Determination of Carbonate Concentrations in Calcareous Soils with Common Vinegar Test

Calcareous soils are those that have free calcium carbonate (CaCO3) and have pH values in the range of 7.0 to 8.3. If they are managed properly, calcareous soils can be used to grow any crop. Before employing any management practices, it is important to know how much carbonate exists in the soil. Soil carbonate is usually quantified by acid dissolution followed by the volumetric analysis of the released carbon dioxide (CO2). In geological sciences, a simple acid test consists of placing a drop of dilute hydrochloric acid on a rock or mineral and observing if there are CO2 bubbles released; the bubbles indicate the presence of carbonate minerals. The household test below uses vinegar and other simple instruments to estimate soil carbonate concentration. Minor revision with an added author.

Experimental study on modeling of Pu sorption onto quartz

Plutonium(IV) sorption onto quartz in carbonate solutions was systematically investigated under anaerobic conditions to analyze the sorption behaviors of Pu(IV) with a non-electrostatic model (NEM). Pu(IV) sorption data was obtained from batch sorption experiments as a function of pH and carbonate concentration. The Pu(IV) sorption onto quartz showed similar tendencies to Th(IV), which is considered to be chemically analogous as a tetravalent actinoid. The distribution coefficient, K d , of Pu(IV) onto quartz showed inverse proportionality to the square of the total carbonate concentration under the investigated pH conditions of 8–11. The modeling study, however, revealed a Th(IV) sorption model, which is ≡SOTh(OH)4 − and ≡SOThOH(CO3)2 2−, could not be applied to simulate the Pu(IV) sorption onto quartz. It was inferred that the electrostatic repulsion between negatively charged ligands limited the formation of ≡SOM(OH)4 − and ≡SOMOH(CO3)2 2− for Pu(IV) with smaller ionic radii than Th(IV). The Pu(IV) sorption model was developed as ≡SOPu(OH)3 and ≡SOPu(OH)4 −. In addition, data of Pu(IV) sorption onto muscovite was obtained in order to be compared with data for quartz.

Effect of Alkali Pollutant in Influencing Crack Propagation in Soils

Shrinkage, deformation, and cracking will occur under extreme climate conditions such as drought, due to the accumulation of salt inside the soil during the evaporation of water on the surface of the soil. In this study, the image processing method was used to quantitatively analyze the dehydration cracking process of clay polluted by alkaline pollutant sodium carbonate on the basis of experiments. The mechanism of the effect of sodium carbonate concentration on the shrinkage cracks of clay was discussed through the analysis and comparison of different concentrations of sodium carbonate samples. The results showed that the water loss and shrinkage cracks of alkaline contaminant clay were developed in different stages. Firstly, first-level cracks developed diagonally or parallel to the edge of the container, and then second-level cracks developed along the main cracks with an angle of close to 90°. Most of the third-level or higher-level cracks were approximately perpendicular to the second-level cracks or the edge of the container and developed in parallel. In the cracking stage, the water loss ratio of the sample had a good positive correlation with the surface crack ratio. The slope of the fitted curve increased with the increase of the sodium carbonate concentration. With the increase of sodium carbonate concentration, the water loss ratio and the width of first-level cracks of clayey soil decreased, and the total length and the number of cracks increased, while the surface cracking ratio increased first and then decreased.

Paper Mill Sludge as a Source of Sugars for Use in the Production of Bioethanol and Isoprene

Paper mill sludge (PMS) solids are predominantly comprised of cellulosic fibers and fillers rejected during the pulping or paper making process. Most sludges are dewatered and discharged into landfills or land spread at a cost to the mill; creating large economic and environmental burdens. This lignocellulosic residual stream can be used as a source of sugars for microbial fermentation to renewable chemicals. The aim of this study was to determine the possibility of converting mill sludge to sugars and then fermentation to either isoprene or ethanol. Chemical analysis indicated that the cellulosic fiber composition between 28 to 68% and hemicellulose content ranged from 8.4 to 10.7%. Calcium carbonate concentration in the sludge ranged from 0.4 to 34%. Sludge samples were enzyme hydrolyzed to convert cellulose fibers to glucose, percent conversion ranged from 10.5 to 98%. Calcium carbonate present with the sludge resulted in low hydrolysis rates; washing of sludge with hydrochloric acid to neutralize the calcium carbonate, increased hydrolysis rates by 50 to 88%. The production of isoprene “very low” (190 to 470 nmol) because the isoprene yields were little. Using an industrial yeast strain for fermentation of the sludge sugars obtained from all sludge samples, the maximum conversion efficiency was achieved with productivity ranging from 0.18 to 1.64 g L−1 h−1. Our data demonstrates that PMS can be converted into sugars that can be fermented to renewable chemicals for industry.

Phacotus lenticularis content in carbonate sediments and epilimnion in four German hard water lakes

Autochthonous calcite precipitation is an important process for C-fixation in hard-water lakes, which is mainly induced by the photosynthesis of planktonic microorganisms. Among these, the widespread calcifying green alga Phacotus lenticularis (Ehrenberg) Diesing contributes to biogenic calcite precipitation in temperate regions. Its role in carbonate precipitation needs to be investigated, because there are no studies dedicated to the quantitative contribution of Phacotus shells to long term carbonate sequestration in hard-water lake sediments. In order to fill this gap, the Phacotus shell content in the sediments of four German hard-water lakes was determined and compared to the fraction of Phacotus shells in the total suspended autochthonous calcite of the euphotic zone.It was found that the Phacotus shells contributed at least 10% to the autochthonous carbonate precipitation in the upper water column in three investigated lakes. During a Phacotus mass occurrence with a cell density of 1.8 × 106 Ind L-1 in Lake Hopfensee, even 59% of the 3.6 mg L-1 total carbonate concentration consisted of Phacotus shells. In contrast to this high amount, the topmost basinal sediment contained a Phacotus shell content between 80 and 36,252 individuals per mg dry sediment, representing only 0.02% to 2.28% of the total carbonate sediment content. In a gravity core from Lake Grosser Ostersee, dating back ~150 years, the Phacotus shell content was continuously below 0.24% whereas the shell diameters remained equal to those of living individuals found in the water column proving that Phacotus shells are capable to persist in the sediment after deposition.A main reason for the large discrepancy between Phacotus shell abundance in the euphotic zone and in sediment was found to be the gross authigenic carbonate precipitation, which dilutes the sedimenting Phacotus shells that accumulate exclusively during short and intensive population peaks in summer. Additionally, dissolution of the carbonate shells during sedimentation was proven to be a relevant factor in Lake Igelsbachsee by means of reducing the number of Phacotus shells reaching the lake bottom. These facts explain that short-term high Phacotus carbonate contents of the total suspended carbonate in the water column do not mirror the contribution of Phacotus shells in the sedimentary record.

Groundwater anomaly related to the 2018 Hokkaido Eastern Iburi earthquake in Northern Japan

<p>In order to study groundwater anomaly related to the 2018 Hokkaido Eastern earthquake (Mw6.6) occurred on 6<sup>th</sup> September, we have measured δD and δ<sup>18</sup>O values of commercial bottled mineral water at two sites in Iburi region, Hokkaido, Northern Japan from June 2015 to May 2019. At the Uenae site, 21km west of the epicenter, both δD and δ<sup>18</sup>O values are constant from June 2015 to February 2018. Then these values have decreased substantially from April 2018 to December 2018 with significant fluctuations. These variations may be attributable to a mixing of groundwater with light δD and δ<sup>18</sup>O values. At the Eniwa site 34km northwest of the epicenter, δD values have decreased slightly and monotonically, while δ<sup>18</sup>O values are constant from June 2016 to October 2018. Observed isotopic variations of the Uenae site are different from those found at the 2016 Tottori earthquake where the δ<sup>18</sup>O value of groundwater increased a couple of months before the seismic event, while the δD value was constant. These data were attributable to water-rock interaction in the aquifer. Thus, the mechanism of groundwater isotopic anomaly may be different between Tottori and Hokkaido earthquakes. In addition to the M6.7 earthquake, CO<sub>2</sub> injection by CCS project at Tomakomai, 13km southwest of the Uene site may be another factor to induce such variations. In order to evaluate the environmental impact of CO<sub>2</sub> injection, we should measure total carbonate concentration and δ<sup>13</sup>C value of carbonate at both sites. Then we will discuss mechanism of groundwater anomaly.</p>

ANALISIS KONDISI RESERVOIR PANAS BUMI DENGAN MENGGUNAKAN DATA GEOKIMIA DAN MONITORING PRODUKSI SUMUR ELS-02 LAPANGAN ELSA

<p><em>A</em><em> good reservoir management is needed </em><em>to maintain</em><em> the </em><em>availability and </em><em>quality of geothermal production fluid. When producing geothermal fluids, there are some changes in reservoir parameters such as declining of reservoir pressure and temperature, chemical composition of geothermal fluids, </em><em>and </em><em>states of fluid that would affect the quality of reservoir by mixing, boiling, or cooling processes that may be happened </em><em>because of</em><em> those changes. </em><em>It is</em><em> becoming a concern on reservoir management. In this case, chemical </em><em>concentrations </em><em>of fluid</em><em>s</em><em> monitoring is one of methods that can perform to reach a well reservoir management of geothermal field. With </em><em>chemical </em><em>monitoring process, current reservoir condition and processes </em><em>that </em><em>occurred during exploitation can be defined</em><em>. In ELS-02 by monitoring and analyzing its enthalpy changes, chloride concentration changes, and NCG concentration changes and supported by its calcium, sulphate, and carbonate concentration profile, two processes could be defined:</em><em> </em><em>mixing with </em><em>surface </em><em>cooler water and reinjection breakthrough.</em><em> </em><em>Other than that, casing leak that causing surface water enter the well could be detected. </em><em>These become a sign to reservoir engineer to prepare for problems that may occur in near time </em><em>term </em><em>relating to well problem </em><em>such as scaling </em><em>and long time problem like massive cooling or drying of reservoir. After all, further development scenario of Elsa field can be made to improve its performance in producing fluids and heats. </em></p><p> </p>

Removal of Phosphorus from High-Phosphorus Manganese Ores by Ammonia-Ammonium Carbonate Leaching Method

High-phosphorus manganese ores provide an important source of manganese, which is regarded as an irreplaceable material in the steel industry. The ammonia-ammonium carbonate leaching method was proposed for the removal of phosphorus and extracting manganese from high-phosphorus manganese ore, both effectively and environmentally. To explore the dissolution behavior of phosphorus and manganese in the ammonia-ammonium carbonate solution, the effect of the ammonia-to-ammonium carbonate concentration ratio, the leaching temperature, and the liquid-to-solid ratio on manganese extraction and dephosphorization rate were investigated. In addition, the composition of precipitated manganiferous sample, which was obtained from high-phosphorus manganese ores by ammonia-ammonium carbonate leaching process, was also studied. The results indicated that more than 99.2% phosphorus was removed and more than 83.5% of manganese was extracted by ammonia-ammonium carbonate leaching under the following conditions: ammonia to ammonium carbonate concentrations: 14:2 mol/L; liquid/solid ratio: 5:1 mL/g; leaching temperature: 25 °C; The precipitated manganiferous sample has little impurities, Mn% is 44.12%, P% is 0.02%, P/Mn = 0.00045.