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Acts 17:26 has been word-for-word translated as "God made of one (henos) blood (haimatos) every ethnic group (ethnos) of humans." "Of one blood" appears in most ancient manuscripts and Patriarch quotations, including Irenaeus, whereas "of one" appears in several preeminent ancient manuscripts and in a Clement quote. Nonetheless, several recent English translations read "from one man," even though "man" does not appear in any early handwritten manuscripts. Some English translators perceive that "man" could be added as an ellipsis word after "one." Ellipses are words that Koine Greek authors omitted from their writings, anticipating that their readers would "supply-in-thought" these missing words in their minds, from the immediately preceding linguistic context. However, inserting "man" here would not match the patterns of any other Koine ellipses. "Of one blood" or "of one" concurs with scientific discoveries, whereas "from one man" conflicts. We are indeed all one blood of God’s creation; and thus there is no room for racial bias.

When wood-based activated carbon was tailored with quaternary ammonium/epoxide (QAE) forming compounds (QAE-AC), this tailoring dramatically improved the carbon's effectiveness for removing perfluorooctanoic acid (PFOA) from groundwater. With favorable tailoring, QAE-AC removed PFOA from groundwater for 118,000 bed volumes before half-breakthrough in rapid small scale column tests, while the influent PFOA concentration was 200 ng/L. The tailoring involved pre-dosing QAE at an array of proportions onto this carbon, and then monitoring bed life for PFOA removal. When pre-dosing with 1 mL QAE, this PFOA bed life reached an interim peak, whereas bed life was less following 3 mL QAE pre-dosing, then PFOA bed life exhibited a steady rise for yet subsequently higher QAE pre-dosing levels. Large-scale atomistic modelling was used herein to provide new insight into the mechanism of PFOA removal by QAE-AC. Based on experimental results and modelling, the authors perceived that the QAE's epoxide functionalities cross-linked with phenolics that were present along the activated carbon's graphene edge sites, in a manner that created mesopores within macroporous regions or created micropores within mesopores regions. Also, the QAE could react with hydroxyls outside of these pore, including the hydroxyls of both graphene edge sites and other QAE molecules. This latter reaction formed new pore-like structures that were external to the activated carbon grains. Adsorption of PFOA could occur via either charge balance between negatively charged PFOA with positively charged QAE, or by van der Waals forces between PFOA's fluoro-carbon tail and the graphene or QAE carbon surfaces.

Sustainable biomaterial binders developed from lignin plus collagen have offered effective binder systems for the fabrication of specialty graphites and graphite electrodes. To further chronicle collagen's synergistic effects and benefits, the authors appraised the formation and evolution of the chars pyrolyzed from lignin, collagen and their blends. Following pyrolysis in a vertical tube furnace at 1000 °C, the lignin-collagen blend yielded more char than did mere lignin or mere collagen. Elemental analysis indicated that along with the release of the oxygenated, nitrogenated, and hydrogen-containing gases, the collagen's presence facilitated carbon-enriched chars with more oxygenated polyaromatic structures. Collagen yielded an aryl (aromatic) carbon source in the aromatic condensation reactions, leading to the continuous cross-linking and growth of the lignin aromatic rings. Per Fourier-transform infrared spectroscopy (FTIR), during pyrolysis, collagen enhanced the hydrogen aromaticity index, and reduced the extent of aromatic substitution. The collagen presence facilitated more removal of functional groups, as indicated by bonded O–H stretching, symmetric CH3 stretching in O–CH3, and aliphatic C–H stretching. Scanning electron microscope (SEM) revealed that collagen served as a thermoplastic bio-binder that formed a thermally-fused framework with lignin. Thus, collagen induced significant differences in solidification behaviors and surface morphologies.

Positively charged polypyrrole (Ppy) was grafted into coconut-based activated carbon (AC), and this increased trifluoroacetate (TFA, CF3COO−) removal from a groundwater source. For batch i...

This research reports an integrated method for synthesizing a quaternary nitrogen-grafted activated carbon that is derived from a subbituminous coal source. The protocol employed nitric acid oxidation, thermal ammonia treatment and methyl iodide quaternization. The quaternized product greatly increased trifluoroacetate (TFA, CF3COO−) removal from a groundwater source. This quaternary nitrogen-grafted carbon (designated AWNQ) exhibited the highest TFA adsorption capacity of 32.9 mg/g and exhibited high energy of adsorption for TFA. Also, when processing groundwater that had been spiked with 200 ppb TFA, this quaternary nitrogen-grafted carbon removed TFA to 3 ppb breakthrough for 1860 BV, which was twelve times longer than the 150 BV for the pristine carbon. The enhanced sorption was attributed to its high quaternary nitrogen ratio (1.30, at.%), which offered 0.69 meq/g positive charge. Furthermore, high regeneration efficiency (89.5%) was achieved by the proposed regeneration protocol. The mixed regenerant (ethanol and NaCl solution) effectively stripped off the loaded TFA and regenerated the quaternary nitrogen sites. This quaternary nitrogen-grafted carbon with its fast and high uptake capacity offered technical promise for TFA removal from groundwater.

The authors tailored coconut-based activated carbons with a quaternary ammonium epoxide (QAE) surfactant that greatly increased the carbon's capacity for sorbing nitrate from water. This QAE-tailored carbon processed deionized water spiked with 50 mg/L NO3− through rapid small scale column tests; and achieved half-breakthrough at 477 bed volumes. This favorably compared to 52 bed volumes for the pristine coconut activated carbon. The QAE employed herein was QUAB 360. Most favorable pretreatment of the carbon was achieved via NaOH immersion, which created extensive phenolic functionality on the carbon's graphene edges, and raised the carbon's slurry pH to 9.3–9.6. These phenolics served as the anchor for the QUAB's epoxide reactions. This pretreatment offered the highest QUAB loading onto the carbon, which in turn netted the most nitrate removal. Per X-ray photoelectron spectroscopy, favorable QUAB360 preloading incurred a 1.62% increase in the quaternary N content of these activated carbons. The phenolic functionality that followed pretreatment was discerned by Boehm titrations; and these mathematically matched with Gaussian-based models that were fitted to incremental titration data. The most favorable QUAB-loaded variants were the ones whose pretreated precursors had exhibited the highest peak of functionality in the 9.3–10.4 pH range—corresponding to the pKa of phenolics. If the precursor pH was below the 9.3–9.6 range—as induced by acids or H2O2, then the QUAB's epoxide intermediate apparently over-reacted with the hydroxylated functionality of other QUAB molecules, rather than with phenolic functionality of the carbon's graphene edge sites.

Unconventional oil and gas residual solid wastes are generally disposed in municipal waste landfills (RCRA Subtitle D), but they contain valuable raw materials such as proppant sands. A novel process for recovering raw materials from hydraulic fracturing residual waste is presented. Specifically, a novel hydroacoustic cavitation system, combined with physical separation devices, can create a distinct stream of highly concentrated sand, and another distinct stream of clay from the residual solid waste by the dispersive energy of cavitation conjoined with ultrasonics, ozone and hydrogen peroxide. This combination cleaned the sand grains, by removing previously aggregated clays and residues from the sand surfaces. When these unit operations were followed by a hydrocyclone and spiral, the solids could be separated by particle size, yielding primarily cleaned sand in one flow stream; clays and fine particles in another; and silts in yet a third stream. Consequently, the separation of particle sizes also affected radium distribution - the sand grains had low radium activities, as lows as 0.207 Bq g-1 (5.6 pCi g-1). In contrast, the clays had elevated radium activities, as high as 1.85-3.7 Bq g-1 (50-100 pCi g-1) - and much of this radium was affiliated with organics and salts that could be separated from the clays. We propose that the reclaimed sand could be reused as hydraulic fracturing proppant. The separation of sand from silt and clay could reduce the volume and radium masses of wastes that are disposed in landfills. This could represent a significant savings to facilities handling oil and gas waste, as much as $100 000-300 000 per year. Disposing the radium-enriched salts and organics downhole will mitigate radium release to the surface. Additionally, the reclaimed sand could have market value, and this could represent as much as a third of the cost savings. Tests that employed the toxicity characteristic leaching protocol (TCLP) on these separated solids streams determined that this novel treatment diminished the risk of radium mobility for the reclaimed sand, clays or disposed material, rendering them better suited for landfilling.

A morphological study of lignin-bound anthracite briquettes was carried out to understand the mechanisms that hold together anthracite fines and silicon grains at elevated temperatures and high abrasion conditions. Lab-scale briquettes were prepared from anthracite fines, lignin, collagen, silicon, and other additives; and then pyrolyzed at 800 °C, 1400 °C and 1600 °C under nitrogen atmosphere to simulate the conditions inside a foundry cupola. The pyrolyzed samples were analyzed by reflected light microscopy, electron microscopy and x-ray diffraction. These analyses gave information on the transformations that lignin-bound anthracite briquettes may undergo in a cupola furnace. Lignin and collagen melted and formed an amorphous carbon phase that linked anthracite and silicon grains. Silicon carbide (SiC) nanowires coated in silicon oxide were formed at 1400 °C, and at 1600 °C most of the silicon was converted to SiC. Silicon carbide nanowires filled the interstitial voids left by volatilization of lignin and collagen. These findings support the idea that lignin and collagen hold anthracite fines at low temperature regimes. Silicon carbide nanowires contribute to briquette strength at high temperature conditions, acting as reinforcing filler and prevent collapse of the lignin-collagen matrix surrounding the anthracite grains.

The authors used a nitric acid (HNO3)-sodium dodecyl benzene sulfonate (SDBS) method to modify a lignite-based activated carbon. These modified carbons were appraised for their removal of Cd(II) from aqueous solutions. Response surface methodology was employed to optimize the preparation factors including nitric acid concentration CN, temperature T and SDBS concentration CS. Statistical analysis indicated that the interaction of CN and CS incurred the most effect on the maximum cadmium adsorption capacity (Qm). The optimal Qm appeared at CN = 3.29 mol/L, T = 76 °C and CS=30,700 mg/L. The optimal protocol achieved 44.21 mg/g Qm for Cd(II) which was about 7 times larger than for this pristine lignite activated carbon (LAC) (6.78 mg/g). The physical-chemical properties of the modified activated carbons following each synthesis step were characterized relative to their surface area, oxygen functionality, and external surface charge. It was confirmed that the developed surface area, functional groups and negative charges were mainly responsible for the higher adsorption capacity for the LAC that have been more favorably tailored by this HNO3-SDBS protocol.

Using waste biomass to prepare various products by environmentally benign processes is a good way to practice green and sustainable development. In this paper, high porosity and surface area biomass activated carbon was obtained by pyrolysis of pine sawdust without using any chemicals after steam bursting pretreatment. Under hydrothermal conditions at 160 ℃, the differences of steam bursting at 300, 500, or 700 psi pressures on the structure and surface chemical groups of the final activated carbons product were compared. The characterization showed that the specific surface areas and micropore volumes decreased with the increase of pressure, while the relative content of oxygen-containing functional groups changed slightly. The sample obtained following 300 psi pretreatment (HPB300) offered the highest BET surface area and pore volume, 962 m2/g and 0.526 cm3/g respectively, and which also achieved the highest adsorption amounts for both methylene blue (MB) and perfluorooctanoic acid (PFOA).

As alternative fuel for the partial replacement of coke in foundry operations, our research team has engineered anthracite briquettes that use lignin in its binder formulation. To understand the mechanism by which lignin provides strength to the briquettes, in this study we characterized the progressive increase in mechanical strength of lignin-containing anthracite briquettes following progressively longer pyrolysis. We compared these results with the progressive change of the Raman signal of lignin that was pyrolized under the same conditions. The rate of strength gain by the anthracite briquettes increased linearly with the pyrolysis time up to a point, and this rate is described by an Arrhenius-like plot, which exhibited an apparent activation energy of 33.6 kJ/mol. We analyze the D and G bands from the Raman signal of pyrolyzed lignin, after isolating these bands via deconvolution. The D band area increased and the G band area decreased with the pyrolysis time up to a point. We correlated both the rate of D-band growth and G-band diminishment with pyrolysis time in Arrhenius-like plots; and these two bands exhibited apparent activation energies of 51.9 and 43.2 kJ/mol respectively. In light of the similar activating energy values obtained during the increase of strength of the anthracite briquette and the formation of a polyaromatic structure using Raman signal, we discerned that the mechanism by which the pyrolyzed lignin strengthened the briquettes was via the creation of poly aromatic structures that connected the grains of anthracite into this rigid network. This network provided resistance to fracture when the briquettes were subjected to the unconfined compressive strength (UCS) test.

Sustainable biomaterial binders were developed from lignin and collagen to replace the conventional petroleum pitch and coal tar pitch binders that have been used when making specialty graphites and graphite electrodes. The team prepared lab-scale graphite electrodes by first creating green composites, by hot-pressing together the lignin, collagen, petroleum coke, and other additives, followed by carbonization and graphitization. Response Surface Methodology (RSM) experimental design was employed, based on Box-Behnken Design (BBD). This was employed to optimize the recipes and processing protocols for the green composite hot-pressing of 3.5 cm diameter × 19 cm long cylinder specimens. Relative to density, the apparent optimum conditions occurred with 13.0% lignin, 3.6% collagen, 27.4% petroleum coke fines, and the balance of petroleum coke particles plus some additives. The green hot-pressing protocol employed 30 MPa pressure at 400 °C for 2 h. Baking peaked at 800 °C, ramped up and down over 13 days. This baked product hosted an apparent density of 1.67 g/mL, and exhibited 6.2% puffing. Another baked product hosted 1.56 g/mL and 1.67% puffing. After the baked product was graphitized, we achieved an apparent density of 1.51 g/mL and resistance of 25–30 μΩm. These results approached the specifications for specialty graphites.

The authors have investigated apparent activation energies of volatiles emission when using (a) lignin alone, (b) collagen alone, or (c) lignin-collagen blends as a thermally-strengthened binder for high-density carbon product manufacturing. Apparent activation energies ( E a ) computed by the Kissinger, the Weibull, and the Flynn-Wall-Ozawa (FWO) methods showed the same trends: with the highest E a for lignin alone (245 kJ/mol), and the lowest for collagen alone (194 kJ/mol). The blends pyrolysis exhibited synergistic presence of collagen, which could help initiate the pyrolysis mass loss reactions at 250–400 °C, and participate in the condensation reactions of aromatic fragments at 400–800 °C, leading to less emission of some gaseous products and more preservation of residual char. In prior Penn State work, it was observed that this thermally-induced preservation and condensation of aromatic structure increased the binding strength of the lignin-collagen binders. The work herein offers thermogravimetric concurrence and insight to this thermal-binding synergism.

Anthracite briquettes were developed using mainly waste anthracite fines, plant byproducts of rice hulls and rice hull ash and silicon metal powder as an ecofriendly fuel and as an alternative to conventional coke used in a cupola furnace. Si metal powder reacts with anthracite to form SiC, which provides high mechanical strength to an anthracite briquette when it is exposed to a high temperature in the cupola furnace. Rice hull and rice hull ash, which are agricultural byproducts with high SiO2 content were investigated as partial substitutes for silicon as the former are inexpensive relative to silicon metal. The formation of SiC was investigated under different conditions using X-ray diffraction and transmission electron microscopy. In addition, unconfined compressive strength of the briquettes was measured when the rice hull or ash substituted Si powder partially or completely. When anthracite briquettes prepared with elemental Si powder and either rice hull ash or rice hull powder were pyrolyzed at 1400 °C for 2 h, SiC formed and the briquettes showed high mechanical strength in the range of 2000–4000 kPa, which is enough to keep their structural integrity in a cupola furnace.

When comparing a novel collagen and alkali silicate core binder system to a conventional phenolic urethane binder system during full-scale trials, the phenolic urethane incurred a 33.3 % higher emissions rate than did the novel binder system. This was chronicled during several hours of stack tests in a full-scale trial demonstration of 3500 novel cores at a high-volume automotive ductile iron foundry. Baseline phenolic urethane emissions were determined immediately prior to running the collagen and alkali silicate cores, when making an identical casting. Approximately 10 % of the demonstration iron castings were inspected for defects, of which none (0 %) were scrapped on account of core-related defects. Also, the novel core’s shakeout was complete. These favorable results were achieved with humidity-free storage of the cores over the 10 days that the cores were made. These novel demonstration cores required somewhat longer curing time in the core-making machine, than did conventional phenolic urethane cores; and this curing rate was influenced by air flow and pressure into the core box. Also, tensile specimen tests of the collagen and alkali silicate-adhered system were higher than that of the conventional phenolic urethane system. When exposed to high humidity levels (80–95 % relative humidity) for prolonged periods of time (10 days), the collagen and alkali silicate-adhered tensile specimens degraded in terms of tensile strength and scratch hardness. These losses mostly rebounded when the tensile specimens were re-dried.

Improved structure–property relationships for activated carbon were obtained by devising realistic, large-scale, structural models. Herein, an improved approach was employed to construct atomistic models of a lignite precursor of activated carbon, based on the high resolution transmission electron micrographs (HRTEM) of pyrolyzed lignite coal, in combination with experimental pore size distribution analysis of tailored lignite-based activated carbon. Benzene sorption was experimentally characterized at 303 and 318 K and resulted in 13–18% mass gain. To model the carbon structure and benzene sorption, we have devised two structures, including either micropores (4–20 A) or micro/mesopores (4–40 A). For the 303 K conditions, the predictions of the two models are consistent with experimental observations. For the micro/mesoporous model, benzene molecules sorbed in both micropores and mesopores, as the mesopores provide access to the internal part of the carbon structure, and benzene molecules would pass readily through these small mesopores to the final sorption sites in micropores of 14–18 A in size. The most favored sorption energy was −37.45 kJ mol−1, with a preferred rotation angle from 20–30°, and a second favored angle from 30–40° relative to the graphene surface. These benzene molecules were aggregated in T-shaped and parallel-displaced configurations, with a separation distance of 5.75 A from the benzene centers of mass to the carbon surface in a monolayer state. The most favored position was found to be parallel to and between two carbon surfaces, especially close to 5- or 7-membered rings.

A novel core binder system has been devised that is comprised of hydrolyzed collagen and alkali silicates. Cores that employ this hybrid binder were tested in a full-scale demonstration at a partner foundry. Among the 244 iron castings manufactured at this facility while using these hybrid binders, none of the iron castings were rejected as scrap due to core-related defects. The core regions of these iron castings exhibited no deformation, veining, or erosion from molten iron exposure. Moreover, these hybrid silicate-collagen cores demonstrated satisfactory shakeout during full-scale demonstrations. This hydrolyzed collagen-alkali silicate binder yielded cores that achieved a higher tensile strength and less hot distortion than conventional phenolic urethane binders.

Construction of large-scale atomistic representations of activated carbon aids exploration of structure–property relationships. The construction approaches for existing structures are limited in the control over the distribution of structural features. Here, an initial atomistic representation of a lignite-based activated carbon was constructed using a construction strategy that allows control over the distributions of stacking, degree of orientation, and pore size. Fringe3D was used to produce a collection of 42 molecules within 25 stacks comprised of graphene sheets with control over their length, orientation, and stack height. Vol3D populated the specified 100 × 100 × 100 A cuboid volume with an assumed Gaussian distribution of stack width, without changing orientation and thus retaining regional organization. Eight of these were combined to create a large-scale structure. The pore size distribution was captured due to smaller microporosity caused by packing inefficiencies of the stacks and by inclusion of additional desired porosity. To demonstrate the control over the extent of curvature, three 200 × 200 × 200 A structures overall were constructed with varying extent of curvature. The construction protocols were efficient producing large-scale structures (∼330,000 atoms) constructed far more rapidly than traditional strategies using a personal computer.

Testing was conducted to evaluate the effects of hydroacoustic cavitation (HAC) treatment on spiral separation when processing nominal −1500 µm Illinois-basin bituminous coal. Cavitation was produced either by flow through an ultrasonic resonator chamber or enhanced cavitation by initial flow through a cavitation box followed by flow through the ultrasonic chamber. After treatment, the slurry was passed through a hydrocyclone for desliming, and the underflow stream was used as spiral feed. Spiral tests were carried out using a two-stage spiral at three volumetric flow rates for different HAC treatment conditions. HAC treatment reduced the overall size distribution of the spiral feed material. Likewise, desliming of the treated material led to a reduction in the ash values for each size interval. For example, after HAC treatment, the ash value of the deslimed material was reduced to 25% compared to 41% for the untreated deslimed material. Subsequent spiral separation of the treated material produced clean ...

A novel method has been developed for immobilizing (tailoring) polypyrrole (PPy) into activated carbon (AC) in a manner that facilitates the removal of sulfate, and then electrochemically regenerating the tailored activated carbon. This tailoring was achieved by sorbing pyrrole into AC pores, then oxidizing the pyrrole by means of either a FeCl 3 oxidant or electrochemical oxidation. The resultant oxidized PPy hosted a positive charge that sorbed sulfate from acid mine drainage (AMD) water. Next, the spent AC/PPy was electrochemically reduced such that the nitrogen functionality became neutrally charged, and released the sorbed sulfate. This AC/PPy was then electrochemically oxidized such that it regained a positive charge, and again sorbed sulfate. When processing rapid small scale column tests (RSSCTs) with AMD water that contained 773 mg/L SO 4 2− the media processed 23 bed volumes before breakthrough occurred. Subsequent to these RSSCTs, electrochemical reduction at −2.0 V (vs Ag/AgCl) released 95% of this sorbed sulfate, and subsequent oxidation at 0.4 V yielded a media that had restored 61.5% of its initial sulfate-sorption capacity.

Polyurethane (PU) media impregnated by different amounts of MgO were synthesized and estimated for the removal performance of high-level Mn(II) in aqueous phase. The kinetic tests of Mn(II) removal (130 mg L � 1 initial Mn(II) concentration) by MgO impregnated PU (PUMgO) showed that the highest

Positively charged nitrogen functional groups were introduced onto the surface of granular activated carbon (GAC), and these increased perchlorate anion removal from drinking water sources. Nitrogen functionalization involved three treatment steps: (1) introducing oxygen groups onto the GAC, (2) incorporating nitrogen groups by thermal treatment in ammonia flow to replace O with N, and (3) quaternerizing pyridine-like groups to create positively charged pyridinium-like groups. Functionalized bituminous GAC provided 6 times more perchlorate removal than its predecessor, pristine bituminous GAC. The conversion of pyridine-like groups (after step 2) to pyridinium-like groups by quaternization (step 3) was confirmed by analysis of the XPS N 1s signals and surface charge analysis. Redox peaks, observed during cyclic voltammetry analysis of the functionalized GAC, evidenced that these nitrogen functional groups were electrochemically active, so that they sorbed perchlorate when they were oxidized, and then desorbed perchlorate when reduced. Moreover, after sorbing perchlorate onto pyridinium-GAC in RSSCTs, the GAC media could be regenerated by electrochemical reduction, and its capacity for perchlorate adsorption was mostly restored. This tailored functionality and redox regeneration of a relatively inexpensive media such as activated carbon could offer novel opportunity to the adsorption industry.

A novel method of removing sulfate from acid mine drainage (AMD) water was developed by depositing polypyrrole into the pores of wood-based activated carbon (RGC) using in situ chemical oxidative polarization. This polypyrrole-tailored activated carbon hosted positively charged polypyrrole functionality that offered sorption capacity for sulfate. Specifically, in batch tests, the polypyrrole-grafted RGC achieved a sulfate loading of 48 mg/g, this being 8 times higher than for pristine RGC. Rapid Small Scale Column Tests appraised the polypyrrole-tailored RGC for removing 773 mg/L sulfate from AMD water. The more favorably tailored carbon removed sulfate to half-breakthrough at 24 bed volumes (BV). This compared to 1.5 BV for pristine activated carbon. Per mass and charge balance, 9% of the nitrogen in the polypyrrole functionality was active for capturing sulfate. On this tailored carbon, the nitrogen content was 12.9%, as characterized by X-ray photoelectron spectroscopy. With this polypyrrole tailoring, the carbon’s pore volume distributions diminished to one-third, as characterized by argon adsorption.

An organoclay was prepared using montmorillonite and hexadecylpyridinium chloride (HDPyCl) and tested for the removal of nitrate and perchlorate anions from aqueous solutions. The cationic surfactant modified organoclay was prepared at room temperature using HDPyCl corresponding to 4 times the cation exchange capacity (CEC) of Na-montmorillonite. Powder X-ray diffraction (XRD) analysis of the above organoclay showed a large basal spacing of 40.27 A with the intercalation of HDPy cations in the interlayers probably as a result of a paraffin-type bilayer arrangement. The adsorption data of nitrate and perchlorate were fitted to the Langmuir and Freundlich adsorption isotherms and pseudo-first order and pseudo-second order kinetic models to better understand their adsorption mechanisms. The nitrate and perchlorate uptakes by this organoclay could be described well using the Langmuir isotherm while their uptake kinetics fitted well to the pseudo-second order model. The maximum adsorption capacities of nitrate and perchlorate by the organoclay, HDPy-montmorillonite were calculated at 0.67 and 1.11 mmol g− 1, respectively. Nitrate and perchlorate uptake kinetics were found to be fast as equilibrium was reached within 4 h. Furthermore, the uptakes of nitrate and perchlorate by HDPy-montmorillonite were found to be highly selective in the presence of Cl−, SO42 − and CO32 −, the most abundant naturally occurring anions. Therefore, the HDPy-montmorillonite could be used as a highly efficient adsorbent for the separation of nitrate and perchlorate from drinking or waste water and ground water.

The authors have developed bindered anthracite briquettes that can replace conventional coke as a fuel in foundry cupolas. The anthracite briquettes included fine anthracite grains that were bindered together with collagen, lignin and silicon. These binders gave the briquettes high mechanical strength through the full spectrum of temperatures encountered in a foundry cupola furnace – from ambient temperature up to 1550 °C. The bindered anthracite briquettes offered the same structural strength and fuel content as has conventional foundry grade coke. The conventional coking process involves pyrolyzing coal at 1000 °C for a day; and this consumes about 15% of the raw coal’s energy, while releasing volatile organic air pollutants. In contrast, the briquetting process consumes scant energy, without releasing pollutants. During two full-scale demonstrations that each employed 4 tons of these briquettes, the anthracite briquettes performed similarly to the foundry grade coke, while the briquettes replaced up to 25% of the coke. During briquette replacements, the cupola temperatures, off-gas CO/CO 2 proportions, tuyere back-pressures, and metal-to-fuel ratios were maintained or improved. The iron castings produced during this briquette replacement were of the same high quality and composition as when mere coke was used; and these iron castings were sold. Observations through the tuyere windows – where oxygen-enriched air was lanced into the bottom of the cupola – showed that these anthracite briquettes reached the cupola’s melting zone while maintaining their physical integrity. Once these briquettes reached the level of the tuyere windows, they exhibited faster burning in the oxygen-enriched air than did conventional coke.

The authors and collaborators have devised innovative technologies that decrease foundry costs, pollution, materials use, and energy. These include: (a) applying advanced oxidation to green sand and baghouse dust to diminish clay, coal, sand, volatile organic compounds (VOCs), and costs; (b) replacing phenolic urethane core binders with collagen-alkali silicate binders to diminish VOCs; (c) replacing coke with anthracite fines held together with biomaterial to reduce energy and costs. It is proposed by the authors that if a foundry were to concurrently employ all these innovative technologies (with 50% anthracite bricks), it could potentially diminish overall costs by 6.6%, life cycle energy costs by 15%, VOC pollution by 57%, sand by 85%, clay and coal by 50%, and iron scrap by 9%. These computations are per full-scale operations for advanced oxidation; and R&D results for replacing binders and coke. This paper also notes that when electricity comes primarily from coal fired power plants, electric induction furnaces consumes more life cycle energy than do cupolas for melting iron.

The current study uses nuclear magnetic resonance, Fourier-transform infrared spectroscopy and Raman spectroscopy to investigate the evolution of refined softwood and hardwood lignins under various pyrolytic exposures. Little chemical change occurred at pyrolysis temperatures of 250 and 300 °C, whereas significant mass loss and chemical change was observed at 400 and 500 °C. These losses were mainly attributed to evolution of methoxyl, hydroxyl, and propyl groups. Mass loss plateaued following pyrolysis at 500 °C, but rearrangements continued to occur at higher temperatures, resulting in char that became increasingly polyaromatic in nature. Following brief pyrolytic exposures at 500 and 600 °C, the refined hardwood and softwood lignins yielded coal-like products. Lignin pyrolyzed at higher temperatures yielded chars with greater order, similar in composition to coke. These coal and coke-like products are called “lignin-based carbon” (LBC). The polyaromatic nature of the LBC after high temperature pyrolysis was perceived as the result of radical formation and recombination, leading to fused aromatic structures, which occurs more readily at higher temperatures.

In this work, octadecyltrimethylammonium (ODTMA) chloride was used to prepare MCM-41 at room temperature while cetyltrimethylammonium (CTMA) bromide was used to synthesize MCM-48 and layered organosilica material under hydrothermal conditions. These synthetic organosilica materials, in addition to a commercially available organoclay, Cloisite®10A, were characterized by powder X-ray diffraction (XRD) and tested with the occluded surfactant as sorbents for nitrate. The Langmuir and Freundlich models were applied with determination of the equilibrium isotherms and the isotherm constants. Adsorption kinetics data were tested using pseudo-first-order, pseudo-second-order and intraparticle diffusion models. The results showed that the highest nitrate uptake capacities were achieved with Cloisite®10A (0.359 ± 0.003 meq/g) followed by a layered organosilica (0.287 ± 0.008 meq/g). MCM-48and MCM-41 silica adsorbed 0.096 ± 0.002 and 0.157 ± 0.005 meq/g of nitrate, respectively. Kinetics studies showed that the adsorption followed pseudo-second-order kinetic model. Layered organosilica gave a good fit to the Langmuir model among all the studied samples with correlation coefficient (R2) close to unity (0.99).

A novel method has been developed for anchoring quaternary ammonium/epoxide-forming compounds (QAEs) within bituminous based granular activated carbons (GACs). This modified GAC was then used to remove perchlorate from groundwater. The effect of the preparation temperature (T), solution pH (pH) and the dry mass ratio of QAE-to-GAC (R) over the perchlorate adsorption capacity (Qe) were studied by the Response Surface Methodology. The combined effects of these variables were fitted to a quadratic model to determine the more favorable preparation protocol for perchlorate removal. Statistical analysis revealed that: (1) the interaction of T and pH incurred the most effect on Qe; and (2) two of the more favorable preparation protocols became apparent: one was at 75 °C, pH 11 and R of 1.73 g QAE/g GAC (U17), the other was at 35 °C, pH 14 and R of 4.00 g QAE/g GAC (U2). Rapid small scale column tests were further employed to evaluate the performance of the QAE-anchored GACs for perchlorate removal. U17 and U2 exhibited 18–20 times longer bed life (BV) to 6 ppb breakthrough than did the Pristine GAC (900 BV), when processing groundwater that had been spiked with 30–35 ppb perchlorate. This indicated the statistical method enhanced GAC’s perchlorate removal efficiency.

A novel method has been developed for anchoring quaternary ammonium/epoxide-forming compounds (QAE) within bituminous and wood based granular activated carbons (GACs). This QAE-anchored GAC was then used to enhance perchlorate removal from perchlorate-spiked natural groundwater. Specifically, for the bituminous based carbon, while processing natural groundwater that had been spiked with 30–35 ppb perchlorate, and passing this water through rapid small scale column tests, the bed volumes (BV) to 2 ppb perchlorate breakthrough increased from 870 BV for pristine GAC up to 21,000 BV for the corresponding GAC that had been pre-anchored with QUAB360 (360 Da). However, the wood based GAC that had been anchored with this QUAB360 achieved only 3000 BV. None of the QAE leached out of these GACs during the column tests. The bituminous GAC that had been pre-anchored with QAE hosted more positive surface charge at pH 7.5 than did the wood based QAE–GAC. Per X-ray photoelectron spectroscopy, the QAE anchored into the GACs increased their N-content by 1–1.3%. By means of multiple analyses, the authors surmised that the active quaternary ammonium sites within the tailored bituminous-based GAC were more exposed and thus more accessible for perchlorate adsorption than those within wood based GAC.

In this study, octadecyltrimethylammonium (ODTMA) chloride was used to prepare MCM-41 at room temperature while MCM-48 and a mesoporous layered organosilica (MCM-50) were synthesized under hydrothermal conditions using cetyltrimethylammonium (CTMA) bromide. These synthetic organosilicas in addition to a commercially available organoclay, Cloisite® 10A were characterized by powder X-ray diffraction (XRD) and tested with the occluded surfactant as adsorbents for perchlorate. Adsorption data were modeled using the Langmuir and Freundlich adsorption isotherms. Adsorption kinetics data were tested using pseudo-first-order, pseudo-second-order and intraparticle (in pores of MCM-41 and MCM-48 or interlayers in the case of layered silica and organoclay, Cloisite®) diffusion models. The results showed that the highest perchlorate uptake capacities were achieved with MCM-48 silica (0.421 ± 0.007 meq/g) followed by mesoporous layered organosilica (0.400 ± 0.006 meq/g). Cloisite® 10A and MCM-41 silica adsorbed 0.280 ± 0.003 and 0.246 ± 0.003 meq/g of perchlorate, respectively. Kinetics studies showed that the adsorption followed pseudo-second-order kinetics model. The good fit of the experimental data and the values of correlation coefficients (R 2 ) indicated the applicability of Langmuir model to perchlorate adsorption in the present study.

Studies on arsenic removal by zero-valent iron (ZVI)–based system have focused mostly on batch or small scale tests. In this research, pilot-scale studies were carried out on arsenic removal by technologies developed in rapid small-scale column tests (RSSCTs). Pilot-scale studies can provide significant information on final scale-up to full-scale operation, which RSSCT inherently was not able to provide. In addition, comparison between pilot column and RSSCT breakthrough profiles could help validate RSSCT design, especially RSSCT for arsenic. Results from pilot studies indicate that arsenic removal by a system of ZVI plus iron-tailored granular activated carbon showed significant promise for practical applications. The best performance was achieved when ZVI worked together with carbon pretailored by an iron-salt evaporation method. In addition, the similarity in arsenic breakthrough curves between RSSCTs and pilot studies serves to confirm that it is appropriate to assume proportional diffusivity...

Lignin that had been extracted from Kraft black liquor was investigated as a fusing binder in briquetted anthracite fines for a foundry coke substitute. Cupola “heat zone” pyrolytic temperatures of 300–1550 °C were appraised, with the focus on 900 °C. Briquettes with favorable strength were made with 86–92% anthracite fines, 2.3–8.6% lignin, 4.5% silicon metal powder, and 0.9% hydrolyzed collagen (denatured collagen) by mass. Briquettes were pyrolyzed under a nitrogen atmosphere or a starved air condition to simulate a cupola pyrolytic heat zone, and then crushed after this pyrolysis so as to discern their unconfined compressive (UC) strength. These tests mimicked key features of the crushing load that coke endures in a cupola. After 30 min of 900 °C pyrolysis, UC strength reached 2200–3000 kPa (320–440 psi), when these briquettes contained 4.5% softwood lignin or 2.3% hardwood lignin. With ⩾6.5% hardwood lignin, the UC strength after 900 °C pyrolysis reached 6000–6500 kPa. When no lignin was incorporated into the briquette, the UC strength after 900 °C pyrolysis was a mere 200 kPa. Denatured collagen quantity affected lignin heat zone strength, despite by itself losing strength around 300 °C: with 4.5% lignin present, 1.8% denatured collagen doubled the strength of 0.45% denatured collagen briquettes. Adding tannic acid to the briquettes greatly increased the UC strength as well. Lignin provided strength up to 1400 °C. Moreover above 1100 °C, silicon carbide nanowires greatly enhanced UC strength relative to lignin alone. Briquettes with lignin gained UC strength very quickly when flash pyrolyzed to 900 °C, which is important in the cupola. The results herein showed that the bindered briquettes burned at an equal rate as did coke when these were burned at 1100 °C in air. The briquettes also contained an energy density that was 38% higher by volume than that of coke. Harnessing these high temperature pyrolytic lignin fusing reactions creates a valuable foundry coke substitute for the future, as well as large scale applications for otherwise underutilized industrial streams of lignin.

Metalcasting within the United States aims to meet ever-more stringent environmental standards as new process technologies are developed. Conventional foundry core binders are responsible for up to 70% of a foundry's volatile organic compound (VOC) emissions. New core binder technologies are essential for environmental sustainability within foundries. Herein, conventional and novel foundry core binders were appraised using thermal gravimetric analysis (TGA), dynamic mechanical analysis (DMA), hot distortion testing (HDT), and (Pilot-scale) molten iron erosion tests. Inherently, these tests cannot replace full-scale casting trials to evaluate binder effectiveness, however, these tests were performed to more fully elucidate binder properties that might cause casting defects or other unwanted behaviors at high temperatures. During each of these lab protocols, the combination of collagen plus alkali silicate as binders exhibited properties that matched or exceeded those of conventional phenolic urethane. Also, in iron erosion testing, the collagen/alkali silicate binder exhibited the same low erosion as conventional phenolic urethane. In hot distortion testing, the collagen–alkali silicate binder exhibited longer resistance to thermal bending, and comparable thermal flexibility to conventional phenolic urethane.

A variety of oraganosilicas such as MCM-41 and MCM-48 and composites of rice husks with MCM-48 were synthesized under an array of conditions and characterized by powder X-ray diffraction (XRD). Various MCM-41 mesoporous materials were prepared at room temperature using different surfactants. MCM-48 silica and its composites with rice husks were synthesized under hydrothermal conditions using cetyltrimethylammonium (CTMA) bromide and rice husks. Both untreated and carbonized rice husks were used for preparing composites of rice husk with MCM-48. Organo-clay minerals procured from two commercial sources were also investigated for their perchlorate uptake. Among the MCM-41 materials, the sample prepared from octadecyltrimethylammonium (ODTMA) chloride showed the highest perchlorate uptake capacity of 0.227 ± 0.006 meq/g while MCM-48 showed the highest perchlorate uptake capacity of 0.437 ± 0.011 meq/g among all the oraganosilicas and organo-clay minerals tested here. The uptake of perchlorate by organosilicas and organo-clay minerals is due to residual positive charge on the surfactants located in the mesopores of organosilicas and interlayers of organo-clay minerals.

Silicon carbide nanowires (SCNWs) were grown from anthracite fine surfaces through a simple one-step carbothermal process with silicon powder as the Si precursor. This straightforward and fast formation of SCNWs made it possible to maintain the binding of briquetted waste anthracite fines at very high temperatures as an alternative fuel in foundry cupola furnaces. This SCNW mechanism could thus provide the crucial hot crushing strength in the cupola heat zone and melt zone. Progressive thermal tests exhibited that the formation of the SCNWs started from 1100 C, and was favored at 1400 C. No extra metal catalyst was needed for the growth of the SCNWs. Characterizations were performed by XRD, SEM, EDS, TEM, and SAED. The SCNWs were 30–60 nm in diameter and were typically grown by stacking the (1 1 1) lattice plane of 3C-SiC along the [1 1 1] direction. Many non-epitaxial branches of the nanowires were also formed through this one-step process as observed by TEM. The results suggest that the SCNWs were most likely grown through the vapor–solid mechanism.

Removal of perchlorate (ClO4−) while using granular-activated carbon (GAC) that had been preloaded with cetylpyridinium chloride was appraised using Rapid Small-Scale Column tests (RSSCT) and pilot-scale demonstration. ClO4− competed with nitrate, sulfate, chloride, and other anions for ion exchange sites on the preloaded carbon. Tests used native groundwater from Fontana, CA, which contained nitrate of 32 mg/L as NO3−, 7 μg/L as ClO4−, and 1.9 μg/L (as U) of uranyl carbonate species (predominantly UO2(CO3)34−) species. RSSCT with Fontana groundwater exhibited ClO4− breakthrough at 25,000 bed volumes. When the same groundwater was spiked to three times the native NO3− concentration, ClO4− breakthrough occurred at 12,000 bed volumes. When the total dissolved solids (TDS) increased from the native 250 mg/L up to 660–810 mg/L TDS, by adding magnesium sulfate, sodium bicarbonate, or sodium chloride, the bed-life for removing ClO4− increased by 10%–30%. This result was attributed to perchlorate's comp...

The perchlorate uptake of hydrotalcite- and hydrocalumite-type layered double hydroxides (LDHs), and surfactant modified clay minerals were compared. Perchlorate uptake by both hydrotalcite- and hydrocalumite-type LDHs was in the range of 0.011 to 0.197 meq/g from a 2 mM perchlorate solution. The nitrate form of Mg:Al LDH had the highest uptake of 0.197 ± 0.033 meq/g, and the carbonate form of LDH the lowest uptake of 0.011 ± 0.003 meq/g. Octadecyltrimethylammonium (ODTMA), Dodecyltrimethylammonium (DoDTMA), and hexadecyltrimethylammonium (HDTMA) clay minerals removed perchlorate in the range of 0.025 to 0.348 meq/g from a 2 mM perchlorate solution. Synthetic HDTMA (5.0 CEC) Na-1-mica exhibited the highest adsorption of perchlorate with 0.348 ± 0.011 meq/g, while DoDTMA montmorillonite had the lowest adsorption with 0.025 ± 0.009 meq/g. Tested under the same conditions, a surfactant modified carbon showed an uptake of 0.303 ± 0.005 meq/g and this carbon is currently being used for filtration of drinking water. Hydrophobic organo-clay minerals with larger interlayer distance resulted in higher perchlorate uptake by exchange/adsorption on the residual charge of the cationic surfactants. The uptake by LDH was by anion exchange on the surfaces and, for the nitrate form of hydrotalcite, also from the interlayer spaces. The mechanisms of uptake were confirmed by X-ray diffraction (XRD) and scanning electron microscopy. This study indicated that cationic surfactant containing organo-clay minerals may be useful materials for the removal of perchlorate from water and could serve as alternatives to surfactant modified-activated carbons.

Mesoporous MCM-41 silica and rice husk composites were synthesised under hydrothermal conditions using cetyltrimethylammonium bromide (CTAB) as an organic template, aqueous ammonia solution (NH4OH) and rice husk, the latter as a silica source and substrate for the deposition of MCM-41. Both untreated and carbonised rice husks were used for preparing composites at a temperature of 100–120°C for 24–48 h. The as synthesised composites or hybrid materials were characterised by using XRD and SEM and they were found to be useful for the uptake of perchlorate. These composites could be used to separate perchlorate from solutions in column operation without the necessity for their pelletisation because the rice husk substrates are several millimetres in size.

Thiosulfate (S2O32−) hosts redox stability in time frame of days, rendering it a candidate ion exchange competitor in anoxic groundwaters during the brief time frames of treatment processes. Indeed, this research determined that the oxyanion thiosulfate (S2O32−) competed with perchlorate (ClO4−) for sorption onto activated carbons that had been preloaded with a quaternary ammonium surfactant. Moreover, this research showed that when proper prechlorination oxidized this S2O32− to sulfate (SO42−), this competition was diminished. When rapid small-scale column test employed Redlands, CA, groundwater that contained a native 30 μg/L ClO4−, this exhibited a 6 μg/L ClO4− breakthrough after 33,000 bed volumes (BVs) when processed through bituminous-based granular-activated carbon that had been preloaded with a quaternary ammonium surfactant, namely, 0.24 g/g dicocoalkyldimethylammonium chloride (Arquad 2C-75). When this same water was spiked with 1,000 μg/L S2O32−, 6 μg/L of ClO4− broke through at 17,000...

Here we demonstrate that the as-prepared MCM-41 mesoporous silica material, which is synthesized using cetyltrimethylammonium bromide as a cationic surfactant exhibits very high capacity for perchlorate uptake from solutions. Thus we discover a new function for the as-synthesized mesoporous materials containing cationic surfactants. These materials are shown to have better capacity than the currently used activated carbon, which is preloaded with cationic surfactant. As-synthesized MCM-41 has a higher removal of perchlorate with 0.378 ± 0.038 meq/g than the surfactant modified activated carbon sample, which removed 0.304 ± 0.005 meq/g i.e., MCM-41 has a 24 % higher capacity than the surfactant modified activated carbon sample for perchlorate uptake because of higher surfactant content and higher positive charge in the former. The residual positive charge on the cationic surfactant micelles trapped in mesopores of silica is responsible for the high perchlorate uptake. The excess positive charge on the micelles in the as-synthesized MCM-41 silica is balanced by bromide ions and these ions are involved in exchange with perchlorate ions.

Temporal changes in the pore structure of granular activated carbons (GACs) were investigated for two reactivated and one virgin GAC during water treatment. One reactivated GAC had experienced five cycles of treatment and reactivation (5xReac), whereas the other had experienced twelve cycles (12xReac). For the virgin GAC that became loaded with natural organic matter (NOM), nearly all pore volume loss occurred in pores 40 A. For the 5xReac, the greatest loss of pore volume occurred in the 100–500 A pores. The 12xReac GAC experienced some loss of pore volume in the 100–500 A pores. For each GAC, NOM adsorption initially caused pore volume loss in pores that were only slightly wider than the NOM itself. Subsequent to this initial stage, NOM was mostly retained in the 20–40 A pores for the virgin GAC and in the 100–500 A pores for the 5xReac GAC. This was followed by gradual migration of the NOM into smaller pores. A lull in NOM loading revealed distinctions in ho...

A protocol was devised for preparing pyrolyzed coals that could be made in-situ at foundries to capture volatile organic compound (VOC) emission. This pyrolysis created extensive micropore volume in lignite over a broad range of temperature and time; and could use waste heat from cupola exhaust gases by a heat-exchange tube. For foundry application, moderate porous carbon with relatively uniform pores over wide ranges of temperature and time would be more practical than highly porous activated carbon (AC) that requires narrowly-controlled operations. This pyrolysis protocol was developed in a thermogravimetric analyzer (TGA) and in a small tube furnace, while using lignite, bituminous coal, and anthracite. The lignite yielded the most pore volume; and this was relatively uniform (0.1–0.13 mL/g of pores) while temperatures were 600–900 °C, and times were 0–60 min. Smaller grain sizes yielded improved porosity; and this corresponded to more release of phenols and naphthalenes from smaller grains, as discerned by TGA–mass spectroscopy (MS). TGA–MS also revealed that improved pore development between 600–800 °C corresponded to the release of CO 2 and H 2 O; and concurrently higher slurry pH linked to less oxygenated functionality. Adsorption of benzene was compared between the in-situ porous carbon and a commercial AC.

Rapid small-scale column tests (RSSCTs) examined the removal of 29 endocrine disrupting compounds (EDCs) and pharmaceutical/personal care products (PPCPs). The RSSCTs employed three lignite variants: HYDRODARCO 4000 (HD4000), steam-modified HD4000, and methane/steam-modified HD4000. RSSCTs used native Lake Mead, NV water spiked with 100-200 ppt each of 29 EDCs/PPCPs. For the steam and methane/steam variants, breakthrough occurred at 14,000-92,000 bed volumes (BV); and this was 3-4 times more bed volumes than for HD4000. Most EDC/PPCP bed life data were describable by a normalized quantitative structure-activity relationship (i.e. QSAR-like model) of the form: where TPV is the pore volume, rho(mc) is the apparent density, CV is the molecular volume, C(o) is the concentration, (8)chi(p) depicts the molecule's compactness, and FOSA is the molecule's hydrophobic surface area.

The authors monitored hydrogen peroxide (H2O2), ozone (O3), and apparent hydroxyl radical (OH·) concentrations in the liquid phase, along with gas phase ozone when operating an advanced oxidation (AO) system that included H2O2, O3, sonication, and underwater plasma (UWAP). The OH· radical converted non-fluorescent terephthalic acid to fluorescent hydroxyterephthalic acid (HTA). As determined from HTA formation, when a 500 ppm H2O2 dose in tap water was combined with O3 and sonication, nearly twice as much OH· (0.72 ppm) accumulated than with H2O2 alone. When UWAP accompanied H2O2, O3, and sonication, these together generated 15–35% more OH· than when UWAP was excluded. When ozone was introduced into this AO system, the AO system decomposed almost all the O3. This research has been conducted as a part of a study that has appraised this advanced oxidation system (Sonoperoxone) in green sand foundries, where it has diminished volatile organic compound (VOC) and hazardous air pollutant (HAP) emissions by 20–7...

Analytical pyrolysis was conducted to study a relative comparison of the hydrocarbon and greenhouse gas emissions of three foundry sand binders as follows: (a) conventional phenolic urethane resin, (b) biodiesel phenolic urethane resin, and (c) collagen-based binder. These binders are used in the metal casting industry for making cores that are used to create internal cavities within castings. In this study, the core samples were flash pyrolyzed in a Curie-point pyrolyzer at 920 degrees C with a heating rate of about 3000 degrees C/sec. This simulated some key features of the fast heating conditions that the core binders would experience at the metal-core interface when molten metal is poured into green sand molds. The core samples were also pyrolyzed in a thermogravimetric analyzer (TGA) from ambient temperature to 1000 degrees C with a heating rate of 30 degrees C/min, and this simulated key features of the slow heating conditions that the core binders would experience at distances that are further away from the metal-core interface during casting cooling. Hydrocarbon emissions from flash pyrolysis were analyzed with a gas chromatography-flame ionization detector, while hydrocarbon and greenhouse gas (CO and CO2) emissions from TGA pyrolysis were monitored with mass spectrometry. The prominent hazardous air pollutant emissions during pyrolysis of the three binders were phenol, cresols, benzene, and toluene for the conventional phenolic urethane resin and biodiesel resin, and they were benzene and toluene for the collagen-based binder. It was also found that volatile organic compound and polycyclic aromatic hydrocarbon emissions considerably decreased in order from conventional phenolic urethane resin to biodiesel resin to collagen-based binder. These results have shown some similarity with those for stack emission testing conducted at demonstration scale and/or full-scale foundries, and the similar trends in the two sets of results offered promise that bench-scale analytical pyrolysis techniques could be a useful screening tool for the foundries to compare the relative emissions of alternative core binders and to choose proper materials in order to comply with air-emission regulations.

Iron-impregnated activated carbons have been found to be very effective in arsenic removal. Oxyanionic arsenic species such as arsenate and arsenite adsorb at the iron oxyhydroxide surface by forming complexes with the surface sites. Our goal has been to load as much iron within the carbon pores as possible while also rendering as much of the iron to be available for sorbing arsenic. Surface oxidation of carbon by HNO 3 /H 2 SO 4 or by HNO 3 /KMnO 4 increased the amount of iron that could be loaded to 7.6–8.0%; arsenic stayed below 10 ppb until 12,000 bed volumes during rapid small-scale tests (RSSCTs) using Rutland, MA groundwater (40–60 ppb arsenic, and pH of 7.6–8.0). Boehm titrations showed that surface oxidation greatly increased the concentration of carboxylic and phenolic surface groups. Iron impregnation by precipitation or iron salt evaporation was also evaluated. Iron content was increased to 9–17% with internal iron-loading, and to 33.6% with both internal and external iron loading. These iron-tailored carbons reached 25,000–34,000 bed volumes to 10 ppb arsenic breakthrough during RSSCTs. With the 33.6% iron loading, some iron peeled off.

Endocrine disrupting chemicals and pharmaceuticals represent two classes of emerging contaminants that are ubiquitously present in municipal wastewater effluents. Some of these contaminants have been shown to impact aquatic organisms at trace concentrations (i.e., ng/L). Moreover, the public has expressed human health concerns regarding the presence of emerging contaminants in water reuse projects. The primary objective of this investigation was to determine the efficacy of various membranes and activated carbons for the removal of endocrine disruptors, pharmaceuticals, and personal care products. A suite of structurally diverse target compounds was selected for evaluation based largely upon occurrence and molecular structure. Several membrane types and applications were evaluated at pilot- and/or full-scale, including: microfiltration, ultrafiltration, nanofiltration, reverse osmosis, electrodialysis reversal, membrane bioreactors, and combinations of membranes in series. Granular activated carbon was evaluated at bench-scale using rapid small scale column tests and at two full-scale utilities. Microfiltration and ultrafiltration were found to reject very few target compounds; however, some loss of steroidal type compounds was observed. Nanofiltration and reverse osmosis were capable of significant rejection of nearly all target compounds, though compounds were detectable at trace levels in permeates. Granular activated carbon was highly effective at removing all target chemicals. However, break-through curves clearly demonstrated that compounds with greater hydrophilicity breach activated carbon faster than hydrophobic compounds. In full-scale applications, the impact of regeneration was observed as activated carbon filters that received regular regeneration had minimal breakthrough of organic contaminants, while non-regenerated filters displayed no removal of target compounds. Findings confirm that membrane and carbon processes are capable of greatly reducing the concentrations of emerging contaminants; however, several compounds are detectable in membrane permeate and carbon effluent.

The effects of advanced oxidation (AO) processing on the properties of green sand were studied via pouring cast iron into green sand molds. Upon cooling, the green sand molds were autopsied at various distances from the metal−sand interface. Autopsy green sand samples collected from a mold that incorporated AO water were characterized and compared to controlled samples collected from a similar autopsied mold made with conventional tap water (TAP). It was found that the AO processing removed a coating of coal pyrolysis products from the clay surface that typically accumulated on the clay surface. As a result, the AO-conditioned green sand retained 10−15% more active clay as measured by the standard ultrasonic methylene blue titration than did the TAP-conditioned green sand. The AO processing also nearly doubled the generation of activated carbon from the normalized amount of coal composition of the green sand during the casting process. The AO-enhanced activated carbon generation and the AO-incurred clay s...