Sample pre-treatment and the determination of some chemical properties of acid sulfate soil materials

Soil Research ◽  
2004 ◽  
Vol 42 (6) ◽  
pp. 667 ◽  
Author(s):  
Crystal A. Maher ◽  
Leigh A. Sullivan ◽  
Nicholas J. Ward
Keyword(s):  
Organic Matter ◽  
Chemical Properties ◽  
Water Soluble ◽  
Acid Sulfate Soil ◽  
Acid Sulfate ◽  
Systematic Analysis ◽  
Oven Drying ◽  
Soluble Sulfate ◽  
Pre Treatment

This study provides a systematic analysis of the effect of common acid sulfate soil (ASS) sample pre-treatments (namely freezing, oven drying, and grinding) on chromium-reducible sulfur (SCR) and water-soluble sulfate determinations. The results show that oven drying and hand grinding of the samples prior to analysis resulted in a decrease in SCR (i.e. up to 20% compared to those of frozen samples). This lower SCR value was partly due to the oxidation of sulfides in the oven. For oven-dried ASS materials, more intensive grinding in a ring mill increased SCR values, most likely by abrading coatings from pyrite grains. For oven-dried mineral ASS materials the highest SCR values were obtained with 1 min of ring mill grinding, but for soils with appreciable organic matter (such as peat), 5 min of ring mill grinding gave the highest values. The results indicate that for some ASS materials, oven drying, regardless of the ensuing grinding procedure, results in underestimated SCR values. This study also demonstrates that an artifact of oven drying ASS materials can be greatly increased water-soluble sulfate contents.

scholarly journals Chemical characterization of fine particular matter in Changzhou, China and source apportionment with offline aerosol mass spectrometry

2016 ◽  
Author(s):  
Zhaolian Ye ◽  
Jiashu Liu ◽  
Aijun Gu ◽  
Feifei Feng ◽  
Yuhai Liu ◽  
...  
Keyword(s):  
Trace Elements ◽  
Organic Matter ◽  
Organic Carbon ◽  
Source Apportionment ◽  
Major Ions ◽  
Chemical Properties ◽  
Chemical Characterization ◽  
Water Soluble ◽  
Traffic Emissions ◽  
Aerosol Mass

Abstract. Knowledge on aerosol chemistry in densely populated regions is critical for reduction of air pollution, while such studies haven't been conducted in Changzhou, an important manufacturing base and polluted city in the Yangtze River Delta (YRD), China. This work, for the first time, performed a thorough chemical characterization on the fine particular matter (PM2.5) samples, collected during July 2015 to April 2016 across four seasons in Changzhou city. A suite of analytical techniques were employed to characterize organic carbon / elemental carbon (OC / EC), water-soluble organic carbon (WSOC), water-soluble inorganic ions (WSIIs), trace elements, and polycyclic aromatic hydrocarbons (PAHs) in PM2.5; in particular, an Aerodyne soot particle aerosol mass spectrometer (SP-AMS) was deployed to probe the chemical properties of water-soluble organic aerosols (WSOA). The average PM2.5 concentrations were found to be 108.3 μg m−3, and all identified species were able to reconstruct ~ 80 % of the PM2.5 mass. The WSIIs occupied about half of the PM2.5 mass (~ 52.1 %), with SO42−, NO3− and NH4+ as the major ions. On average, nitrate concentrations dominated over sulfate (mass ratio of 1.21), indicating influences from traffic emissions. OC and EC correlated well with each other and the highest OC / EC ratio (5.16) occurred in winter, suggesting complex OC sources likely including both secondarily formed and primarily emitted OA. Concentrations of eight trace elements (Mn, Zn, Al, B, Cr, Cu, Fe, Pb) can contribute up to 6.0 % of PM2.5 during winter. PAHs concentrations were also high in winter (140.25 ng m−3), which were predominated by median/high molecular weight PAHs with 5- and 6-rings. The organic matter including both water-soluble and water-insoluble species occupied ~ 20 % PM2.5 mass. SP-AMS determined that the WSOA had an average atomic oxygen-to-carbon (O / C), hydrogen-to-carbon (H / C), nitrogen-to-carbon (N / C) and organic matter-to-organic carbon (OM / OC) ratios of 0.36, 1.54, 0.11, and 1.74, respectively. Source apportionment of WSOA further identified two secondary OA (SOA) factors (a less oxidized and a more oxidized OA) and two primary OA (POA) factors (a nitrogen enriched hydrocarbon-like traffic OA and a cooking-related OA). On average, the POA contribution overweighed SOA (55 % vs. 45 %), indicating the important role of local anthropogenic emissions to the aerosol pollution in Changzhou. Our measurement also shows the abundance of organic nitrogen species in WSOA, and the source analyses suggest these species likely associated with traffic emissions, which warrants more investigations on PM samples from other locations.

scholarly journals Status and Speciation of Silicon and Its Interaction with Physico-Chemical Properties

2021 ◽  
pp. 1-11
Author(s):  
Isaiah Ufuoma Efenudu ◽  
Ehi Robert Orhue ◽  
Ogochukwu Jennifer Ikeh ◽  
Michael Aimiesomon Erhayimwen ◽  
Blessing James
Keyword(s):  
Organic Matter ◽  
Acidic Medium ◽  
Soil Depth ◽  
Chemical Properties ◽  
Water Soluble ◽  
Sequential Fractionation ◽  
Soil Redox ◽  
Parent Materials ◽  
Physico Chemical ◽  
Negative Effect

The effectiveness of three different extractants soil mixtures—HCl, HCl + H2S04, and DTPA-TEA, in order to determine Si from soil and the forms of Silicon as influenced by different parent materials under acidic medium. Seven forms of Silicon; namely water soluble, specifically adsorbed, oxides bound, organic matter bound, exchangeable, residual, total viz sequential fractionation. Extractable Si value established in this study was (50.0 mg kg-1), indicating negative effect on plant physiology. The physico-chemical properties decreased significantly with increase in soil depth vs soil parent materials. In addition, the forms of Si in the parent materials decreased in the pattern RES, bound residual fractions > EXC, soluble & exchangeable fractions > OM, organic matter fraction. Among the properties the silt fraction, pH & OM significantly and positively correlated with the forms of silicon, with negative correlation vs clay which maybe due to silicon adsorption by clayey fraction of the soil (redox). Therefore the soil maybe be maintained and conserved for farming activities.

Effects of microorganism within organic matter on the mechanical behaviour of solidified municipal dredged mud

2020 ◽  
Vol 57 (12) ◽  
pp. 1832-1843 ◽  
Author(s):  
Yongfeng Deng ◽  
Jun Wu ◽  
Yunzhi Tan ◽  
Yujun Cui ◽  
Chao-sheng Tang ◽  
...  
Keyword(s):  
Organic Matter ◽  
High Throughput Sequencing ◽  
Ph Value ◽  
Treatment Method ◽  
Drying Method ◽  
Oven Drying ◽  
Microbial Identification ◽  
Loading Method ◽  
Pre Treatment

Municipal mud consists of organic matter naturally deposited in a microbial-rich environment, and its common pre-treatment in the laboratory is normally different from that in situ. In this study, an improved pre-loading method and the common pre-treatment method (by air or oven drying) were first applied to investigate the effect of microorganisms within organic matter on performance of the solidified soils. Results reveal that (i) Atterberg limits in the pre-loading method were higher than those in the drying method; (ii) the time-dependent strength became stable for the solidified soils pre-treated by the drying method, while strength decreased for the soils pre-treated by the pre-loading method; (iii) pH value of solidified soils by the pre-loading method decreased more significantly. After excluding the possible porosity influence on solidified soils, the effects of microorganisms within organic matter were investigated by microbial identification tests, including fluorescence detection and high-throughput sequencing. The pre-treatment procedure changed the vitality and diversity of microorganisms, leading to a rebalance between acid erosion and cement hydration during long-term curing. At the end, the long-term strength of the solidified municipal mud by the traditional pre-treatment method (by air or oven drying) could be overevaluated.

scholarly journals CONVERSION CALCIUM CARBONATE AS FILLER OF THERMOPLASTICS

2017 ◽  
Vol 60 (4) ◽  
pp. 100 ◽  
Author(s):  
Lyudmila V. Rudakova ◽  
Sabukhi I. Niftaliev ◽  
Ekaterina S. Natarova
Keyword(s):  
Calcium Carbonate ◽  
Aqueous Extract ◽  
Chemical Properties ◽  
Total Content ◽  
Component Composition ◽  
Water Soluble ◽  
Preliminary Heat Treatment ◽  
Crushed Material ◽  
Wide Range

X-ray and laser diffraction methods were used to determine basic physical and chemical properties of conversion calcium carbonate. It was found that for obtaining standard product for use as a filler, it is necessary to regrind it. The results of dispersion changes in conversion chalk (chalk stone) were expressed in terms of median (D50), maximum (D98) and minimum (D10) particle size. It was established that during the grinding process a transition occurs from the initial odiomodal distribution to the bimodal distribution, which is characterized by a sufficiently wide range of the sizes of the particles of the crushed material. The optimum parameters of grinding were determined. With the help of SEM method, used before and after grinding of conversion calcium carbonate, it was established that the particles of primary material are represented by polycrystalline dense aggregates of spherical shape, due to mass crystallization of calcium carbonate at the condition of high supersaturation according to polynuclear growth mechanism. The component composition of water-soluble impurities was quantitatively estimated on the basis of the determination of the content of nitrate N-NO3- and ammonium N-NH4+ forms of nitrogen in various forms of presence-total, bound, water-soluble, and additional determination of the Ca2+ content of calcium ions in aqueous extract. It has been experimentally established that preliminary heat treatment of conversion calcium carbonate allows to significantly reduce the total content of water-soluble substances in the ground product by more than 5 times: at a temperature of 400 ° C, the degree of removal by NH4+ and NO3- ions is ~ 40-50%, and at 500 ° C - ~ 60% for NO3- and ~ 90% for NH4+. The estimation of the possibility of using the obtained product as a filler of polymer composite materials was done comparing the main parameters (CIELab  (W and L) color characteristics, bulk density, dispersed composition, specific surface, pH of aqueous extract) with known finely ground natural chalk and microcalcite. Forcitation:Rudakova L.V., Niftaliev S.I., Natarova E.S. Conversion calcium carbonate as filler of thermoplastics. Izv. Vyssh. Uchebn. Zaved. Khim. Khim. Tekhnol. 2017. V. 60. N 4. P. 100-107.

scholarly journals Studies on the Determination of Water-soluble Chloride and Water-soluble Sulfate in Food Blue No. 1 Aluminium Lake

1995 ◽  
Vol 36 (6) ◽  
pp. 717-724_1 ◽  
Author(s):  
Mika KIMURA ◽  
Mika UMEMOTO ◽  
Sumiko TSUJI ◽  
Tadashi SHIBATA ◽  
Makiko YAMADA ◽  
...  
Keyword(s):  
Water Soluble ◽  
Soluble Sulfate
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