Multiscale investigation on the formation path of the apatite phase in bioactive glasses

In this study, variation in microstructure, diffusion of chloride (Cl−) ions, and binding of chloride in concrete exposed to solutions containing MgSO4 (MS) in NaCl (NC) under the wetting-drying cycle are analyzed and reported. The results reveal that the amount of compounds such as ettringite (E), calcium hydroxide (CH), gypsum (G), calcite (CC), and calcium chloroaluminate (CCA) varies with the depth of concrete from the exposure face. Among exposure solutions, the amount of E was higher in NC + MS solutions compared with NC solutions and with increased MS content. The amount of CCA was higher in NC solutions compared with NC + MS solutions with an increase in NC content. The amount of CH was higher in concrete subjected to NC + MS solutions than to NC solutions and decreased with an increase in NC content. The amount of CCA was mostly higher in ordinary portland cement (OPC) with 20% fly ash concrete (O20FA-C) than in OPC concrete (OPC-C) followed by portland pozzolana cement (PPC) concrete (PPC-C). The amount of E was higher in O20FA-C than in PPC-C followed by OPC-C. Free chloride content (Cf) and apparent chloride diffusion coefficient (D) were reduced in the presence of MgSO4 mainly due to the effect of filling of pores with E. PPC-C exhibited better performance against ingress of chloride (Cl−) ions than that of O20FA-C followed by OPC-C. MS in exposure solutions reduced chloride binding. The concrete made with OPC exhibited higher chloride binding than O20FA followed by PPC.

Lightweight cellular hollow concrete (LCHC) block is a type of masonry unit that has excellent thermal and acoustic performance, fire resistance and high weathering resistance, and manufactured by precast technique. This work presents an experimental study, which investigates the effects of volumetric partial replacement of Portland cement by calcium sulfate anhydrite on precast properties, especially hardening time of the products, thermal insulation properties and mechanical properties of the blocks. LCHC block is produced by the mixing of Portland cement (PC), anhydrite III (ANH), expanded perlite (EP), pumice (PU) and calcite (CA) for building applications. The physical and mechanical properties of LCHC blocks having various replacement levels of ANH are studied. Experimental studies were carried out on both 10x10x10 cm3 cube specimens and 19x19x39 cm3 block specimens. In this research work, LCHC blocks with 16 different mixture batches were cast into a mould with vibro-compacting, de-moulded immediately and transferred to a storage area for curing up to 28 days in normal air condition. The unit weights and compressive strengths of the cube specimens decreased as the ANH replacement level increased, depending on the decrease in the cement ratio. However, it was observed that the compressive strength of the block specimens increased up to the volumetric replacement level of 1.86 %. As expected, the thermal conductivity values of the specimens decreased with the decrease in unit weight. The most notable change on the specimens occurred in the hardening time. The hardening process of the specimens can be completed up to 90 times faster than the control mixture. In addition, within the scope of the study, three formulations are presented in which the compressive strength and the elastic modulus of the wall sections made with LCHC blocks can be calculated, and thermal conductivity value of masonry block unit can be calculated.

The in situ chemical immobilization method reduces the activity of heavy metals in soil by adding chemical amendments. It is widely used in farmland soil with moderate and mild heavy metal pollution due to its high efficiency and economy. However, the effects of different materials depend heavily on environmental factors such as soil texture, properties, and pollution levels. Under the influence of lead–zinc ore smelting and soil acidification, Cd is enriched and highly activated in the soils of northwestern Guizhou, China. Potato is an important economic crop in this region, and its absorption of Cd depends on the availability of Cd in the soil and the distribution of Cd within the plant. In this study, pot experiments were used to compare the effects of lime (LM), apatite (AP), calcite (CA), sepiolite (SP), bentonite (BN), and biochar (BC) on Cd accumulation in potatoes. The results showed that the application of LM (0.4%), AP (1.4%), and CA (0.4%) had a positive effect on soil pH and cations, and that they effectively reduced the availability of Cd in the soil. In contrast, the application of SP, BN, and BC had no significant effect on the soil properties and Cd availability. LM, AP, and CA treatment strongly reduced Cd accumulation in the potato tubers by controlling the total ‘flux’ of Cd into the potato plants. In contrast, the application of SP and BN promoted the migration of Cd from the root to the shoot, while the effect of BC varied by potato genotype. Overall, calcareous materials (LM, CA, and AP) were more applicable in the remediation of Cd-contaminated soils in the study area.

Contamination of soils by nickel (Ni) has become a serious environmental problem throughout the world, and this substance wields dangerous effects on the ecosystem and food chain. A pot experiment was conducted to examine the effect of rice straw (RS), rice straw biochar (BI), and calcite (CC) at 1% and 2% application rates in a Ni-contaminated soil. The objective was to potentially stabilize Ni and reduce its bioavailability to spinach (Spinacia Oleracea L.). Spinach plants were grown in a Ni-contaminated Ultisol (commonly known as a red clay soil). Plant growth parameter results indicated that a BI 2% application rate significantly increased the root and shoots dry biomass increased by 1.7- and 6.3-fold, respectively, while essential nutrients were enhanced in the spinach plant compared to those in the untreated soil (CK). Moreover, adding amendments significantly decreased CaCl2 extractable Ni by 62.5% 94.1%, and 87.2%, while the toxicity characteristics leaching procedure (TCLP) fell by 26.7%, 47.8%, and 41.7% when using RS, BI, and CC, respectively, at 2% compared to CK. The Ni concentrations in the spinach roots declined by 51.6%, 73.3%, and 68.9%, and in the shoots reduced by 54.1%, 76.7%, and 70.8% for RS, BI, and CC, at a 2% application rate, respectively. Bio-concentration factor (BCF) and translocation factor (TF) dropped significantly by as much as 72.7% and 20%, respectively, for BI 2% application rate. Results of the present study clearly indicated that biochar potential soil amendments for Ni stabilization, thereby reducing its bioavailability in the Ni-contaminated soil. This process enhanced the safety of food to be consumed and mitigated security risks.

The presence of Ni above the permissible limit in agriculture soils poses negative effects on soil health, crop quality, and crop productivity. Surprisingly, the usage of various organic and inorganic amendments can reduce Ni mobility in the soil and its distribution in the crops. A pot experiment was conducted to elucidate the effects of olive pulp biochar (BR), calcite (CAL), and wheat straw (WS), as sole amendments and their mixtures of 50:50 ratio, added to Ni polluted soil on Ni mobility in the soil, Ni immobilization index (Ni − IMi), soil enzymatic activities, Ni distribution in parts of chili plant, Ni translocation factor and bioaccumulation factor in fruit, plant growth parameters and oxidative stress encountered by the plants. Outcomes of this pot experiment revealed that amendments raised soil pH, improved soil enzymatic activities, values of Ni − IMi, while significantly reduced bioavailable Ni fraction in the post-harvest soil. However, the highest activities of acid phosphatase, urease, catalase, and dehydrogenase by 50, 70, 239, and 111%, respectively, improvement in Ni − IMi up to 60% while 60% reduction in the bioavailable Ni fraction was observed in BR + CAL treatment, compared to control was noted. Among all amendments, the top most reduction in Ni concentrations in shoots, roots, fruit, Translocation Factor (TF), and Bioaccumulation Factor (BAF) values of fruit by 72%, 36%, 86%, 72%, and 86%, in BR + CAL treatment, compared to control. Moreover, the plants growing on BR + CAL amended Ni contaminated soil showed the topmost improvement in plant phonological parameters while encountered the least oxidative stress. Such findings refer to the prospective usage of BR + CAL at 50:50 ratio than BR, CAL, WS alone, and BR + WS as well as WS + CAL for reducing Ni mobility in the soil, improving Ni − IMi, soil enzymatic activities, plant phonological and oxidative stress while reducing Ni distribution in plant parts. Novelty statement In this experiment, it was hypothesized that amending Ni polluted soil with olive pulp biochar (BR), CAL, and WS as alone soil amendments and their combinations at 50:50 ratios can reduce Ni bioavailability in soil, Ni distribution in chili plant and oxidative stress encountered by the plants. Moreover, these amendments may improve, soil enzymatic activities, Ni immobilization index, plant phenological traits. Therefore, it was aimed to undertake useful scientific planning and research, to restore and rehabilitate the dwellings, biological resources and to minimize the sufferings of the peoples in nutrient-poor Ni contaminated soils, by improving soil health and chili productivity.

Scale deposition in water pipe due to hard water circulation often leads to various technical and economical problems. The conventional chemical treatment methods uses hazardous chemical which affects human health as well as water chemistry. This study shows the effect of physical water treatment method like pulsating electromagnetic field on water characteristics and scale reduction under different turbulent flow conditions and pipe materials. The scale removal rate was analyzed by the formation of aragonite crystal in water pipes in place of calcite crystals after electromagnetic treatment. The morphology of aragonite and calcite crystals was analyzed by field emission scanning electron microscope on different pipe materials. The water flow rate was maintained at 3, 5 and 7 L/min. After electromagnetic treatment result shows that the scale removal rate increases from pipe wall and reduces the total dissolved solids (TDS), electrical conductivity (EC), hardness and alkalinity of water. These water characteristics are further decreases on increasing the flow rate from 3 to 7 L/min. The reduction rate of these water characteristics was higher for the first 15 hours of circulation time than the remaining 15 hours. On investigating the effect of electromagnetic treatment on pipe material, it was obtained that the polyvinyl chloride (PVC) pipe is much effective than galvanized iron (GI) and copper pipes.

Regarding the generally accepted view of the minerals formed in solving the problem of ecosystem pollution, this research aims to track the role of seasonal minerals in overcoming widespread pollution problems in Lake Edku. At eleven locations inside Lake Edku and three locations in the outside the water inlets, some physical and chemical parameters that affect the formation of minerals and salts were detected seasonally. As a result of human activities from 1972 to 2020, the applied remote sensing technology showed a decrease in the area of Edku Lake by 13.3%. The saturation index (SI) of twelve minerals formed in fifty-six seasonal water samples collected from fourteen locations inside and outside the lake was estimated. The saturation index (SI) of anhydrite (ANH), gypsum (GYP), calcium phosphate (CP), magnesium phosphate (MP), calcite (CAL), aragonite (ARG), dolomite (DOL), magnesite (MGS), fluorapatite (FAP), hydroxyapatite (HAP), octacalcium phosphate (OCP), and carbonate-fluorapatite (CFAP) was calculated. The presented SI values of apatite and phosphate minerals including FAP (SI 30.63-65.65), CFAP (SI 28.14-40.02), HAP (SI 24.83-31.81), Ca3(PO4)2 (SI 23.99-25.95), OCP (SI 19.96-25.47), and Mg3(PO4)2 (SI 15.80-17.46) were high. Palmer-Roger's diagram and piper ternary diagram models reflected the abundance of NaCl in lake water with 30, 40, 46, and 75% in winter, spring, summer, and autumn, respectively. Using correlation matrix, multiple stepwise regression and cluster analysis for statistical analysis, the relationship between sedimentary minerals and outflow and drainage, as well as the role of sedimentary minerals in reducing pollution in the lake area, was outlined.

The calcareous soil of coast reef is limited in distribution, and is seldom used in engineering and lacks engineering geological research. In order to find out the spatial distribution and physical and mechanical characteristics of the calcareous soil on the coast reef, and service design, we referred to the results of previous studies on calcareous soils and collected the existing geological data in Timor-leste, and carried out field geological survey, drilling, standard penetration test and laboratory physical and mechanical test. We have studied the landform, spatial distribution, mineral chemical composition, grain size distribution, specific gravity, permeability coefficient and shear strength of calcareous soil in Timor-leste coast reef. We have summarized the physical and mechanical characteristics of calcareous soil in coast reef under the landform of sand dam and lagoon. Our study results are as following:(1)The landform of Timor-leste coast reef has its own characteristics. The land is low hill landform, the coast area is bay landform. The bay has developed sand bar, sand beach and lagoon. (2)The study area has developed six unit layers from top to bottom in the stratigraphic space:Unit 1 modern calcareous gravelly sand on the surface of sand bar, Unit 2 very soft to soft clay/silt at the lagoon surface, Unit 3 thick layers of calcareous gravelly sand in the upper part, Unit 4 silty/clayey gravelly sand/grave at the middle part, Unit 5 sitly/clay gravelly sand/grave at the lower part and Unit 6 highly to moderately weathered phyllite at the bottom. (3)The calcareous soil in Timor-leste is composed of pebbled sand lithologically and gravel locally, containing about 19% fine-grained soil. The mineral composition is mainly aragonite and calcite, followed by mica and quartz. The sediment is mainly derived from marine coral clasts and partly from terrestrial sediments. Calcareous soils, similar to atolls and barrier reefs, are also characterized by the presence of land-based sediments. (4)The special gravity of calcareous soil on coast reef is 2.70,which is larger than quartz sand, reflecting the unique special gravity formed by different mineral composition. (5)Coast-reef calcareous soil is mainly medium sand, coarse sand and gravel, but the permeability coefficient is lower than the conventional value due to the presence of more fine grains. Attention should be paid when filling. (6)The cohesion of calcareous gravelly sand of coast reef is 0, and the internal friction Angle is 33 degrees in loose state, 36 degrees in dense state, and 41 degrees in dense state, which is similar to the mature empirical evaluation of quartz gravelly sand. Our studies show that the calcareous soil in Timor-leste coast reef contains some feldspar, quartz. The mechanical strength of rock and soil is similar to that of conventional quartz sand. The empirical relationship of rock and soil parameters evaluated by the quartz sand in situ test can be applied to the calcareous soil of east Timor shore reef with reliable results. The determination of the physical and mechanical properties of calcareous soil in timor-leste coast reef provides a reference for similar types of calcareous soil geotechnical engineering applications.

The data-set contains the 3D reconstruction of seawater micro-droplets on cleaved calcite in n-decane measured with AFM which can be used for the assessment of pinning effects along the three-phase contact line. The reconstruction was created from force-distance curves obtained at each pixel of the AFM image following the description in the referenced paper. The reconstruction has the dimensions 1024x1024x1024 and a voxel size of 0.0383 μm × 0.0383 μm × 0.0383 μm with the values 0,1,2 representing n-decane, calcite and seawater respectively. Further, the data-set contains the original height map of the calcite surface underneath the droplet with greater accuracy with the dimensions 128 x 128, a pixel size of 0.29 μm x 0.29 μm. We recommend applying a median filter to remove instrumental artefacts. In combination, the reconstruction allows for small scale contact angle measurements and to correlate these measurements to the natural roughness of cleaved calcite.

In the paper, an investigation of copper metallurgical slags found in the South Urals and dating to the Bronze Age between 4000 and 1300 BCE is carried out. Four main mineralogical types are distinguished according to their mineral composition: Cr-rich spinel containing olivine, sulphide-containing olivine, sulphide containing glassy and pyroxene type. First type of slags is composed of zoned olivine, magnetite and glass having relicts of Cr-rich spinels and serpentinites that indicate the use of azurite-malachite ores from ultrabasic rocks. These finds were determined in sites of the Early Yamna period in the Cis-Urals and are widespread in Sintashta culture. The second type is composed of skeletal olivine crystals, magnetite and wustite with copper sulphides droplets. It type belongs to Alakul period. The raw material sources are sulphide ores from a secondary enrichment zone of VMS, skarn and Cu-porphyry deposits. The sulphide containing glassy type is mainly composed of glass with copper and sulphide droplets. The slags were recovered in the Srubna sites. The raw material sources were rich sulphide ores of cupriferous sandstones. The pyroxene type is composed of augite, pigeonite and/or wollastonite with a small amount of glass and sulphide inclusions. According to the composition of glass, slags can be distinguished into the Cis-Uralian type, including cupriferous sandstones, and Trans-Uralian type having various volcanogenic-hydrothermal deposits as raw materials. Essential Ca, P, Ba and REE impurities in slag glass demonstrate the use of barite, calcite and bone fluxes. The phase diagrams, crystallisation temperatures and experimental data revealed that slag melt temperatures ranged between 1150–1300 ° C.

For decades, the streams and rivers in northern areas of Pakistan are being explored for gold but the source rock for primary gold is yet to be located. Recent geological surveys have identified several areas for follow-up study for Cu-Au mineralization in Chitral and Gilgit-Baltistan regions. The rocks exposed at various localities are variably altered and/ or mineralized and intensely deformed, which mostly include diorite, granodiorite, greenschists, limestones and undeformed volcanic rocks and granitoids of the Kohistan island arc. The results of petrographic and X-ray diffraction (XRD) analyses of a variety of representative rock samples from a number sites have revealed that mineralization in the Chitral and Gilgit-Baltistan regions is dominantly in the form of pyrite, tetrahedrite, chalcopyrite and galena with subordinate amounts of magnetite, malachite and azurite. The associated/ gangue minerals include albite, quartz, actinolite, biotite, chlorite, epidote, calcite, garnet, illite and titanite (sphene). Diffraction patterns of glycolated samples did not show the existence of swelling clay (e.g., smectite). Sericitic, chloritic and carbonatic alterations have been observed in the studied altered rocks. Mass balance calculations indicate that most of the sulfide-bearing samples are enriched in Cu, Au, Sb, As and Pb and depleted in the rest of the metals reflecting differences in elements mobility during the ore-forming processes. Some of the mineralized rocks especially limestone have experienced a significant volume change due to mobilization of some of the major element oxides e.g. CaO, Fe2O3, SiO2 and ore-forming components e.g. Cu and Pb. The mineralization is of epithermal type in most of the investigated sites, however a few areas show ore formation though orogenic processes and very rarely the ore deposit displays features of the volcanogenic massive sulfide type. Some of the areas are quite promising with respect to their ore element contents and the highly mineralized zones lie in close proximity to major structures in the region. Besides, results from the current study indicate that the mineralization shows close spatial association and hence a strong genetic link with strike slip faults especially where they bend and merge together.

The Shurijeh Formation is a Late Jurassic-Early Cretaceous (Late Kimmeridgian-Hauterivian) siliciclastic rock unit of the Kopet-Dagh Basin, up to 392 m thick. In the Estarkhi section, it rests disconformably on the Mozduran carbonate Formation (Oxfordian), and is disconformably overlain by carbonate rocks of the Tirgan Formation (Barremian-Aptian). The sandstones are predominantly subarkose, sublitharenite, feldspathic litharenite and litharenite with minor quartzarenite, rich in quartz and feldspars, sedimentary and igneous rock fragments (plutonic), and rarely metamorphic fragments. Based on petrological and geochemical studies, minor diagenetic events in the early diagenetic stage include cementation by calcite and iron oxide. Deep Burial diagenetic events were dominated by compaction, cementation (silica, dolomite, chlorite), fracturing, dissolution, pressure solution, and albitization. Minor late diagenetic events include dissolution and cementation (calcite, iron oxide). Based on diagenetic events a temperature of >80°C during burial diagenesis is suggested for Shurijeh Formation. Existing porosity is secondary, resulting largely from dissolution of feldspar and carbonate cement, with some fracture porosity. Porosity and permeability of 11 core plugs averages 7.78% and 4.84 md, and the point count of 38 thin sections shows an average porosity of 10.05%. The good porosity and permeability of the middle part of the section predict an acceptable reservoir potential for this formation in the study area.

کربنات‌های سازند جهرم به سن ائوسن و سازند آسماری به سن الیگوسن- میوسن، مخازن میدان خشت را در ناحیة فارس واقع در حوضة فورلندی زاگرس تشکیل می‌دهند. در این پژوهش ویژگی‌های مخزنی بخش بالایی سازند جهرم در میدان خشت براساس تلفیق نتایج آنالیز رخساره‌ای و ویژگی‌های دیاژنزی نمونه‌ها در چهارچوب تخلخل و تراوایی بررسی شده است. سازند جهرم در پهنة فارس با لیتولوژی غالب آهکی در یک رمپ کربناته با تغییرات زیاد در ویژگی‌ها و کیفیت مخزنی نهشته شده است. بررسی‌های پتروگرافی به شناسایی پنج ریزرخسارة کربناته منجر شد. پنج گروه سنگی در چاه خشت-2 با در نظر گرفتن کنترل‌کننده‌های اولیه و ثانویه در توزیع نوع و اندازة منافذ شناسایی شد. از گونة سنگی 1 به سمت گونة سنگی 5، کیفیت مخزنی افزایش می‌یابد. دیاژنز به دو صورت افزاینده و کاهندة تخلخل و تراوایی بر کیفیت مخزنی تأثیر گذاشته است. کراس پلات تخلخل و تراوایی همراه با بررسی‌های پتروگرافی مقاطع نازک نشان می‌دهد توسعة سیمان انیدریتی به‌صورت فراگیر و تراکم، بیشترین تأثیر را بر کاهش کیفیت مخزنی داشته‌اند؛ در حالی که دولومیتی‌شدن، شکستگی و انحلال نومولیتس‌ها نقش مهمی در افزایش کیفیت مخزنی ایفا کرده‌اند؛ بنابراین ویژگی‌های کلی مخزن جهرم در میدان خشت، عمدتا با ویژگی‌های دیاژنتیکی شکل گرفته است. استفاده از نرم‌افزار سیکلولاگ در چاه خشت-2 و چاه کمکی خشت-3 به شناسایی دو چرخة رسوبی برای سازند جهرم منجر شد. روند منفی منحنی تغییر طیفی (پایین‌آمدن سطح آب دریا) در چرخة رسوبی دوم دربرگیرندة بخش بالایی سازند جهرم (توالی مطالعه‌شده) است که کیفیت مخزنی متوسط تا بالایی دارد.

The paper describes a new technique for processing experimental data on sorption capacity (E) of variously composed natural soils in relation to heavy metals in aqueous solutions. The calculation scheme is based on an inhomogeneous system of equations, compiled from the data on mineral composition of soils and the E values. Such a system of equations was compiled for the experimental data on the sorption characteristics of natural soils (as suspensions) with respect to Cu2+ ions (of up to 1000 mg/l) from CuSO4·5H2O solutions. The highest sorption characteristics with respect to Cu2+ ions from solutions of CuSO4·5H2O were associated with uneven-grained aggregates of calcite and chlorite followed by quartz and montmorillonite; dolomite and hydromica had the lowest sorption characteristics.

calcite U-Pb and trace-element data from tectonic veins in Thailand

The mineral calcite was evaluated for recrystallization, a process known to change the location of ions in the mineral lattice without apparent change in mineral chemistry. Calcite lattice reconfiguration is cause for concern because it is a ubiquitous mineral with considerable reactivity that plays an important role in contaminant uptake and possible release. The intrinsic factor, crystal growth, and extrinsic factor, pH, were selected as possible driving forces for calcite recrystallization. Calcite growth experiments were conducted using a dual syringe pump technique. Geochemical analysis revealed calcite growth to be affected by syringe pump rate, a variable that showed no correlation with surface roughness. In order to trace recrystallization of laboratory grown calcite, an ion exchange technique with 45Ca radioisotope and a separate 40Ca stable isotope concentration analysis were used during resuspension batch experiments. There was no evident change in any of the radioisotope tracer experiments, indicating calcite stability. Additionally, 40Ca stable isotope concentration measurements support the same idea of calcite stability and its ability to maintain dynamic equilibrium.

Taiyuan Basin is a Cenozoic fault basin. The formation of faults block and horst in the basin is controlled by the north-south and east-west faults. The karst thermal mineral water is mainly distributed in the area between the Sanji horst and the Tianzhuang fault. The main aquifers of karst thermal water are the carbonate of the Ordovician Fengfeng group, the upper and lower Majiagou groups. We took 18 geothermal water samples in the field, and collected the hydrochemical data of 9 geothermal water and 3 geothermal water in the existing literature. According to the analysis and test results, the hydrochemical type of karst thermal water is SO4-Ca ·Mg type. According to the ion concentration relationship and the saturation index of the main mineral in the thermal mineral water, it can be inferred that the hydrochemical type is mainly affected by the gypsum layer. In addition to the dissolution of calcite and dolomite, the dissolution of gypsum plays a leading role in the process of groundwater dissolution and filtration. According to the mineral saturation index, Ca2+ produced by gypsum dissolution and the increase of geothermal mineral water temperature also lead to the saturation of calcite or dolomite, which may lead to precipitation. The effect of the dissolution of gypsum on the dissolution of calcite and dolomite has an inhibitory effect. The age of karst thermal mineral water in the Xiwenzhuang uplift is more than 20, 000 a, which is mixed with ancient water. The temperature of karst thermal reservoir is 72.6~91.1 ℃, and the depth of circulation is 2123~2663 m. Long-term water-rock interactions provide the time of conduction heating and enriched mineral components for the thermal mineral water. As the high value area of the temperature, TDS and Sr concentration in karst thermal mineral water, Xiwenzhuang uplift is the catchment area of thermal mineral water in the basin, and also the best area of regional thermal mineral water. The increasing trend of TDS and Sr concentration reflects the obvious dissolution and filtration of groundwater from recharge area to drainage area in the basin. There are occurred such a trend: cold underground water with low TDS and hydrochemical type of HCO3-Ca ·Mg to karst thermal mineral water with high TDS and hydrochemical type of SO4-Ca ·Mg.

Manganese removal processes and geochemical behavior in residues from passive treatment of mine drainage

In light of the development and urban growth of the city of Al-Nasiriya, the road construction sector consumes the largest amount of aggregates. The research aims to study suitability of the sediments of the sand dunes extending on one side of the international road between Nasiriya – Baghdad near the check point of Fadak as fine aggregate used for the purposes of roads construction. The results of the geotechnical evaluation of physical properties showed that the grain size analysis of the fine aggregate did not meet the requirements of the Iraqi specification and according to these results, the aggregate needs to modify. Based on liquid limits and plasticity indices and according to Iraqi specification the deposits are suitable for using as sub-grade course materials and to construct the shoulders of the road but not suitable for using as sub-base course materials. While the results of chemical tests indicate that incompatibility of the rates of organic matters and calcium carbonates with Iraqi specification. On the other hand, the chemical analysis of the sediments showed that the rates of the chlorides, sulfates, gypsum, total soluble salts and pH they were within acceptable limits of standard specifications. The mineral components of the soils were characterized by clay minerals (kaolinite and montmorillonite) and non-clay minerals (quartz, feldspar, and calcite).