Potential of mining, agro-industrial, and urban wastes for the remediation of acidic mine water

Author(s):  
Antonio Aguilar Garrido ◽  
Francisco Javier Martínez Garzón ◽  
Mario Paniagua López ◽  
Manuel Sierra Aragón ◽  
Emilia Fernández Ondoño ◽  
...  

<p>Mining is a crucial industry worldwide because of its economic and social importance. However, the increasing number of operating mines raises major concerns for health and the environment. The intense mining activity generates large quantities of wastes associated with several environmental problems. For example, the generation of acid mine drainages (AMD) by oxidation of sulphide ores stored in tailings deposits, leachates high concentrations of potentially harmful elements (PHEs), which poses severe pollution problems to the environment (aquatic and terrestrial ecosystems). This study evaluates the acid neutralisation capacity and the removal effectiveness of inorganic PHEs present in an AMD of different waste materials. This study is a first approach to future studies to develop pilot remediation studies using designed waste-derived Technosols. The waste used includes 4 mining wastes (iron oxide and hydroxide sludges [IO], marble cutting and polishing sludge [MS], gypsum spoil [GS], and carbonated waste from a peat extraction [CW]), 3 urban wastes (composted sewage sludge [WS], bio-stabilised material from municipal solid waste [BM], and vermicompost from pruning and gardening [VC]), and 3 agro-industrial wastes (2 solid olive-mill by-products [OW, OL] and composted greenhouse waste [GW]). All waste materials were spiked with the acidic water (AMD<sub>L</sub>) prepared in the laboratory from the oxidation of pyritic tailings from the Aznalcóllar mine accident (1998). Afterward, they were stirred for 24 h and filtered, separating the waste (solid phase) from the leachate (liquid phase). In the leachate (AMD<sub>L</sub> treated), pH<sub>(L) 1:5</sub>, EC<sub>(L) 1:5</sub>, and inorganic PHEs concentrations were measured, the latter by ICP-MS. The acidic water showed a strongly acidic character (pH<sub>(L)</sub> ~ 2.89), high salinity (EC<sub>(L)</sub> ~ 3.76 dS m<sup>-1</sup>), and high concentrations of PHEs. Among them, As, Cd, Cr, Cu, Ni, Pb, Sb, Th, Tl, U, V, Y, and Zn stood out since they far exceed various legal limits widely used worldwide and/or because their high toxicity to humans, animals, plants or microorganisms. The most abundant were Zn (32.21 mg l<sup>-1</sup>), Cu (6.24 mg l<sup>-1</sup>), As (2.86 mg l<sup>-1</sup>), Sb (0.82 mg l<sup>-1</sup>), Pb (0.60 mg l<sup>-1</sup>), and Cd (0.45 mg l<sup>-1</sup>). All wastes were effective in neutralising the acidic pH<sub>(L)</sub> of the AMD, as the leachates showed pH<sub>(L)</sub> close to 7. In contrast, changes in the EC<sub>(L)</sub> have been very irregular among the wastes used. In general, all wastes have been effective in adsorbing the PHEs. Inorganic wastes have been much more effective than organic ones, with adsorption efficiencies above 95% for many of the PHEs (particularly for those in higher concentrations). The waste with the best remediation behaviour were IO, CW, MS, GS, and VC. Conversely, GW and WS were the worst at removing PHEs present in AMD. Therefore, this study shows that many of wastes tested are suitable for the construction of Technosols from these wastes to prevent soil pollution by AMD discharge.</p>

Nanomaterials ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 330
Author(s):  
Hengli Xiang ◽  
Genkuan Ren ◽  
Yanjun Zhong ◽  
Dehua Xu ◽  
Zhiye Zhang ◽  
...  

Fe3O4@C nanoparticles were prepared by an in situ, solid-phase reaction, without any precursor, using FeSO4, FeS2, and PVP K30 as raw materials. The nanoparticles were utilized to decolorize high concentrations methylene blue (MB). The results indicated that the maximum adsorption capacity of the Fe3O4@C nanoparticles was 18.52 mg/g, and that the adsorption process was exothermic. Additionally, by employing H2O2 as the initiator of a Fenton-like reaction, the removal efficiency of 100 mg/L MB reached ~99% with Fe3O4@C nanoparticles, while that of MB was only ~34% using pure Fe3O4 nanoparticles. The mechanism of H2O2 activated on the Fe3O4@C nanoparticles and the possible degradation pathways of MB are discussed. The Fe3O4@C nanoparticles retained high catalytic activity after five usage cycles. This work describes a facile method for producing Fe3O4@C nanoparticles with excellent catalytic reactivity, and therefore, represents a promising approach for the industrial production of Fe3O4@C nanoparticles for the treatment of high concentrations of dyes in wastewater.


Author(s):  
W D Fraser ◽  
B H Durham ◽  
J L Berry ◽  
E B Mawer

We evaluated a novel assay for the measurement of 1,25 dihydroxyvitamin D (1,25 (OH)2D). Immunoextraction of 1,25 (OH)2D is performed using a mini column containing a solid-phase monoclonal antibody followed by radioimmunoassay (RIA) using an 125I-labelled 1,25 (OH)2D derivative tracer and Sac-cell separation. The mean recovery of 1,25(OH)2D3 was 101%, linearity was excellent, inter- and intra-assay coefficients of variation were 9, 8 and 13% and 11, 10 and 14% at low, medium and high concentrations of 1,25(OH)2D3, respectively. The cross-reactivity of vitamin D metabolites was <0·0015% for 25-hydroxyvitamin D3, 24, 25 dihydroxyvitamin D3 and dihydrotachysterol and 0·54% for lα calcidol. 1,25 dihydroxyvitamin D2 cross-reactivity was 79%. The detection limit of the assay was 5pmol/L. Comparison with a commercial radio receptor assay (RRA) and an in-house RIA gave regression equations of y = 0·94x+11·8 ( r = 0·98) and y = 0·91x-1·7 ( r = 0.95), respectively, with no major discrepancies between the methods in all patient groups studied. Plasma concentrations of 1,25 (OH)2D obtained with the assay were as follows: normal, unsupplemented subjects: mean 88, range 48–155 pmol/L, n = 68, patients with chronic renal failure: mean 11, range 3–36 pmol/L, n = 27, primary hyperparathyroidism: mean 198, range 130–299 pmol/L, n = 23, Paget's disease: mean 92, range 42–149 pmol/L, n = 24, osteomalacia: mean 43, range 27–61 pmol/L, n = 9. A minimum sample volume of 300 μL is required, the hands-on time is significantly less than other commercial assays and the measuring procedure is gamma counting rather than scintillation counting. The assay offers several advantages over previous methods and should allow more laboratories to offer measurement of 1,25 (OH)2D as part of their repertoire.


2012 ◽  
Vol 727-728 ◽  
pp. 1585-1590
Author(s):  
Neuza Evangelista ◽  
Jorge Alberto Soares Tenório ◽  
José Roberto Oliveira ◽  
Paulo R. Borges ◽  
Taiany Coura M. Ferreira

Ceramic fibers are characterized by their light weight, high degree of purity, low heat storage, low thermal conductivity, thermal shock resistance and superior corrosion resistance in high-temperature environments. In addition, they can be produced extensively in substitution to all materials used in the coating of almost all heating equipment as well as contributing to the reduction of energy consumption. Such characteristics make them ideal in the coating of distributors, mufflers, heating ovens, among others, as highly demanded by the mining and metallurgical industries, among others. After use in the process of industrial production, generated waste will lose their insulation capacity and thus require safe disposal. The present work focuses specifically on ceramic and glass wools aiming at an evaluation of their recycling prospect of incorporation into cement mortars and concrete. This residues were pulverized and displayed ~30µm average particle size. The scan electronic microscopy (SEM) presented elongated, thin and straight particles, which is very different than flocular structure of cement. The X-rays diffraction revealed amorphous structure for glass wool and crystalline structure for ceramics wool. The chemical analysis showed high concentrations of Al2O3 and silica in both residues, with higher percentage of calcium oxide in glass wool.


2001 ◽  
Vol 29 (2) ◽  
pp. 163-177 ◽  
Author(s):  
Emil Rudolf ◽  
Jan Peychl ◽  
Miroslav Červinka

Many human activities, particularly industrial ones, result in an ever-growing production of toxic waste materials. The dynamics of the toxic effects of chromium acetate hydroxide, which is found in high concentrations in a waste sediment produced in the Czech Republic, were assessed by using a battery of in vitro tests carried out on two cell lines: L-929 (mouse fibroblasts) and Hep 2 (human laryngeal cells). Various markers of cell damage were assessed by phase-contrast, video and fluorescence microscopy, fluorometry, and DNA analysis. Chromium acetate hydroxide, over a concentration range of 1–0.02mol/l induced immediate cell death by fixation, whereas, at 0.002mol/l, the treated cells died in a much slower, more discrete manner. All the detected markers of cell damage, whether immediate or slow, clearly demonstrated that the cells died by necrosis. On the other hand, test concentration of 0.001mol/l appeared to constitute a threshold at which no pathological changes of Hep 2 cells were observed over 96 hours. We conclude that chromium acetate hydroxide has a high toxic potential in vitro, which should be considered when studying the toxicity of waste materials containing it.


2014 ◽  
Vol 881-883 ◽  
pp. 797-800
Author(s):  
He Liu ◽  
Jun Li ◽  
Ping Geng ◽  
Yu Tang He ◽  
Tao Ma

In this manuscript, flavor compounds development of Cheddar Cheese with addition of soybean pectin gel was investigated during ripening. A rapid and simple Solid-Phase Microextraction (SPME) procedure was used for identifying and classifying the volatile compounds. The result showed that addition of soybean pectin gel to cheese had similar flavor profiles with full-fat cheeses. Higher levels of acid volatile compounds and aldehydes were obtained in comparison with experimental cheese. Results simultaneously indicated that experimental cheeses contained high concentrations of volatile amine as soybean pectin gel promoting the volatile substances.


2021 ◽  
Author(s):  
juyeon Lee ◽  
minjune Yang

&lt;p&gt;This study conducted a rhizofiltration experiment for uranium-removal with the edible plants (&lt;em&gt;Lactuca sativa, Brassica campestris &lt;/em&gt;L., &lt;em&gt;Raphanus sativus &lt;/em&gt;L., and &lt;em&gt;Oenanthe javanica&lt;/em&gt;) which generally consumed in South Korea. Various batch experiments were performed with different initial uranium concentrations, pH conditions, and genuine groundwater. The results showed the uranium accumulation and bioconcentration factor (BCF) of plant roots increase with an increase in initial uranium concentrations in the solution. Of the four plants, the amount of uranium accumulated in &lt;em&gt;Raphanus sativus &lt;/em&gt;L. roots was 1215.8 &amp;#956;g/g DW with the maximum BCF value of 2692.7. The BCF value based on various pH conditions (pHs 3, 5, 7 and 9) of artificial solutions was highest at pH 3 for all four plants, and the BCF value of &lt;em&gt;Brassica campestris &lt;/em&gt;L. was the maximum of 11580.3 at pH 3. As a result of rhizofiltration experiments with genuine groundwater contaminated with uranium, the BCF values of &lt;em&gt;Raphanus sativus &lt;/em&gt;L. were 1684.7 and 1700.1, the highest among the four species, in Oesam-dong and Bugokdong groundwater samples with uranium concentration of 83 and 173 &amp;#956;g/L. From SEM/EDS analysis, it was confirmed that uranium in contaminated groundwater was adsorbed as a solid phase on the root surface. These results demonstrate that &lt;em&gt;Raphanus sativus &lt;/em&gt;L. not only has a high tolerance to high concentrations of uranium and low pH conditions but also has a remarkable potential for uranium accumulation capacity.&lt;/p&gt;


1989 ◽  
Vol 35 (9) ◽  
pp. 1949-1954 ◽  
Author(s):  
K Beever ◽  
J Bradbury ◽  
D Phillips ◽  
S M McLachlan ◽  
C Pegg ◽  
...  

Abstract These highly sensitive assays are based on the interaction between thyroid autoantibodies and 125I-labeled autoantigens. Serum samples are incubated with labeled thyroid peroxidase (TPO) or thyroglobulin (Tg) to allow the formation of antibody-labeled antigen complexes. The complexes are then precipitated by addition of solid-phase Protein A. In the presence of high concentrations of TPO antibody or Tg antibody, more than 50% of the respective labeled antigen was precipitated, whereas only 1-2% was precipitated in the absence of autoantibody. Interassay CVs were 3.2% and 5.7%, respectively, for the anti-TPO and anti-Tg assays. There was no cross-reactivity between Tg antibody and TPO antibody. Results correlated highly significantly with results from other assay systems based on antigen-coated cells or plastic supports, but the assays described here were considerably more sensitive. Scatchard analysis of the assay data provided information on the affinity and serum concentration of TPO autoantibodies (ka approximately 10(9) L/mol and concentrations up to 1 g/L) and Tg autoantibodies (ka approximately 4 x 10(10) L/mol and concentrations up to 1 g/L). Overall, these assays provide a sensitive, precise, and convenient system for measuring and investigating the properties of thyroid autoantibodies.


2018 ◽  
Vol 5 (4) ◽  
pp. 93 ◽  
Author(s):  
Rajeev Ravindran ◽  
Shady Hassan ◽  
Gwilym Williams ◽  
Amit Jaiswal

Agro-industrial waste is highly nutritious in nature and facilitates microbial growth. Most agricultural wastes are lignocellulosic in nature; a large fraction of it is composed of carbohydrates. Agricultural residues can thus be used for the production of various value-added products, such as industrially important enzymes. Agro-industrial wastes, such as sugar cane bagasse, corn cob and rice bran, have been widely investigated via different fermentation strategies for the production of enzymes. Solid-state fermentation holds much potential compared with submerged fermentation methods for the utilization of agro-based wastes for enzyme production. This is because the physical–chemical nature of many lignocellulosic substrates naturally lends itself to solid phase culture, and thereby represents a means to reap the acknowledged potential of this fermentation method. Recent studies have shown that pretreatment technologies can greatly enhance enzyme yields by several fold. This article gives an overview of how agricultural waste can be productively harnessed as a raw material for fermentation. Furthermore, a detailed analysis of studies conducted in the production of different commercially important enzymes using lignocellulosic food waste has been provided.


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