scholarly journals Cost-Effective Remediation Using Microscale Zvi: Comparison of Commercially Available Products

2020 ◽  
Vol 27 (2) ◽  
pp. 211-224
Author(s):  
Alena Pavelková ◽  
Vojtěch Stejskal ◽  
Ondřejka Vološčuková ◽  
Jaroslav Nosek
Keyword(s):  
Reaction Rate ◽  
Cost Effective ◽  
Zero Valent Iron ◽  
Contaminated Water ◽  
Fundamental Properties ◽  
Basic Parameters ◽  
Application Potential ◽  
Reduction Capacity ◽  
Remediation Process ◽  
Slow Decomposition

AbstractZero-valent iron is very effective in the treatment of groundwater contaminated with chlorinated hydrocarbons and solvents broadly used in industrial production. In terms of its sustainability and cost, a legitimate effort has been devoted to the optimization of the remediation process, which can be demanding and expensive. In this study, the application potential and fundamental properties of several commercial micro-sized zero-valent iron (μZVI) were investigated. Although the manufacturers report the basic parameters of μZVI, it has been shown that the actual reactivity of apparently similar products varies notably. This work was focused on monitoring of frequently occurring contaminants. The actual contaminated water from the Pisecna locality -former landfill of industrial waste, with high levels of chlorinated ethenes and ethanes (PCE, TCE, cis-1,2-DCE and 1,2-DCA) was used for the experiment. The degree of dechlorination reached over 85 % 32 days after the application of μZVI in several samples and a far higher reaction rate for smaller particles was observed. Also, the amount of cis-1,2-DCE, which is characterized by slow decomposition, decreased by more than 95 % over the course of the experiment. Smaller particles showed a much longer sedimentation rate and gradual fractionation was also observed. Monitoring of ORP and pH also suggested that the smaller particles possessed a reduction capacity that was sufficiently high even at the end of the experiment. Laboratory tests with apparently similar μZVI samples indicated considerable differences in their reaction rate and efficiency.

Enhancing the application potential of dissipative controlled rocking connections through detailing and design

2021 ◽  
Author(s):  
Brandon McHaffie ◽  
Peter Routledge ◽  
Alessandro Palermo
Keyword(s):  
Linear Time ◽  
Time History ◽  
Cost Effective ◽  
Real Structure ◽  
Construction Costs ◽  
Alternative Design ◽  
Design Philosophy ◽  
History Analysis ◽  
Application Potential ◽  
The University

<p>Research on low-damage systems has been significant in the past decade. These systems combine post- tensioning, which provides self-centring; and typically use replaceable devices, which give energy dissipation. WSP has used recent research, carried out at the University of Canterbury, on low-damage bridge piers and applied this into a real structure – the Wigram-Magdala Link Bridge. This is believed to be the first bridge in New Zealand and possibly worldwide to adopt such a system. Given this was the first application of the system to a real structure, there were some valuable learnings during design and construction. Firstly, the application of axial dissipaters has some limitations due to available material sizes, construction difficulty and aesthetics. Secondly, there is still some additional cost and complexity associated with using the low-damage system. Given these difficulties, this paper presents an alternative design philosophy which better captures the benefits of the low-damage system, which include cost-effective repair method, controlled damage and additional robustness and resilience. The alternative design philosophy presented is expected to result in reduced construction costs by reducing pier and foundation demands. Peak displacements and forces will be compared to the results from non-linear time history analysis to verify the performance of the low-damage connection using scaled ground motions. Furthermore, the paper will present the possible application of an alternative dissipation device, the lead extrusion damper, which can further improve the performance of low-damage connections.</p>

Removeal of Arsenic(III) from Water by Using a New Class of Zero-Valent Iron Modified Mesoporous Silica Molecular Sieves SBA-15

2011 ◽  
Vol 356-360 ◽  
pp. 423-429
Author(s):  
Meng Ye ◽  
Jin Huang ◽  
Rui Chen ◽  
Qi Zhuang He
Keyword(s):  
Molecular Sieves ◽  
Cost Effective ◽  
Zero Valent Iron ◽  
Preparation Process ◽  
X Ray Diffraction ◽  
Wet Impregnation ◽  
X Ray ◽  
New Class ◽  
Transmission Electron ◽  
Removal Of Arsenic

An elevated arsenic (As) content in groundwater imposes a great threat to people worldwide. Thus, developing new and cost-effective methods to remove As from groundwater and drinking water becomes a priority. Using Zero-Valent iron (ZVI) to remove As from water is a proven technology. In this study, ZVI modified SBA-15 mesoporous silicamolecular sieves (ZVI-SBA-15), was prepared, characterized, and used for removing arsenic from water. Wet impregnation, drying, and calcination steps led to iron inclusion within the mesopores. Iron oxide was reduced to ZVI by NaBH4, and the ZVI modified SBA-15 was obtained. Fourier-transform infrared spectroscopy confirmed the preparation process of the nitrate to oxide forms. The structure of the materials was confirmed by Powder X-ray diffraction. Its data indicated that the structure of ZVI-SBA-15 retained the host SBA-15 structure. Brunauer-Emmett-Teller analysis revealed a decrease in surface area and pore size, indicating ZVI-SBA-15 coating on the inner surfaces. Transmission electron micrographs also confirmed that modified SBA-15 retained the structure of the parent SBA-15 silica.It has a high uptake capability(more than 90 pecent) make it potentially attractive absorbent for the removal of arsenic from water.

Technological Interventions in Management of Hg Contaminated Water

2018 ◽  
pp. 126-140
Author(s):  
Vidushi Abrol ◽  
Sharada Mallubhotla ◽  
Sundeep Jaglan
Keyword(s):  
Human Health ◽  
Cost Effective ◽  
Industrial Wastes ◽  
Mercury Contamination ◽  
Contaminated Water ◽  
Treatment Techniques ◽  
Innovative Methods ◽  
Technological Interventions ◽  
Treatment Technologies ◽  
Ancient Times

Rising cases of environmental mercury hazards has led to a need for cost-effective mercury treatment techniques. Extensive use of mercury from ancient times has resulted in water contamination that may require remediation. Mercury contamination is tedious to treat and may pose a risk to human health and the environment. To deal with this threat of mercury contamination, industrial wastes and wastewaters containing mercury requires treatment for its removal and immobilization. This chapter provides a synopsis of the availability, performance, and technologies for management of mercury in water. It covers the innovative methods to treat the mercury contamination like biosorption. In this chapter, the technological aspects available for the mercury treatment technologies are reviewed. It describes the theory, design, and operation of the technologies; provides information on commercial availability and use; and includes data on performance, where available.

Transient Analysis of Heated Vapor Extraction System for Effective Remediation

2003 ◽  
Author(s):  
R. S. Jadhav ◽  
R. S. Amano ◽  
J. Jatkar ◽  
R. J. Lind
Keyword(s):  
Research Effort ◽  
Cost Effective ◽  
Extraction System ◽  
Vapor Extraction ◽  
Discrete Phase Modeling ◽  
Discrete Phase ◽  
Chemical Companies ◽  
Time Required ◽  
Volume Method ◽  
Remediation Process

A soil remediation process has gained an enormous attention for the last decade in order to make the surroundings environmentally friendly. The areas around chemical companies or waste disposal sites have been seriously contaminated from the chemicals and other polluting materials that are disposed off. Different soil remedial processes are used for different types of pollutants. The present research effort is concentrated on modeling the Heated Vapor Extraction System, which is a very efficient and cost effective process. A numerical model is developed and Finite Volume Method is used to solve the model. The analysis uses the species transport and discrete phase modeling to predict the time required to clean the soil under specific conditions. The analysis was used as a mathematical computational tool to predict various parameters for the process so that the process can be made more efficient and effective in remedial achievements.

scholarly journals Simultaneous Stripping of Ammonia from Leachate: Experimental Insights and Key Microbial Players

Water ◽  
2020 ◽  
Vol 12 (9) ◽  
pp. 2494
Author(s):  
Łukasz Jurczyk ◽  
Justyna Koc-Jurczyk ◽  
Adam Masłoń
Keyword(s):  
Removal Efficiency ◽  
Reaction Rate ◽  
Batch Reactor ◽  
Cost Effective ◽  
16S Rrna Genes ◽  
Rrna Genes ◽  
Community Shift ◽  
Biological Removal ◽  
Novel Approach ◽  
Aeration System

Air stripping is commonly used to remove the ammonia in multistage treatment systems for municipal landfill leachate (LFL). This paper proposes a novel approach combining the process of stripping with biological removal of ammonia, based on simultaneous nitrification and denitrification (SND) in a single hybrid sequencing batch reactor (HSBR). To avoid the accumulation of free ammonia (N-FAN), the shallow aeration system was used for the treatment of raw LFL with N-TAN level of 1520 mg/L and pH 9.24. The mean N-FAN removal efficiency of 69% with the reaction rate of 55 mg L−1 h−1 and mean ammonium (N-NH4+) removal efficiency of 84% with the reaction rate of 44 mg L−1 h−1 were achieved within a month in such an HSBR (R1). The comparative HSBR (R2), with conventional aeration system maintaining the same concentration of dissolved oxygen (DO ≤ 1 mg/L), was removing only trace amounts of N-FAN and 48% of N-NH4+. The quantitative analysis of 16S rRNA genes indicated that the number of total bacteria, Actinobacteria, Bacteroidetes, Firmicutes, and Beta- and Gammaproteobacteria increased during the operation of both HSBRs, but was always higher in R1. Moreover, the bacterial community shift was observed since the beginning of the experiment; the relative abundance of Firmicutes, and Beta- and Gammaproteobacteria increased by 5.01, 3.25 and 9.67% respectively, whilst the abundance of Bacteroidetes and Actinobacteria decreased by 15.59 and 0.95%. All of the surveyed bacteria groups, except Gammaproteobacteria, correlated significantly negatively (p < 0.001) with the concentrations of N-NH4+ in the outflows from R1. The results allow us to suppose that simultaneous stripping and SND in a single reactor could be a promising, cost-effective and easy-to-operate solution for LFL treatment.

Cr(vi) removal by combined redox reactions and adsorption using pectin-stabilized nanoscale zero-valent iron for simulated chromium contaminated water

RSC Advances ◽  
2015 ◽  
Vol 5 (80) ◽  
pp. 65068-65073 ◽  
Author(s):  
Dan Chen ◽  
Kai Yang ◽  
Hongyu Wang ◽  
Jun Zhou ◽  
Huining Zhang
Keyword(s):  
Redox Reaction ◽  
Redox Reactions ◽  
Zero Valent Iron ◽  
Contaminated Water ◽  
Nanoscale Zero Valent Iron

Pectin-stabilized nanoscale zero-valent iron was used to removal Cr(vi) and the main mechanisms were redox reaction and adsorption.

scholarly journals Hybrid Beads of Zero Valent Iron Oxide Nanoparticles and Chitosan for Removal of Arsenic in Contaminated Water

Water ◽  
2021 ◽  
Vol 13 (20) ◽  
pp. 2876
Author(s):  
Mian Fawaz Ahmed ◽  
Muhammad Asad Abbas ◽  
Azhar Mahmood ◽  
Nasir M. Ahmad ◽  
Hifza Rasheed ◽  
...  
Keyword(s):  
Iron Oxide ◽  
Iron Oxide Nanoparticles ◽  
Ph Value ◽  
Zero Valent Iron ◽  
Polluted Water ◽  
Oxide Nanoparticles ◽  
Contaminated Water ◽  
Contact Period ◽  
Removal Of Arsenic ◽  
Optimized Conditions

Water contaminated with highly hazardous metals including arsenic (As) is one of the major challenges faced by mankind in the present day. To address this pressing issue, hybrid beads were synthesized with various concentrations of zero valent iron oxide nanoparticles, i.e., 20% (FeCh-20), 40% (FeCh-40) and 60% (FeCh-60) impregnated into a polymer of chitosan. These hybrid beads were employed as an adsorbent under the optimized conditions of pH and time to facilitate the efficient removal of hazardous arsenic by adsorption cum reduction processes. X-ray Diffraction (XRD), Scanning Electron Microscopy (SEM), Fourier Transform Infrared Spectroscopy (FTIR), Brunauer- Emmett-Teller BET, a porosity test and wettability analysis were performed to characterize these hybrid beads. The porosity and contact angle of the prepared hybrid beads decreased with an increase in nanoparticle concentration. The effects of various adsorption factors such as adsorbent composition, contact period, pH value and the initial adsorbate concentration were also evaluated to study the performance of these beads for arsenic treatment in contaminated water. FeCh-20, FeCh-40 and FeCh-60 have demonstrated 63%, 81% and 70% removal of arsenic at optimized conditions of pH 7.4 in 10 h, respectively. Higher adsorption of arsenic by FeCh-40 is attributed to its optimal porosity, hydrophilicity and the presence of appropriate nanoparticle contents. The Langmuir adsorption kinetics described the pseudo second order. Thus, the novel beads of FeCh-40 developed in this work are a potent candidate for the treatment of polluted water contaminated with highly toxic arsenic metals.

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