scholarly journals Mg/Al LDH Enhances Sulfate removal and Clarification of AMD Wastewater in Precipitation Processes

Materials ◽  
2019 ◽  
Vol 12 (14) ◽  
pp. 2334 ◽  
Author(s):  
Paulina Maziarz ◽  
Jakub Matusik ◽  
Tiina Leiviskä
Keyword(s):  
Acid Mine Drainage ◽  
Calcium Hydroxide ◽  
Settling Velocity ◽  
Mine Drainage ◽  
Low Ph ◽  
Initial Concentration ◽  
Sulfate Removal ◽  
Ph Increase ◽  
Double Hydroxide ◽  
Different Doses

The sulfate removal from acid mine drainage (AMD) water (initial concentration: 5301 mg/L) was investigated by precipitation and/or adsorption using calcium hydroxide (Ca(OH)2) and synthetic layered double hydroxide (LDH) of the Mg/Al type. The exclusive use of LDH efficiently removed sulfates (64.2% reduction); however, alteration of its structure was observed due to low pH. The use of Ca(OH)2 in different doses calculated in relation to gypsum stoichiometry allowed to achieve an 86% removal of sulfates. Depending on the equilibrium pH, gypsum or ettringite were the main identified phases. The two-step removal, involving the use of Ca(OH)2 followed by LDH, was less efficient than the use of the Ca(OH)2/LDH mixture when the stoichiometric amount of Ca(OH)2 in relation to gypsum was applied. The application of mixture resulted in a fast pH increase, which prevented destruction of the LDH structure. Most importantly, the use of mixture significantly reduced the sludge volume and enhanced its settling velocity.

Fluvial metal transport near sources of acid mine-drainage: Relationships of soluble, suspended and deposited metal

1996 ◽  
Vol 60 (399) ◽  
pp. 325-335 ◽  
Author(s):  
Stephen Boult
Keyword(s):  
Acid Mine Drainage ◽  
Mine Drainage ◽  
Low Ph ◽  
Metal Distribution ◽  
Intermediate Step ◽  
Acid Mine ◽  
Deposited Metal ◽  
Metal Load ◽  
Ph Increase ◽  
Fe Hydroxide

AbstractThe Afon Goch (Anglesey, UK) is a short (12 km source to estuary) stream highly contaminated by acid mine drainage (AMD) throughout its length, due to past-mining at the head of the stream. Metal distribution is strongly controlled by the pH, which increases downstream particularly at confluences with two unpolluted tributaries. A pH increase causes precipitation of metals, primarily Fe as hydroxide, thus altering the transport of the metal load, potentially allowing storage of metal within the river as deposited material. However, further work suggests that the controls on whether metal can behave non-conservatively, and therefore the controls on metal distribution, are more complicated than being purely pH dependent. This is because much of the Fe load, even at the low pH at the head of the stream, is not soluble Fe3+but colloidal Fe hydroxide. Consequently, coagulation is a requisite intermediate step between precipitation and potential for settling. It is possible that in reaches of the stream away from tributary confluences, the process of coagulation is the predominant influence on metal distribution. Furthermore, because much of the metal load in the water column is very fine, its deposition results in a sediment in which the metals can be intimately associated with a biofilm at the sediment/water interface. Such associations change both deposition and erosion characteristics of the sediment and have implications for subsequent diagenesis and mineral morphology.

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 Microbial stratification in low pH oxic and suboxic macroscopic growths along an acid mine drainage

2014 ◽  
Vol 8 (6) ◽  
pp. 1259-1274 ◽  
Author(s):  
Celia Méndez-García ◽  
Victoria Mesa ◽  
Richard R Sprenger ◽  
Michael Richter ◽  
María Suárez Diez ◽  
...  
Keyword(s):  
Acid Mine Drainage ◽  
Mine Drainage ◽  
Low Ph ◽  
Acid Mine

scholarly journals Effect of COD/SO42- Supply Ratio Variations of Sulfate-Reducing Bacteria of Sulphood Raise in Acid Mine Drainage

2018 ◽  
Vol 73 ◽  
pp. 05009
Author(s):  
Hardyanti Nurandani ◽  
Utomo Sudarno ◽  
Oktaviana Angelica ◽  
Serafina Katrin ◽  
Junaidi Junaidi
Keyword(s):  
Acid Mine Drainage ◽  
Sulphur Dioxide ◽  
Mine Drainage ◽  
Removal Rate ◽  
Batch Reactor ◽  
Septic Tank ◽  
Mining Activities ◽  
Sulfate Reducing ◽  
Acid Mine ◽  
Sulfate Removal

Sulphur dioxide gas is one of most contaminating gas in the air. Sulphur gas can be produced by mining activities. Sulphur gas will be harmful if bond with CO2 to form as Sulphur Dioxide. To reduce the Sulphur Dioxide gas concentration we must inhibite the sulphur gas formation from mining activities. The inhibition of sulphur gas could be done by reduce the sulphate concentration in acid mine drainage. One of important factor that influencing the reduce of sulphate is COD/SO42- ratio. The effect of COD/SO42- ratio on bacterial growth and sulfate removal process can be investigated with anaerobic batch reactor. The laundry septic tank sediments were inoculated on an anaerobic batch reactor which were contacted with artificial coal acid mine water wastes with 1000 sulfate concentrations and 2000 mg SO42- /L. In an anaerobic batch reactor there are five reactors with variations of COD / SO42-1.0, 1.5, 2.0, 4.0, and 8.0 ratios. Efficiency ratio and the best sulfate removal rate is in reactor ratio 2.0 with value efficiency of 46.58% and a reduction rate of 29.128 mg / L.day in an anaerobic batch reactor. The efficiency of the removal rate decreased when the COD / SO42->2.0 ratio decreased. The fastest pH decline was in the COD/SO42-8.0 ratio variation in the anaerobic batch reactor and. The COD / SO42-ratio can help the sulfate reduction process in the optimum value by affecting the sulfate-reducing bacterial metabolism in the balance of the acceptor and the electron donor.

scholarly journals Efficient Low-pH Iron Removal by a Microbial Iron Oxide Mound Ecosystem at Scalp Level Run

2017 ◽  
Vol 83 (7) ◽  
Author(s):  
Christen L. Grettenberger ◽  
Alexandra R. Pearce ◽  
Kyle J. Bibby ◽  
Daniel S. Jones ◽  
William D. Burgos ◽  
...  
Keyword(s):  
Acid Mine Drainage ◽  
Bacterial Community ◽  
Microbial Communities ◽  
Mine Drainage ◽  
Iron Oxidation ◽  
Cost Effective ◽  
Low Ph ◽  
Content Type ◽  
Oxidation Rates ◽  
Acid Mine

ABSTRACT Acid mine drainage (AMD) is a major environmental problem affecting tens of thousands of kilometers of waterways worldwide. Passive bioremediation of AMD relies on microbial communities to oxidize and remove iron from the system; however, iron oxidation rates in AMD environments are highly variable among sites. At Scalp Level Run (Cambria County, PA), first-order iron oxidation rates are 10 times greater than at other coal-associated iron mounds in the Appalachians. We examined the bacterial community at Scalp Level Run to determine whether a unique community is responsible for the rapid iron oxidation rate. Despite strong geochemical gradients, including a >10-fold change in the concentration of ferrous iron from 57.3 mg/liter at the emergence to 2.5 mg/liter at the base of the coal tailings pile, the bacterial community composition was nearly constant with distance from the spring outflow. Scalp Level Run contains many of the same taxa present in other AMD sites, but the community is dominated by two strains of Ferrovum myxofaciens, a species that is associated with high rates of Fe(II) oxidation in laboratory studies. IMPORTANCE Acid mine drainage pollutes more than 19,300 km of rivers and streams and 72,000 ha of lakes worldwide. Remediation is frequently ineffective and costly, upwards of $100 billion globally and nearly $5 billion in Pennsylvania alone. Microbial Fe(II) oxidation is more efficient than abiotic Fe(II) oxidation at low pH (P. C. Singer and W. Stumm, Science 167:1121–1123, 1970, https://doi.org/10.1126/science.167.3921.1121 ). Therefore, AMD bioremediation could harness microbial Fe(II) oxidation to fuel more-cost-effective treatments. Advances will require a deeper understanding of the ecology of Fe(II)-oxidizing microbial communities and the factors that control their distribution and rates of Fe(II) oxidation. We investigated bacterial communities that inhabit an AMD site with rapid Fe(II) oxidation and found that they were dominated by two operational taxonomic units (OTUs) of Ferrovum myxofaciens, a taxon associated with high laboratory rates of iron oxidation. This research represents a step forward in identifying taxa that can be used to enhance cost-effective AMD bioremediation.

scholarly journals Stream Monitoring and Preliminary Co-Treatment of Acid Mine Drainage and Municipal Wastewater along Dunkard Creek Area

2020 ◽  
Vol 2 (2) ◽  
Author(s):  
Dongyang Deng ◽  
Lian-shin Lin ◽  
Andrea Nana Ofori-Boadu
Keyword(s):  
Acid Mine Drainage ◽  
Phase I ◽  
Phase Ii ◽  
Municipal Wastewater ◽  
Mine Drainage ◽  
Combined Treatment ◽  
Stream Monitoring ◽  
Acid Mine ◽  
Sulfate Removal ◽  
Wide Range

This study investigated coal-mine drainage (AMD) and municipal wastewater (MWW) contaminant concentrations and conducted the combined treatment in phases I and II: phase I, evaluating effects of mixing the two based on extent of acid neutralization and metals removal; phase II: conducting anaerobic batch reactor treatment of AMD and MWW under varying COD/sulfate ratios (0.04-5.0). In phase I, acid mine drainage water quality conditions are as follows: pH 4.5, acidity 467.5 mg/L as CaCO3, alkalinity 96.0 mg/L as CaCO3, Cl- 11.8 mg/L, SO42- 1722 mg/L, TDS 2757.5 mg/L, TSS 9.8 mg/L, BOD 14.7 mg/L, Fe 138.1 mg/L, Mg 110.8 mg/L. Mn 7.5 mg/L, Al 8.1 mg/L, Na 114.2 mg/L, and Ca 233.5 mg/L. Results of the mixing experiments indicated significant removal of selected metals (Fe 85~98%, Mg 0~65%, Mn 63~89%, Al 98~99%, Na 0~30%), acidity (77~95%) from the mine water and pH was raised to above 6.3. The Phase II results suggested under the wide range of COD/sulfate ratios, COD and sulfate removal varied from 37.4%-100% and 0%-93.5% respectively. During biological treatment, alkalinity was generated which leads to pH increase to around 7.6-8.5. The results suggested feasibility of the proposed technology for co-treatment of AMD and MWW. A conceptual design of co-treatment system which is expected to remove a matrix of pollutants has been provided to utilize all the locally available water resources to achieve the optimum treatment efficiency. The technology also offers an opportunity to significantly reduce capital and operating costs compared to the existing treatment methodologies used.

scholarly journals Mesoporous Poly(melamine-co-formaldehyde) Particles for Efficient and Selective Phosphate and Sulfate Removal

Molecules ◽  
2021 ◽  
Vol 26 (21) ◽  
pp. 6615
Author(s):  
Konstantin B. L. Borchert ◽  
Christine Steinbach ◽  
Berthold Reis ◽  
Niklas Gerlach ◽  
Philipp Zimmermann ◽  
...  
Keyword(s):  
Acid Mine Drainage ◽  
Mine Drainage ◽  
Selective Adsorption ◽  
Mineral Resources ◽  
Hybrid Particles ◽  
Aquatic Life ◽  
Acid Mine ◽  
Surface Areas ◽  
Sulfate Removal ◽  
Adsorption Capacities

Due to the existence-threatening risk to aquatic life and entire ecosystems, the removal of oxyanions such as sulfate and phosphate from anthropogenic wastewaters, such as municipal effluents and acid mine drainage, is inevitable. Furthermore, phosphorus is an indispensable resource for worldwide plant fertilization, which cannot be replaced by any other substance. This raises phosphate to one of the most important mineral resources worldwide. Thus, efficient recovery of phosphate is essential for ecosystems and the economy. To face the harsh acidic conditions, such as for acid mine drainage, an adsorber material with a high chemical resistivity is beneficial. Poly(melamine-co-formaldehyde) (PMF) sustains these conditions whilst its very high amount of nitrogen functionalities (up to 53.7 wt.%) act as efficient adsorption sides. To increase adsorption capacities, PMF was synthesized in the form of mesoporous particles using a hard-templating approach yielding specific surface areas up to 409 m2/g. Different amounts of silica nanospheres were utilized as template and evaluated for the adsorption of sulfate and phosphate ions. The adsorption isotherms were validated by the Langmuir model. Due to their properties, the PMF particles possessed outperforming maximum adsorption capacities of 341 and 251 mg/g for phosphate and sulfate, respectively. Furthermore, selective adsorption of sulfate from mixed solutions of phosphate and sulfate was found for silica/PMF hybrid particles.

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