scholarly journals Synthesis and Application of Cationised Cellulose for Removal of Cr(VI) from Acid Mine-Drainage Contaminated Water

2020 ◽  
Author(s):  
Anita Etale ◽  
Dineo S. Nhlane ◽  
Alseno K. Mosai ◽  
Jessica Mhlongo ◽  
Aaliyah Khan ◽  
...  
Keyword(s):  
Acid Mine Drainage ◽  
13C Nmr ◽  
Quaternary Ammonium ◽  
Mine Drainage ◽  
Contaminated Water ◽  
Acid Mine ◽  
13C Nuclear Magnetic Resonance ◽  
Cellulose Fibrils ◽  
Water Ph ◽  
Pseudo Second Order

Cationised hemp cellulose was prepared by etherification with two quaternary ammonium salts: 3-chloro-2-hydroxypropyl trimethyl ammonium chloride (CHPTAC) and glycidyltrimethylammonium chloride (GTMAC) and examined for (i) the efficiency of Cr(VI) removal under acid mine-drainage (AMD) conditions, and (ii) antibacterial activity. Adsorbents were characterised by electron microscopy, Fourier transform infrared (FTIR), CP-MAS 13C nuclear magnetic resonance (NMR) spectroscopy, elemental composition and surface charge. FTIR and solid state 13C NMR confirmed the introduction of quaternary ammonium moieties on cellulose. 13C NMR also showed that cationisation decreased the degree of crystallisation and lateral dimensions of cellulose fibrils. Nevertheless, 47 % - 72% of Cr(VI) ions were removed from solutions at pH 4, by 0.1 g of CHPTAC and GTMAC-cationised cellulose, respectively. Adsorption kinetics followed the pseudo-second order model and isotherms were best described by the Freundlich and Dubinin-Radushkevich models. When GTMAC-modified cellulose was applied to AMD contaminated water (pH 2.7), however, Cr(VI) uptake removal decreased to 22% likely due to competition from Al and Fe ions. Nevertheless, cationised materials displayed considerable antibacterial effects, reducing the viability of Escherichia coli by up to 45 % after just 3 hours of exposure. Together, these results suggest that cationised cellulose can be applied in the treatment of Cr(VI)-contaminated mine water particularly if pre-treatments to reduce Fe and Al concentrations are applied.

scholarly journals Synthesis and application of cationised cellulose for removal of Cr(VI) from acid mine-drainage contaminated water

2021 ◽  
Vol 4 ◽  
pp. 4
Author(s):  
Anita Etale ◽  
Dineo S. Nhlane ◽  
Alseno K. Mosai ◽  
Jessica Mhlongo ◽  
Aaliyah Khan ◽  
...  
Keyword(s):  
Acid Mine Drainage ◽  
Quaternary Ammonium ◽  
Mine Drainage ◽  
Contaminated Water ◽  
Acid Mine ◽  
Cellulose Fibrils ◽  
Water Ph ◽  
Pseudo Second Order ◽  
Fe Ions ◽  
C Nmr

Background: Acid mine drainage (AMD) leads to contamination of surface and ground water by high levels of toxic metals including chromium. In many cases, these waters are sources of drinking water for communities, and treatment is therefore required before consumption to prevent negative health effects. Methods: Cationised hemp cellulose was prepared by etherification with two quaternary ammonium salts: 3-chloro-2-hydroxypropyl trimethyl ammonium chloride (CHPTAC) and glycidyltrimethylammonium chloride (GTMAC) and examined for (i) the efficiency of Cr(VI) removal under acid mine-drainage (AMD) conditions, and (ii) antibacterial activity. Adsorbents were characterised by electron microscopy, Fourier transform infrared (FTIR), CP-MAS 13C nuclear magnetic resonance (NMR) spectroscopy, elemental composition and surface charge. Results: FTIR and solid state 13C NMR confirmed the introduction of quaternary ammonium moieties on cellulose. 13C NMR also showed that cationisation decreased the degree of crystallisation and lateral dimensions of cellulose fibrils. Nevertheless, 47 %  - 72 % of Cr(VI) ions were removed from solutions at pH 4, by 0.1 g of CHPTAC and GTMAC-cationised cellulose, respectively. Adsorption kinetics followed the pseudo-second order model and isotherms were best described by the Freundlich and Dubinin-Radushkevich models. When GTMAC-modified cellulose was applied to AMD contaminated water (pH 2.7); however, Cr(VI) removal decreased to 22% likely due to competition from Al and Fe ions. Cationised materials displayed considerable antibacterial effects, reducing the viability of Escherichia coli by up to 45 % after just 3 hours of exposure. Conclusions: Together, these results suggest that cationised cellulose can be applied in the treatment of Cr(VI)-contaminated mine water particularly if pre-treatments to reduce Fe and Al concentrations are applied.

Effects of acid mine drainage on clay minerals suspended in the Tinto River (Río Tinto, Spain). An experimental approach

Clay Minerals ◽  
1999 ◽  
Vol 34 (1) ◽  
pp. 99-108 ◽  
Author(s):  
E. Galan ◽  
M. I. Carretero ◽  
J . C. Fernandez-Caliani
Keyword(s):  
Acid Mine Drainage ◽  
Mine Drainage ◽  
Drainage Basin ◽  
Acid Rock Drainage ◽  
Chemical Degradation ◽  
Acid Rock ◽  
Tinto River ◽  
Acid Mine ◽  
Mineral Stability ◽  
Water Ph

AbstractThe Tinto river is one of the most polluted stream environments in the world, as a result of both acid mine drainage and natural acid rock drainage. Two representative samples from the phyllosilicate-rich rocks exposed in the drainage basin (Palaeozoic chlorite-bearing slates and Miocene smectite-rich marls) were treated with acid river water (pH = 2.2) for different times to constrain the effects of extreme hydrogeochemical conditions on clay mineral stability. Illite and kaolinite did not show appreciable variations in their crystal chemistry parameters upon treatment. Chlorite underwent an incipient chemical degradation evidenced by the progressive loss of Fe in octahedral positions coupled with a shortening of the b unit-cell parameter, although no weathering products of chlorite were observed. Smectite and calcite were rapidly and fully dissolved thus neutralizing the water acidity, and subsequently Fe and Al oxy-hydroxides and opaline silica precipitated from the aqueous solution, together with a neoformed amorphous silicate phase largely enriched in Al and Mg.

scholarly journals EFISIENSI SISTEM LAHAN BASAH BUATAN ALIRAN PERMUKAAN DENGAN VARIASI DEBIT DALAM MENYISIHKAN MANGAN PADA AIR ASAM TAMBANG

2020 ◽  
Vol 6 (1) ◽  
Author(s):  
Nopi Stiyati Prihatini ◽  
Chairul Abdi ◽  
Yudha Ajie Pratama ◽  
Ihsan Noor
Keyword(s):  
Acid Mine Drainage ◽  
Constructed Wetland ◽  
Mine Drainage ◽  
Ph Value ◽  
Surface Flow ◽  
Acid Mine Water ◽  
Acid Mine ◽  
Water Ph ◽  
Ph Increase ◽  
High Concentrations

Terbentuknya air asam tambang  (AAT) merupakan salah satu dampak dari adanya aktifitas pertambangan. Air asam tambang memiliki ciri pH asam berkisar antara 3-5, warna air kuning kemerahan, dengan konsentrasi besi (Fe) dan mangan (Mn) yang tinggi. Penyisihan Mn menjadi tantangan tersendiri karena mangan hanya dapat disisihkan jika konsentrasi Fe AAT kurang dari 5 mg/L. Teknologi yang kini dikembangkan untuk menyisihkan Mn air asam tambang adalah sistem lahan basah buatan (LBB). Kinerja LBB dipengaruhi oleh debit AAT. Untuk mengetahui efesiensi penyisihan mangan (Mn) dan nilai pH pada LBB, maka pada penelitian ini digunakan Lahan Basah Buatan Aliran Permukaan (LBB-AP) berdimensi 150cm x 50 cm x 75 cm beraliran kontinyu dengan variasi debit. Pada penelitian ini akan divariasi debit AAT yaitu D0 7,1 mL/menit; D1 8,8 mL/meni; D2 10,5 mL/menit, dan D3 12,2 mL/menit. Hasil penelitian menunjukkan peningkatan pH terbaik pada D0 7,1 mL/menit periode ke 4 dengan nilai pH 4,3. Kemampuan penyisihan Mn terbaik pada LBB D0 7,1 mL/menit periode ke 1 sebesar 3,3 mg/L dengan efisiensi sebesar 62%. Kata Kunci : air asam tambang, lahan basah buatan aliran permukaan, mangan, variasi debit. The formation of acid mine drainage (AAT) is one of the impacts of mining activities. Acid mine water has a characteristic low water pH ranging from 3-5, the color of reddish-yellow water, and has high concentrations of iron (Fe) and manganese (Mn). Mn removal is a challenge because manganese can only be removed if the concentration of Fe AAT is less than 5 mg / L. One of the technologies that can be used to remove Mn from acid mine drainage is the constructed wetland system (CW). CW performance is influenced by AAT debits. To determine the efficiency of removal of manganese (Mn) and the pH value in CW, then in this study used Surface Flow Constructed Wetland (SFCW) with dimensions of 150cm x 50 cm x 75 cm with the continuous flow with variations in debit. In this study, AAT debit will be varied, namely D0 7.1 mL / min; D1 8.8 mL / min; D2 10.5 mL / min, and D3 12.2 mL / min. The results showed the best pH increase at CW D0 7.1 mL/min for the 4th period with a pH value of 4.3. The best Mn removal ability at CW D0 7.1 mL/min in the first period was 3.3 mg / L with an efficiency of 62%. Keywords: Acid mine drainage, Debit variation, Manganese, Surface flow Constructed Wetland.

scholarly journals Attenuation of pollution arising from acid mine drainage by a natural wetland on the Witwatersrand

2017 ◽  
Vol Volume 113 (Number 1/2) ◽  
Author(s):  
Marc S. Humphries ◽  
Terrence S. McCarthy ◽  
Letitia Pillay ◽  
◽  
◽  
...  
Keyword(s):  
Acid Mine Drainage ◽  
Metal Accumulation ◽  
Mine Drainage ◽  
Distal Portion ◽  
Contaminated Water ◽  
Natural Wetland ◽  
Mining Operations ◽  
Acid Mine ◽  
Pollutant Sources

Abstract Wetlands are well known to be efficient at sequestering pollutants from contaminated water. We investigated metal accumulation in the peats of the Klip River, a natural wetland that has received contaminated water from gold mining operations in Johannesburg for over 130 years. Previous work conducted in the downstream portion identified the wetland as an important system for sequestering metals. We focused on the upstream section of the wetland, more proximal to the source of acid mine drainage, to provide a better understanding of the pollutant sources and the role of the wetland in pollutant attenuation. Geochemical and mineralogical analyses of peat cores revealed considerable metal enrichments in the peat ash, particularly in Co, Ni, Zn, Pb, Cu and U. Metal concentrations are typically between 4 to 8 times higher than those previously reported for the downstream, more distal portion of the wetland. The distribution of metal accumulation within the peat profiles suggests that contamination arises from a combination of sources and processes. Elevated concentrations in the shallow peat are attributed to the input of contaminated surface water via tributaries that drain the Central Rand Goldfield, whereas enrichments in the deeper peat suggest significant sub-surface inflow of contaminated water through the underlying dolomitic rocks. Metal immobilisation occurs through a combination of mechanisms, which include the precipitation of gypsum, metal sulfides, Fe-Mn oxyhydroxides and phosphates. Our study highlights the environmental and economic importance of natural wetland systems which have the ability to accumulate large quantities of metals and thus remediate polluted waters.

Cellulose-Supported Ferrihydrites for the Removal of As(III), As(V) and Cr(VI) from Mining-Contaminated Water

2020 ◽  
Author(s):  
Anita Etale ◽  
Dineo Nhlane ◽  
Alseno K. Mosai ◽  
Yannick Nuapia
Keyword(s):  
Gas Adsorption ◽  
Mine Drainage ◽  
Point Of Zero Charge ◽  
Contaminated Water ◽  
Cellulose Nanofibres ◽  
Infrared And Raman Spectroscopy ◽  
Water Ph ◽  
Pseudo Second Order ◽  
Acidic Conditions ◽  
High Concentrations

Mining-induced water contamination remains a significant concern in many regions of the world due to the high concentrations of toxic ions often associated with it. In this study, cellulose-supported ferrihydrite composites (CNF-Fe) were prepared by seeding of ferrihydrite nanoparticles on cellulose nanofibres (CNFs) and employed for the removal of As(III), As(V) and Cr(VI) from contaminated water. The adsorbent was characterized by electron microscopy, gas adsorption, point of zero charge (pHPZC), X-ray diffractometry (XRD), as well as infrared and Raman spectroscopy. Compared to parent CNFs, CNF-Fe adsorbents had lower crystallinity and a higher surface area: 218.76 m2 g-1. Further, with a pHPZC of 6.3, CNF-Fe was positively charged at low pH and suitable for adsorption of anions at acidic conditions characteristic of acid mine drainage. In single-ions solutions, the removal efficiency of CNF-Fe was in the order Cr(VI)>As(V)>As(III) (i.e. 0.15, 0.12 and 0.11 mg g-1 respectively). Adsorption kinetics followed the pseudo second-order model and isotherms were best fitted by the Freundlich, Dubinin-Radushkevich, and Temkin models. However, when CNF-Fe was applied to AMD-contaminated water (pH 2.7), Cr(VI) uptake decreased to ~39% which was likely due to competition from sulphate and selenium ions. Nevertheless, the adsorbent displayed regeneration capabilities with ~98% As and ~45% Cr desorbed after 24 hours of treatment. Together, these results suggest that cellulose supported ferrihydrite composites can be applied in treatment of mine drainage-contaminated water in conjunction with pre-treatments that limit SO42- and selenium concentrations.

scholarly journals Assessment of the Combined Use of Basic Oxygen Furnace Sludge and Hydrogen Peroxide in the Treatment of Acid Mine Drainage

2021 ◽  
Author(s):  
Sandrine F. Araujo ◽  
Cláudia L. Caldeira ◽  
Virgínia S.T. Ciminelli ◽  
Ricardo P. Borba ◽  
Joanna P. Rodrigues ◽  
...  
Keyword(s):  
Acid Mine Drainage ◽  
Mine Drainage ◽  
Metal Removal ◽  
Basic Oxygen Furnace ◽  
Deionized Water ◽  
Basic Oxygen ◽  
Acidic Solutions ◽  
Acid Mine ◽  
Removal Capacity ◽  
Water Ph

Abstract We recently demonstrated the use of basic oxygen furnace sludge (BOFS) to remove arsenic and sulfate from acidic solutions, which was found to be an interesting alternative for the reuse of steel waste. In this study, four systems were evaluated to determine whether BOFS is stable in acidic solutions and capable of removing As, Mn, and sulfate from acid mine drainage (AMD). In the S1 system (BOFS/DEIONIZED WATER pH 2.5), the stability of the residue was evaluated by placing the BOFS in deionized water acidified with H2SO4 until the pH reached 2.5. This system was maintained for 408 h under agitation to evaluate the possible solubilization of metals present in the BOFS. The results showed that only Ca and Mg were solubilized, and the pH increased from 2.5 to 12 after 408 h. The S3 system (BOFS/AMD) evaluated the metal removal capacity by BOFS and achieved 100% removal of As and Mn and 70% removal of sulfate after 648 h. In the first 30 min, the pH increased from 2.5 to 9.0, which was maintained until the end of the experiment. Simultaneously, S4 and S5 systems (BOFS/AMD / H2O2) were also evaluated using the oxidizing agent H2O2 (29% w/w) in the following proportions: 0.5 mM in S4 and 1 mM in S5. The removal of As, Mn, and sulfate in these systems was similar to that in the S3 system, which contained only BOFS. The results demonstrated that the formation of iron oxides was not accelerated by H2O2 and that iron, which is present in high concentrations in BOFS, was not the primary agent influencing metal removal from AMD.

Integrated Environmental Monitoring of AMD Affected Waters using Hyperspectral Imaging and In-situ Analytics

2020 ◽  
Author(s):  
Hernan Flores ◽  
Sandra Lorenz ◽  
Robert Jackisch ◽  
Laura Tusa ◽  
Cecilia Contreras ◽  
...  
Keyword(s):  
Acid Mine Drainage ◽  
Near Infrared ◽  
Mine Drainage ◽  
Chemical Properties ◽  
Hyperspectral Data ◽  
Dissolved Metals ◽  
Mining Sites ◽  
Acid Mine ◽  
Field Samples ◽  
Water Ph

<p>One of the potential major consequences of mining activities is the degradation of the surrounding ecosystems by Acid Mine Drainage (AMD). A high-resolution hyperspectral drone-borne survey provides a useful, fast, and non-invasive tool to monitor the acid mine drainage mineralogy in mining sites. In this study, we propose to integrate drone-borne visible-to-near infrared (VNIR) hyperspectral data and physicochemical field data from water and sediments together with laboratory analysis for precise mineralogical and surface water mapping. The Tintillo River is an extraordinary case of the collection of acidic leachates in southwest Spain. This river is highly contaminated, with large quantities of dissolved metals (Fe, Al, Cu, Zn, etc.) and acidity, which later discharged into the Odiel River. At the confluence of the Tintillo and Odiel rivers, different geochemical and mineralogical processes typical of the interaction of very acidic water (pH 2.5 – 3.0) with circum-neutral water (pH 7.0 – 8.0) occur. The high contrast among waters makes this area propitious for the use of hyperspectral data to characterize both rivers and better evaluate mine water bodies with remote sensing imagery. We present an approach that makes use of a supervised random forest regression for the extended mapping of water properties, using the data from collected field samples, as training set for the algorithm. Experimental results show water surface maps that quantify the concentration of dissolved metals and physical-chemical properties along the covered region and mineral classification maps distribution (jarosite, goethite, schwertmannite, etc.). These results highlight the capabilities of drone-borne hyperspectral data for monitoring mining sites by extrapolating the hydrochemical properties from certain and specific areas, covered during field campaigns, to larger regions where accessibility is limited. By following this method, it is possible to rapidly discriminate and map the degree of AMD contamination in water for its future treatment or remediation.</p>

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