scholarly journals Removal of Transition Metals from Contaminated Aquifers by PRB Technology: Performance Comparison among Reactive Materials

2021 ◽  
Vol 18 (11) ◽  
pp. 6075
Author(s):  
Celia Margarita Mayacela-Rojas ◽  
Antonio Molinari ◽  
José Luis Cortina ◽  
Oriol Gibert ◽  
Carlos Ayora ◽  
...  
Keyword(s):  
Transition Metals ◽  
Natural Zeolite ◽  
Performance Comparison ◽  
Permeable Reactive Barrier ◽  
Column Tests ◽  
Reactive Material ◽  
Reactive Barrier ◽  
Reactive Materials ◽  
Experimental Values ◽  
Natural Clinoptilolite

The most common reactive material used for the construction of a permeable reactive barrier (PRB) is zero valent iron (ZVI), however, its processing can generate corrosive effects that reduce the efficiency of the barrier. The present study makes a major contribution to understanding new reactive materials as natural and synthetic, easy to obtain, economical and environmentally friendly as possible substitutes for the traditional ZHV to be used as filters in the removal of three transition metals (Zn, Cu, Cd). To assess the ability to remove these pollutants, a series of batch and column tests were carried out at laboratory scale with these materials. Through BACH tests, four of seven substances with a removal percentage higher than 99% were prioritized (cabuya, natural clinoptilolite zeolites, sodium mordenite and mordenite). From this group of substances, column tests were performed where it is evidenced that cabuya fiber presents the lowest absorption time (≈189 h) while natural zeolite mordenite shows the highest time (≈833 h). The latter being the best option for the PRB design. The experimental values were also reproduced by the RETRASO code; through this program, the trend between the observed and simulated values with respect to the best reactive substance was corroborated.

scholarly journals Application of permeable reactive barriers near roads for chloride ions removal

2010 ◽  
Vol 42 (2) ◽  
pp. 249-259 ◽  
Author(s):  
Joanna Fronczyk ◽  
Katarzyna Pawluk ◽  
Marta Michniak
Keyword(s):  
Activated Carbon ◽  
Chloride Ions ◽  
Permeable Reactive Barriers ◽  
Zero Valent Iron ◽  
Permeable Reactive Barrier ◽  
Polluted Water ◽  
Reactive Material ◽  
Reactive Materials ◽  
Run Off ◽  
Reactive Barriers

Application of permeable reactive barriers near roads for chloride ions removal One of the most critical sources of pollutants are road run-offs. Road run-off is a complex mixture of toxicants e.g. heavy metals, de-icing agents, organic compounds and water suspensions of solid substances. One of the most negative impact on the environment has sodium chloride which is used as de-icing agent. In the case of incorrect environment protection in the vicinity of roads pollutants may migrate to groundwater causing hazard to sources of potable water. One of the methods to prevent the migration of pollutants to groundwater is imposing the flow of polluted water through a reactive material filling a permeable reactive barrier (PRB). This paper examines the feasibility of selected reactive materials for the reduction chlorides concentration in road run-offs. Four different reactive materials: zero valent-iron, activated carbon, zeolite and geza rock have been chosen for studies. The tests results indicated that the most popular reactive materials used in PRB technology, activated carbon and zero-valent iron, removed exhibited the highest efficiency in chloride ions removal. Moreover, the composition of road run-off in samples collected along roads in Warsaw was determinated.

scholarly journals Evaluation of Zeolite as a Potential Reactive Medium in a Permeable Reactive Barrier (PRB): Batch and Column Studies

Geosciences ◽  
2020 ◽  
Vol 10 (2) ◽  
pp. 59
Author(s):  
Liana Carolina Carvalho Rocha ◽  
Lazaro Valentin Zuquette
Keyword(s):  
Permeable Reactive Barrier ◽  
Column Experiments ◽  
Single Element ◽  
Order Kinetic ◽  
Transport Parameters ◽  
Column Studies ◽  
Reactive Medium ◽  
Reactive Material ◽  
Reactive Barrier ◽  
Batch Tests

The purpose of this work is to evaluate the capacity of a natural zeolite to be used as a reactive material in a permeable reactive barrier (PRB) to remove inorganic contaminants from groundwater. To this aim, zeolite samples were subjected to characterization tests, column experiments, batch tests and a flushing process to evaluate the adsorption and desorption capacities of the zeolite. In the column experiments, the samples were subjected to eight successive cycles involving the percolation of a potassium aqueous solution (1500 mg/L) and a subsequent flushing process with water. Batch tests were conducted by mixing 20 g of zeolite with 100 mL of single-element aqueous solutions of K and Zn with concentrations of 200 mg/L. The results indicate that the zeolite rock is composed predominantly of clinoptilolite species and has a Si/Al ratio of 6.8, a high cationic exchange capacity (CEC) of 180 cmolc/kg and a high K+ adsorption rate with a removal efficiency of 78%. The adsorption isotherms of the zeolite follow the Langmuir model and are well fit by a pseudo-second-order kinetic model showing a high correlation coefficient (r2 > 0.999) for both K+ and Zn2+ cations. Additionally, the contaminant transport parameters for K+ ions (Rd = 24.9; Dh = 1.32 × 10–2 cm2/s and α = 1.42) reveal that the zeolite is resistant to the dispersion of ions in the barrier, indicating that the material has advantageous characteristics for use in a PRB. However, the flushing process of the material is not efficient, indicating that the appropriate use of the zeolite is in clean-up systems in which the adsorbent material can be exchanged after losing its efficiency as a reactive barrier.

scholarly journals Assessment of optimum width and longevity of a permeable reactive barrier installed in an acid sulfate soil terrain

2015 ◽  
Vol 52 (7) ◽  
pp. 999-1004 ◽  
Author(s):  
Udeshini Pathirage ◽  
Buddhima Indraratna
Keyword(s):  
Groundwater Flow ◽  
Residence Time ◽  
Cost Effective ◽  
Permeable Reactive Barriers ◽  
Permeable Reactive Barrier ◽  
Reactive Material ◽  
Reactive Barrier ◽  
Acidic Groundwater ◽  
Different Types ◽  
Optimum Width

Removal of contaminants from groundwater using permeable reactive barriers (PRBs) is a cost-effective and popular engineering solution used throughout the world. Dissolved pollutants in groundwater are removed through geochemical processes that make PRBs effective for different types of contaminants. In achieving this, it is vital to determine the optimum width of the PRB to allow adequate residence time within the barrier and to establish its longevity. For this purpose, both field monitoring and geochemical modelling were conducted for a trial PRB located in the Shoalhaven Floodplain, south of Wollongong in Australia. In this study, the optimum PRB width is evaluated numerically, based on the neutralization effectiveness, i.e., when acidic groundwater travels through the alkaline PRB. A model developed previously has been extended considering the residence time, reaction kinetics, mineral precipitation–induced reduction in porosity and hydraulic conductivity, influent concentrations of the contaminants, and groundwater flow velocity. Longevity of the PRB is determined with respect to groundwater flow rates and amount of reactive material consumed.

Testing of Different Substrate Materials for Sulphate Reducing Reactive Barrier to Treat Acid Mine Drainage

2009 ◽  
Vol 71-73 ◽  
pp. 573-576 ◽  
Author(s):  
Elina A. Vestola
Keyword(s):  
Mine Drainage ◽  
Growth Conditions ◽  
Solid Substrate ◽  
Substrate Material ◽  
Permeable Reactive Barrier ◽  
Column Tests ◽  
Reactive Barrier ◽  
Batch Tests ◽  
Nickel Copper ◽  
Treat Acid Mine Drainage

The aim of this study was to find cheap, solid substrate material for sulphate reducing bacteria (SRB) to be used in permeable reactive barrier (PRB) and infiltration beds to treat acidic, nickel-, copper- and iron-rich mine drainage. Laboratory experiments were carried out to examine the reactivity and utilisation of different substrate materials. The materials of interest were peat, sawdust, cucumber compost and cellulose. Limestone, phosphorus and nitrogen were added to the mixture to create optimum growth conditions for SRB. Based on a batch tests, cucumber compost was chosen to be examined in larger-scale column tests. Results from the column tests were promising. Nickel (43 mg L-1), copper (24 mg L-1) and iron (95 mg L-1) were precipitated almost completely and the concentration of sulphate was decreased approximately 20 %. pH values increased from 2.7 to 8. Based on laboratory tests results it appears that cucumber compost was suitable substrate material for SRB in PRBs and infiltration beds treating AMD.

scholarly journals Reactive Sandpacks for In-Situ Treatment of Construction Dewatering Effluent

2013 ◽  
Vol 2 (2) ◽  
pp. 85-87 ◽  
Author(s):  
Elizabeth Priebe ◽  
David R. Lee
Keyword(s):  
Groundwater Contamination ◽  
Contaminated Soils ◽  
Groundwater Remediation ◽  
Permeable Reactive Barrier ◽  
Hypothetical Situation ◽  
Environmental Liabilities ◽  
Reactive Material ◽  
Groundwater Contaminants ◽  
Reactive Barrier

Dealing with contaminated effluent can be problematic when dewatering is required in the course of removing buried tanks, excavating contaminated soils or constructing groundwater remediation systems. An engineering solution put forward in this paper is the emplacement of a sandpack, around the dewatering well(s), that reacts with and sequesters groundwater contaminants of concern. If an appropriate granular reactive material is available, placing that material around the dewatering well screen can achieve a degree of contaminant treatment in-situ that may considerably reduce the costs of storing, securing and treating the water before it is released. In the preferred situation, the contaminants remain underground and the extracted water is suitable for surface release as it is pumped from the ground. We used laboratory columns of granular reactive material (clinoptilolite) and a radiostrontium tracer to evaluate the usefulness of this approach in a hypothetical situation where the water table needed to be lowered 2 m in order to install a permeable reactive barrier. Results were consistent with the concept of reducing the environmental liabilities of construction dewatering in areas of groundwater contamination.

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