Acidity Content Research Articles

The effect of organic characteristics andbromide on disinfection by‐products formation by chlorination

In this study, organic fractions, namely, humic acid, fulvic acid, hydrophobic ‐base, ‐neutral, hydrophilic ‐acid, ‐base, and ‐neutral were extracted from source water. First, the characteristics of the organic fractions, such as carboxylic acidity, phenolic acidity, ultraviolet absorbance, and aromatic content were analyzed. Then each fraction was chlorinated separately, and the THMFP, HAAFP, and AOXFP of the chlorinated water measured. Further, the effect of bromide on halogenated organic formation were also studied. The results indicate that the characteristics of the aquatic organic matter, including carboxylic/phenolic acidity, aromatic/aliphatic content, ultraviolet absorbance, appear to affect the formation of halogenated organics. Hydrophobic organics, having higher phenolic acidity, aromatic content, and ultraviolet absorbance, have higher chlorine consumption and produce higher concentrations of halogenated organics than hydrophilic organics. As far as bromide effect is concerned, the THMFP values (in μ mole/L) of humic acid were found to be decreased with increasing bromide concentration, the reverse was true for hydrophilic neutral organics, while the THMFP and HAAFP variation of fulvic acid with bromide was minor. Furthermore, the portion of THMFP and HAAFP contributed by brominated species was increased with increasing bromide concentration, and the brominated THMFP and HAAFP converted from hydrophilic neutral organics were higher than those from humic acid or fulvic acid. These phenomena may be explained by the preference of aliphatic precursors to undergo bromination, while aromatic precursors prefer chlorination.

Alkaline Swelling of Hemp Woody Core Chips

Swelling of hemp woody core chips after alkaline (peroxide) impregnation at 70 °C, as is practised in alkaline peroxide mechanical pulping (APMP) processes is examined, in relation to pulp yield and chemical composition of the chips. In contrast to wood chips, maximum swelling is attained at elevated temperature (70 °C) without chemical treatment, possibly as the result of relatively high porosity of hemp woody core cell walls. Alkaline swelling at 70 °C correlates with the xylan:lignin ratio. Swelling at ambient temperature shows some correlation with acidic group content. Apparent pore size distributions were examined, using 1H NMR spin-spin relaxation. Several apparent pore size distributions could be distinguished within each sample. Elevated temperature, NaOH and peroxide addition are influencing apparent pore size distribution and total pore volume differently. Addition of peroxide results in remarkably enlarged apparent pore sizes, which emphasizes its importance (apart from bleaching) in APMP pulping, enhancing fiber flexibility and fibrillation.

Environmental impact of brown coal mining in Sokolovo basin with especially trace metal mobility

Abstract The metal contamination in soil and water samples from the area surrounding the coal mine drainage reservoir was studied, the main environmental risk are high acidity and high contents of berillium in drainage water. In solid samples there is serious contamination by arsenic, berillium and copper from mining activities. Contamination by lead and zinc mainly comes from domestic wastes. The metal enrichment factor defined is decreasing in the order Cu > As > Cr > Fe > Be > Zn > Cd > Pb.

Extension of Postharvest Life of Bell Peppers with Low Oxygen

Green bell peppers (Capsicum annum L cv California Wonder) were stored in oxygen/nitrogen mixtures at 10, 30, 50, 70 and 210 (air) ml O 2 litre -1 for 4 weeks at 10°C. Decay, weight loss, colour, titratable acidity and soluble solids contents, internal CO 2 and ethylene were evaluated. After 2 weeks, 33% of the air-stored peppers had decayed while only 9% of those stored in 10 ml litre -1 O 2 had decayed. The benefit of 10 ml litre -1 O 2 in reducing decay continued through 4 weeks of storage. The 30 and 50 ml litre -1 O 2 atmospheres slightly reduced decay for a short time while the incidence of decay in 70 ml litre -1 O 2 was not different from the control. Peppers stored in 10 ml litre -1 O 2 had significantly lower internal CO 2 than the air control and other low O 2 treatments. A slower decrease in green colour of peppers stored in low O 2 indicates a retardation of colour change by low O 2 treatments during storage. Low respiration and ethylene synthesis rates may be the primary factors in quality retention.

Laboratory studies on the leaching of aldicarb through a tropical soil from Belize, Central America

Studies in temperate regions indicate that the carbamate insecticide aldicarb and its metabolites leach readily through agricultural soils into groundwater. However, little is known about the fate of this nematicide in tropical regions, where its leaching potential may be even greater because of high annual rainfall and the acidic nature and low organic content of many tropical soils. Examination of the leaching behaviour of aldicarb and its metabolites in columns containing soil from Belize, Central America, indicated that total carbamate residues (TCR) could rapidly reach concentrations > 15 mg L−1 in porewater 1 m below the soil surface within 70 days of application. These values are well in excess of the US EPA Health Advisory level of 0.01 mg L−1. TCR retention within a given depth interval in the soil columns relative to incoming TCR flux was greatest between 0 and 0.1 m, reflecting high organic matter contents in the upper soil. Retention below 0.1 m was relatively consistent with depth, while differences in relative retention between columns were due to a greater duration of leaching for the second column. Aldicarb was rapidly oxidized to aldicarb sulfoxide and aldicarb sulfone in these soils. The high concentration and mobility of TCR in this acidic soil is attributed to the transformation of the parent compound to the sulfoxide metabolite, which has a lower degradation rate and organic carbon partioning coefficient than aldicarb.

Effect of seasonal drought and cactus X virus infection on the crassulacean acid metabolism ofAgave sisalanaplants growing in a neotropical savanna

Healthy and cactus X virus-infected Agave sisalana plants were collected during the dry and rainy seasons in two contrasting savanna sites. At site 1, the soil water content showed no seasonal variations, but at site 2 it was much lower during the dry season than in the rainy season. When compared to healthy plants (HP), virus infection reduced the total leaf area, the Δ of titratable acidity and the water content of the plants, regardless of the season. In virus-infected plants at site 1 (VIP-1) the magnitude of the effect elicited by the virus did not differ between seasons, whereas, in virus-infected plants at site 2 (VIP-2) the deleterious effect of the virus was more pronounced during the dry season. In the dry season, VIP-1 and VIP-2 accumulated more fructans along the diurnal cycle and had higher net diurnal carbon gain than HP, with higher values in VIP-2. With the onset of rain the total leaf area of VIP-2 increased and the Δ of titratable acidity and water content reached the values seen in VIP-1. During the rainy season there was less accumulation of fructans and the net diurnal carbon gain was lower in both VIP-1 and VIP-2 compared with HP, with VIP-2 showing the lower values. In VIP-1 and VIP-2 there was also a marked reduction in the diurnal accumulation of α-amino-N at both seasons. The data obtained in young developing leaves allowed us to discuss the present data in terms of alterations in the plants sink/source ratio caused by drought and cactus X virus infection

Rock phosphate dissolution and bicarbonate-soluble-P in some soils from South-Western Australia

Samples were collected from 228 soils from the main agricultural areas of Western Australia (W.A.) and their chemical and textural properties analysed. Soils were incubated for 7 days with North Carolina rock phosphate at a rate equivalent to 1022 �g Ca g(-1) and 383 �g P g(-1) soil. Subsequently, the amount of rock phosphate (RP) that had dissolved was determined by measuring the increase in extractable calcium (�Ca) and changes in plant-available P were estimated by a sodium bicarbonate extraction (�Bic-P). Only 29 soils dissolved more than 40% of the added RP and these occur in the wettest area of W.A., to the west of the 800 mm rainfall isohyet. They represent a variety of soil types including Vertisols, Spodosols, Alfisols and Ultisols. Simple and multiple regressions were carried out to investigate the soil properties responsible for RP dissolution and associated P availability. No single soil property adequately predicted RP dissolution or concomitant changes in bicarbonate-P. Titratable acidity and sand content together explained 61% of the variance in RP dissolution; titratable acidity was the most predictive single variable for bicarbonate-P but only explained 56% of the variance. Stepwise regression showed that titratable acidity and pH(CaCl2) together explained 79% of the variance in bicarbonate-P. The most suitable soils for RP application are sandy, humic or peaty podzols where much of the dissolved P remains available to plants. The other soils (mainly red and yellow earths and Vertisols) which dissolved much RP contain larger amounts of extractable aluminium (by dithionite or oxalate) which is the soil component largely responsible for P-sorption in these W.A. soils. These results indicate that RP fertilizers will be most effective on the humic, sandy podzols of the western and southern coastal plains of WA.

Extracellular ATP induces stellation and increases glial fibrillary acidic protein content and DNA synthesis in primary astrocyte cultures

Extracellular ATP induces stellation and increases glial fibrillary acidic protein content and DNA synthesis in primary astrocyte cultures

Amelioration of Streamwater Acidity by Catchment Liming-Response of Podzolic Soils to Pasture Improvement

Abstract The effects of agricultural improvement by cultivation, re-seeding, lime and fertiliser additions on the soil solution chemistry of acid podzolic soils have been investigated in a field experiment in a mid-Wales catchment. the treatment resulted in an increase in the pH, alkalinity and calcium content of soil waters from the surface, organic-rich horizon. in the year following treatment, soil waters in the mineral horizons became more acid and had higher aluminium concentrations than observed at the control site. This response is ascribed to soil water acidification resulting from increased nitrification rates following liming and cultivation. in subsequent years, soil water acidity in these lower horizons was neutralised by lime-rich water percolating from the surface. No changes in stream water acidity and calcium content were observed in the catchment containing the area of agriculturally improved soils. This suggests that the selective treatment of moorland catchments to improve agricultural ...

Untersuchungen an Arrhenatheretalia-Gesellschaften in Südnorwegen unter soziologischen, ökologischen, pflanzengeographischen und syntaxonomischen Aspekten

Summary Plant sociological research was carried out on meadow vegetation in the district of Hordaland and Telemark in southern Norway, enabling the following meadow communities to be determined: Conopodium majus - Geranium sylvaticum - community Typical Geranium sylvaticum - community Galium mollugo - Geranium sylvaticum - community Galium mollugo - Leucanthemum vulgare - community With the help of E llenberg ’s factor indices (1979) the authors give an ecological characterisation of the four communities and their variants as for light, temperature, and moisture factors, acidity, and nutrient content of soil. A phytogeographical characterisation of the investigated vegetation types was performed with the help of the diagnoses of areal (M eusel et al. 1965, 1978). A comprehensive plant sociological comparison of the four investigated communities was made with adequate meadow communities of the Middle European Polygono-Trisetion alliance and of the Arrhenatherion alliance. The sociological relationships of the Arrhenatheretalia communities of both research areas were thus determined. Suggestions are made as to the syntaxonomical ordering of the investigated communities of southern Norway.

Changes in organic structural group composition of humic and fulvic acids with depth in sediments from similar geographical but different depositional environments

A series of soil and swamp sediments from the Myall Lake National Park region, New South Wales, Australia have been studied by traditional wet chemical techniques and by solid state 13C NMR. Amino acid, carbohydrate, total acidity, phenolic, phenoxy and alkyl contents have been measured. Results obtained support previous literature reports that NMR carboxyl content measurements correlate better with total acidity than wet chemical COOH measurements. Large discrepancies (×20) between NMR and traditional chemical methods of measuring carbohydrate contents were also observed. The carbohydrate content of humic and fulvic acids measured by NMR or traditional methods drops rapidly with increasing soil or sediment depth probably because of metabolization by microorganisms. Fulvic acids contain more carboxylic acid and decreased alkyl carbon than their humic acid counterparts from the same source. The structure of humic acids however more closely reflect their depositional environment. For example, more phenolic and phenoxy carbon is present in forest humic acids because of the high lignin input.

Properties of “nono,” a Nigerian fermented milk food

A total of 100 samples of nono produced in Hanwa, Bomo and Biye villages in Zaria local Government area, Nigeria, were analysed for proximate composition, acidity, diacetyl, minerals, total aerobic, lactic acid bacterial and yeast counts. pH values were fairly uniform and ranged from 4.1–4.4. In contrast, the samples varied considerably in proximate composition and in titratable acidity (TA) and diacetyl contents; values for TA and diacetyl ranged from 0.54–0.90% and 1.3–9.4 μg/ml respectively. The samples also differed in their content of minerals; Calcium and phosphorous ranged from .01–0.3% and .02‐.04% respectively and were considerably lower than those of milk and plain yogurt. Aerobic plate counts and counts for lactic acid bacteria and yeasts were very high in nono and minimum counts observed were 1.6 × 109, 1.1 × 108 and 1.5 × 107 viable units per gram respectively.

Effects of Chemical Treatments on Ultra-High-Yield Pulping. VI. The Relative Effect of Lignin Oxidation and Sulfonation

ABSTRACT The chemical properties and performance of aspen percarbonate (P) and sulfite (S) chemimechanical pulp (CMP) fibers are very comparable. The PCMP, when compared with SCMP of the same yield, has a slightly higher tear index, same beatability and light scattering coefficient, but a lower tensile index and brightness. The strength properties of these fibers are closely related to the total acidic group content resulting from lignin oxidation (carboxyls) and sulfonation (sulfonate).

Time Required for Oral Ranitidine to Decrease Gastric Fluid Acidity

This study documented gastric fluid acidity in ambulatory surgical patients 30-120 min after they had taken a 300-mg tablet of ranitidine, as changes specific to this relatively brief dose-to-sampling interval previously had not been delineated. At 20-120 min before outpatient surgery, ranitidine was given with 15 mL of water to 112 ASA physical status I-III adults without increased risk factors for aspiration of acidic gastric contents. After induction of general endotracheal anesthesia, the gastric fluid was aspirated. Volume and pH were compared with a reference group (pH = 1.6 +/- 1; n = 161) that did not receive an H2-antagonist or water. Of 40 patients sampled at 30-60 min after dosing, 26 had pH greater than or equal to 2.5; mean pH was 3.9 +/- 2 (P less than 0.05 vs reference by Wilcoxon signed rank and chi 2 tests). Beyond 90 min, 28 of 28 patients had a pH greater than or equal to 2.5, with a mean of 6.3 +/- 1. No significant differences were noted with respect to mean gastric volume. We conclude that in patients without additional risk factors, oral ranitidine consistently prevents acid production when it is administered more than 90 min before induction of anesthesia.

Reactions of urea phosphate in calcareous and alkaline soils: I. Ammonia volatilization

Abstract Nitrogen (N) loss in the form of volatilized ammonia (NH3) is a considerable problem when ammonium (NH4 +) forming fertilizers are applied to calcareous or alkaline soils. The volatilization of NH3 from urea phosphate (UP) and urea (U) was studied on three selected soils (Hayhook SL, Laveen L, and Latene L) with the use of a laboratory aeration system. Urea phosphate and U were each applied at rates of 0, 50, 100, and 200 mg N kg‐1 soil, either to the surface dry or in solution or mixed with the soil. The volatilized NH3 was trapped in sulfuric acid, sampled periodically, and analyzed for N with the semi microkjeldahl distillation apparatus. The highest N loss in the form of NH3 occurred when U was applied to Hayhook soil (neutral to acidic, coarse textured, and low CaCO3 content). However, UP applied to Hayhook soil resulted in the lowest NH3‐N loss. Less NH3‐N loss was found from U application to Laveen and Latene soils (fine textured with higher CaCO3 content) than with Hayhook soil. The gener...

ACIDIC PHOSPHOLIPIDS IN SYNAPTOSOMAL PLASMA MEMBRANES DURING REPEATED EPISODES OF PHYSICAL ETHANOL DEPENDENCE IN THE RAT

The effects of repeated episodes of ethanol intoxication and the hyperexcitable state of withdrawal on the synaptosomal concentration of acidic phospholipids were studied in rats. There was no indication that cumulative changes in the synaptosomal acidic phospholipid composition in general occurred during multiple episodes of ethanol intoxication and withdrawal. There was, however, a statistically significant decrease in acidic phospholipid concentration (phosphatidylinositol; PI) in synaptosomal membranes from animals revealing spontaneous convulsive behaviour during ethanol withdrawal. Hypothetically this may reflect an inability to increase acidic phospholipid membrane content and thus to adaptively increase the seizure threshold during withdrawal.

Phospholipid changes in the bones of the hypophosphatemic mouse

The mineral and lipid composition of the bones of 35 day old hypophosphatemic (Hyp/Y) and control (+/Y) mice were compared in order to test the hypothesis that phosphate status has an effect on the complexed acidic phospholipid content of developing bones. The Hyp/Y bones were found to be rachitic and osteomalacic, having significantly reduced mineral content. That mineral was shown by X-ray diffraction to consist of larger/more perfect crystals than that in +/Y animals, indicating either a preference for crystal growth rather than new mineral deposition, or an increased mineral turnover. The increased crystal perfection was confirmed by chemical analyses which showed an increased calcium to phosphorus ratio in the Hyp/Y bones. The bones of Hyp/Y animals had significantly reduced complexed acidic phospholipid contents relative to those of control animals. Since these complexes are believed to play a role in vitro and in vivo mineral deposition, it is suggested that the deficiency of these complexes contributes to the mineralization defect. The magnitude of the complexed acidic phospholipid deficiency in the Hyp/Y animals indicates the importance of phosphate for the formation of these lipids. Although the proportion of phosphatidylserine and phosphatidylinositol and lysophospholipids tended to be reduced in the Hyp/Y bones, the absence of other statistically significant phospholipid abnormalities in the bones and brains of these animals suggests that the lipid defect is not systemic, but is associated with a decrease in phosphate at the site of bone formation.

Adsorption of atrazine on humic acids

Abstract The adsorption of atrazine on four fractions of humic acids with different molecular weights was investigated at the range of pH value 2.5–6.2. The amounts of adsorbed atrazine decreased with increasing pH for all humic acids fractions. No adsorption was observed at pH 5.5 and higher. The increase of relative nitrogen percentages and also decreases of C/N ratios in adsorption products were investigated. Changes of these parameters were influenced by the acidic functional group content in the different fractions of humic acids. The atrazlne adsorption kinetics was investigated also. No appreciable changes in adsorbed amounts were observed after 20 hours. The adsorption process involved two phases ‐ rapid followed by slow adsorption.

Characterization of a rural area in terms of dry and wet deposition

Atmospheric gaseous pollutants (NO 2, SO 2, NH 3, HNO 3) and related ionic species in water-soluble fine particulates and rainwater were monitored from September 1986 to January 1987 with the aim of estimating the acid deposition over a rural area near Rome. A wet-only rain collector and an annular denuder-filter pack sampling system for gases and aerosols were employed to avoid chemical artifact formation. A comparison of the wet and dry deposition rates indicates that atmospheric removal by precipitation was the dominant sink for sulfate and nitrate at the sampling site. Ion balance analysis showed that the main compounds present in aerosols were (NH 4) 2SO 4 and NH 4NO 3, since the ammonium neutralization factor approached 100% and the acidity content was very low. The marked enrichment of H +, SO 4 2− and NO 3 − in preparation compared with NH 4 + could be explained by assuming either that SO 2 and NO 2 are oxidized in cloud droplets or that acidic sulfate and nitrate are scavenged directly in-cloud or below-cloud.

Comparison of the adsorption of maize root mucilage and polygalacturonic acid on montmorillonite homoionic to divalent lead and cadmium

Root mucilage material (RM) was isolated from maize plants grown in the field, and its affinity to montmorillonite (M) homoionic to Pb2+ and Cd2+ was compared with that of a commercial polygalacturonic acid (PGA). Adsorption isotherms of the commercial and natural materials on the two clay systems were compared in unbuffered systems at pH 3 and pH 6. Adsorption of PGA occurred only at pH 3, and was higher on M-Pb than on M-Cd. In contrast, the adsorption of RM was higher on M-Cd than on M-Pb. Total amounts of RM adsorbed at pH 3 were about 3 times lower on M-Cd and 20 times lower on M-Pb than the respective amounts of PGA adsorbed at the same pH. Polygalacturonic acid had a high content of relatively well dissociated (pKa = 3.5) carboxylic groups, and adsorbed on the clay surface at pH values lower than its pKa. At pH 6, the dissociation of the acid groups favoured its solubility, and the metal cations were then probably displaced by ion exchange. The lower affinity of RM to the clay materials was related to its average molecular weight, which was lower than that of PGA, and to its water solubility, which was higher than that of PGA. The low pH dependence of the adsorption of RM was related to its lower carboxylic acidity and higher content in hydroxyl and amino groups.