Pilot Scale Testing of a New Radium-226 Removal Process

1985 ◽  
Vol 20 (2) ◽  
pp. 55-67
Author(s):  
W.B. Anderson ◽  
P.M. Huck ◽  
T.M.R. Meadley ◽  
T.P. Hynes
Keyword(s):  
Treatment Process ◽  
No Reduction ◽  
High Surface ◽  
High Surface Area ◽  
Barium Chloride ◽  
Pilot Scale ◽  
Activity Levels ◽  
New Process ◽  
Removal Efficiencies ◽  
New Treatment

Abstract This paper describes the on-going pilot scale development of a new treatment process designed to remove radium-226 from uranium milling effluents. Presently, decants from Canadian uranium mining and milling tailings areas are treated with barium chloride to remove radium-226 prior to discharge into the environment. This is usually accomplished in large natural or man-made ponds which provide an opportunity for a (Ba,Ra)SO4 precipitate to form and subsequently settle. Sand filtration is sometimes used as a polishing step. This new process differs from conventional and other experimental processes in that it involves the use of a fluidized bed to facilitate the deposition of a (Ba,Ra)SO4 precipitate on a granular medium of high surface area. As a stand-alone treatment process, the new process is consistently able to reduce incoming radium-226 activity levels by 90-99%. Effluent levels of 10 pCi/L (0.370 Bq/L) or less have been achieved, depending on the influent activity levels. Recent testing of the process as a polishing step has demonstrated radium removal efficiencies up to 60% when the process influent was already less than 5 pCi/L (0.185 Bq/L). The process has been operated at temperatures ranging from 26°C down to 0.3°C with no reduction in efficiency. In contrast to treatment times in the order of days for conventional settling pond systems and hours for mechanical stirred tank/filtration systems, the new process is able to achieve these radium removal efficiencies in times on the order of one minute.

Development of a New Process for Treating Uranium Mining Effluents

1985 ◽  
Vol 17 (2-3) ◽  
pp. 337-350 ◽  
Author(s):  
P. M. Huck ◽  
W. B. Anderson ◽  
R. C. Andrews
Keyword(s):  
Granular Medium ◽  
Treatment Process ◽  
High Surface ◽  
High Surface Area ◽  
Uranium Mining ◽  
New Process ◽  
Solids Separation ◽  
Removal Efficiencies ◽  
New Treatment ◽  
Short Times

Decants from Canadian uranium mining tailings areas are treated to remove radium-226 prior to discharge into the environment. This paper describes the development of a new treatment process for these effluents. This new process differs from existing systems in that it involves the use of a fluidized bed to facilitate (Ba,Ra)SO4 coprecipitation on a granular medium of high surface area. No solids separation step is required, as the granular material is free draining. The new process has been demonstrated to provide radium-226 removal efficiencies consistently exceeding 90% in contact times of about 20 seconds. These short times are in contrast to times on the order of days for conventional pond systems or hours for mechanical systems involving stirred tank precipitation reactors.

scholarly journals Modern Trends in Design of Catalysts for Transformation of Biofuels into Syngas and Hydrogen: From Fundamental Bases to Performance in Real Feeds

Energies ◽  
2021 ◽  
Vol 14 (19) ◽  
pp. 6334
Author(s):  
Vladislav Sadykov ◽  
Mikhail Simonov ◽  
Nikita Eremeev ◽  
Natalia Mezentseva
Keyword(s):  
Natural Gas ◽  
High Surface ◽  
High Surface Area ◽  
Internal Heat ◽  
Pilot Scale ◽  
Platinum Group Metals ◽  
Atomic Scale ◽  
Active Components ◽  
Structured Catalysts ◽  
Metal Support Interaction

This review considers problems related to design of efficient structured catalysts for natural gas and biofuels transformation into syngas. Their active components are comprised of fluorite, perovskite and spinel oxides or their nanocomposites (both bulk and supported on high surface area Mg-doped alumina or MgAl2O4) promoted by platinum group metals, nickel and their alloys. A complex of modern structural, spectroscopic and kinetic methods was applied to elucidate atomic-scale factors controlling their performance and stability to coking, such as dispersion of metals/alloys, strong metal-support interaction and oxygen mobility/reactivity as dependent upon their composition and synthesis procedures. Monolithic catalysts comprised of optimized active components loaded on structured substrates with a high thermal conductivity demonstrated high activity and stability to coking in processes of natural gas and biofuels reforming into syngas. A pilot-scale axial reactor equipped with the internal heat exchanger and such catalysts allowed to efficiently convert into syngas the mixture of natural gas, air and liquid biofuels in the autothermal reforming mode at low (~50–100 °C) inlet temperatures and GHSV up to 40,000 h−1.

scholarly journals Pilot-Scale Assessment of a Novel Farrowing Creep Area Supplementary Heat Source

Animals ◽  
2019 ◽  
Vol 9 (11) ◽  
pp. 996
Author(s):  
Benjamin C. Smith ◽  
Brett C. Ramirez ◽  
Steven J. Hoff ◽  
Laura L. Greiner
Keyword(s):  
Heat Source ◽  
High Surface ◽  
Average Daily Gain ◽  
High Surface Area ◽  
Weight Ratio ◽  
Pilot Scale ◽  
Swine Industry ◽  
Productivity Losses ◽  
Significant Difference ◽  
The Us

Pre-weaning morality (PWM) is attributed to a poor creep area microclimate and causes major economic and productivity losses for the US swine industry. Piglets need supplementary heat to overcome a high surface area to body weight ratio and minimal thermoregulation. A pilot-scale study was conducted to evaluate a semi-enclosed heated microclimate (SEHM) as a supplementary heat source for farrowing creep areas over six farrowing cycles (from January to July 2019) in two rooms with 24 farrowing stalls in each room. Six SEHMs (each SEHM covers two stalls) were randomly distributed to each room and compared to heat lamps (HLs) for productivity and electricity usage. Data from 113 (SEHM) and 101 litters (HL) showed no significant difference between treatments in average daily gain (p = 0.26), 252.4 ± 8.0 g hd−1 d−1 (SEHM) and 260.3 ± 8.1 g hd−1 d−1 (HL) and PWM (p = 0.08), 9.67% ± 0.82% (SEHM) and 12.04% ± 0.87% (HL). However, a significant difference (p = 0.02) was noted in the PWM attributed to over-lay mortalities, 4.05% ± 0.76% (SEHM) compared to 6.04% ± 0.78% (HL). The SEHM electricity averaged 3.25 kWh d−1 (2.91, 3.59 kWh d−1; 95% CI), which was significantly different (p < 0.01) from the HL equivalent (125 W bulb; 6 kWh d−1).

Anaerobic-Aerobic Lagoon Treatment of Kraft Mill Effluent for Enhanced Removal of AOX

1993 ◽  
Vol 28 (3) ◽  
pp. 549-570 ◽  
Author(s):  
E.G.-H. Lee ◽  
M.F. Crowe ◽  
H. Stutz
Keyword(s):  
Treatment Process ◽  
Pilot Scale ◽  
Aerobic Treatment ◽  
Simple Modification ◽  
Kraft Mill Effluent ◽  
Kraft Mill ◽  
Removal Efficiencies ◽  
Adsorbable Organic Halide ◽  
Aox Removal ◽  
Kraft Effluent

Abstract A continuous-flow sequential anaerobic-aerobic lagoon treatment process was developed and evaluated for removal of adsorbable organic halide (AOX) from whole-mill kraft effluent at both laboratory and pilot-scale. The rationale underlying the development of the process was that the AOX removal efficiency of aerated lagoons currently in use might be significantly increased through relatively simple modification. Bench-scale studies showed that sequential anaerobic-aerobic treatment of whole-mill kraft effluent resulted in AOX-removal efficiencies of over 70% at hydraulic retention times (HRTs) of 10 days, 5 days and 2 days. In contrast, only 20%, 35% and 36% removal was obtained in a control aerobic lagoon. Pilot-scale studies showed that up to 65% removal of AOX from whole-mill kraft effluent was consistently obtained at HRTs ranging from 5 to 10 days. This compares with typical AOX removal efficiencies in conventional aerated lagoons of about 25%. Conversion of the anaerobic section in the pilot-scale lagoon from a simple sludge blanket to a combination of sludge blanket and submerged biofilm further increased AOX removal efficiencies to about 70%.

A strategy in wastewater treatment process for significant reduction of excess sludge production

2002 ◽  
Vol 45 (12) ◽  
pp. 127-134 ◽  
Author(s):  
N. Shiota ◽  
A. Akashi ◽  
S. Hasegawa
Keyword(s):  
Wastewater Treatment ◽  
Treatment Process ◽  
Pilot Scale ◽  
Aeration Tank ◽  
Excess Sludge ◽  
Wastewater Treatment Process ◽  
Conventional Activated Sludge ◽  
New Process ◽  
Treatment Step ◽  
Sludge Production

A novel wastewater treatment process (S-TE PROCESS®) with significantly reduced production of excess sludge has been developed. The process consists of two different stages, one for a biological wastewater treatment and the other for a thermophilic aerobic digestion of the resulting sludge. A portion of return sludge from the wastewater treatment step is injected into a thermophilic aerobic sludge digester (TASD), in which the injected sludge is solubilized by the action of thermophilic aerobic bacteria. The solubilized sludge is returned to the aeration tank in the wastewater treatment step for its further degradation. Pilot-scale facilities of the S-TE process and the conventional activated sludge process as a control, both treating the same industrial wastewater, were comparatively operated for totally 270 days. As a result, 93% reduction in overall excess sludge production was achieved in the S-TE operation. The SS solubilization rate in TASD was stable at around 30%. Only a slight increase in the effluent SS and TOC concentrations was observed compared with those of the control facility. Otherwise the removal efficiency of TOC was approximately 95% for both plants. A full-scale plant treating domestic sewage was operated for three years, showing 75% reduction of overall excess sludge production. It was concluded that the new process was feasible.

scholarly journals Sorption to Biochar Impacts β-Glucosidase and Phosphatase Enzyme Activities

Agriculture ◽  
2018 ◽  
Vol 8 (10) ◽  
pp. 158 ◽  
Author(s):  
Erika Foster ◽  
Emily Fogle ◽  
M. Cotrufo
Keyword(s):  
Enzyme Activity ◽  
Surface Area ◽  
Enzyme Activities ◽  
Extracellular Enzymes ◽  
High Surface ◽  
High Surface Area ◽  
Activity Levels ◽  
Agricultural Field ◽  
Protein Assay ◽  
Laboratory Assay

Extracellular enzymes catalyze biogeochemical reactions in soil, cycling carbon and nutrients in agricultural systems. Enzymes respond quickly to soil management, including organic amendment inputs, such as biochar, a charcoal-like solid byproduct of bioenergy production. In a previous agricultural field trial, a pine biochar amendment caused an approximately 40% decrease in the enzyme activities of β-glucosidase (BG) and phosphatase (PHOS). The large surface area of the pine biochar has the potential to sorb nutrients and other organic molecules. To test if sorption caused decreased enzyme activity, we used a laboratory assay to quantify the activity of two sorbed enzymes: BG and acid PHOS, involved in the cycling of carbon and phosphorous. The enzymes were incubated with three solid phases: (1) the high surface area pine biochar, (2) the agricultural soil, and (3) a low surface area grass biochar, for an additional comparison. We quantified the sorbed enzymes at pH 6, 7, and 8, using a Bradford protein assay, and measured the immobilized enzyme activities via high-throughput fluorometric analysis. After sorption onto pine biochar, detectable BG and PHOS activity levels dropped by over 95% relative to the soil, supporting direct sorption as one mechanism that reduces enzyme activity in biochar amended soil. This laboratory assay demonstrated that sorption could account for the lack of priming of native soil organic matter and changes in soil phosphorous cycling after pine biochar addition.

Synthesis and Characterization of Non-Surfactant Mesoporous Chitosan/Silica Composite Sorbent and its Purification of Sugarcane Juice Bioresources

2014 ◽  
Vol 700 ◽  
pp. 286-289
Author(s):  
Pei Pei Chen ◽  
Chun Ming Zheng ◽  
Xiang Zhi Chen ◽  
Zhi Wu Yang ◽  
Jun Xia ◽  
...  
Keyword(s):  
High Surface ◽  
High Surface Area ◽  
Pilot Scale ◽  
Composite Sorbent ◽  
Silica Composite ◽  
Lower Quantity ◽  
Decolorization Efficiency ◽  
Amine Groups ◽  
Template Free

Mesoporous chitosan-silica composite sorbent has been successfully synthesized by a simple and facile template-free hydrolyzing route from single cheap silica precursor of sodium silicate. The overall decolorization efficiency and capacity for sugar juice between pure chitosan and composite sorbent are very close in field pilot-scale, while much lower quantity of chitosan (only 10 wt.%) is used to build the composite sorbent. The success of increased purification performance and sorption capacity of sugar juice is ascribed to the appropriate pore structure of the composite sorbent with high surface area (395 m2/g), large pore size (7.73×10-9 m) and high percentage of accessible free amine groups of chitosan (70 %).

scholarly journals The Treatment of PPCP-Containing Sewage in an Anoxic/Aerobic Reactor Coupled with a Novel Design of Solid Plain Graphite-Plates Microbial Fuel Cell

2014 ◽  
Vol 2014 ◽  
pp. 1-13 ◽  
Author(s):  
Yi-Tang Chang ◽  
Chu-Wen Yang ◽  
Yu-Jie Chang ◽  
Ting-Chieh Chang ◽  
Da-Jiun Wei
Keyword(s):  
Fuel Cell ◽  
Microbial Fuel Cell ◽  
Coulombic Efficiency ◽  
High Surface ◽  
High Surface Area ◽  
Electricity Production ◽  
Aerobic Reactor ◽  
Removal Efficiencies ◽  
High Concentrations ◽  
Novel Design

Synthetic sewage containing high concentrations of pharmaceuticals and personal care products (PPCPs, mg/L level) was treated using an anoxic/aerobic (A/O) reactor coupled with a microbial fuel cell (MFC) at hydraulic retention time (HRT) of 8 h. A novel design of solid plain graphite plates (SPGRPs) was used for the high surface area biodegradation of the PPCP-containing sewage and for the generation of electricity. The averageCODCrand total nitrogen removal efficiencies achieved were 97.20% and 83.75%, respectively. High removal efficiencies of pharmaceuticals, including acetaminophen, ibuprofen, and sulfamethoxazole, were also obtained and ranged from 98.21% to 99.89%. A maximum power density of 532.61 mW/cm2and a maximum coulombic efficiency of 25.20% were measured for the SPGRP MFC at the anode. Distinct differences in the bacterial community were presented at various locations including the mixed liquor suspended solids and biofilms. The bacterial groups involved in PPCP biodegradation were identified asDechloromonasspp.,Sphingomonassp., andPseudomonas aeruginosa. This design, which couples an A/O reactor with a novel design of SPGRP MFC, allows the simultaneous removal of PPCPs and successful electricity production.

In Situ microscopy of the anodic etching of silicon

1995 ◽  
Vol 53 ◽  
pp. 232-233
Author(s):  
Frances M. Ross ◽  
Peter C. Searson
Keyword(s):  
Composite Structures ◽  
High Surface ◽  
High Surface Area ◽  
Chemical Properties ◽  
Selective Etching ◽  
Silicon On Insulator ◽  
Second Phase ◽  
Porous Layers ◽  
New Class ◽  
Porous Semiconductors

Porous semiconductors represent a relatively new class of materials formed by the selective etching of a single or polycrystalline substrate. Although porous silicon has received considerable attention due to its novel optical properties1, porous layers can be formed in other semiconductors such as GaAs and GaP. These materials are characterised by very high surface area and by electrical, optical and chemical properties that may differ considerably from bulk. The properties depend on the pore morphology, which can be controlled by adjusting the processing conditions and the dopant concentration. A number of novel structures can be fabricated using selective etching. For example, self-supporting membranes can be made by growing pores through a wafer, films with modulated pore structure can be fabricated by varying the applied potential during growth, composite structures can be prepared by depositing a second phase into the pores and silicon-on-insulator structures can be formed by oxidising a buried porous layer. In all these applications the ability to grow nanostructures controllably is critical.

Sign in / Sign up

Export Citation Format

Share Document