Enhanced bioremediation of trichloroethene contaminated by a biobarrier system

2000 ◽  
Vol 42 (3-4) ◽  
pp. 429-434 ◽  
Author(s):  
C.M. K ◽  
L. Yang
Keyword(s):  
Soil Column ◽  
Column Experiment ◽  
Cost Effective ◽  
Microbial Consortia ◽  
Soil Columns ◽  
Chlorinated Solvent ◽  
Aerobic Cometabolism ◽  
Enhanced Bioremediation ◽  
Cost Effective Alternative

The industrial solvent trichloroethylene (TCE) is among the most ubiquitous chlorinated compounds found in groundwater contamination. The objective of this study was to develop a barrier system, which includes a peat (used as the primary substrates) layer to enhance the aerobic cometabolism of TCE in situ. A laboratory-scale column experiment was conducted to evaluate the feasibility of using this peat biobarrier to remediate aquifers contaminated by TCE. This system was performed using a series of continuous-flow glass columns including a soil column, a peat column, followed by two consecutive soil columns. Activated sludges were inoculated in all three soil columns to provide microbial consortia for TCE cometabolism. Simulated TCE contaminated groundwater with a flow rate of 0.25 L/day was pumped into the system. Effluent samples from each column were analyzed for TCE and its degradation byproducts [cis-dichloroethylene (cis-DCE) and vinyl chloride (VC)]. Average removal efficiency was 96% for TCE over a 60-day operating period. Accumulation of VC was observed due to the depletion of oxygen in the system. Results from this laboratory study reveal that the developed biobarrier treatment scheme would be expected to provide a more cost-effective alternative to remediate chlorinated-solvent contaminated aquifers.

Sustainability Study of In-situ Hydroponic Vetiver System for Urban Wastewater Management in Developing Countries: A Theoretical Review

2020 ◽  
Vol 17 (4) ◽  
pp. 97-103
Author(s):  
Kaushik Ghosh ◽  
Arup Sarkar
Keyword(s):  
Developing Countries ◽  
Cost Effective ◽  
Developed Countries ◽  
Wastewater Management ◽  
Urban Wastewater ◽  
Current State ◽  
Cost Effective Alternative ◽  
Urban Wastewater Treatment

Urban wastewater management is a crucial challenge in the small and medium towns situated in the developing countries worldwide. These towns are also facing an increasing gap between infrastructure and population growth. A conventional approach to curb these problems is the application of cost-intensive electro-mechanical sewerage technologies, as adopted in developed countries. The first part of this paper derives a set of indicators to framework a sustainable urban wastewater treatment system by reviewing the current state of wastewater management in developing countries, for example, the sample case study being India. The second part evaluates the potential performance of the proposed alternative in-situ hydroponic vetiver system (HVS) against those set of sustainability indicators by reviewing the worldwide performance of the HVS. The objective of this paper is to assess the potential viability of the HVS as a sustainable and cost-effective alternative for developing countries. The current analysis can aid in mainstreaming the use of HVS in policy making and urban planning.

Evaluation of Bonded Concrete Overlay of Asphalt under Accelerated Loading

2020 ◽  
pp. 036119812096138
Author(s):  
Moinul Mahdi ◽  
Zhong Wu ◽  
Tyson D. Rupnow
Keyword(s):  
Cost Effective ◽  
Loading Path ◽  
Portland Cement Concrete ◽  
Wheel Load ◽  
Aged Asphalt ◽  
Interface Bond Strength ◽  
Cost Effective Alternative ◽  
Bonded Concrete Overlay ◽  
Falling Weight

Bonded concrete overlay of asphalt (BCOA), previously known as ultra-thin whitetopping (UTW), has been widely used to repair aged asphalt concrete (AC) pavements with moderate distresses. Because of the increasing costs of roadway maintenance, Louisiana has a great interest in determining whether thin BCOA (usually 2–6 in.) is a suitable and cost-effective alternative to the current practice of roadway maintenance. The objective of the study was to evaluate the performance of BCOA pavement and to identify the influence of in-situ interface bond strength on the performance of BCOA pavements. Three full-scale BCOA test sections with thicknesses of 6 in., 4 in., and 2 in. of Portland cement concrete (PCC) over an aged asphalt pavement were tested under accelerated pavement test (APT) loading under typical pavement conditions in southern Louisiana. Each section was trafficking-loaded to a failure (i.e., all the slabs in the loading path were cracked) under alternating load magnitudes of 9 kips and 16 kips of the ATLaS dual-tire wheel load. A falling weight deflectometer (FWD) backcalculated the effective thickness, a trench-cutting investigation was undertaken, and in-situ pull-off test revealed that a good bond was established initially between the PCC and AC layer. Several non-destructive test (NDT) methods indicated that the distresses of a BCOA slab could be coupled with a possible debonding at the PCC-asphalt interface. This paper mainly focuses on the APT results and the performance of BCOA test sections with different overlay thickness.

In-Situ Comparison of Bioremediation Methods for a Number 6 Residual Fuel Oil Spill in Lee County, Florida

1991 ◽  
Vol 1991 (1) ◽  
pp. 533-540 ◽  
Author(s):  
Mark A. Jones ◽  
Jeffrey H. Greenfield
Keyword(s):  
Feasibility Study ◽  
Cost Effective ◽  
Fuel Oil ◽  
Single Application ◽  
Residual Fuel Oil ◽  
Ring Compounds ◽  
Cost Effective Method ◽  
Enhanced Bioremediation ◽  
Small Plot

ABSTRACT On July 5, 1988, as a result of overfilling, about 3,200 barrels of No. 6 fuel was spilled onto surface soils surrounding a Florida Power and Light Company storage tank, and spread over about 60,000 square feet of soil. About 2,300 barrels were recovered, leaving 900 barrels in the upper six to eight inches of the soil. The spill was chosen as the site for a trial of in-situ enhanced bioremediation. An initial feasibility study in the laboratory was followed by groundwater monitoring, field remediation, and a small-plot research program. In the feasibility study, lower concentrations of nutrients applied periodically were almost as effective as a single application using a larger concentration. The small-plot study indicated that treatment with added bacteria and nutrients offered the greatest reduction in hydrocarbons. Addition of bacteria alone provided no advantage. In the field remediation program, two- and three-ring compounds were completely degraded, while four-, five-, and six-ring compounds were more resistant. The research demonstrated that in-situ enhanced bioremediation can be a cost-effective method for treating soils contaminated with No. 6 fuel oil.

scholarly journals UV Sensitization of Nitrate and Sulfite: A Powerful Tool for Groundwater Remediation

Environments ◽  
2018 ◽  
Vol 5 (11) ◽  
pp. 117 ◽  
Author(s):  
Yaal Lester ◽  
Asmaa Dabash ◽  
Darine Eghbareya
Keyword(s):  
Organic Contaminants ◽  
Groundwater Remediation ◽  
Ultra Violet ◽  
Cost Effective ◽  
Organic Chemicals ◽  
Treatment Processes ◽  
Hydrated Electrons ◽  
Cost Effective Alternative ◽  
High Doses

Groundwater contamination by nitrate and organic chemicals (for example, 1,4-dioxane) is a growing worldwide concern. This work presents a new approach for simultaneously treating nitrate and 1,4-dioxane, which is based on the ultra-violet (UV) sensitization of nitrate and sulfite, and the production of reactive species. Specifically, water contaminated with nitrate and 1,4-dioxane is irradiated by a UV source (<250 nm) at relatively high doses, to sensitize in situ nitrate and generate OH•. This leads to the oxidation of 1,4-dioxane (and other organics) and the (undesired) production of nitrite as an intermediate. Subsequently, sulfite is added at an optimized time-point, and its UV sensitization produces hydrated electrons that react and reduces nitrite. Our results confirm the effectivity of the proposed treatment: UV irradiation of nitrate (at >5 mg N/L) efficiently degraded 1,4-dioxane, while producing nitrite at levels higher than its maximum contaminant level (MCL) of 1 mg N/L in drinking water. Adding sulfite to the process after 10 min of irradiation reduces the concentration of nitrite without affecting the degradation rate of 1,4-dioxane. The treated water contained elevated levels of sulfate; albeit at much lower concentration than its MCL. Treating water contaminated with nitrate and organic chemicals (often detected concomitantly) typically requires several expensive treatment processes. The proposed approach presents a cost-effective alternative, employing a single system for the treatment of nitrate and organic contaminants.

scholarly journals Permeable Reactive Barriers for Preventing Water Bodies from a Phosphorus-Polluted Agricultural Runoff-Column Experiment

Water ◽  
2019 ◽  
Vol 11 (3) ◽  
pp. 432 ◽  
Author(s):  
Agnieszka Bus ◽  
Agnieszka Karczmarczyk ◽  
Anna Baryła
Keyword(s):  
Agricultural Soils ◽  
Sandy Loam ◽  
Soil Column ◽  
Column Experiment ◽  
Agricultural Runoff ◽  
Permeable Reactive Barriers ◽  
P Loss ◽  
Loam Soil ◽  
Reactive Barriers

This paper aims to examine the potential of permeable reactive barriers (PRBs) as an in-situ removal approach for phosphate polluted agricultural runoff. Four different reactive materials (RMs) of: autoclaved aerated concrete (AAC), Polonite®, zeolite and limestone were tested. The study was conducted as a column experiment with a sandy loam soil type charging underlying RM layers with phosphorus (P) and a soil column without RM as a reference. The experiment was carried out over 90 days. During this time the P-PO4 load from the reference column equaled 6.393 mg and corresponds to 3.87 kg/ha. Tested RMs are characterized by high P-PO4 retention equaling 99, 98, 88 and 65% for Polonite®, AAC, zeolite and limestone, respectively. At common annual P loss rates of 1 kg/ha from intensively used agricultural soils, the PRB volume ranged from 48 to 67 m3 would reduce the load between 65 and 99% for the RMs tested in this study.

scholarly journals Molecular epidemiological study of microtubule-associated protein-like 4-anaplastic lymphoma kinase fusion gene using immunohistochemistry as a cost effective alternative to fluorescence in situ hybridization for Indian patients with adenocarcinoma lung

2017 ◽  
Vol 03 (01) ◽  
pp. 045-049
Author(s):  
Anurag Mehta ◽  
Ullas Batra
Keyword(s):  
In Situ Hybridization ◽  
Fluorescence In Situ Hybridization ◽  
Epidemiological Study ◽  
Anaplastic Lymphoma Kinase ◽  
Fusion Gene ◽  
Cost Effective ◽  
Gene Fusions ◽  
Anaplastic Lymphoma ◽  
Cost Effective Alternative

Abstract Background: With fluorescence in situ hybridization (FISH) as the main-stay for the detection of anaplastic lymphoma kinase (ALK) rearrangements, the ALK Break Apart FISH Probe Kit has become a Food and Drug Association-approved companion diagnostic for targeted therapy with the ALK inhibitor crizotinib in lung cancers. The objective of this molecular epidemiological study was to estimate the prevalence of microtubule-associated protein-like 4-ALK (EML4-ALK) fusion gene using immunohistochemistry (IHC) as a cost effective alternative to FISH for Indian patients with nonsmall-cell cancer (NSCC)-adenocarcinoma, favor adenocarcinoma lung and NSCC- Not otherwise specified (NOS). Materials and Methods: Patients with NSCC-adenocarcinoma, favor adenocarcinoma lung, and nonsmall cell lung cancer-NOS histology were considered for this study. Permission was obtained from the Ethics Committee before the start of the study. Clinical characteristics and treatment details were collected from the patient's medical records. IHC analysis was performed using a Ventana automated immunostainer (Benchmark XT). Detection was performed using OptiView DAB Detection and Amplification Kit. Results: A total of 200 NSCC-adenocarcinoma, favour adenocarcinoma and NSCC-NOS patients were included in the study. There were 122 (61%) men and 78 (39%) women with a median age of 57 years. Of the 200 patients, 43 (21.5%) were nonsmokers and 175 (87.5%) had Stage-IV disease at the time of initial diagnosis. 48 (24%) cases were positive for epidermal growth factor receptor mutations, whereas EML4-ALK fusion gene was present in 27 (13.5%) patients. 25 of the 27 patients with ALK positivity received crizotinib therapy. Conclusions: The incidence of EML4-ALK gene fusions (13.5%) in this Indian population is four-fold high than the previous reported incidences and supports the claim of several recent studies that a relatively new ALK clone, 5A4, and D5F3 from Leica/Novocastra and cell signaling technology/Ventana, respectively can accurately identify ALK rearranged lung adenocarcinoma. The inclusion of IHC for the detection of EML4-ALK gene fusions as a low cost alternative seems justified in low resource setting.

scholarly journals UV sensitization of nitrate and sulfite: A powerful tool for groundwater remediation

2018 ◽  
Author(s):  
Yaal Lester ◽  
Asmaa Dabash ◽  
Darine Eghbareya
Keyword(s):  
Organic Contaminants ◽  
Groundwater Remediation ◽  
Cost Effective ◽  
Organic Chemicals ◽  
New Approach ◽  
Treatment Processes ◽  
Hydrated Electrons ◽  
Cost Effective Alternative ◽  
High Doses

Groundwater contamination by nitrate and organic chemicals (e.g. 1,4-dioxane) is a growing worldwide concern. This work presents a new approach for simultaneously treating nitrate and 1,4-dioxane, which is based on UV sensitization of nitrate and sulfite, and the production of reactive species. Specifically, water contaminated with nitrate and 1,4-dioxane is irradiated by a UV source (&lt; 250 nm) at relatively high doses, to sensitize in-situ nitrate and generate HO•. This leads to the oxidation of 1,4-dioxane (and other organics), and the (undesired) production of nitrite as an intermediate. Subsequently, sulfite is added at an optimized time-point, and its UV sensitization produces hydrated electrons which reacts and reduces nitrite. Our results confirmed the effectivity of the proposed treatment: UV irradiation of nitrate (at &gt; 5 mg N/L) efficiently degraded 1,4-dioxane, while producing nitrite at levels higher than 1 mg N/L (its MCL in drinking water). Adding sulfite to the process after 10 minutes of irradiation reduced the concentration of nitrite, without affecting the degradation rate of 1,4-dioxane. The treated water contained elevated levels of sulfate; albeit at much lower concentration than its MCL. Treating water contaminated with nitrate and organic chemicals (often detected concomitantly) typically requires several (expensive) treatment processes. The proposed approach may present a cost-effective alternative, employing a single system for the treatment of nitrate and organic contaminants

Enhanced Bioremediation as a Cost Effective Approach Following Thermally Enhanced Soil Vapour Extraction for Sites Requiring Remediation of Chlorinated Solvents

2009 ◽  
Author(s):  
Anna-Maria Kozlowska ◽  
Steve R. Langford ◽  
Manjit S. Kahlon ◽  
Haydn G. Williams
Keyword(s):  
Thermal Treatment ◽  
Chlorinated Solvents ◽  
Cost Effective ◽  
Treatment Area ◽  
Treatment Zone ◽  
Thermal Remediation ◽  
Enhanced Bioremediation ◽  
Target Treatment ◽  
Soil Vapour Extraction

Thermally enhanced bioremediation can be a more cost-effective alternative to full scale in-situ thermal treatment especially for sites contaminated with chlorinated solvents, where reductive dechlorination is or might be a dominant biological step. The effect of Thermally Enhanced Soil Vapour Extraction (TESVE) on indigenous microbial communities and the potential for subsequent biological polishing of chlorinated solvents was investigated in field trials at the Western Storage Area (WSA) – RSRL (formerly United Kingdom Atomic Energy Authority - UKAEA) Oxfordshire, UK. The WSA site had been contaminated with various chemicals including mineral oil, chloroform, trichloroethane (TCA), carbon tetrachloride and tetrachloroethene (PCE). The contamination had affected the unsaturated zone, groundwater in the chalk aquifer and was a continuing source of groundwater contamination below the WSA. During TESVE the target treatment zone was heated to above the boiling point of water increasing the degree of volatilization of contaminants of concern (CoC), which were mobilised and extracted in the vapour phase. A significant reduction of concentrations of chlorinated solvent in the unsaturated zone was achieved by the full-scale application of TESVE – In Situ Thermal Desorption (ISTD) technology. The rock mass temperature within target treatment zone remained in the range of 35°–44° C, 6 months after cessation of heating. The concentration of chlorinated ethenes and other CoC were found to be significantly lower adjacent to the thermal treatment area and 1 to 2 orders of magnitude lower within the thermal treatment zone. Samples were collected within and outside the thermal treatment zone using BioTraps® (passive, in-situ microbial samplers) from which the numbers of specific bacteria were measured using quantitative polymerase chain reaction (qPCR) methods of analysis. High populations of reductive dechlorinators such as Dechalococcoides spp. and Dehalobacter spp., were found within the zone that was subjected to thermal remediation and moderate levels of Dehalobacter sp were found outside the treatment area. These results confirm dehalogenating bacteria are present within the site and suggest populations have bounced back following thermal treatment. The thermally treated zone showed a greater number of active indigenous bacteria — indicating that the conditions following TESVE treatment selectively promote the growth of desirable bacteria. This might result from elimination of micro-organisms competing for hydrogen as an electron donor, increased biovailability of CoC or a reduction in its inhibiting properties. This paper aims to show the potential for biologically mediated contaminant reduction in assisting thermal remediation projects. During and post active thermal remediation this approach can help reduce total treatment costs by providing an inexpensive final polishing step or by being a complementary process within the perimeter of heated zone and inside hotspots during the cool-down phase.

2D Color-Intensity Representation of Ultrasonic Thickness Gauge Measurements

2020 ◽  
pp. 1192-1198
Author(s):  
M.S. Mohammad ◽  
Tibebe Tesfaye ◽  
Kim Ki-Seong
Keyword(s):  
Cost Effective ◽  
The Other ◽  
Thickness Gauge ◽  
Color Intensity ◽  
Digital Readout ◽  
Flat Surfaces ◽  
Video Cameras ◽  
Wide Range ◽  
Cost Effective Alternative ◽  
Ultrasonic Thickness

Ultrasonic thickness gauges are easy to operate and reliable, and can be used to measure a wide range of thicknesses and inspect all engineering materials. Supplementing the simple ultrasonic thickness gauges that present results in either a digital readout or as an A-scan with systems that enable correlating the measured values to their positions on the inspected surface to produce a two-dimensional (2D) thickness representation can extend their benefits and provide a cost-effective alternative to expensive advanced C-scan machines. In previous work, the authors introduced a system for the positioning and mapping of the values measured by the ultrasonic thickness gauges and flaw detectors (Tesfaye et al. 2019). The system is an alternative to the systems that use mechanical scanners, encoders, and sophisticated UT machines. It used a camera to record the probe’s movement and a projected laser grid obtained by a laser pattern generator to locate the probe on the inspected surface. In this paper, a novel system is proposed to be applied to flat surfaces, in addition to overcoming the other limitations posed due to the use of the laser projection. The proposed system uses two video cameras, one to monitor the probe’s movement on the inspected surface and the other to capture the corresponding digital readout of the thickness gauge. The acquired images of the probe’s position and thickness gauge readout are processed to plot the measured data in a 2D color-coded map. The system is meant to be simpler and more effective than the previous development.

Sign in / Sign up

Export Citation Format

Share Document