Effect Of Sulfate Concentration Research Articles

Effect of sulfate concentration and scraping on aerobic fixed biofilm reactors

The influence of the sulfate concentration and biofilm scraping on the treatment performance and biofilm structure of aerobic fixed film reactors was studied in rotating tubular reactors (RTRs). The RTRs operated at 22(±3)°C treating diluted milk powder (0.9 g COD/1; COD/SO 2− 4 ratio of 20) at an organic loading rate of 30 g COD per m 2 carrier material per day. The reference RTR gave the following removal efficiencies: COD tot, 76%; COD sol, 91%; N totN, 51%; N orgN, 70%; PO 3− 4P, 45%. COD removal was linear as a function of the reactor length (2 mg COD/cm reactor). The biomass yield coefficient amounted to 0.44(±0.13) g DM/g COD removed. High sulfate concentrations appreciably reduced the yield to 0.28(±0.06) g DM/g COD rem but did not significantly influence the COD and nutrient removal capacity, despite the longer hydraulic retention time (12′07″) compared to the reference RTR (6′25″). Daily removal of about 15% of the biofilm by biomass scraping did not significantly affect the reactor performance. Biofilm samples growing in the reference and the sulfate amended reactor showed comparable specific oxygen uptake rates (15 mg O 2/g VS · h). In the reactor treating sulfate-rich wastewater, large populations (6.3–7.5 log CFU/g VS) of lactate, acetate, propionate and butyrate oxidizing sulfate reducing bacteria (SRB) were present. Their number as well as their sulfate reducing activity (13.5 ± 9.5 mg SO 2− 4S/g VS · h) was higher compared to the reference RTR. The addition of molybdate (30 mM) to the influent showed that SRB could account for 50% and 10% of the COD removal in the sulfate amended and reference RTR, respectively. It is concluded that wastewaters with a low COD SO 2− 4 ratio are particularly suited for aerobic fixed film processes because of the low waste biomass production.

Effects of sulfate concentration and sludge retention time on the interaction between methane production and sulfate reduction for butyrate

The effects of sulfate concentration and COD/S ratio on the anaerobic degradation of butyrate were investigated by using 2.0 L anaerobic chemostat-type reactor at 35°C. The study was conducted over a wide range of the COD/S ratio (1.5 to 148) by varying COD concentrations (2500–10000 mg/L) and sulfate concentrations (68–1667 mg-S/L) in the substrate. The sludge retention time at each COD/S ratio was changed from 5 to 20 days. The interaction between methane producing bacteria (MPB) and sulfate-reducing bacteria (SRB) was evidently influenced by COD/S ratio in the substrate. When COD/S ratio was 6.0 or more, methane production was the predominate reaction and over 80% of the total electron flow was used by MPB. At the COD/S ratio of 1.5, SRB utilzed over 50% of the total electron flow. A large amount of sulfate reduction resulted in not only the decrease of methane production, but also the rapid increase of the bacterial growth. The degradation pathway of butyrate and the composition of bacterial populations in the reactor were also dominated by COD/S ratio. In sulfate depleted condition, butyrate was degraded to methane via acetate and hydrogen by MPB. On the other hand, butyrate was firstly degraded into sulfide and acetate in sulfate rich conditions by SRB, and the produced acetate was then degraded by acetate consuming MPB and SRB. The methanogenesis from acetate was inhibited by the high concentration of sulfide.

Effects of sulfate concentration in the overlying water on sulfate reduction and sulfur storage in lake sediments

We investigated the effects of sulfate concentration on sulfate reduction and net S storage in lake sediments using34S as a tracer. The water overlying intact sediment cores from the hypolimnion of Mares Pond, MA, was replaced with two Na234SO4 solutions at either ambient (70 μM) or elevated (260 μM) sulfate concentrations. The δ34S of the added sulfate was 4974 ‰. Over two months, the net sulfate reduction rate in the ambient sulfate treatment was zero, while the net rate for the high sulfate treatment was 140 μmoles/m2/d. The water overlying the cores was kept under oxic conditions and the sediment received no fresh carbon inputs, thus the net rate reported may underestimate the in situ rate. Gross sulfate reduction rates calculated by isotope dilution were approximately 350 μmoles/m2/d for both treatments. While the calculation of gross sulfate reduction rates in intact sediment cores can be complicated by differential diffusion of34S and32S, isotopic fractionation, and the possible formation of ester sulfates, we believe these effects to be small. The results suggest that sulfate reduction is not strongly sulfate-limited in Mares Pond. The difference in net sulfate reduction rates between treatments resulted from a decrease in sulfide oxidation and suggests the importance of reoxidation in controlling net S storage in lake sediments. In both treatments the CRS and organic S fractions were measurably labelled in34S. Below the sediment surface, the CRS fraction was the more heavily labelled storage product for reduced sulfides.

酪酸の嫌気的分解に及ぼす硫酸塩濃度およびＣＯＤ／Ｓ比の影響

酪酸の嫌気的分解に及ぼす硫酸塩濃度およびＣＯＤ／Ｓ比の影響

High susceptibility of human articular cartilage glycosaminoglycan synthesis to changes in inorganic sulfate availability

The effect of sulfate concentration in the medium on glycosaminoglycan synthesis in articular cartilage of five different species was examined in relation to the physiological serum sulfate concentration in these species. Only the rate of sulfated glycosaminoglycan synthesis in human articular cartilage was sensitive to small deviations from the physiological sulfate concentration. A reduction in the sulfate concentration from 0.3 mM (physiological) to 0.2 mM resulted in a 33% reduction in glycosaminoglycan synthesis. In addition, we studied the effect of arthritic and "osteoarthritic" alterations in murine cartilage on the dependence of glycosaminoglycan synthesis on low sulfate concentrations. Arthritic and "osteoarthritic" cartilage had a similar dependence on the sulfate concentration in the medium as normal cartilage. Glycosaminoglycan synthesis in human articular cartilage appears to be very sensitive to the potential sulfate-depleting effects of drugs used in the treatment of rheumatoid arthritis and osteoarthritis.

Effect of sulfate concentration on glycosaminoglycan synthesis in explant cultures of bovine articular cartilage

The effects of the sulfate- and FCS concentration on the rate of synthesis and the biochemical properties of glycosaminoglycans, synthesized in bovine articular cartilage in vitro, were studied. 20 % FCS in the culture medium stimulated the rate of synthesis. In media without FCS, the rate of synthesis decends from day 0 on. The differences in incorporation rates of [ 35S]-sodium sulfate and 1,6-[ 3H]-glucosamine-HCl into glycosaminoglycans in serum free media containing 9 μM and 900 μM sulfate were used to discuss the inorganic sulfate concentration in cartilage. In 9 μM sulfate medium, the newly synthesized glycosaminoglycans contain higher levels of unsulfated disaccharides than the endogenous glycosaminoglycans. In each culture medium, the ratio 6-sulfated disaccharides to 4-sulfated disaccharides of the newly synthesized glycosaminoglycans becomes higher after 3 days in culture. The glycosaminoglycan synthesis is underestimated, when chondrocytes are cultured in media containing less than 200 μM sulfate.

Formation of dermatan sulfate by cultured human skin fibroblasts. Effects of sulfate concentration on proportions of dermatan/chondroitin.

[3H,35S]Dermatan/chondroitin sulfate glycosaminoglycans produced during culture of fibroblasts in medium containing varying concentrations of sulfate were tested for their susceptibility to chondroitin ABC lyase and chondroitin AC lyase. Chondroitin ABC lyase completely degraded [3H]hexosamine-labeled and [35S] sulfate-labeled dermatan/chondroitin sulfate to disaccharides. Chondroitin AC lyase treatment of the labeled glycosaminoglycans produced different results. With this enzyme, dermatan/chondroitin sulfate formed at high concentrations of sulfate yielded small glycosaminoglycans and larger oligosaccharides but almost no disaccharide. This indicated that the dermatan/chondroitin sulfate co-polymer contained mostly iduronic acid with only an occasional glucuronic acid. As the medium sulfate concentration was progressively lowered, there was a concomitant increase in the susceptibility to degradation by chondroitin AC lyase. Thus, the labeled glycosaminoglycans formed at the lowest concentration of sulfate yielded small oligosaccharides including substantial amounts of disaccharide. The smaller chondroitin AC lyase-resistant [3H,35S]dermatan/chondroitin sulfate oligosaccharides were analyzed by gel filtration. Results indicated that, in general, the iduronic acid-containing disaccharide residues present in the undersulfated [3H,35S]glycosaminoglycan were sulfated, whereas the glucuronic acid-containing disaccharide residues were non-sulfated. This work confirms earlier reports that there is a relationship between epimerization and sulfation. Moreover, it demonstrates that medium sulfate concentration is critical in determining the proportions of dermatan to chondroitin (iduronic/glucuronic acid) produced by cultured cells.

Metabolism of inorganic sulphate in the isolated perfused rat liver. Effect of sulphate concentration on the rate of sulphation by phenol sulphotransferase.

1. The metabolism of inorganic [(35)S]sulphate (Na(2) (35)SO(4)) was studied in the isolated perfused rat liver at three initial concentrations of inorganic sulphate in the perfusion medium (0, 0.65 and 1.30mm), in relation to sulphation and glucuronidation of a phenolic drug, harmol (7-hydroxy-1-methyl-9H-pyrido[3,4-b]indole). 2. [(35)S]Sulphate rapidly equilibrated with endogenous sulphate in the liver. It was excreted in bile and reached, at the lowest concentration in the perfusion medium, concentrations in bile that were much higher than those in the perfusion medium; at the higher sulphate concentrations, these concentrations were equal. The physiological concentration of inorganic sulphate in the liver, available for sulphation of drugs, is similar to the plasma concentration. 3. At zero initial inorganic sulphate in the perfusion medium, the rate of sulphation was very low and harmol was mainly glucuronidated. At 0.65mm-sulphate glucuronidation was much decreased and considerable sulphation took place, indicating efficient competition of conjugation by sulphation. At 1.30mm-sulphate the sulphation increased still further. 4. The results suggest that an important factor in sulphation is the relatively high K(m) of synthesis of adenosine 3'-phosphate 5'-sulphatophosphate (the co-substrate of sulphation) for inorganic sulphate, which is of the order of the plasma concentration of inorganic sulphate. The steady-state adenosine 3'-phosphate 5'-sulphatophosphate concentration may determine the rate of sulphate conjugation of drugs in the rat in vivo.

Effects of sulfate concentration, electroendosmotic flow, and electrical resistance of agars and agaroses on counterimmunoelectrophoresis with adenovirus antigens and antisera

The sulfate concentration, electroendosmosis (EE), and electrical resistance of 23 commonly used agars and agaroses were measured by standard techniques and related to counterimmunoelectrophoresis (CE) with adenovirus antigens and antisera. Statistical analyses of the test procedures themselves showed that the tests had sufficient reproducibility to warrant further analyses on the interaction or combined effects of these parameters on adenovirus CE tests. Both sulfate concentration and EE were related to CE by cubic polynomial equations; sulfate was directly related to EE by a linear equation. Resistance was somewhat linearly related to CE, but the differences among agars were too small to show a clear correlation. The data show that the fixed charges of the sulfate anion are major, although probably not the only, contributors to EE. The combined EE calculations from spectrophotometrically-scanned and hand-measured slides were used to predict the usefulness of new lots of agaroses for diagnostic adenovirus CE tests, according to the derived equation, CE score = 4.9 + 112.1 EE −397.1 EE 2 + 329.1 EE 3. The best stabilizing media for adenovirus CE tests had sulfate concentrations of 0.37% ± 0.16% and EE cathodic mobility ratios of 0.17 ± 0.03.

The ecology and distribution of Promenetus exacuous Say (Gastropoda: Planorbidae) in southern Manitoba

Promenetus exacuous inhabits limited environments in southern Manitoba. Shallow water depth and vegetation seem to be important factors affecting geographic distribution. Except for extremes, temperature, substrate, and type of water body appear to have little effect. P. exacuous generally appears to prefer water with relatively low sulphate concentrations. The effect of sulphate concentration on population fluctuation is not well understood. Several other gastropods are usually associated with P. exacuous, but none duplicates its distribution in southern Manitoba.