scholarly journals Enriched Co-Treatment of Pharmaceutical and Acidic Metal-Containing Wastewater with Nano Zero-Valent Iron

Minerals ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 220
Author(s):  
Thobeka Pearl Makhathini ◽  
Jean Mulopo ◽  
Babatunde Femi Bakare
Keyword(s):  
Mine Drainage ◽  
Oxygen Demand ◽  
Cost Effective ◽  
Zero Valent Iron ◽  
Silica Sand ◽  
Reaction Products ◽  
Sulfate Removal ◽  
Total Dissolved Nitrogen ◽  
Nano Zero Valent Iron ◽  
Co Precipitation

Among traditional hazardous waste sources, pharmaceutical-containing wastewater and acidic mine drainage need treatment to preserve the expected water supply quality. A nano zero-valent iron (nZVI)-enriched treatment of these two streams is evaluated for simultaneous removal of various heavy metal ions, organic pollutants, sulfates, the efficiency of the treatment system, and separation of reaction products in the fluidized-bed reactor. The reactor packed with silica sand was inoculated with sludge from an anaerobic digester, then 1–3 g/L of nZVI slurry added to cotreat a hospital feed and acid mine wastewater at 5:2 v/v. The biotreatment process is monitored through an oxidation–reduction potential (Eh) for 90 days. The removal pathway for the nZVI used co-precipitation, sorption, and reduction. The removal load for Zn and Mn was approximately 198 mg Zn/g Fe and 207 mg Mn/g Fe, correspondingly; achieving sulfate (removal efficiency of 94% and organic matter i.e., chemical oxygen demand (COD), biological oxygen demand (BOD), dissolved organic carbon (DOC), total dissolved nitrogen (TDN) reduced significantly, but ibuprofen and naproxen achieved 31% and 27% removal, respectively. This enriched cotreatment system exhibited a high reducing condition in the reactor, as confirmed by Eh; hence, the nZVI was dosed only a few times in biotreatment duration, demonstrating a cost-effective system.

Mechanisms and Remediation Technologies of Sulfate Removal from Acid Mine Drainage

2012 ◽  
Vol 610-613 ◽  
pp. 3252-3256
Author(s):  
Mei Qin Chen ◽  
Feng Ji Wu
Keyword(s):  
Heavy Metals ◽  
Acid Mine Drainage ◽  
Mine Drainage ◽  
Metal Corrosion ◽  
Sulfate Ion ◽  
High Concentration ◽  
Biological Reduction ◽  
Acid Mine ◽  
Sulfate Removal ◽  
Co Precipitation

Acid mine drainage (AMD) has properties of extreme acidification, quantities of sulfate and elevated levels of soluble heavy metals. It was a widespread environmental problem that caused adverse effects to the qualities of ground water and surface water. In the past decades, most of investigations were focused on the heavy metals as their toxicities for human and animals. As another main constitution of AMD, sulfate ion is nontoxic, yet high concentration of sulfate ion can cause many problems such as soil acidification, metal corrosion and health problems. More attention should be paid on the sulfate ion when people focus on the AMD. In the paper, sulfate removal mechanisms include adsorption, precipitation, co-precipitation and biological reduction were analyzed and summarized. Meanwhile, the remediation technologies, especially the applications of them in China were also presented and discussed.

scholarly journals Application of horizontal-flow anaerobic immobilized biomass reactor for bioremediation of acid mine drainage

2015 ◽  
Vol 14 (3) ◽  
pp. 399-410 ◽  
Author(s):  
R. P. Rodriguez ◽  
D. V. Vich ◽  
M. L. Garcia ◽  
M. B. A. Varesche ◽  
M. Zaiat
Keyword(s):  
Sulfate Reduction ◽  
Mine Drainage ◽  
Low Cost ◽  
Mining Industry ◽  
Oxygen Demand ◽  
Horizontal Flow ◽  
Sulfate Removal ◽  
Effluent Recirculation ◽  
Initial Ph ◽  
Immobilized Biomass

The production of low-pH effluent with sulfate and metals is one of the biggest environmental concerns in the mining industry. The biological process for sulfate reduction has the potential to become a low-cost solution that enables the recovery of interesting compounds. The present study analyzed such a process in a horizontal-flow anaerobic immobilized biomass (HAIB) reactor, employing ethanol as the carbon and energy source. Results showed that a maximal efficiency in the removal of sulfate and ethanol could only be obtained by reducing the applied sulfate load (225.1 ± 38 g m−3 d−1). This strategy led to over 75% of chemical oxygen demand (COD) and sulfate removal. Among the COD/SO42− studied ratios, 0.67 showed the most promising performance. The effluent's pH has naturally remained between 6.8 and 7.0 and the complete oxidation of the organic matter has been observed. Corrections of the influent pH or effluent recirculation did not show any significant effect on the COD and sulfate removal efficiency. Species closely related to strains of Clostridium sp. and species of Acidaminobacter hydrogenomorfans and Fusibacter paucivorans that can be related to the process of sulfate reduction were found in the HAIB reactors when the initial pH was 5 and the COD/SO42− ratio increased to 1.0.

scholarly journals Synthesis of Poly-Alumino-Ferric Sulphate Coagulant from Acid Mine Drainage by Precipitation

Metals ◽  
2019 ◽  
Vol 9 (11) ◽  
pp. 1166 ◽  
Author(s):  
Brian Mwewa ◽  
Srećko Stopić ◽  
Sehliselo Ndlovu ◽  
Geoffrey S. Simate ◽  
Buhle Xakalashe ◽  
...  
Keyword(s):  
Acid Mine Drainage ◽  
Mine Drainage ◽  
Environmental Concern ◽  
Oxygen Demand ◽  
Ferric Sulphate ◽  
Brewery Wastewater ◽  
Metal Mining ◽  
Acid Mine ◽  
Sludge Disposal ◽  
Co Precipitation

The wastes generated from both operational and abandoned coal and metal mining are an environmental concern. These wastes, including acid mine drainage (AMD), are treated to abate the devastating effects they have on the environment before disposal. However, AMD contains valuable resources that can be recovered to subsidize treatment costs. Two of the major constituents of coal AMD are iron and aluminium, which can be recovered and engineered to function as coagulants. This work examines the potential of producing a poly-alumino-ferric sulphate (AMD-PAFS) coagulant from coal acidic drainage solutions. The co-precipitation of iron and aluminium is conducted at pH values of 5.0, 6.0 and 7.0 using sodium hydroxide in order to evaluate the recovery of iron and aluminium as hydroxide precipitates while minimizing the co-precipitation of the other heavy metals. The precipitation at pH 5.0 yields iron and aluminium recovery of 99.9 and 94.7%, respectively. An increase in the pH from 5.0 to 7.0 increases the recovery of aluminium to 99.1%, while the recovery of iron remains the same. The precipitate formed at pH 5.0 is used to produce a coagulant consisting of 89.5% and 10.0% iron and aluminium, respectively. The production of the coagulant is carried out by dissolving the precipitate in 5.0% (w/w) sulphuric acid. Subsequently, the treatment of the brewery wastewater shows that the AMD-PAFS coagulant is as efficient as the conventional poly ferric sulphate (PFS) coagulant. The turbidity removal is 91.9 and 87.8%, while the chemical oxygen demand (COD) removal is 56.0 and 64.0% for AMD-PAFS and PFS coagulants, respectively. The developed process, which can easily be incorporated into existing AMD treatment plants, not only reduces the sludge disposal problems but also creates revenue from waste.

scholarly journals Study on treatment of acid mine drainage by nano zero-valent iron synergistic with SRB immobilized particles

2020 ◽  
Vol 26 (5) ◽  
pp. 200333-0
Author(s):  
Xianjun Wang ◽  
Junzhen Di ◽  
Bing Liang ◽  
Yu Yang ◽  
Yanrong Dong ◽  
...  
Keyword(s):  
Acid Mine Drainage ◽  
Mine Drainage ◽  
Ph Value ◽  
Zero Valent Iron ◽  
Main Body ◽  
Matrix Component ◽  
Sulfate Reducing ◽  
Acid Mine ◽  
Nano Zero Valent Iron ◽  
Reducing Bacteria

In view of the serious pollution and high cost of treatment of acid mine drainage (AMD) in coal mine, the polyving akohol (PVA) and boric acid embedding cross-linking method was used to prepare the immobilized particles for treatment of AMD with sulfate-reducing bacteria (SRB) and nano zero-valent iron (nano-Fe<sup>0</sup>) as the main body. In order to explore the specification and dosage of each matrix component of immobilized particle, a series of single factor tests and orthogonal tests were carried out to determine the optimal ratio of each matrix component. The results shows that when the SRB quality additive percentage was 30%, the nano-Fe<sup>0</sup> dosage was 4%, the corn cob particle size was 60 mesh and the dosage was 3%, the SO<sub>4</sub><sup>2-</sup>, Cr<sup>6+</sup> and Cr<sup>3+</sup> removal rates were 82.99%, 99.78% and 38.78%, respectively, the TFe and COD release rates were 4.26 mg·L<sup>-1</sup> and 1,033.4 mg·L<sup>-1</sup>, respectively, and the pH value was 8.04, and the treatment effect was the best.

scholarly journals Efficient Removal of Hexavalent Chromium from an Aquatic System Using Nanoscale Zero-Valent Iron Supported by Ramie Biochar

Nanomaterials ◽  
2021 ◽  
Vol 11 (10) ◽  
pp. 2698
Author(s):  
Xiangpeng Tan ◽  
Muhammad Shaaban ◽  
Jianwei Yang ◽  
Yajun Cai ◽  
Buyun Wang ◽  
...  
Keyword(s):  
Hexavalent Chromium ◽  
Photoelectron Spectroscopy ◽  
Interaction Mechanism ◽  
Reduction Reaction ◽  
Zero Valent Iron ◽  
Adsorption Activity ◽  
X Ray ◽  
Nano Zero Valent Iron ◽  
Multiple Interaction ◽  
Co Precipitation

In this study, ramie biochar (RBC) was used to activate nano zero-valent iron (nZVI) to enhance hexavalent chromium (Cr(VI)) removal. The best results were obtained at a pyrolysis temperature of 600 °C, a biochar particle size of < 150 μm, and an iron to carbon ratio = 1:1. Under the optimal conditions, the removal of Cr(VI) by RBC600-nZVI (98.69%) was much greater than that of RBC600 (12.42%) and nZVI (58.26%). Scanning electron microscopy (SEM), X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), and X-ray photoelectron spectroscopy (XPS) revealed that the reaction mechanism at the Fe and Cr interface was a multiple interaction mechanism with reduction dominated, adsorption, and co-precipitation simultaneously. The enhanced performance of RBC600-nZVI resulted from the effective dispersion of nZVI on the surface of RBC600, therefore increasing the adsorption activity sites. At the same time, RBC600 and nZVI exerted a synergistic influence on the composite structure, which jointly promoted the reduction reaction of Cr(VI) and removed more Cr(VI). This study shows that RBC-nZVI is a potentially valuable remediation material that not only provides a new idea for the utilization of ramie waste, but also effectively overcomes the limitations of nZVI, thus, achieving efficient and rapid remediation of Cr(VI).

Nano Zero Valent Iron Composites for Water Decontamination: A Review

2018 ◽  
Vol 5 (2) ◽  
pp. 88-101
Author(s):  
Nivedita Shukla ◽  
Amit Saxena ◽  
Vatsana Gupta ◽  
Ashok Singh Rawat ◽  
Sarita Shrivastava ◽  
...  
Keyword(s):  
Zero Valent Iron ◽  
Water Decontamination ◽  
Nano Zero Valent Iron

scholarly journals Nano Zero Valent Iron (nZVI) as an Amendment for Phytostabilization of Highly Multi-PTE Contaminated Soil

Materials ◽  
2021 ◽  
Vol 14 (10) ◽  
pp. 2559
Author(s):  
Maja Radziemska ◽  
Zygmunt M. Gusiatin ◽  
Jiri Holatko ◽  
Tereza Hammerschmiedt ◽  
Andrzej Głuchowski ◽  
...  
Keyword(s):  
Plant Biomass ◽  
Absorption Spectrometry ◽  
Zero Valent Iron ◽  
Festuca Rubra ◽  
Control Series ◽  
Flame Atomic Absorption ◽  
Zn Content ◽  
Nano Zero Valent Iron ◽  
Average Plant

In recent years, a lot of attention has been given to searching for new additives which will effectively facilitate the process of immobilizing contaminants in the soil. This work considers the role of the enhanced nano zero valent iron (nZVI) strategy in the phytostabilization of soil contaminated with potentially toxic elements (PTEs). The experiment was carried out on soil that was highly contaminated with PTEs derived from areas in which metal waste had been stored for many years. The plants used comprised a mixture of grasses—Lolium perenne L. and Festuca rubra L. To determine the effect of the nZVI on the content of PTEs in soil and plants, the samples were analyzed using flame atomic absorption spectrometry (FAAS). The addition of nZVI significantly increased average plant biomass (38%), the contents of Cu (above 2-fold), Ni (44%), Cd (29%), Pb (68%), Zn (44%), and Cr (above 2-fold) in the roots as well as the soil pH. The addition of nZVI, on the other hand, was most effective in reducing the Zn content of soil when compared to the control series. Based on the investigations conducted, the application of nZVI to soil highly contaminated with PTEs is potentially beneficial for the restoration of polluted lands.

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