scholarly journals Demonstration of simultaneous biological sulphate reduction and partial sulphide oxidation in a hybrid linear flow channel reactor

2019 ◽  
Author(s):  
TS Marais ◽  
RJ Huddy ◽  
STL Harrison ◽  
RP van Hille
Keyword(s):  
Rapid Development ◽  
Reduction Rate ◽  
Cost Effective ◽  
Flow Channel ◽  
Elemental Sulphur ◽  
Sulphate Reduction ◽  
Channel Reactor ◽  
Linear Flow ◽  
Sulphide Oxidation ◽  
Concept Evaluation

AbstractSemi-passive remediation systems have the potential to treat low-volume, sulphate-rich, mining impacted waters in a cost-effective and sustainable way. This paper describes the “proof of concept” evaluation of a hybrid linear flow channel reactor, capable of sustaining efficient biological sulphate reduction and partial oxidation of the sulphide product to elemental sulphur. Key elements include the presence of a sulphate-reducing microbial community, immobilised onto carbon fibres and the rapid development of a floating biofilm at the air-liquid interface. The biofilm consists of heterotrophic species and autotrophic sulphide oxidisers. It impedes oxygen mass transfer into the bulk volume and creates a suitable pH-redox microenvironment for partial sulphide oxidation. Demonstration of the concept was successful, with near 20 complete reduction of the sulphate in the feed (1 g/l), effective management of the sulphide generated (95-100% removal) and recovery of a portion of the sulphur by harvesting the elemental-sulphur-rich biofilm. The biofilm re-formed within 24 hours of harvesting, with no decrease in volumetric sulphate reduction rate during this period. Colonisation of the carbon microfibers by sulphate reducing bacteria ensured biomass retention, suggesting the reactor could remain effective at high volumetric flow rates.

scholarly journals Demonstration of simultaneous biological sulphate reduction and partial sulphide oxidation in a hybrid linear flow channel reactor

2020 ◽  
Vol 34 ◽  
pp. 101143 ◽  
Author(s):  
T.S. Marais ◽  
R.J. Huddy ◽  
S.T.L. Harrison ◽  
R.P. van Hille
Keyword(s):  
Flow Channel ◽  
Sulphate Reduction ◽  
Channel Reactor ◽  
Linear Flow ◽  
Sulphide Oxidation

Effects of reactor geometry and electron donor on performance of the hybrid linear flow channel reactor

2020 ◽  
Vol 197 ◽  
pp. 105462
Author(s):  
T.S. Marais ◽  
R.J. Huddy ◽  
R.P. van Hille ◽  
S.T.L. Harrison
Keyword(s):  
Electron Donor ◽  
Flow Channel ◽  
Channel Reactor ◽  
Linear Flow ◽  
Reactor Geometry

Chemoautotrophic symbionts in the gills of the bivalve mollusc Lucinoma borealis and the sediment chemistry of its habitat

1986 ◽  
Vol 227 (1247) ◽  
pp. 227-247 ◽  
Keyword(s):  
Reduction Rate ◽  
Gill Tissue ◽  
Elemental Sulphur ◽  
Sulphate Reduction ◽  
Sediment Chemistry ◽  
Dissolved Iron ◽  
The Mean ◽  
Low Levels ◽  
High Concentrations ◽  
Sulphur Species

Lucinoma borealis has enlarged gills, which contain numerous prokaryotes in specialized cells (bacteriocytes) in the subfilamentar region. The gills also contain high concentrations of elemental sulphur and of a c -type cytochrome. Homogenates of gill tissue show ribulosebisphosphate car­boxylase and phosphoribulokinase activity; they also show activity for adenylylsulphate reductase, an enzyme concerned in the oxidation of sulphur, and will phosphorylate ADP on the addition of sulphite or sulphide. Fixation of bicarbonate by gill tissue from starved animals is enhanced in the presence of 100 μm sulphide. The sediment in which the animals live contains 1–6 μg atoms per litre of dissolved iron and hence there is very little dissolved sulphide, 200 nM, or less (80 nmol dm -3 sediment). Thiosulphate concentrations are also low, 300 nM, or less (120 nmol dm -3 sediment). In contrast, there are acid-labile sulphide concentrations up to 14 mmol dm -3 and elemental sulphur concentrations up to 4 mg atom per cubic decimetre of sediment. The mean sulphate reduction rate in the sediment varied seasonally with temperature over the range 1640–4920 nmol sulphate reduced per hour per cubic decimetre. L. borealis was usually found below the region of maximum sulphate reduction. Hydrogen, methane and carbon monoxide concentrations were all 160 nmol dm -3 , or less. Despite the low levels of dissolved sulphide the association between prokaryote and host appears to be able to exploit this habitat by the oxidation of reduced sulphur species; ways in which the bivalve may be able to extract these from the sediment are discussed. The bivalves may obtain half their carbon from the autotrophic prokaryotes.

scholarly journals Challenges for Evaluation of the Safety of Engineered Nanomaterials

2021 ◽  
Vol 43 (1) ◽  
pp. 4-7
Author(s):  
Linda J. Johnston ◽  
Norma Gonzalez-Rojano ◽  
Kevin J. Wilkinson ◽  
Baoshan Xing
Keyword(s):  
Rapid Development ◽  
Sustainable Use ◽  
Cost Effective ◽  
Engineered Nanomaterials ◽  
Full Potential ◽  
Effective Strategies ◽  
Toxicological Studies ◽  
Regulatory Guidelines ◽  
Significant Effort ◽  
Safe By Design

Abstract Nanotechnology has developed rapidly in the last two decades with significant effort focused on the development of nano-enabled materials with new or improved properties that offer solutions for current world challenges. The commercialization of products containing engineered nanomaterials (ENM) has progressed much more rapidly than the development of practical approaches to ensure their safe and sustainable use. The lack of adequate detection and characterization techniques and reproducible and validated methods for toxicological studies have been identified as major limitations. The rapid development of ENM of increasing complexity and diversity and concerns over the adequacy of existing regulations also contribute to safety concerns with these materials. The full potential of nanotechnology can only be realized when feasible, cost-effective strategies to ensure a safe-by-design approach, effective risk assessment approaches and appropriate regulatory guidelines are in place.

Recent Advances on Visible-Light-Promoted Copper Catalysis in Organic Reactions

Synthesis ◽  
2021 ◽  
Author(s):  
Yang Xiong ◽  
Sijia Li ◽  
Haijing Xiao ◽  
Guozhu Zhang
Keyword(s):  
Visible Light ◽  
Copper Complexes ◽  
Rapid Development ◽  
Cost Effective ◽  
Organic Reactions ◽  
Copper Catalysis ◽  
Synthetic Chemistry ◽  
Recent Advances ◽  
Intense Activity

In recent years, visible-light-mediated copper photocatalysis have emerged as an attractive strategy for the diverse constructions of basic bonds in an ecologically benign and cost-effective fashion. The intense activity and increasing work of these areas stimulated the exploit of the distinctive properties of copper photocatalysis and the rapid development and expansion of their applications. In this review, we focus on introducing a series of significant achievements in copper complexes as standalone photocatalysis in organic reactions to make an attempt to exhibit their potential capabilities and high flexibilities in synthetic chemistry.

Journey Toward Process Convergence in TSV Technology

2010 ◽  
Vol 2010 (DPC) ◽  
pp. 001282-001321
Author(s):  
Sesh Ramaswami ◽  
John Dukovic
Keyword(s):  
Process Integration ◽  
Semiconductor Industry ◽  
Rapid Development ◽  
Chemical Mechanical Planarization ◽  
Cost Effective ◽  
Superior Performance ◽  
Wafer Level ◽  
Unit Process ◽  
Integration Schemes ◽  
Process Convergence

Continuous demand for more advanced electronic devices with higher functionality and superior performance in smaller packages is driving the semiconductor industry to develop new and more advanced 3D wafer-level interconnect technologies involving TSVs (through-silicon vias). The TSVs are created either on full-thickness wafer from the wafer front-side ¡V as part of wafer-fab processing during Middle-Of-Line (¡§via middle¡¨) or Back-End-Of-Line (¡§via last BEOL¡¨) ¡V or from the wafer backside after wafer thinning (¡§via last backside¡¨). Independent of the specific approach, the main steps include via etching, lining with insulator, copper barrier/seed deposition, via fill, and chemical mechanical planarization (CMP). Over the past year, the industry has been converging toward some primary unit processes and integration schemes for creating the TSVs. A common cost-of-ownership framework has also begun to emerge. Active collaboration underway among equipment suppliers, materials providers and end users is bringing about rapid development and validation of cost-effective TSV technology in end products. This presentation will address unit-process and integration challenges of TSV fabrication in the context of 20x100ƒÝm and 5x50ƒÝm baseline process flows at Applied Materials. Highlights of wafer-backside process integration involving wafers bonded to silicon or glass carriers will also be discussed.

Smartphone-based analytical biosensors

The Analyst ◽  
2018 ◽  
Vol 143 (22) ◽  
pp. 5339-5351 ◽  
Author(s):  
Xiwei Huang ◽  
Dandan Xu ◽  
Jin Chen ◽  
Jixuan Liu ◽  
Yangbo Li ◽  
...  
Keyword(s):  
Mobile Health ◽  
Mass Production ◽  
Point Of Care ◽  
Rapid Development ◽  
Cost Effective

With the rapid development, mass production, and pervasive distribution of smartphones in recent years, they have provided people with portable, cost-effective, and easy-to-operate platforms to build analytical biosensors for point-of-care (POC) applications and mobile health.

Stern Flap for Resistance Reduction of Planing Hull Craft: A Case Study with a Fast Crew Boat Model

2012 ◽  
Author(s):  
Omar Yaakob ◽  
Suhaili Shamsuddin ◽  
Kho King Koh
Keyword(s):  
Reduction Rate ◽  
Cost Effective ◽  
Systematic Investigation ◽  
Percent Reduction ◽  
Geometrical Characteristics ◽  
Resistance Reduction ◽  
Cost Effective Method ◽  
Zero Degree ◽  
Resistance Performance

Kajian terhadap pelbagai cara mengurangkan rintangan bot peronda telah dilakukan oleh ramai penyelidik. Kaedah yang dikaji termasuk penggunaan kepak buritan, baji buritan dan suntikan gelembung mikro. Walau bagaimanapun, disebabkan oleh sifatnya yang mudah dan praktikal, kepak buritan didapati amat berpotensi. Kertas kerja ini membentangkan kajian terhadap kesan kepak buritan terhadap prestasi rintangan bot kelasi berbentuk planing. Ujian model dijalankan bagi membuktikan keberkesanan kepak bagi mengurangkan rintangan. Lima kepak berlainan telah digunakan dalam rangka kajian sistematik bagi menentukan ciri geometrik optimum kepak buritan. Hasil ujian model menunjukkan empat kepak menambah rintangan kapal manakala kepak kelima pada sudut sifar mengurangkan rintangan sehingga 7.2 peratus pada 23 knots dan pengurangan purata sekitar 4.5 peratus. Pada 23 knots, pengurangan 8.2 peratus kuasa berkesan diperolehi. Kata kunci: Reka bentuk bot peronda, ujian model, pesawat laju The study on various methods of reducing the resistance of patrol craft have been carried out by many researchers. These methods included the application of stern flaps, stern wedges, and microbubble injection. However, due to its simplicity and practicality, stern flap is the most promising and cost effective method. The effect of a stern flap on the resistance performance of the planing hull crew boat is presented. Model tests were conducted to prove the effectiveness of the stern flap on reducing planing hull craft resistance. Five different stern flap designs were tested as part of systematic investigation to determine the optimum geometrical characteristics of the stern flap. Results of model resistance experiments showed that four of the flaps tested showed an increase in resistance while the flap at zero degree angle reduced the total resistance by 7.2 percent at 23 knots, and an average reduction rate of 4.5 percent. At 23 knots, an 8.2 percent reduction in effective power was predicted. Key words: Patrol boats design, model testing, fast craft

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