Surface and Subsurface Decontamination Technology

Volume 2: Facility Decontamination and Decommissioning; Environmental Remediation; Environmental Management/Public Involvement/Crosscutting Issues/Global Partnering ◽

10.1115/icem2013-96230 ◽

2013 ◽

Author(s):

Matt Tuck ◽

Beth Wray ◽

Mark Musgrave

Keyword(s):

Environmental Remediation ◽

Extraction Process ◽

Chemical Extraction ◽

Specific Chemical ◽

Substrate Complex ◽

Inorganic Substances ◽

Sequential Chemical Extraction ◽

Contaminated Waste ◽

Safety Considerations ◽

Waste Destruction

A number of proven technologies applicable to the chemical and physical decontamination of radioactive and non-radioactive contaminants within the environmental remediation and radiological waste management sectors exist. Previous work generally acknowledges that these methods have limitations such as production of large volumes of waste, destruction of the substrate, complex safety considerations [1a] and application of special precautions to meet disposal acceptance criteria [2]. A method that removes a variety of contaminants from the surface and subsurface of porous materials, with minimal contaminated waste arisings, is highly desirable. TechXtract® is a patented, sequential chemical extraction process developed to remove radionuclides, PCBs, and other hazardous organic and inorganic substances from solid materials such as concrete, brick, steel, and exotic metals [3]. The technology uses multifarious task-specific chemical formulations and engineered applications to achieve surface penetration and removal of the contaminants from the atomic voids of metals and other substrates, or the capillaries and gel pores of concretes. TechXtract® is proven to remove a variety of contaminants from various substrates, allowing free release of the substrate as waste for disposal, or re-use, whilst producing minimal secondary waste. Data from testing of TechXtract’s capabilities and evidencing the technology’s efficacy during site based applied research and development is presented here.

Download Full-text

Assessment of heavy metal removal efficiencies by naturally fermented and a. niger fermented pineapple wastes from contaminated sewage sludge

Linnaeus Eco-Tech ◽

10.15626/eco-tech.2007.043 ◽

2007 ◽

pp. 429-438

Author(s):

Dominica del Mundo Dacera ◽

Sandhya Babel

Keyword(s):

Citric Acid ◽

Sewage Sludge ◽

Metal Removal ◽

Heavy Metal Removal ◽

Extraction Procedure ◽

Extraction Process ◽

Chemical Extraction ◽

Sequential Chemical Extraction ◽

Removal Efficiencies

Heavy metals in sewage sludge can pose a long term environmental risk due to their toxicity,non-biodegradability and consequent persistence, This study assessed the efficiencies ofvarious organic extractants such as naturally fermented and A�pergillus niger (A. niger)fermented raw liquid from pineapple wastes, in the chemical extraction process, to extract Cr,Cu, Pb, Ni and Zn, from anaerobically digested sewage sludge in Thailand. Pineapple wastesare a good source of sugar and protein and have been utilized experimentally in theproduction of citric acid by fennentation with the fungus A. niger. Comparison of theextraction efficiencies of these extractants with commercial citric acid was also investigated attwo hours leaching time and pH 3 and greater. Results of the study revealed that at pHapproaching 4, A. niger fermented liquid seemed to exhibit the best removal efficiency forpractically all metals studied, attaining as much as 72% removal for Zn, 70% for Ni, 50% forCr and 37% for Cu, although effectivity of removal seemed to be less apparent for Pb. Themost readily solubilized metal seemed to be Zn with the most removal of 92% attained bynaturally fermented raw liquid, The effectivity of removal by A. niger fem1ented liquid maybe due to the presence of citric acid and other carboxylic acids as confirmed by the HPLC andIR studies of the fem1ented liquid, Moreover, variation in metal removal efficiencies may beattributed to the fonns of metals in the sludge, as evidenced by chemical speciation studiesusing sequential chemical extraction procedure, with metals predominantly in theexchangeable and oxidizable phases showing ease of leachability,

Download Full-text

Heavy metals extraction from anaerobically digested sludge

Water Science & Technology ◽

10.2166/wst.2002.0275 ◽

2002 ◽

Vol 46 (10) ◽

pp. 1-8 ◽

Cited By ~ 31

Author(s):

M.M. Marchioretto ◽

H. Bruning ◽

N.T.P. Loan ◽

W.H. Rulkens

Keyword(s):

Heavy Metals ◽

Municipal Wastewater ◽

Extraction Efficiency ◽

Extraction Process ◽

Chemical Extraction ◽

Second Phase ◽

Specific Situation ◽

Ph Values ◽

Sequential Chemical Extraction ◽

Removal Of Heavy Metals

This paper reports on the chemical extraction efficiency in the removal of heavy metals from sludge from an activated-sludge system, which receives as influent both industrial and municipal wastewater. Utilizing a series of chemical extractants in a sequential order comprised the first phase of the research, called sequential chemical extraction (SCE). The work started with the well-known Tessier method followed by Veeken and by Sims and Kline SCE schemes. Afterwards, modified versions of Tessier and Veeken schemes were applied. The second phase, named chemical extraction using pH progressive changes, concerns an alternative to the extraction process. Four acids were tested: nitric, hydrochloric, oxalic and citric and the pH values as well as the time were varied. Some conclusions reveal that although modifying Tessier and Veeken schemes provides more consistent results, SCE is still an imperfect method regarding specificity and selectivity. Besides, it is not advisable to apply one SCE scheme developed for one specific situation to another one, once the accurateness of the method depends on several factors such as sort of material and chemicals, contact time, temperature, etc. The extraction efficiency increases using nitric or hydrochloric acids at low pH values, promoting high extraction efficiency level.

Download Full-text

Mercury Speciation in Various Coals Based on Sequential Chemical Extraction and Thermal Analysis Methods

Energies ◽

10.3390/en14092361 ◽

2021 ◽

Vol 14 (9) ◽

pp. 2361

Author(s):

Yinjiao Su ◽

Xuan Liu ◽

Yang Teng ◽

Kai Zhang

Keyword(s):

Thermal Stability ◽

Coal Combustion ◽

Decomposition Methods ◽

Chemical Extraction ◽

Anthropogenic Source ◽

Coal Rank ◽

Coal Pyrolysis ◽

Mercury Emissions ◽

Sequential Chemical Extraction ◽

Removal Technology

Coal combustion is an anthropogenic source of mercury (Hg) emissions to the atmosphere. The strong toxicity and bioaccumulation potential have prompted attention to the control of mercury emissions. Pyrolysis has been regarded as an efficient Hg removal technology before coal combustion and other utilization processes. In this work, the Hg speciation in coal and its thermal stability were investigated by combined sequential chemical extraction and temperature programmed decomposition methods; the effect of coal rank on Hg speciation distribution and Hg release characteristics were clarified based on the weight loss of coal; the amount of Hg released; and the emission of sulfur-containing gases during coal pyrolysis. Five species of mercury were determined in this study: exchangeable Hg (F1), carbonate + sulfate + oxide bound Hg (F2), silicate + aluminosilicate bound Hg (F3), sulfide bound Hg (F4), and residual Hg (F5), which are quite distinct in different rank coals. Generally, Hg enriched in carbonates, sulfates, and oxides might migrate to sulfides with the transformation of minerals during the coalification process. The order of thermal stability of different Hg speciation in coal is F1 < F5 < F2 < F4 < F3. Meanwhile, the release of Hg is accompanied with sulfur gases during coal pyrolysis, which is heavily dependent on the coal rank.

Download Full-text

Development of a Tellurium Speciation Study Using IC-ICP-MS on Soil Samples Taken from an Area Associated with the Storage, Processing, and Recovery of Electrowaste

Molecules ◽

10.3390/molecules26092651 ◽

2021 ◽

Vol 26 (9) ◽

pp. 2651

Author(s):

Magdalena Jabłońska-Czapla ◽

Katarzyna Grygoyć

Keyword(s):

Inductively Coupled Plasma ◽

Total Concentration ◽

Soil Samples ◽

Chemical Extraction ◽

Soil Extraction ◽

Inductively Coupled ◽

Sequential Chemical Extraction ◽

Icp Ms ◽

Speciation Study ◽

Plasma Mass Spectrometry

The optimization and validation of a methodology for determining and extracting inorganic ionic Te(VI) and Te(IV) forms in easily-leached fractions of soil by Ion Chromatography-Inductively Coupled Plasma-Mass Spectrometry (IC-ICP-MS) were studied. In this paper, the total concentration of Te, pH, and red-ox potential were determined. Ions were successfully separated in 4 min on a Hamilton PRPX100 column with 0.002 mg/kg and 0.004 mg/kg limits of detection for Te(VI) and Te(IV), respectively. Soil samples were collected from areas subjected to the influence of an electrowaste processing and sorting plant. Sequential chemical extraction of soils showed that tellurium was bound mainly with sulphides, organic matter, and silicates. Optimization of soil extraction allowed 20% average extraction efficiency to be obtained, using 100 mM citric acid as the extractant. In the tested soil samples, both tellurium species were present. In most cases, the soils contained a reduced Te form, or the concentrations of both species were similar.

Download Full-text

A Preliminary Study on Dependence of Mercury Distribution on the Degree of Coalification in Ningwu Coalfield, Shanxi, China

Energies ◽

10.3390/en14113119 ◽

2021 ◽

Vol 14 (11) ◽

pp. 3119

Author(s):

Yinjiao Su ◽

Xuan Liu ◽

Yang Teng ◽

Kai Zhang

Keyword(s):

Linear Correlation ◽

Bituminous Coal ◽

Rank Correlation ◽

Correlation Coefficients ◽

Chemical Extraction ◽

Mercury Distribution ◽

Sequential Chemical Extraction ◽

Average Proportion ◽

Total Proportion ◽

The Relationship

Mercury (Hg) is a toxic trace element emitted from coal conversion and utilization. Samples with different coal ranks and gangue from Ningwu Coalfield are selected and investigated in this study. For understanding dependence of mercury distribution characteristics on coalification degree, Pearson regression analysis coupled with Spearman rank correlation is employed to explore the relationship between mercury and sulfur, mercury and ash in coal, and sequential chemical extraction method is adopted to recognize the Hg speciation in the samples of coal and gangue. The measured results show that Hg is positively related to total sulfur content in coal and the affinity of Hg to different sulfur forms varies with the coalification degree. Organic sulfur has the biggest impact on Hg in peat, which becomes weak with increasing the coalification degree from lignite to bituminous coal. Sulfate sulfur is only related to Hg in peat or lignite as little content in coal. However, the Pearson linear correlation coefficients of Hg and pyritic sulfur are relatively high with 0.479 for lignite, 0.709 for sub-bituminous coal and 0.887 for bituminous coal. Hg is also related to ash content in coal, whose Pearson linear correlation coefficients are 0.504, 0.774 and 0.827 respectively, in lignite, sub-bituminous coal and bituminous coal. Furthermore, Hg distribution is directly depended on own speciation in coal. The total proportion of F2 + F3 + F4 is increased from 41.5% in peat to 87.4% in bituminous coal, but the average proportion of F5 is decreased from 56.8% in peat to 12.4% in bituminous coal. The above findings imply that both Hg and sulfur enrich in coal largely due to the migration from organic state to inorganic state with the increase of coalification degree in Ningwu Coalfield.

Download Full-text

Enzymatic Extraction and Characterization of Pectin from Cocoa Pod Husks (Theobroma cacao L.) Using Celluclast® 1.5 L

Molecules ◽

10.3390/molecules26051473 ◽

2021 ◽

Vol 26 (5) ◽

pp. 1473

Author(s):

Licelander Hennessey-Ramos ◽

Walter Murillo-Arango ◽

Juliana Vasco-Correa ◽

Isabel Cristina Paz Astudillo

Keyword(s):

Acid Content ◽

Galacturonic Acid ◽

Extraction Process ◽

Chemical Extraction ◽

Enzymatic Extraction ◽

Acid Yield ◽

Physicochemical Features ◽

Enzyme Dosage ◽

Cocoa Pod Husks

Cocoa pod husks are a waste generated during the processing of cocoa beans. We aimed to explore the enzymatic extraction of pectin using cellulases. The extraction process was optimized using a central composite design (CCD) and analyzed by response surface methodology (RSM). The parameters optimized were feedstock concentration (%), enzyme dosage (µL/g), and time (h). Three dependent variables were studied: pectin yield (g/100 g dry husk) (R2 = 97.02), galacturonic acid content (g/100 g pectin) (R2 = 96.90), and galacturonic acid yield (g/100 g feedstock) (R2 = 95.35). The optimal parameters were 6.0% feedstock concentration, 40 µL g−1 of enzyme, and 18.54 h, conditions that produced experimentally a pectin yield of 10.20 g/100 g feedstock, 52.06 g galacturonic acid/100 g pectin, and a yield 5.31 g galacturonic acid/100 g feedstock. Using the chemical extraction method, a yield of 8.08 g pectin/100 g feedstock and a galacturonic acid content of 60.97 g/100 g pectin were obtained. Using assisted sonication, a pectin yield of 8.28 g/100 g feedstock and a galacturonic acid content of 42.77 g/100 g pectin were obtained. Enzymatically optimized pectin has rheological and physicochemical features typical of this biomaterial, which provides an interesting alternative for the valorization of cocoa husks.

Download Full-text

OBSERVATIONS IMPLICATING AN EXTRACELLULAR ENZYMIC MECHANISM OF CONTROL OF BONE MORPHOGENESIS

Journal of Histochemistry & Cytochemistry ◽

10.1177/22.2.88 ◽

1974 ◽

Vol 22 (2) ◽

pp. 88-103 ◽

Cited By ~ 29

Author(s):

MARSHALL R. URIST ◽

HISASHI IWATA ◽

STUART D. BOYD ◽

PETER L. CECCOTTI ◽

MARLYS OKADA ◽

...

Keyword(s):

Chemical Reactions ◽

Phosphate Buffer ◽

Bone Matrix ◽

Chemical Extraction ◽

Ammonium Bromide ◽

Property A ◽

Noncollagenous Proteins ◽

Buffer Solutions ◽

Sequential Chemical Extraction ◽

Chloroform Methanol

Data on physicochemical conditions leading to loss of the bone morphogenetic property of bone matrix in neutral buffer solutions support the concept of an enzymic control mechanism better than a chemical blocking reaction or denaturation. The loss is associated with release of 35S-labeled constituents and not prevented by ε-amino caproic acid, an inhibitor of cathepsins. The loss is also associated with release of 35S-cysteine-labeled protein; about 60% of the yield is sustained by the addition of only 3 mmoles/liter of iodoacetic acid. A latent period of about 12 hr, decreased by extraction of bone matrix with CaCl2, is characterized by release of protein polysaccharide and other noncollagenous proteins. Release of sialic acid from the bone matrix by neuraminidase at pH 7.4 has no effect upon bone yield. At 2°C, Tris-HCl buffer or ethylenediaminetetraacetic acid extracts noncollagenous proteins without loss of bone yield; at 37°C, pH 7.4, these solutions also activate endogenous enzymes and reduce bone yield. The component of bone matrix responsible for reduction in bone yield is separable from bone matrix by extraction with phosphate buffer, by catheptic digestion of bone matrix in acidic buffer solutions, by sequential chemical extraction of noncollagenous proteins with cold slightly acidic salt solutions or by extraction-denaturation with chloroform-methanol. Detergents neither extinguish nor denature the morphogenetic property but some solubilize or extract degradative enzymes; hexodecyl trimethyl ammonium bromide, at pH 5.0, is positively charged and extracts hydrophobic proteins, including part of the bone morphogenetic property. A special selection of sulfhydryl chemical inhibitors remarkably different from the selection inhibiting known enzymes preserves the bone morphogenetic property of bone matrix; p-chloromercuribenzoate preservation is reversible by chemical reactions with cysteine. Reduction in bone yield in phosphate buffer is not attributable to a chemical block because chloroform-methanol extraction of the agent does not restore bone yield and is not attributable to denaturation because bone yield sustained by p-chloromercuribenzoate is lost by chemical reactions with cysteine. An hypothetical insoluble bone morphogenetic protein (BMP) firmly bound to collagen is degraded by a soluble neutral proteinase (BMPase). Digestion of the hypothetical BMP occurs without loss of the 640-A electron micrographic image of bone collagen, resembles tryptic digestion and is more selective as well as physiologic in action.

Download Full-text

Determination of lead speciation in melting furnace fly ash by sequential chemical extraction

Chemosphere ◽

10.1016/j.chemosphere.2008.11.071 ◽

2009 ◽

Vol 75 (2) ◽

pp. 272-277 ◽

Cited By ~ 13

Author(s):

Takashi Okada ◽

Toshihiko Matsuto

Keyword(s):

Fly Ash ◽

Melting Furnace ◽

Chemical Extraction ◽

Sequential Chemical Extraction ◽

Lead Speciation

Download Full-text

TENSILE STRENGTH OF SINGLE CONTINUOUS FIBER EXTRACTED FROM MENGKUANG LEAVES

Jurnal Teknologi ◽

10.11113/jt.v76.5521 ◽

2015 ◽

Vol 76 (3) ◽

Cited By ~ 3

Author(s):

Muhammad Syahmi Hamizol ◽

Puteri Sri Melor Megat-Yusoff*

Keyword(s):

Tensile Strength ◽

Inverse Relationship ◽

Cellulose Fiber ◽

Extraction Process ◽

Alkaline Treatment ◽

Chemical Extraction ◽

Cellulose Content ◽

Continuous Fiber ◽

Extraction Parameters ◽

Optimum Extraction

The focus of this paper is to obtain a continuous cellulose fiber (CCF) from mengkuang leaves of the pandanus genus using chemical extraction process and to measure its tensile properties. The higher the concentration of sodium hydroxide (NaOH) and the longer soaking times employed during the alkaline treatment of the mengkuang leaves, the higher the cellulose content extracted. The highest tensile strength of 520 MPa was measured for single CCF treated with optimum extraction parameters of 2% NaOH for 60 minutes. Amount of cellulose content of the extracted fiber showed an inverse relationship with the fiber’s tensile strength. The removal of lignin and hemicellulose content during extraction process may have caused the reduction in the fiber’s tensile strength.

Download Full-text