Study on variation rules between heavy metal ions' concentration and pH value in acid mine drainage

Author(s):  
Yunzhang Rao ◽  
Guoliang Chen ◽  
Hong Wu ◽  
Shuitai Xu
2014 ◽  
Vol 535 ◽  
pp. 758-763 ◽  
Author(s):  
Si Min Liu ◽  
Yu Long Liu ◽  
Jia Yu Song ◽  
Hao Deng

The aim of the study is to investigate removal of Cu, Ni, Zn, Cd and Pb in acid mine drainage (AMD) using modified oxygen releasing compounds (MORCs) of which CaO2 is the main ingredient. When the MORCs are placed into AMDs, OH- will be released gently and continuously which can neutralize H+ and precipitate heavy metal ions as hydroxide/carbonates. Four types of artificial AMDs contained Cu, Ni, Zn, Cd and Pb ions with/without sulfate were prepared in the laboratory. The removal rates of the heavy metals were measured after adding MORCs to the artificial AMDs. The results showed that the removal rates of Cu, Ni, Zn, Cd and Pb in all 4 artificial AMDs, after 72 hours, are more than 97%, even to 100%. However, after 96 hours, Cu, Ni, Zn, Cd and Pb deposits can be re-dissolved by 16.4%, 11.2%, 7.0%, 5.0% and 4.8%, respectively, in the single-metal artificial AMDs; Pb and Cd deposits are more stable. Sulfate in the multi-metal artificial AMD hardly has effects on re-dissolution of the heavy metal deposits; and only Ni deposits in the single-metal AMD with sulfate and Cu deposits in the single-metal AMD without sulfate are re-dissolved significantly. It suggested that the MORCs should be an efficient material to remove Cu, Ni, Zn, Cd and Pb from AMDs after 72 hours than lime or limestone.


Author(s):  
Indah Purnamasari ◽  
Endang Supraptiah

One used method to reduce heavy metal ions in acid mine drainage is to adsorb them by coal fly ash. This research aimed to study the isotherms equilibrium and the adsorpstion kinetics that fit with decreasing metals ion. Acid mine draigane and fly ash were charge into batch coloumn adsorption with specified comparison. Variables investigated were dactivated and activated fly ash, adsorption times (0, 20, 30, 40,50, and 60 minutes), adsorben weights (10, 20, 30, 40, 50, and 60 gram), and pH (1, 3, 5, 7, and 9). The results showed that fly ash can be used to reduce the levels of heavy metal ions Fe and Mn. Coal fly ash adsorption model of acid mine drainage fits to Freundlich adsorption isotherm in all condition. First order pseudo model kinetics is suitable for Fe and Mn adsorption processes. The value of adsorpsi rate constants vary around : Fe and Mn (deactivated fly ash) 0.2388 min-1 with R2 = 0.4455 and 0.4173 min-1 with R2 = 0.9781, Fe and Mn (activated fly ash) 0.5043 min-1 dengan R2 = 1 and 0.2027 min-1 with R2 = 0.8803.


2021 ◽  
Vol 11 (2) ◽  
Author(s):  
Tebogo M. Mokgehle ◽  
Nikita T. Tavengwa

AbstractAcid mine drainage is the reaction of surface water with sub-surface water located on sulfur bearing rocks, resulting in sulfuric acid. These highly acidic conditions result in leaching of non-biodegradeable heavy metals from rock which then accumulate in flora, posing a significant environmental hazard. Hence, reliable, cost effective remediation techniques are continuously sought after by researchers. A range of materials were examined as adsorbents in the extraction of heavy metal ions from acid mine drainage (AMD). However, these materials generally have moderate to poor adsorption capacities. To address this problem, researchers have recently turned to nano-sized materials to enhance the surface area of the adsorbent when in contact with the heavy metal solution. Lately, there have been developments in studying the surface chemistry of nano-engineered materials during adsorption, which involved alterations in the physical and chemical make-up of nanomaterials. The resultant surface engineered nanomaterials have been proven to show rapid adsorption rates and remarkable adsorption capacities for removal of a wide range of heavy metal contaminants in AMD compared to the unmodified nanomaterials. A brief overview of zeolites as adsorbents and the developent of nanosorbents to modernly applied magnetic sorbents and ion imprinted polymers will be discussed. This work provides researchers with thorough insight into the adsorption mechanism and performance of nanosorbents, and finds common ground between the past, present and future of these versatile materials.


2013 ◽  
Vol 773 ◽  
pp. 283-288
Author(s):  
Xing Zou ◽  
Xiang Quan Chen ◽  
Hai Chao Xie ◽  
Xiao Dan Qiu

The manganese sulfate solution leached from low-grade pyrolusite with pyrite and H2SO4 contains heavy metal ions of high concentration, influencing the quality of the final products of manganese compounds and causing manganese ions not to be electrolyzed. The present study was focused on the separation of Co, Ni and Zn ions from the leached solution with BaS. By controlling the pH value at 5.0-6.5, temperature at 50-60°C, reaction time at 15 min and mixing velocity at 78 rpm, the heavy metal ions could be separated effectively. Under the above optimized conditions, the ion concentration of Co, Ni, and Zn in the solution was reduced to 0.06 mg.L-1, 0.27mg.L-1 and 0.01mg.L-1, and the separation efficiency was 99.72%, 99.18% and 99.9% respectively. The obtained pure solution meets the demands of manganese electrowinning.


2017 ◽  
Vol 228 (9) ◽  
Author(s):  
Varinporn Asokbunyarat ◽  
Eric D. van Hullebusch ◽  
Piet N. L. Lens ◽  
Ajit P. Annachhatre

Metals ◽  
2018 ◽  
Vol 8 (8) ◽  
pp. 596 ◽  
Author(s):  
Yongwei Song ◽  
Heru Wang ◽  
Jun Yang ◽  
Yanxiao Cao

Acid mine drainage is highly acidic and contains large quantities of Fe and heavy metal elements. Thus, it is important to promote the transformation of Fe into secondary iron minerals that exhibit strong heavy-metal removal abilities. Using simulated acid mine drainage, this work analyzes the influence of monovalent cations (K+, NH4+, and Na+) on the Fe2+ oxidation and total Fe deposition efficiencies, as well as the phases of secondary iron minerals in an Acidithiobacillus ferrooxidans system. It also compares the Cr(VI) (K2Cr2O7) and As(III) (As2O3) removal efficiencies of different schwertmannites. The results indicated that high concentrations of monovalent cations (NH4+ ≥ 320 mmol/L, and Na+ ≥ 1600 mmol/L) inhibited the biological oxidation of Fe2+. Moreover, the mineralizing abilities of the three cations differed (K+ > NH4+ > Na+), with cumulative Fe deposition efficiencies of 58.7%, 28.1%, and 18.6%, respectively [n(M) = 53.3 mmol/L, cultivation time = 96 h]. Additionally, at initial Cr(VI) and As(III) concentrations of 10 and 1 mg/L, respectively, the Cr(VI) and As(III) removal efficiencies exhibited by schwertmannites acquired by the three mineralization systems differed [n(Na) = 53.3 > n(NH4) = 53.3 > n(K) = 0.8 mmol/L]. Overall, the analytical results suggested that the removal efficiency of toxic elements was mainly influenced by the apparent structure, particle size, and specific surface area of schwertmannite.


2010 ◽  
Vol 82 (1) ◽  
pp. 146-153 ◽  
Author(s):  
XU Xiaochun ◽  
XIE Qiaoqin ◽  
CHEN Fang ◽  
WANG Jun ◽  
WU Wentao

2001 ◽  
Vol 42 (9) ◽  
pp. 1877-1884
Author(s):  
Keiko Sasaki ◽  
Tagiru Ogino ◽  
Yuji Endo ◽  
Kunihiko Kurosawa

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