the other one with intermittent (6 h venting/6 h rest) venting mode. On-line O2 and CO2 gas measuring system was applied to measure O2 utilisation and CO2 production during biodegradation of diesel for 5 months. Biodegradation rate of TPH was calculated from respiration rate measured by the on-line gas measuring system. There were no apparent differences between calculated biodegradation rates from two columns with different venting modes. The variation of biodegradation rates corresponded well with trend of the remaining TPH concentrations comparing other biodegradation indicators, such as C17/pristane and C18/phytane ratio, dehydrogenase activity, and the ratio of hydrocarbon utilising bacteria to total heterotrophic bacteria. These results suggested that the on-line measuring system of respiration rate would be applied to monitoring biodegradation rate and to determine the potential applicability of bioventing process for bioremediation of oil contaminated soil.

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In situ bioremediation of explosives-contaminated soil: A soil column study

Bioresource Technology ◽

10.1016/s0960-8524(96)00152-6 ◽

1997 ◽

Vol 59 (2-3) ◽

pp. 169-176 ◽

Cited By ~ 14

Author(s):

R. Boopathy ◽

D.L. Widrig ◽

J.F. Manning

Keyword(s):

Contaminated Soil ◽

Soil Column ◽

In Situ Bioremediation ◽

Column Study

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Assessment of In Situ Bioremediation of Oil Contaminated Soil and Groundwater in a Petroleum Refinery: A Laboratory Soil Column Study

Petroleum Science and Technology ◽

10.1080/10916466.2012.690482 ◽

2014 ◽

Vol 32 (13) ◽

pp. 1553-1561 ◽

Cited By ~ 3

Author(s):

M. Zargar ◽

M. H. Sarrafzadeh ◽

B. Taheri ◽

A. Keshavarz

Keyword(s):

Contaminated Soil ◽

Petroleum Refinery ◽

Soil Column ◽

In Situ Bioremediation ◽

Column Study

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Effects of Long-Term Freeze–Thaw Cycles on the Properties of Stabilized/Solidified Lead-Zinc-Cadmium Composite-Contaminated Soil

International Journal of Environmental Research and Public Health ◽

10.3390/ijerph18116114 ◽

2021 ◽

Vol 18 (11) ◽

pp. 6114

Author(s):

Zhongping Yang ◽

Jiazhuo Chang ◽

Yao Wang ◽

Xuyong Li ◽

Shu Li

Keyword(s):

Compressive Strength ◽

Contaminated Soil ◽

Triaxial Compression ◽

Soil Column ◽

Column Leaching ◽

Freeze Thaw ◽

Triaxial Compressive Strength ◽

Zinc Cadmium ◽

Lead Zinc

Lead, zinc, and cadmium were used to prepare a composite-contaminated soil to replicate common situations, in which soil is usually simultaneously contaminated by multiple metals. To examine the long-term durability of stabilized/solidified (S/S) contaminated soil, specimens were subjected to a series of freeze–thaw (F-T) cycles, up to ninety times (one day per cycle), prior to testing. Triaxial compression tests, soil column leaching tests, and X-ray diffraction analysis were then employed to study the mechanical properties, environmental influences, and micro-mechanisms of the S/S lead-zinc-cadmium composite-contaminated soils after long-term F-T. The results showed that triaxial compressive strength increases within three F-T cycles, then decreases before slightly increasing or stabilizing after thirty F-T cycles. The stage of decreased cohesion thus occurs between three and fourteen F-T cycles, with variation in other factors similar to that of the triaxial compressive strength. The cohesion mainly increases between three and seven cycles. The soil column leaching test showed that the permeability of soil is more than four times higher than that of soil not subject to freeze–thaw cycles after ninety F-T cycles. XRD tests further revealed that the chemical composition of S/S contaminated soil and the occurrence of each heavy metal (HM) remained unchanged under F-T treatment.

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