Phosphate and Calcium Control in Short Frequent Hemodialysis with the NxStage System One Cycler: Mass Balance Studies and Comparison with Standard Thrice-Weekly Bicarbonate Dialysis

2018 ◽  
Vol 45 (4) ◽  
pp. 334-342 ◽  
Author(s):  
Chiara Carla Maria Brunati ◽  
Francesca Gervasi ◽  
Costanza Casati ◽  
Maria Luisa Querques ◽  
Alberto Montoli ◽  
...  
Keyword(s):  
Mass Balance ◽  
Total Plasma ◽  
Concentration Increase ◽  
Single Session ◽  
Home Hemodialysis ◽  
Hemodialysis Prescription ◽  
Frequent Hemodialysis ◽  
P Removal

Background: Short frequent dialysis with NxStage System One cycler (NSO) has become increasingly popular as home hemodialysis prescription. Short dialysis sessions with NSO might not allow adequate phosphate (P) removal. Methods: Single-session and weekly balances of P and calcium (Ca) were compared in 14 patients treated with NSO (6 sessions/week) and in 14 patients on standard bicarbonate dialysis (BHD). Results: NSO and BHD showed similar plasma P fall, with end-dialysis plasma P slightly lower in BHD (2.2 ± 0.5 vs. 2.7 ± 0.8 mg/dL, p < 0.02). Single-session P removal was lower in NSO, but weekly removal was higher (3,488 ± 1,181 mg vs. 2,634 ± 878, p < 0.003). Plasma Ca increase was lower in NSO, with similar PTH fall. Ca balance varied according to start plasma Ca, dialysate to blood Ca gradient and net ultrafiltration. Conclusions: short, frequent home hemodialysis with NSO, on a 6/week-based prescription, allows higher weekly P removal than BHD. With the dialysate Ca concentration in use (6 mg/dL), total plasma Ca and iCa concentration increase is lower in NSO.

Seasonal variation in phosphorus removal processes _within reed beds - mass balance investigations

2003 ◽  
Vol 48 (5) ◽  
pp. 59-66 ◽  
Author(s):  
T.R. Headley ◽  
D.O. Huett ◽  
L. Davison
Keyword(s):  
Mass Balance ◽  
Loading Rate ◽  
First Year ◽  
Dominant Form ◽  
Reed Beds ◽  
Ground Biomass ◽  
Below Ground ◽  
Removal Processes ◽  
Second Year ◽  
P Removal

The phosphorus (P) removal processes in two pairs of High and Low Loaded reed beds were investigated during five periods within a 27-month study. The uptake/release of P was measured in seven mass balance compartments. With the exception of the first year of operation, the reed beds consistently removed over 96% of the influent P load, with total phosphorus (TP) concentrations being reduced from 0.5 mg/L to generally less than 0.005 mg/L across the range of loading rates and seasons studied. During the first year, uptake by Phragmites australis accounted for greater than 75% of P removed, and was equally distributed between above and below-ground biomass. During the second and third years, three seasonal stages were identified in the uptake and cycling of P by P. australis. A period of rapid above-ground growth and uptake occurred during spring fuelled partly by P reserves accumulated in rhizomes during the previous year. During summer, uptake by above-ground biomass was governed by the influent P loading rate, while the amount of P held in below-ground biomass remained relatively stable. During autumn and winter, P appeared to be translocated from senescent shoots to reserves in the rhizomes. Approximately 85% of the below-ground biomass P occurred in the top 20 cm of the substrate. Gravel fixation increased in importance from 12% in the first year to approximately 30% of P removed in the second year, with a highly significant correlation between the influent P loading rate and P fixed by the gravel. The weakly-bound P fraction from a sequential extraction was the dominant form of P fixed by the gravel. HCl extracts were inappropriate for the examination of sorption processes as they dissolved large amounts of mineral P from within the basaltic gravel. The bottom 30 cm of the substrate became the most important site for gravel fixation during the second year. Incorporation of P into the detritus/microbiota/other compartment increased after the first year to become one of the most important P removal processes, probably consisting mainly of leaf litter and slowly accreted organic sediments.

scholarly journals Quantification of biologically and chemically bound phosphorus in activated sludge from full-scale plants with biological P-removal

2021 ◽  
Author(s):  
Francesca Petriglieri ◽  
Jette F. Petersen ◽  
Miriam Peces ◽  
Marta Nierychlo ◽  
Kamilla Hansen ◽  
...  
Keyword(s):  
Wastewater Treatment ◽  
Activated Sludge ◽  
Mass Balance ◽  
Wastewater Treatment Plants ◽  
Raman Microspectroscopy ◽  
Full Scale ◽  
P Fractions ◽  
P Content ◽  
Total P ◽  
P Removal

AbstractLarge amounts of phosphorus (P) are present in activated sludge from municipal wastewater treatment plants, where it exists in the form of metal salt precipitates or biologically bound into the biomass as nucleic acids, cell membrane components, and the extracellular polymeric substances or, in special polyphosphate-accumulating organisms (PAOs), as intracellular polyphosphate. Only recently, methods that reliably allow an absolute quantification of the different P-fractions, such as sequential extraction, Raman microspectroscopy, solid-state 31P magic angle spinning (MAS) NMR, and solution state 31P NMR have been developed. This study combines these techniques to obtain a comprehensive P mass-balance of activated sludge from four wastewater treatment plants with enhanced biological phosphate removal (EBPR). The total content of P and various cations was measured by chemical analysis (ICP-OES), and different P fractions were extracted for chemical characterization. Chemically bound P constituted 38-69% of total P, most likely in the form of Fe, Mg, or Al minerals, while organically bound P constituted 7-9%. By using Raman microspectroscopy and solution state 31P NMR and 31P MAS NMR spectroscopy before and after anaerobic P-release experiments, poly-P was quantified and constituted 22-54% of total P in the activated sludges and was found in approx. 25% of all bacterial cells. Moreover, Raman microspectroscopy in combination with fluorescence in situ hybridization (FISH) was used to quantify the species-specific intracellular poly-P of known PAO genera (Tetrasphaera, Ca. Accumulibacter, Dechloromonas) and other microorganisms known to possess high level of poly-P, such as the filamentous Ca. Microthrix. They were all abundant, as measured by quantitative-FISH and amplicon sequencing, and accumulated large amount of poly-P, depending on their cell-size, contributing substantially to the P-removal. Interestingly, in all four EBPR plants investigated, only 1-13% of total poly-P was stored by unidentified PAO, highlighting that most PAOs in the full-scale EBPR plants investigated are now known.HighlightsExhaustive P mass-balance of main organic and inorganic P-species in four EBPR plantsQuantification of poly-P of FISH-defined PAO and other species with high P contentTotal P content was 36-50 mgP/gSS of which 31-62% was in biomass and as poly-PA high fraction of all cells (25-30%) contained a high content of poly-PKnown PAOs contained almost all poly-P in the EBPR plants investigated

scholarly journals Postdialytic Rebound of Serum Phosphorus: Pathogenetic and Clinical Insights

2002 ◽  
Vol 13 (4) ◽  
pp. 1046-1054 ◽  
Author(s):  
Roberto Minutolo ◽  
Vincenzo Bellizzi ◽  
Mario Cioffi ◽  
Carmela Iodice ◽  
Paolo Giannattasio ◽  
...  
Keyword(s):  
Protein Intake ◽  
Serum Phosphate ◽  
Single Session ◽  
Medium Term ◽  
P Values ◽  
V Protein ◽  
End Of Treatment ◽  
Deep Compartment ◽  
To Receive ◽  
P Removal

ABSTRACT. To gain insights into postdialytic rebound of serum phosphate (PDR-P), serum phosphate (P), calcium (Ca), and parathyroid hormone (PTH), levels were compared from the end of treatment (T0) to the subsequent 30 to 120 min and up to 68 hr in uremic patients who underwent with crossover modality a single session of two dialytic treatments characterized by different convective removal: standard hemodialysis (HD) and hemodiafiltration (HDF). In HDF,versusHD, P removal was greater (1171 ± 90versus814 ± 79 mg;P< 0.05) in the presence of similar predialytic P levels (6.0 ± 0.2 and 5.9 ± 0.4 mg/dl) and Kt/V (1.35 ± 0.06 and 1.34 ± 0.05); however, the serum P values at T0 did not differ (3.0 ± 0.2versus3.3 ± 0.2 mg/dl). In HDF, PDR-P was more rapid (30 minversus90 min) and of a greater extent (at T120: +69 ± 6%versus+31 ± 4%;P< 0.0001). The higher P levels were maintained throughout the interdialytic period. Ca × P and PTH changed in parallel. Thereafter, patients were randomized to receive either HD or HDF for 3 mo. During this period, in the presence of similar Kt/V, protein intake, and dose of phospate binder, predialytic serum P levels diminished in HDF (from 5.8 ± 0.2 to 4.4 ± 0.3 mg/dl;P< 0.05), but they remained unchanged in HD. A similar pattern of changes was detected in Ca × P. Therefore, PDR-P is likely dependent on the mobilization of phosphate from a deep compartment induced by the intradialytic removal of this solute. Enhancement of convective removal acutely amplifies the entity of the phenomenon but allows a better control of Ca-P homeostasis in the medium term.

The AF-BNR-SCP process as a way to reduce global sludge production: comparison with classical approaches on a full scale basis

2002 ◽  
Vol 46 (10) ◽  
pp. 89-96 ◽  
Author(s):  
P. Battistoni ◽  
S. Pezzoli ◽  
D. Bolzonella ◽  
P. Pavan
Keyword(s):  
Wastewater Treatment ◽  
Mass Balance ◽  
Wastewater Treatment Plants ◽  
Economic Benefits ◽  
Full Scale ◽  
Sludge Reduction ◽  
Specific Production ◽  
Mass Balances ◽  
P Removal ◽  
Sludge Production

The paper presents a comparison between the performances of two full scale wastewater treatment plants operating in Italy, considering the mass balances including P treatments, and results coming from an analysis of 16 similar plants in Europe and USA, in order to evaluate sludge overproduction due to chemical P removal adoption. Specific production of 9.5 and 12.5 kgTS/P.E.y were found for a BNR and denitrification plant scheme respectively. These results were compared, on a mass balance basis, with the performances coming from the adoption of the integrated waste/wastewater cycles, in which OFMSW fermentation is used as C source to promote BNR performances and P removal from anaerobic supernatants as struvite crystals. ASM2 simulations are used to verify the advantages coming from this approach in terms of sludge reduction. A complete mass balance of the process is carried out, and it is shown that this last process allows us to achieve the lowest sludge production among the processes considered, coupling this with the economic benefits coming from OFMSW disposal and struvite crystallisation.

scholarly journals The effects of frequent nocturnal home hemodialysis: the Frequent Hemodialysis Network Nocturnal Trial

2011 ◽  
Vol 80 (10) ◽  
pp. 1080-1091 ◽  
Author(s):  
Michael V. Rocco ◽  
Robert S. Lockridge ◽  
Gerald J. Beck ◽  
Paul W. Eggers ◽  
Jennifer J. Gassman ◽  
...  
Keyword(s):  
Home Hemodialysis ◽  
Frequent Hemodialysis

The Development of Swallowing Respiratory Coordination

2009 ◽  
Vol 18 (1) ◽  
pp. 19-24
Author(s):  
Maggie-Lee Huckabee
Keyword(s):  
Cortical Activation ◽  
First Year ◽  
Healthy Children ◽  
Nasal Airflow ◽  
Single Session ◽  
Primary Finding ◽  
Patterns Of Behavior ◽  
Cortical Modulation ◽  
First Year Of Life ◽  
Swallowing Apnea

Abstract Research exists that evaluates the mechanics of swallowing respiratory coordination in healthy children and adults as well and individuals with swallowing impairment. The research program summarized in this article represents a systematic examination of swallowing respiratory coordination across the lifespan as a means of behaviorally investigating mechanisms of cortical modulation. Using time-locked recordings of submental surface electromyography, nasal airflow, and thyroid acoustics, three conditions of swallowing were evaluated in 20 adults in a single session and 10 infants in 10 sessions across the first year of life. The three swallowing conditions were selected to represent a continuum of volitional through nonvolitional swallowing control on the basis of a decreasing level of cortical activation. Our primary finding is that, across the lifespan, brainstem control strongly dictates the duration of swallowing apnea and is heavily involved in organizing the integration of swallowing and respiration, even in very early infancy. However, there is evidence that cortical modulation increases across the first 12 months of life to approximate more adult-like patterns of behavior. This modulation influences primarily conditions of volitional swallowing; sleep and naïve swallows appear to not be easily adapted by cortical regulation. Thus, it is attention, not arousal that engages cortical mechanisms.

Effects of Mixed Dietary Supplements on Total Plasma Homocysteine Concentrations (tHcy): A Randomized, Double-Blind, Placebo-Controlled Trial

2012 ◽  
Vol 82 (4) ◽  
pp. 260-266 ◽  
Author(s):  
Salah E. Gariballa ◽  
Sarah J. Forster ◽  
Hilary J. Powers
Keyword(s):  
Older Patients ◽  
Controlled Trial ◽  
Plasma Homocysteine ◽  
Acute Illness ◽  
Vitamin B ◽  
Total Plasma ◽  
Double Blind ◽  
Double Blind Placebo ◽  
Nutrient Supplement ◽  
Plasma Thcy

Background: Although a number of studies have reported raised total plasma homocysteine (tHcy) concentrations in free-living older people, there are no data on homocysteine response to a mixed nutrient supplement in older patients. A raised plasma homocysteine concentration in older patients is partly a reflection of their co-morbidity, including impaired renal function, and there is uncertainty about the extent to which dietary interventions can improve plasma tHcy. Aim: To determine the plasma tHcy response to dietary supplements during acute illness. Methods: Two-hundred and thirty-six hospitalized, acutely ill older patients, who were part of a randomized double-blind placebo-controlled trial, were assigned to receive a daily oral nutritional supplement drink containing 1.3 mg of vitamin B2, 1.4 mg of vitamin B6, 1.5 μg of B12, 200 μg of folic acid, or a placebo, for 6 weeks. Outcome measures were plasma tHcy concentration at baseline, 6 weeks, and 6 months. Results: The mean plasma tHcy concentration fell among patients given the supplements (mean difference 4.1 µmol/L [95 % C.I, 0.14 to 8.03), p = 0.043], but tHcy concentration increased between 6 weeks and 6 months, after patients stopped taking the supplements [mean difference -2.0 µmol/L (95 % C.I, -03.9 to -0.18), p = 0.033]. About 46 % of patients in the placebo group and 55 % of patients in the supplement group had hyperhomocysteinemia (>14 µmol/L) at baseline compared with 45 % and 29 % at the end of the treatment period. Conclusions: A mixed nutrient supplement containing physiological amounts of B vitamins significantly reduced plasma tHcy concentrations in older patients recovering from acute illness.

Relationship between total plasma homocysteine and the risk of aneurysms – a meta-analysis

VASA ◽  
2020 ◽  
pp. 1-6
Author(s):  
Hanji Zhang ◽  
Dexin Yin ◽  
Yue Zhao ◽  
Yezhou Li ◽  
Dejiang Yao ◽  
...  
Keyword(s):  
Large Scale ◽  
Meta Analysis ◽  
Single Species ◽  
Total Plasma ◽  
Control Groups ◽  
Randomized Controlled ◽  
Randomized Controlled Studies ◽  
The Difference ◽  
The Relationship ◽  
Healthy Participants

Summary: Our meta-analysis focused on the relationship between homocysteine (Hcy) level and the incidence of aneurysms and looked at the relationship between smoking, hypertension and aneurysms. A systematic literature search of Pubmed, Web of Science, and Embase databases (up to March 31, 2020) resulted in the identification of 19 studies, including 2,629 aneurysm patients and 6,497 healthy participants. Combined analysis of the included studies showed that number of smoking, hypertension and hyperhomocysteinemia (HHcy) in aneurysm patients was higher than that in the control groups, and the total plasma Hcy level in aneurysm patients was also higher. These findings suggest that smoking, hypertension and HHcy may be risk factors for the development and progression of aneurysms. Although the heterogeneity of meta-analysis was significant, it was found that the heterogeneity might come from the difference between race and disease species through subgroup analysis. Large-scale randomized controlled studies of single species and single disease species are needed in the future to supplement the accuracy of the results.

Review of Single-session therapy.

1993 ◽  
Vol 11 (2) ◽  
pp. 223-226
Author(s):  
Dael M. Waxman
Keyword(s):  
Single Session
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