Groundwater for Sustainable Development, Apr 1, 2020
Water shortage is one of the most critical problems all around the world, especially in arid and ... more Water shortage is one of the most critical problems all around the world, especially in arid and semi-arid regions. Using groundwater can be an efficient solution in such lands. Although significant care and appropriate water resource management strategies are required to be implemented. Nowadays, subsurface dams (SSD) are widely used worldwide since they are proved to have advantages over surface dams in some cases. Selection of the suitable site for SSD construction is critical. This selection is made based on advantages and disadvantages of each location. Multi-criteria decision-making methods (MCDM) is an efficient method for optimum site selection. In this study, 10 regions were chosen as alternatives for construction of subsurface dams in Isfahan province of Iran. These alternatives were then ranked using ELECTRE I, II and modified ELECTRE III based on geological, hydrological, climatological and socio-economical criteria. Results from different ELECTRE methods are combined by applying the grade average, and Borda and Copeland ranking strategies. Application of an advanced MCDM method reduced uncertainties in subsurface dams (SSD) site selection. Alternative 5 (Hoseinabad) was introduced as the best location for subsurface dam construction. This methodology can be used as a basis for more detailed field investigations
Abstract The oxidation of sulfide minerals is of central importance due to the acid mine drainage... more Abstract The oxidation of sulfide minerals is of central importance due to the acid mine drainage (AMD) production. The bio-oxidation of pyrrhotite, pyrite, marcasite, and arsenopyrite was carried out with mesophilic bacteria (Acidithiobacillus ferrooxidans, A. thiooxidans, and Leptospirillum ferrooxidans) at 34 °C for 30 days. Bio-oxidation tests showed that marcasite has a high potential in producing AMD compared to pyrrhotite. Arsenopyrite has different behavior in the presence and the absence of additives (i.e., FeSO4·7H2O and sulfur). While the absence of additives increased the nickel and zinc dissolution, their presence increased the total iron dissolution. Sulfur and jarosite were observed on the surfaces of pyrrhotite and arsenopyrite. With the formation of these passivation layers, the continuous iron extraction is effectively suppressed. This study is helpful to comparatively evaluate the AMD production of sulfide minerals in an oxidizing environment and to study the effects of passivation layers on their biooxidation in different conditions.
The effect of the electrokinetic process on the extraction of trapped water was evaluated in the ... more The effect of the electrokinetic process on the extraction of trapped water was evaluated in the Miduk copper mine’s tailings slurry. The effect of the dewatering process on copper removal was also studied. The initial electroosmotic permeability was determined using a one-dimensional cell. In the next step, the effect of voltage and polarity reversal was evaluated for three scenarios: T1 (2 V/cm), T2 (2 V/cm), and T3 (1 V/cm). In addition, the polarity reversal method was applied to T2 and T3. To compare the amount of water extraction and energy consumption, three indices were considered and calculated: index of dry tone, water extraction, and normal water extraction. Moreover, the effect of electrokinetics on the final moisture content, physicochemical variation, and chemical composition were investigated. The results indicated that the calculated electroosmotic permeability ranged from 1.23 × 10–9 to 1.36 × 10–9 m2/V·S, which is acceptable for electrokinetic experiments. The water extraction experiments showed average flow rates of 1.68, 1.84, and 1.73 mL/h in T1, T2, and T3, respectively. The maximum amount of water extracted in T2 was ≈ 6% more than in T3. However, considering electric energy consumption, the highest efficiency of water extraction was achieved by applying a voltage gradient of 1 V/cm for 24 h. Consequently, polarity reversal affected the water extraction efficiency by reducing energy consumption. Furthermore, moisture reduction due to the dewatering process decreased the pH variation and copper release and transport. Roughly 35% of the extractable copper was removed on the anode side of T2, which was determined to be the most efficient for remediation.
Groundwater for Sustainable Development, Apr 1, 2020
Water shortage is one of the most critical problems all around the world, especially in arid and ... more Water shortage is one of the most critical problems all around the world, especially in arid and semi-arid regions. Using groundwater can be an efficient solution in such lands. Although significant care and appropriate water resource management strategies are required to be implemented. Nowadays, subsurface dams (SSD) are widely used worldwide since they are proved to have advantages over surface dams in some cases. Selection of the suitable site for SSD construction is critical. This selection is made based on advantages and disadvantages of each location. Multi-criteria decision-making methods (MCDM) is an efficient method for optimum site selection. In this study, 10 regions were chosen as alternatives for construction of subsurface dams in Isfahan province of Iran. These alternatives were then ranked using ELECTRE I, II and modified ELECTRE III based on geological, hydrological, climatological and socio-economical criteria. Results from different ELECTRE methods are combined by applying the grade average, and Borda and Copeland ranking strategies. Application of an advanced MCDM method reduced uncertainties in subsurface dams (SSD) site selection. Alternative 5 (Hoseinabad) was introduced as the best location for subsurface dam construction. This methodology can be used as a basis for more detailed field investigations
Abstract The oxidation of sulfide minerals is of central importance due to the acid mine drainage... more Abstract The oxidation of sulfide minerals is of central importance due to the acid mine drainage (AMD) production. The bio-oxidation of pyrrhotite, pyrite, marcasite, and arsenopyrite was carried out with mesophilic bacteria (Acidithiobacillus ferrooxidans, A. thiooxidans, and Leptospirillum ferrooxidans) at 34 °C for 30 days. Bio-oxidation tests showed that marcasite has a high potential in producing AMD compared to pyrrhotite. Arsenopyrite has different behavior in the presence and the absence of additives (i.e., FeSO4·7H2O and sulfur). While the absence of additives increased the nickel and zinc dissolution, their presence increased the total iron dissolution. Sulfur and jarosite were observed on the surfaces of pyrrhotite and arsenopyrite. With the formation of these passivation layers, the continuous iron extraction is effectively suppressed. This study is helpful to comparatively evaluate the AMD production of sulfide minerals in an oxidizing environment and to study the effects of passivation layers on their biooxidation in different conditions.
The effect of the electrokinetic process on the extraction of trapped water was evaluated in the ... more The effect of the electrokinetic process on the extraction of trapped water was evaluated in the Miduk copper mine’s tailings slurry. The effect of the dewatering process on copper removal was also studied. The initial electroosmotic permeability was determined using a one-dimensional cell. In the next step, the effect of voltage and polarity reversal was evaluated for three scenarios: T1 (2 V/cm), T2 (2 V/cm), and T3 (1 V/cm). In addition, the polarity reversal method was applied to T2 and T3. To compare the amount of water extraction and energy consumption, three indices were considered and calculated: index of dry tone, water extraction, and normal water extraction. Moreover, the effect of electrokinetics on the final moisture content, physicochemical variation, and chemical composition were investigated. The results indicated that the calculated electroosmotic permeability ranged from 1.23 × 10–9 to 1.36 × 10–9 m2/V·S, which is acceptable for electrokinetic experiments. The water extraction experiments showed average flow rates of 1.68, 1.84, and 1.73 mL/h in T1, T2, and T3, respectively. The maximum amount of water extracted in T2 was ≈ 6% more than in T3. However, considering electric energy consumption, the highest efficiency of water extraction was achieved by applying a voltage gradient of 1 V/cm for 24 h. Consequently, polarity reversal affected the water extraction efficiency by reducing energy consumption. Furthermore, moisture reduction due to the dewatering process decreased the pH variation and copper release and transport. Roughly 35% of the extractable copper was removed on the anode side of T2, which was determined to be the most efficient for remediation.
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