scholarly journals Release of Heavy Metals from the Pyrite Tailings of Huangjiagou Pyrite Mine: Batch Experiments

2016 ◽  
Vol 8 (1) ◽  
pp. 96 ◽  
Author(s):  
Liangqian Fan ◽  
Xi Zhou ◽  
Hongbing Luo ◽  
Jie Deng ◽  
Li Dai ◽  
...  
2019 ◽  
Vol 42 (1) ◽  
pp. 1-7 ◽  
Author(s):  
Sadia Qayyum ◽  
Ke Meng ◽  
Sidra Pervez ◽  
Faiza Nawaz ◽  
Changsheng Peng

Abstract Soil contamination with heavy metal content is a growing concern throughout the world as a result of industrial, mining, agricultural and domestic activities. Fungi are the most common and efficient group of heavy metal resistant microbe family which have potential for metal bioleaching. The use of filamentous fungi in bioleaching of heavy metals from contaminated soil has been developed recently. The current study intends to isolate a strain with the ability to degrade the pH value of the liquid medium. Identification results based on morphological and molecular biological analysis gave a 98% match to Aspergillus flavus. Batch experiments were conducted to select the optimal conditions for bioleaching process which indicated that 130 mg/ L sucrose, neutral pH and temperature of 30°C were more suitable during 15-day bioleaching experiments using A. flavus. In one-step bioleaching, the bioleaching efficiencies were 18.16% for Pb, 39.77% for Cd and 58.22% for Zn+2, while two-step bioleaching showed efficiencies of 16.91% for Pb, 49.66% for Cd and 65.73% for Zn+2. Overall, this study indicates that bioleaching of heavy metals in contaminated soil using A. flavus has the potential for contaminated soil remediation.


2015 ◽  
Vol 3 (3) ◽  
pp. 35-39
Author(s):  
Sannasi Palsan ◽  
Chai Swee Fern ◽  
Stephanie Bernardine ◽  
Lim Fan Shiang

Saraca thaipingensis or ‘Gapis’ tree, classified under the Fabaceae family is a native of Taiping; copious over Peninsular Malaysia and Southeast Asia. The withered and fallen dead leaves were collected from INTI International University’s garden walkway. To date, literature has yet to capture the use of S. thaipingensis tree parts or refuse as potential biosorbent material for the removal of heavy metals thus verifying the novelty of this study. Batch experiments were carried out with the leaf powder to study the effects of dosage, particle size and contact time towards Cr(VI) removal (%) at 1-100 mg/L. Results showed that Cr(VI) removal increased from 52.22% to 99.31% (p < 0.05) with increase in biosorbent dosage (0.005, 0.010, 0.015, 0.020, 0.025 and 0.050 g). The different particle size ranges tested were: 107-125, 126-150, 151-250, 251-500, and 501- 1000 ?m. Highest Cr(VI) removal of 99.53% was obtained with the 151-250 ?m particle size; further size decrease did not yield more removal (p > 0.05). The optimal Cr(VI) removal was recorded after 45 min (99.62%) and 90 min (99.76%) contact time (p > 0.05). Further characterization and optimization studies are being carried out to develop a novel, sustainable, low cost yet effective leaf powder based biosorbent material.


2021 ◽  
Vol 900 (1) ◽  
pp. 012003
Author(s):  
M Balintova ◽  
Z Kovacova ◽  
S Demcak ◽  
Y Chernysh ◽  
N Junakova

Abstract Removal of heavy metals from the environment is important for living beings. The present work investigates the applicability of the natural and MnO2 - coated zeolite as sorbent for the removal of copper from synthetic solutions. Batch experiments were carried out to identify the influence of initial pH and concentration in the process of adsorption. A maximum removal efficiency of Cu(II) was observed in 10 mg/L for natural (95.6%) and modified (96.4%) zeolite, where the values was almost identical, but at concentration of 500 mg/L was the removal efficiency of modified zeolite three times higher. Based on the correlation factors R2, the Langmuir isotherms better describe the decontamination process than Freundlich. The optimum pH value was set at 5.0.


Author(s):  
Celestin Defo ◽  
Ravinder Kaur

Adsorption kinetics of Ni, Cr, and Pb on gravels collected from constructed wetland was studied at varied metal concentrations and contact period for estimating the removal of heavy metals from wastewater. Batch experiments were conducted by shaking 120 ml of metal solutions having 5 concentration levels each of Ni (1.0, 2.0, 3.5, 5.0 and 6.0 mg l-1), Cr (1.0, 2.0, 3.0, 4.5 and 6.0 mg l-1), and Pb (1.0, 3.0, 6.0, 8.0 and 12.0 mg l-1) with 50 g of gravels for as function of time. Adsorption of Ni, Cr, and Pb on gravels ranged from 34.8 to 47.2, 42.7-54.9, and 47.5-56.9%, indicating their removal in the order: Pb &gt; Cr &gt; Ni. Freundlich model showed a good fit for Ni and Cr (R2&gt;0.9) while Langmuir model fitted better for Pb (R2= 0.7). The pseudo-second-order model showed the best fit to simulate the adsorption rates of these metals on gravel.


Minerals ◽  
2020 ◽  
Vol 10 (9) ◽  
pp. 763 ◽  
Author(s):  
Pawit Tangviroon ◽  
Kenta Noto ◽  
Toshifumi Igarashi ◽  
Takeshi Kawashima ◽  
Mayumi Ito ◽  
...  

Massive amount of highly contaminated mining residual materials (MRM) has been left unattended and has leached heavy metals, particularly lead (Pb) and zinc (Zn) to the surrounding environments. Thus, the performance of three immobilizers, raw dolomite (RD), calcined dolomite (CD), and magnesium oxide (MO), was evaluated using batch experiments to determine their ability to immobilize Pb and Zn, leached from MRM. The addition of immobilizers increased the leachate pH and decreased the amounts of dissolved Pb and Zn to different extents. The performance of immobilizers to immobilize Pb and Zn followed the following trend: MO > CD > RD. pH played an important role in immobilizing Pb and Zn. Dolomite in RD could slightly raise the pH of the MRM leachate. Therefore, the addition of RD immobilized Pb and Zn via adsorption and co-precipitation, and up to 10% of RD addition did not reduce the concentrations of Pb and Zn to be lower than the effluent standards in Zambia. In contrast, the presence of magnesia in CD and MO significantly contributed to the rise of leachate pH to the value where it was sufficient to precipitate hydroxides of Pb and Zn and decrease their leaching concentrations below the regulated values. Even though MO outperformed CD, by considering the local availability of RD to produce CD, CD could be a potential immobilizer to be implemented in Zambia.


2016 ◽  
Vol 860 ◽  
pp. 43-46 ◽  
Author(s):  
Ahmad Khodadadi Darban ◽  
Hoda Arabyarmohammadi ◽  
Mahmoud Abdollahy ◽  
Bita Ayati

The affinity of nanoporous biochars functional groups for immobilization Cu, Zn, and Pb in aqueous solution has been studied. BET results revealed the nanoporous structure of the chars. Batch experiments have been designed and performed.The results indicated remarkable sorption capacity in case of each char: in a multi-metal system, B1, B2, and B3 adorbed 24.39, 23.61, 35.69 mg/g copper, 63.36, 90.96, 95.36 mg/g lead, and 20.16, 21.26, and 25.44 mg/g zinc, respectively. To find out the sorption mechanism with a post-sorption FTIR analysis over the biochars has been made. The results suggest the possible competitive immobilization mechanism as Cu being mainly organically bounded to amino, hydroxyl and carboxyl functional groups, Pb forming insoluble hydroxide, phosphate or carbonate, and Zn being mostly sorbed in the residual fraction.


2010 ◽  
Vol 62 (5) ◽  
pp. 1136-1142 ◽  
Author(s):  
Julija Taparcevska ◽  
Liljana Markovska ◽  
Bogdana Koumanova ◽  
Vera Meshko

The kinetics of zinc, cadmium, and lead ions removal by natural zeolite-clinoptilolite has been investigated using an agitated batch adsorber. Batch experiments at constant temperature have been performed. The influence of agitation speed, initial heavy metals concentration and particle size of the sorbent on the removal efficiency of heavy metals from liquid phase have been studied. A decrease in the initial heavy metals concentration in aqueous solutions prolongs the time needed for equilibrium. Two kinetics models according to the Vermeulen's approximation and the parabolic diffusion model have been tested with the experimental data for adsorption of heavy metals onto natural zeolite. For the systems examined, the fit of the proposed models with the experimental data was shown to be equally good using both models. The diffusion coefficients are calculated from kinetic models of heavy metal ions and they are of the order from 10−5 to 10−6 cm2/min. The diffusion coefficients depend on initial concentration for both models.


Author(s):  
Emine Elmaslar ÖZBAŞ ◽  
Nilgün BALKAYA

This study aimed to remove heavy metals (Cu, Ni, Zn, Pb, Cd) from composts using molasses hydrolysate, produced from molasses by-product of the sugar industry. Batch experiments were conducted to examine the effects of differing experimental conditions on the removal of heavy metals, according to contact time and solid–liquid ratio. Batch experiments achieved removal efficiencies of 66% for Cu(II), 52% for Ni(II), 57% for Zn(II), 51% for Pb (II), and 77% for Cd(II) at 60 minutes and 1:12.5 solid–liquid ratio. Column experiments achieved removal efficiencies of 91% for Cu, 86% for Ni, 99% for Zn, 61% for Pb, and 99% for Cd at 0.55 mL/minute flow rate and a solid–liquid ratio of 1:12.5 g/mL. Producing large quantities of highly acidic and heavy metal contaminated solution, compost with low pH, and decreasing some parameters’ concentrations of compost such as C, TKN, total P are the disadvantages of suggested technology.


Author(s):  
Ja-Young Yoon ◽  
In-Hyun Nam ◽  
Min-Ho Yoon

In the present study we investigated the ability of the microalgal strain Parachlorella sp. AA1 to biologically uptake a radionuclide waste material. Batch experiments were conducted to investigate the biosorption of uranyl ions (U(VI)) in the 0.5–50.0 mg/L concentration range by strain AA1. The results showed that AA1 biomass could uptake U(VI). The highest removal efficiency and biosorption capacity (95.6%) occurred within 60 h at an initial U(VI) concentration of 20 mg/L. The optimum pH for biosorption was 9.0 at a temperature of 25 °C. X-ray absorption near edge structure analysis confirmed the presence of U(VI) in pellets of Parachlorella sp. AA1 cells. The biosorption methods investigated here may be useful in the treatment and disposal of nuclides and heavy metals in diverse wastewaters.


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