Collecting in situ precipitated iron oxides in their natural soil environment

2013 ◽  
Vol 176 (4) ◽  
pp. 497-499 ◽  
Author(s):  
Thilo Rennert ◽  
Carsten W. Mueller ◽  
Tim Mansfeldt ◽  
Johann Lugmeier
Keyword(s):  
Iron Oxides ◽  
Natural Soil ◽  
Soil Environment

scholarly journals Laboratory and In Situ Determination of Hydraulic Conductivity and Their Validity in Transient Seepage Analysis

Water ◽  
2021 ◽  
Vol 13 (8) ◽  
pp. 1131
Author(s):  
Soonkie Nam ◽  
Marte Gutierrez ◽  
Panayiotis Diplas ◽  
John Petrie
Keyword(s):  
Hydraulic Conductivity ◽  
Field Measurements ◽  
Natural Soil ◽  
In Situ Tests ◽  
Seepage Analysis ◽  
Soil Deposits ◽  
Seepage Modeling ◽  
Sample Disturbance

This paper critically compares the use of laboratory tests against in situ tests combined with numerical seepage modeling to determine the hydraulic conductivity of natural soil deposits. Laboratory determination of hydraulic conductivity used the constant head permeability and oedometer tests on undisturbed Shelby tube and block soil samples. The auger hole method and Guelph permeameter tests were performed in the field. Groundwater table elevations in natural soil deposits with different hydraulic conductivity values were predicted using finite element seepage modeling and compared with field measurements to assess the various test results. Hydraulic conductivity values obtained by the auger hole method provide predictions that best match the groundwater table’s observed location at the field site. This observation indicates that hydraulic conductivity determined by the in situ test represents the actual conditions in the field better than that determined in a laboratory setting. The differences between the laboratory and in situ hydraulic conductivity values can be attributed to factors such as sample disturbance, soil anisotropy, fissures and cracks, and soil structure in addition to the conceptual and procedural differences in testing methods and effects of sample size.

scholarly journals Changes in surface characteristics and adsorption properties of 2,4,6-trichlorophenol following Fenton-like aging of biochar

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Liqiang Cui ◽  
Qinya Fan ◽  
Jianxiong Sun ◽  
Guixiang Quan ◽  
Jinlong Yan ◽  
...  
Keyword(s):  
Adsorption Capacity ◽  
Surface Properties ◽  
Aging Process ◽  
Surface Characteristics ◽  
Natural Soil ◽  
Peanut Shell ◽  
Soil Environment ◽  
Polluted Soils ◽  
Physico Chemical

AbstractFenton-like system formed in a natural soil environment deemed to be significant in the aging process of biochar. Aged biochars have distinct physico-chemical and surface properties compared to non-aged biochar. The aged biochar proved to be useful soil amendment due to its improved elements contents and surface properties. The biochar aging process resulted in increased surface area and pore volume, as well as carbon and oxygen-containing functional groups (such as C=O, –COOH, O–C=O etc.) on its surface, which were also associated with the adsorption behavior of 2,4,6-trichlorophenol (2,4,6-TCP). The biochar aging increased the adsorption capacity of 2,4,6-TCP, which was maximum at pH 3.0. The 2,4,6-TCP adsorption capacity of aged-bush biochar (ABB) and aged-peanut shell biochar (APB) was increased by 1.0–11.0% and 7.4–38.8%, respectively compared with bush biochar (BB) and peanut shell biochar (PB) at the same initial concentration of 2,4,6-TCP. All biochars had similar 2,4,6-TCP desorption rates ranging from 33.2 to 73.3% at different sorption temperatures and times. The desorbed components were mainly 2,4,6-TCP and other degraded components, which were low in concentration with small molecule substance. The results indicated that the aged-biochar could be effective for the long-term remediation of naturally organic polluted soils.

scholarly journals Live-Scale Testing of Granular Materials Stabilized with Alkali-Activated Waste Glass and Carbide Lime

2021 ◽  
Vol 11 (23) ◽  
pp. 11286
Author(s):  
Marina Paula Secco ◽  
Débora Thaís Mesavilla ◽  
Márcio Felipe Floss ◽  
Nilo Cesar Consoli ◽  
Tiago Miranda ◽  
...  
Keyword(s):  
Portland Cement ◽  
Mechanical Performance ◽  
Raw Materials ◽  
Sodium Hydroxide Solution ◽  
Fine Sand ◽  
Field Application ◽  
Natural Soil ◽  
In Situ Tests ◽  
Alkali Activated

The increasingly strong search for alternative materials to Portland cement has resulted in the development of alkali-activated cements (AAC) that are very effective at using industrial by-products as raw materials, which also contributes to the volume reduction in landfilled waste. Several studies targeting the development of AAC—based on wastes containing silicon and calcium—for chemical stabilization of soils have demonstrated their excellent performance in terms of durability and mechanical performance. However, most of these studies are confined to a laboratory characterization, ignoring the influence and viability of the in situ construction process and, also important, of the in situ curing conditions. The present work investigated the field application of an AAC based on carbide lime and glass wastes to stabilize fine sand acting as a superficial foundation. The assessment was supported on the unconfined compressive strength (UCS) and initial shear modulus (G0) of the developed material, and the field results were compared with those prepared in the laboratory, up to 120 days curing. In situ tests were also developed on the field layers (with diameters of 450 and 900 mm and thickness of 300 mm) after different curing times. To establish a reference, the mentioned precursors were either activated with a sodium hydroxide solution or hydrated with water (given the reactivity of the lime). The results showed that the AAC-based mixtures developed greater strength and stiffness at a faster rate than the water-based mixtures. Specimens cured under controlled laboratory conditions showed better results than the samples collected in the field. The inclusion of the stabilized layers clearly increased the load-bearing capacity of the natural soil, while the different diameters produced different failure mechanisms, similar to those found in Portland cement stabilization.

Evidence that tropical soil environment can support the growth of Escherichia coli

1998 ◽  
Vol 38 (12) ◽  
pp. 171-174 ◽  
Author(s):  
M. N Byappanahalli ◽  
R. S. Fujioka
Keyword(s):  
Escherichia Coli ◽  
Water Quality ◽  
Tropical Soil ◽  
Soil Conditions ◽  
Natural Soil ◽  
Minimal Amount ◽  
Soil Environment ◽  
Faecal Coliforms ◽  
E Coli ◽  
Faecal Bacteria

Concentrations of faecal coliforms and Escherichia coli in environmental waters have historically been used to establish recreational water quality standards. When these bacteria are used as indices of water quality, it is assumed that there are no significant environmental sources of these bacteria which are unrelated to direct faecal contamination. However, we have previously reported that in tropical island environments such as in Hawaii, these faecal indicators are consistently found at high concentrations in all streams and the source of these faecal bacteria is the soil. To become so well established in soil we hypothesized that these faecal bacteria must have the ability to multiply in the natural soil environment at ambient temperature (23–25°C). Three lines of evidence support this hypothesis: (1) E. coli was shown to grow on 10% soil extract agar, (2) populations of faecal coliforms and E. coli from sewage were shown to immediately increase by about three logs when simple nutrients (glucose and salts) were added to natural soil and (3) faecal coliforms and E. coli increased by two logs within 24 h when a minimal amount of sewage was added to cobalt-irradiated soil. These results indicate that tropical soil environments provide sufficient means to support the growth of faecal coliforms and E. coli. However, under natural soil conditions, indigenous soil microorganisms are much more efficient in obtaining nutrients and we hypothesize that faecal bacteria grow sporadically in response to available nutrients.

scholarly journals Effects of field scale in situ biochar incorporation on soil environment in a tropical highly weathered soil

2020 ◽  
pp. 116009
Author(s):  
Shih-Hao Jien ◽  
Yu-Lin Kuo ◽  
Chien-Sen Liao ◽  
Yu-Ting Wu ◽  
Avanthi Deshani Igalavithana ◽  
...  
Keyword(s):  
Soil Environment ◽  
Field Scale ◽  
Weathered Soil

In-situ mobilization and transformation of iron oxides-adsorbed arsenate in natural groundwater

2017 ◽  
Vol 321 ◽  
pp. 228-237 ◽  
Author(s):  
Di Zhang ◽  
Huaming Guo ◽  
Wei Xiu ◽  
Ping Ni ◽  
Hao Zheng ◽  
...  
Keyword(s):  
Iron Oxides

Studies of Collector Adsorption on Iron Oxides by in Situ ATR-FTIR Spectroscopy

2010 ◽  
Vol 49 (4) ◽  
pp. 1493-1502 ◽  
Author(s):  
E. Potapova ◽  
I. Carabante ◽  
M. Grahn ◽  
A. Holmgren ◽  
J. Hedlund
Keyword(s):  
Ftir Spectroscopy ◽  
Iron Oxides

Iron oxides stimulate microbial monochlorobenzene in situ transformation in constructed wetlands and laboratory systems

2014 ◽  
Vol 472 ◽  
pp. 185-193 ◽  
Author(s):  
Marie Schmidt ◽  
Diana Wolfram ◽  
Jan Birkigt ◽  
Jörg Ahlheim ◽  
Heidrun Paschke ◽  
...  
Keyword(s):  
Iron Oxides ◽  
Constructed Wetlands

Sensing the physical and nutritional status of the root environment in the field: a review of progress and opportunities

2005 ◽  
Vol 143 (5) ◽  
pp. 347-358 ◽  
Author(s):  
L. J. CLARK ◽  
D. J. G. GOWING ◽  
R. M. LARK ◽  
P. B. LEEDS-HARRISON ◽  
A. J. MILLER ◽  
...  
Keyword(s):  
Nutritional Status ◽  
Crop Management ◽  
Soil Conditions ◽  
Plant Responses ◽  
Soil Environment ◽  
Soil Factors ◽  
Remote Sensors ◽  
Soil Measurements ◽  
New Strategies

The challenge that faces agriculture at the start of the 21st Century is to provide security of food production in a sustainable way. Achieving this task is difficult enough, but against a background of climate change, it becomes a moving target. However, one certainty is that soil factors that limit crop growth must be taken into account as new strategies for crop management are developed. To achieve this, it is necessary to measure the physical and nutritional status of the root environment in the field. Before considering measurement methods, our understanding of how the plant interacts with its soil environment is reviewed, so that it is clear what needs to be measured. Soil strength due to soil drying is identified as an important stress that limits agricultural productivity. The scope to measure soil factors that directly affect plant growth is reviewed. While in situ sensors are better developed, progress in the development of remote sensors of soil properties are also reviewed. A robust approach is needed to interpret soil measurements at the field scale and here geostatistics has much to offer. The present review takes a forward look and explores how our understanding of plant responses to soil conditions, the newly emerging sensing technologies and geostatistical tools can be drawn together to develop robust tools for soil and crop management. This is not intended to be an exhaustive review. Instead, the authors focus on those aspects that they consider to be most important and where the greatest progress is being made.

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