A nitrate biosensor based methodology for monitoring anoxic activated sludge activity

An improved methodology based on a nitrate biosensor is developed and applied successfully for in-depth monitoring and study of anoxic activated sludge activities. The major advantages of the methodology are its simplicity, reliability and high data quality. The resulting data allowed for the first time to monitor anoxic respiration rate of activated sludge (nitrate uptake rate (NUR)) at a high time resolution making it clearly comparable with high frequency oxygen uptake rate (OUR) measurements obtained under aerobic conditions. Further, the anoxic respiration data resulting from a pulse addition of carbon source to endogenously respiring anoxic activated sludge shows a clear start-up phenomenon and storage tail that is usually also observed in high-frequency OUR measurements. Finally, the improved methodology can be expected to serve as an anoxic respirometer for activated sludge treatment plants where denitrification process occurs in single-step. Further, it can be used for a variety of purposes e.g. for toxicity and activity monitoring, process control and parameter estimation of the activated sludge process, similar to the aerobic respirometers.

Download Full-text

The New Business Road Test: What Entrepreneurs and Investors Should Do Before Launching a Lean Startup, by John Mullins

10.33829/emprendeytransforma-0101-2019-89-92 ◽

2019 ◽

Vol 1 (1) ◽

pp. 89-92

Author(s):

José Luis Albites Sanabria

Keyword(s):

Road Test ◽

Start Up ◽

Plan B ◽

Entrepreneurial Team ◽

New Business ◽

First Time ◽

Lean Startup ◽

Thought Leaders

John Mullins is a researcher, teacher and one of the world’s foremost thought leaders in entrepreneurship. Over the years, John has been hailed as an inspiration for entrepreneurs who have employed the models outlined in books such as Getting to Plan B or The Customer-Funded Business, in order to transform their ideas into global startup companies. Now in its 5th edition, The New Business Road Test guides the reader through the complex yet gripping process of testing a business idea. How can you be completely sure that your list of start-up ideas is good or bad? How much time or money should you invest in each of these ideas? And, for first-time entrepreneurs, should you embark upon a start-up just because you love your idea? Should you leave a stable job and focus entirely on what feels to you like a good business idea? Mullins’ book offers thoughtful readers guidance on the thorny issues associated with entrepreneurship that you yourself may be facing even as you read this introduction. In order to fully understand the theories behind the tools and advice for testing your idea, we must start by understanding Mullins’ vision of the entrepreneurial world. The book begins by defining three elements crucial to the success of a business: the market, the industry, and the entrepreneurial team.

Download Full-text

Verification of anoxic phosphate uptake as the main biochemical mechanism of the “dephanox” process

Water Science & Technology ◽

10.2166/wst.1997.0365 ◽

1997 ◽

Vol 35 (10) ◽

pp. 87-94 ◽

Cited By ~ 7

Author(s):

R. Sorm ◽

J. Wanner ◽

R. Saltarelli ◽

G. Bortone ◽

A. Tilche

Keyword(s):

Activated Sludge ◽

Nutrient Removal ◽

Uptake Rate ◽

Phosphate Uptake ◽

Biochemical Mechanism ◽

Batch Experiments ◽

Batch Tests ◽

Genetic Probes ◽

Activated Sludge Systems ◽

Removal System

The phenomenon of anoxic phosphate uptake with simultaneous denitrification was studied. For this purpose kinetic batch tests have been carried out by using the activated sludge samples from three modifications of nutrient removal activated sludge systems: two based on an anaerobic-anoxic-oxic (A2/O) system and a third on an anaerobic-oxic (A/O) system. The results showed significant differences in anoxic phosphate uptake rate between activated sludge which was alternatively exposed to anoxic conditions and activated sludge from the A/O arrangement. These differences were also accompanied by different denitrification rates. Simultaneously with batch experiments the microscopic observation of activated sludge samples was carried out. Neisser and Gram stained samples showed clear differences in shape, size and distribution of polyphosphate accumulating bacteria between A2/O and A/O Processes. Moreover, experiments performed using genetic probes confirmed the differences in microbiological composition of activated sludge samples from different nutrient removal system arrangements.

Download Full-text

Broad scope gold(i)-catalysed polyenyne cyclisations for the formation of up to four carbon–carbon bonds

Organic & Biomolecular Chemistry ◽

10.1039/c7ob00235a ◽

2017 ◽

Vol 15 (10) ◽

pp. 2163-2167 ◽

Cited By ~ 14

Author(s):

Zhouting Rong ◽

Antonio M. Echavarren

Keyword(s):

Single Step ◽

Simultaneous Formation ◽

Broad Scope ◽

Carbon Carbon Bonds ◽

Carbon Bonds ◽

First Time ◽

High Stereoselectivity

The polycyclisation of polyeneynes catalyzed by gold(i) has been extended for the first time to the simultaneous formation of up to four carbon–carbon bonds, leading to steroid-like molecules with high stereoselectivity in a single step with low catalyst loadings.

Download Full-text

Hearing from the ocean and into the river: the evolution of the inner ear of Platanistoidea (Cetacea: Odontoceti)

Paleobiology ◽

10.1017/pab.2021.11 ◽

2021 ◽

pp. 1-21

Author(s):

Mariana Viglino ◽

Maximiliano Gaetán ◽

Mónica R. Buono ◽

R. Ewan Fordyce ◽

Travis Park

Keyword(s):

Inner Ear ◽

High Frequency ◽

Sound Production ◽

Marine Species ◽

Late Oligocene ◽

Evolutionary Patterns ◽

Ear Morphology ◽

Cochlear Morphology ◽

First Time ◽

Hearing Abilities

Abstract The inner ear of the two higher clades of modern cetaceans (Neoceti) is highly adapted for hearing infrasonic (mysticetes) or ultrasonic (odontocetes) frequencies. Within odontocetes, Platanistoidea comprises a single extant riverine representative, Platanista gangetica, and a diversity of mainly extinct marine species from the late Oligocene onward. Recent studies drawing on features including the disparate tympanoperiotic have not yet provided a consensus phylogenetic hypothesis for platanistoids. Further, cochlear morphology and evolutionary patterns have never been reported. Here, we describe for the first time the inner ear morphology of late Oligocene–early Miocene extinct marine platanistoids and their evolutionary patterns. We initially hypothesized that extinct marine platanistoids lacked a specialized inner ear like P. gangetica and thus, their morphology and inferred hearing abilities were more similar to those of pelagic odontocetes. Our results reveal there is no “typical” platanistoid cochlear type, as the group displays a disparate range of cochlear anatomies, but all are consistent with high-frequency hearing. Stem odontocete Prosqualodon australis and platanistoid Otekaikea huata present a tympanal recess in their cochlea, of yet uncertain function in the hearing mechanism in cetaceans. The more basal morphology of Aondelphis talen indicates it had lower high-frequency hearing than other platanistoids. Finally, Platanista has the most derived cochlear morphology, adding to evidence that it is an outlier within the group and consistent with a >9-Myr-long separation from its sister genus Zarhachis. The evolution of a singular sound production morphology within Platanistidae may have facilitated the survival of Platanista to the present day.

Download Full-text

Start-Up of A2/O Humic Activated Sludge Systemphosphorus Removal Efficiency Analysis

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.113-116.2201 ◽

2010 ◽

Vol 113-116 ◽

pp. 2201-2207 ◽

Cited By ~ 2

Author(s):

Jun Yin ◽

Lei Wu ◽

Ke Zhao ◽

Yu Juan Yu

Keyword(s):

Activated Sludge ◽

Removal Efficiency ◽

Phosphorus Removal ◽

Removal Rate ◽

Phosphorus Uptake ◽

Phosphorus Release ◽

Activated Sludge System ◽

Start Up ◽

Article Analysis ◽

Sludge Activity

In this article, analysis the start-up of A2/O humic activated sludge system phosphorus removal efficiency and the characteristics of anaerobic phosphorus release, aerobic phosphorus uptake, sludge activity and their change in the Series Technologies process. The results show that A2/O humic activated sludge system phosphorus removal rate stabilized at 90.7% ~ 97.6%. Sludge activity except for anoxic zone 2 increased, along the process showed a gradual decrease trend.

Download Full-text

FABRICATION OF ARRAY MICROSTRUCTURES USING SERIAL AND PARALLEL LOCALIZED ELECTRODEPOSITION

International Journal of Nanoscience ◽

10.1142/s0219581x09006109 ◽

2009 ◽

Vol 08 (03) ◽

pp. 323-332 ◽

Cited By ~ 2

Author(s):

RA'A SAID ◽

NIDAL ALSHWAWREH ◽

YOUSEF HAIK

Keyword(s):

Tissue Engineering ◽

Aspect Ratio ◽

Antenna Arrays ◽

High Aspect Ratio ◽

High Frequency ◽

Neural Recording ◽

Single Step ◽

Fabrication Technique ◽

Ultra High Frequency

To add to the development efforts in enhancing the capabilities of localized electrodeposition (LED) fabrication technique, this paper presents serial and parallel deposition algorithms to fabricate array microstructures. Such arrays can be implemented as microsensors in neural recording applications or as antenna arrays in ultra high frequency applications. Also, magnetic tip microarrays for tissue engineering can be realized. In the case of serial fabrication, an array of high aspect ratio microstructures is realized using the conventional single-tip microelectrode while implementing a multistep fabrication algorithm. In this algorithm, the fabricated microstructure elements within the array are realized one at a time. In the parallel deposition algorithm, the array is realized using a multitip array microelectrode while implementing a single step fabrication algorithm. In this algorithm, the microstructure elements within the array are fabricated simultaneously. The proposed algorithms are compared through a demonstration of fabricated array microstructures.

Download Full-text

A practical way to synthesize chiral fluoro-containing polyhydro-2H-chromenes from monoterpenoids

Beilstein Journal of Organic Chemistry ◽

10.3762/bjoc.12.64 ◽

2016 ◽

Vol 12 ◽

pp. 648-653 ◽

Cited By ~ 9

Author(s):

Oksana S Mikhalchenko ◽

Dina V Korchagina ◽

Konstantin P Volcho ◽

Nariman F Salakhutdinov

Keyword(s):

Aromatic Aldehydes ◽

Single Step ◽

Preparative Synthesis ◽

Aliphatic Aldehydes ◽

First Time

Conditions enabling the single-step preparative synthesis of chiral 4-fluoropolyhydro-2H-chromenes in good yields through a reaction between monoterpenoid alcohols with para-menthane skeleton and aldehydes were developed for the first time. The BF3·Et2O/H2O system is used both as a catalyst and as a fluorine source. The reaction can involve aliphatic aldehydes as well as aromatic aldehydes containing various acceptor and donor substituents. 4-Hydroxyhexahydro-2H-chromenes were demonstrated to be capable of converting to 4-fluorohexahydro-2H-chromenes under the developed conditions, the reaction occurs with inversion of configuration.

Download Full-text

Mass transfer impacts in flocculent and granular biomass from SBR systems

Water Science & Technology ◽

10.2166/wst.2004.0645 ◽

2004 ◽

Vol 50 (10) ◽

pp. 203-212 ◽

Cited By ~ 8

Author(s):

D. Gapes ◽

B.-M. Wilén ◽

J. Keller

Keyword(s):

Mass Transfer ◽

Particle Size ◽

Oxygen Uptake ◽

Activated Sludge ◽

Uptake Rate ◽

Oxygen Uptake Rate ◽

Batch Reactor ◽

Average Particle Size ◽

Gas Analysis ◽

Average Particle

An experimental study was conducted to describe mass transfer impacts within nitrifying aggregates sourced from sequencing batch reactor (SBR) activated sludge systems. Flocculent and granular sludge with high nitrification activity was obtained in two laboratory SBR systems, supplied with a synthetic, ammonium-based feed. The flocculent biomass was fractionated using a sieving procedure, in order to obtain biomass fractions with different particle size distributions. The oxygen uptake rate (OUR) response to changes in dissolved oxygen concentration was measured under highly controlled conditions in a titrimetric and off-gas analysis (TOGA) sensor, and the results used to assess mass transfer effects. As the average particle size of the biomass increased, mass transfer limitations were found to increase significantly. Empirically fitted, apparent KS,O2 values were demonstrated to be highly dependent on particle size, and reflect the mass transfer limitations occurring in the aggregates within a given system. Such parameters thus have little to do with the actual biokinetic parameter from which they are derived. The results obtained from the TOGA sensor study were consistent with those obtained from a microelectrode study on the same nitrifying granules. Together, these studies add considerable weight to the conclusion that consideration of external and internal mass transfer limitations is vital to the accurate description of activated sludge treatment processes, particularly those with a high oxygen uptake rate.

Download Full-text