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 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

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.

scholarly journals Effects of in situ Remediation With Nanoscale Zero Valence Iron on the Physicochemical Conditions and Bacterial Communities of Groundwater Contaminated With Arsenic

2021 ◽  
Vol 12 ◽  
Author(s):  
Ana Castaño ◽  
Alexander Prosenkov ◽  
Diego Baragaño ◽  
Nerea Otaegui ◽  
Herminio Sastre ◽  
...  
Keyword(s):  
Organic Contaminants ◽  
Bacterial Communities ◽  
Intergenic Spacer ◽  
Cost Effective ◽  
Taxonomic Composition ◽  
Sulfate Reducing ◽  
Oxidation Reduction ◽  
Before And After ◽  
Complete Study

Nanoscale Zero-Valent Iron (nZVI) is a cost-effective nanomaterial that is widely used to remove a broad range of metal(loid)s and organic contaminants from soil and groundwater. In some cases, this material alters the taxonomic and functional composition of the bacterial communities present in these matrices; however, there is no conclusive data that can be generalized to all scenarios. Here we studied the effect of nZVI application in situ on groundwater from the site of an abandoned fertilizer factory in Asturias, Spain, mainly polluted with arsenic (As). The geochemical characteristics of the water correspond to a microaerophilic and oligotrophic environment. Physico-chemical and microbiological (cultured and total bacterial diversity) parameters were monitored before and after nZVI application over six months. nZVI treatment led to a marked increase in Fe(II) concentration and a notable fall in the oxidation-reduction potential during the first month of treatment. A substantial decrease in the concentration of As during the first days of treatment was observed, although strong fluctuations were subsequently detected in most of the wells throughout the six-month experiment. The possible toxic effects of nZVI on groundwater bacteria could not be clearly determined from direct observation of those bacteria after staining with viability dyes. The number of cultured bacteria increased during the first two weeks of the treatment, although this was followed by a continuous decrease for the following two weeks, reaching levels moderately below the initial number at the end of sampling, and by changes in their taxonomic composition. Most bacteria were tolerant to high As(V) concentrations and showed the presence of diverse As resistance genes. A more complete study of the structure and diversity of the bacterial community in the groundwater using automated ribosomal intergenic spacer analysis (ARISA) and sequencing of the 16S rRNA amplicons by Illumina confirmed significant alterations in its composition, with a reduction in richness and diversity (the latter evidenced by Illumina data) after treatment with nZVI. The anaerobic conditions stimulated by treatment favored the development of sulfate-reducing bacteria, thereby opening up the possibility to achieve more efficient removal of As.

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.

scholarly journals Comprehensive Evaluation of the Toxicity and Biosafety of Plasma Polymerized Nanoparticles

Nanomaterials ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 1176
Author(s):  
Praveesuda L. Michael ◽  
Yuen Ting Lam ◽  
Juichien Hung ◽  
Richard P. Tan ◽  
Miguel Santos ◽  
...  
Keyword(s):  
Comprehensive Evaluation ◽  
Cost Effective ◽  
Cell Types ◽  
Repeated Injection ◽  
In Vivo Models ◽  
Intravenous Injections ◽  
Cost Effective Alternative ◽  
High Doses

The rapid growth of nanoparticle-based therapeutics has underpinned significant developments in nanomedicine, which aim to overcome the limitations imposed by conventional therapies. Establishing the safety of new nanoparticle formulations is the first important step on the pathway to clinical translation. We have recently shown that plasma-polymerized nanoparticles (PPNs) are highly efficient nanocarriers and a viable, cost-effective alternative to conventional chemically synthesized nanoparticles. Here, we present the first comprehensive toxicity and biosafety study of PPNs using both established in vitro cell models and in vivo models. Overall, we show that PPNs were extremely well tolerated by all the cell types tested, significantly outperforming commercially available lipid-based nanoparticles (lipofectamine) used at the manufacturer’s recommended dosage. Supporting the in vitro data, the systemic toxicity of PPNs was negligible in BALB/c mice following acute and repeated tail-vein intravenous injections. PPNs were remarkably well tolerated in mice without any evidence of behavioral changes, weight loss, significant changes to the hematological profile, or signs of histological damage in tissues. PPNs were tolerated at extremely high doses without animal mortality observed at 6000 mg/kg and 48,000 mg/kg for acute and repeated-injection regimens, respectively. Our findings demonstrate the safety of PPNs in biological systems, adding to their future potential in biomedical applications.

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.

Evaluation of Polyalkastyrene Absorbent Beads for the Remediation of PCE in Groundwater

1999 ◽  
Vol 34 (3) ◽  
pp. 455-468
Author(s):  
M. Venhuis ◽  
S. Lesage ◽  
K.R. Millar ◽  
A.S. Crowe
Keyword(s):  
Organic Contaminants ◽  
Groundwater Remediation ◽  
Treatment Plant ◽  
Cost Effective ◽  
Water Treatment Plant ◽  
Active Systems ◽  
Reactive Barrier ◽  
Pumping System ◽  
Term Maintenance

Abstract Passive groundwater remediation technologies are increasingly considered because they require very little long-term maintenance and are thus more cost effective than active systems such as pump-and-treat, which require the continuous upkeep of a groundwater pumping system and of an above-ground water treatment plant. Barriers are being installed in the ground to either prevent the flow of contaminated water from one property to another, or to remove the contaminants from the water as it passes through a porous reactive barrier. Absorbents which irreversibly incorporate spilled solvents into their structure have been developed to clean surface spills. This project was aimed at evaluating the performance of the absorbents with dissolved organic contaminants. It was found that while they did sorb aqueous phase compounds, it was through adsorption, not absorption and that it was therefore reversible. As adsorbents, the polymers marketed as Imbiber Beads® and Expandabeads® were not as effective as activated carbon.

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.

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.

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