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M Newland

Publications and source records attributed to M Newland.

10 recordsLinked to original sources
PubMed2005

Long-term aeration management for improved N-removal via SND in a sequencing batch reactor.

Management of the aeration length in a sequencing batch reactor (SBR) can improve N-removal by minimising the amount of organic substrate that is oxidised aerobically. This study investigates the long-term effect of aeration control on N-removal via simultaneous nitrification and denitrification (SND) by a mixed culture in a 2L acetate-fed SBR, using PHB as the electron donor for denitrification. The reactor was operated continuously with automated termination of the aerobic phase after ammonium depletion, using the specific oxygen uptake rate (SOUR) as the control parameter. This resulted in an increase of the organic loading rate (OLR) from 0.33 to 0.59 g BOD g(-1)d(-1). Over the first 12 cycles of operation, the PHB content of the biomass increased three-fold and resulted in a progressively increasing SOUR, which allowed an increased amount of nitrogen removal via SND from 34% to 52%. After one month of continuous operation with controlled aeration, the settling efficiency of the biomass had significantly improved (SVI 70 mL g(-1) X). Long-term oxygen management resulted in biomass with a higher capacity for N-removal via SND and improved settling characteristics. Our results may help to explain long-term historical effects of N-removal capabilities in WWTPs and assist design engineers in choosing an appropriate aeration length and OLR.

Aerobiosis↗
PubMed2004

Demonstration of enhanced nutrient removal at two full-scale SBR plants.

The efficacy of sequencing batch reactors (SBRs) to provide high levels of biological nutrient removal has been extensively demonstrated around the world. Environmental Solutions International (ESI) has now constructed over 20 full-scale SBR plants and has confirmed that nutrient removal is enhanced via the process of simultaneous nitrification and denitrification. Over 18 months of operational data from two plants, operating in distinctly different catchments, processing an average of between 2,000 and 2,500 m3/d of wastewater, has clearly shown the efficacy and robustness of the ESI SBR-BNR process. Median effluent total nitrogen and total phosphorus values of 3 mg/L and <0.6 mg/L, respectively, were demonstrated over the 18-month period. This high level of nutrient removal is attributed to the design of the bio-selector which maximises carbon storage for the subsequent denitrification reactions, the effective aeration control which ensures no over-aeration during the air-on cycle as well as the level of operational control provided at these two plants.

Ammonia↗
PubMed2004

Optimisation of storage driven denitrification by using on-line specific oxygen uptake rate monitoring during SND in a SBR.

This study builds on previous experience of maximising the formation of COD as poly-hydroxybutyrate (PHB) and now describes a feedback technique of preserving the use of PHB for denitrification resulting in enhanced nitrogen removal rather than allowing its wasteful oxidation by oxygen. The feedback technique uses on-line SOUR monitoring for detecting the end-point of nitrification and controlling the aerobic phase length accordingly. The laboratory SBR was operated such that all organic substrate (acetate) was rapidly converted to PHB, which then served as the electron donor for nitrogen removal via simultaneous nitrification and denitrification (SND) during the aerobic phase (up to 70% SND). During SBR cycling with a fixed aeration length (240 minutes), PHB was unnecessarily oxidised after ammonium depletion, resulting in little denitrification and poor total nitrogen removal (69%). However, when the aerobic phase length was controlled via the SOUR, up to 1.8 CmM PHB (58 mg L(-1) COD) could be preserved, enabling improved total nitrogen removal (86%). The drop in the SOUR after ammonium depletion was a reproducible event that could be detected even when using raw wastewater and fresh activated sludge. The SOUR-control technique holds promise to build up PHB over a number of SBR cycles. While advanced oxygen-control is used for improved N-removal in several existing WWTPs, this study investigates the importance of oxygen control with relevance to PHB driven SND in sequencing batch reactors.

Aerobiosis↗
PubMed1990

Hybridoma growth limitations: the roles of energy metabolism and ammonia production.

Energy metabolism and the production of ammonia in hybridoma cell culture and its inhibitory effects on cell growth are reviewed. The interactive roles of glucose and glutamine metabolism affect the rate of production of ammonia, and these interactions are described. It is shown that growth inhibition usually occurs between 2-4 mM ammonia although some cell lines have been shown to adapt to much higher concentrations, particularly in continuous culture. In batch cultures cell growth appears to be particularly susceptible to increased ammonia concentrations during the early stages of growth; ammonia increased the rate of cell death in the late stage of batch growth. The specific productivity of monoclonal antibodies is much less sensitive to the released ammonia than is growth; lower volumetric productivities relate to the lower viable cell concentrations which are achieved at the high ammonia levels. Techniques to prevent ammonia accumulation or remove ammonia selectively have been relatively unsuccessful to date.

Ammonia↗
PubMed1989

Multiple uterine rupture and crushing injury of the fetal skull after blunt maternal trauma. A case report.

Multiple pelvic fractures and explosive-type uterine lacerations occurred in a previously healthy 17-year-old primigravida involved in a motor vehicle accident. The fetus suffered a crushed skull and was completely extruded with the placenta from the uterus. Treatment was complicated by severe disseminated intravascular coagulation with secondary fibrinolysis. Thrombelastography enabled us to rapidly evaluate the patient's coagulation status and to monitor her response to goal-directed therapeutic interventions (surgery, specific blood product therapy and epsilon-aminocaproic acid).

Accidents, Traffic↗
PubMed1983

Inhibition of sarcoplasmic reticulum calcium pump by cytosolic protein(s) endogenous to heart and slow skeletal muscle but not fast skeletal muscle.

Cytosol from rabbit heart and slow and fast skeletal muscles was fractionated using (NH4)2SO4 to yield three cytosolic protein fractions, viz., CPF-I (protein precipitated at 30% saturation), CPF-II (protein precipitated between 30 and 60% saturation), and cytosol supernatant (protein soluble at 60% saturation). The protein fractions were dialysed and tested for their effects on ATP-dependent, oxalate-supported Ca2+ uptake by sarcoplasmic reticulum from heart and slow and fast skeletal muscles. CPF-I from heart and slow muscle, but not from fast muscle, caused marked inhibition (up to 95%) of Ca2+ uptake by sarcoplasmic reticulum from heart and from slow and fast muscles. Neither unfractionated cytosol nor CPF-II or cytosol supernatant from any of the muscles altered the Ca2+ uptake activity of sarcoplasmic reticulum. Studies on the characteristics of inhibition of sarcoplasmic reticulum Ca2+ uptake by CPF-I (from heart and slow muscle) revealed the following: (a) Inhibition was concentration- and temperature-dependent (50% inhibition with approx. 80 to 100 micrograms CPF-I; seen only at temperatures above 20 degrees C). (b) The inhibitor reduced the velocity of Ca2+ uptake without appreciably influencing the apparent affinity of the transport system for Ca2+. (c) Inhibition was uncompetitive with respect to ATP. (d) Sarcoplasmic reticulum washed following exposure to CPF-I showed reduced rates of Ca2+ uptake, indicating that inhibition results from an interaction of the inhibitor with the sarcoplasmic reticulum membrane. (e) Concomitant with the inhibition of Ca2+ uptake, CPF-I also inhibited the Ca2+-ATPase activity of sarcoplasmic reticulum. (f) Heat-treatment of CPF-I led to loss of inhibitor activity, whereas exposure to trypsin appeared to enhance its inhibitory effect. (g) Addition of CPF-I to Ca2+-preloaded sarcoplasmic reticulum vesicles did not promote Ca2+ release from the vesicles. These results demonstrate the presence of a soluble protein inhibitor of sarcoplasmic reticulum Ca2+ pump in heart and slow skeletal muscle but not in fast skeletal muscle. The characteristics of the inhibitor and its apparently selective distribution suggest a potentially important role for it in the in vivo regulation of sarcoplasmic reticulum Ca2+ pump, and therefore in determining the duration of Ca2+ signal in slow-contracting muscle fibers.

Animals↗