high alkalinity
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S.V. Pysarenko ◽  
V.Yu. Chernenko ◽  
O.E. Chygyrynets ◽  
O.M. Kaminskiy ◽  

X-ray spectral studies of the chemical composition of Irshansk ilmenite concentrates showed that it is leukoxenized mineral with a high (up to 79%) content of titanium oxide and inclusions of pseudorutile. The process of alkaline leaching of Ti4+ from ilmenite is investigated in the work. The study of the temperature effect on the reaction of ilmenite with potassium hydroxide at atmospheric pressure revealed that a temperature of 453 K is sufficient to obtain potassium titanate. A further increase in temperature does not provide a significant increase in the yield of water-soluble titanium. It is found that the optimal and sufficient ratio between ilmenite and potassium hydroxide is 1:2. An increase in the amount of potassium hydroxide in the reaction mixture is unsuitable, since it reduces the yield of soluble titanium and the final product will have a high alkalinity due to the presence of alkali which did not react. The main process of leaching with the formation of solid melt is completed in the first 30 minutes of the process. Infrared spectroscopy and X-ray diffraction showed that potassium titanate (K2TiO3) is formed under the studied conditions of alkaline leaching of ilmenite.

2021 ◽  
Kevin Spicka ◽  
Lisa Holding Eagle ◽  
Chris Longie ◽  
Kyle Dahlgren ◽  
AJ Gerbino ◽  

Abstract The Bakken formation is well known for producing brine very high in total dissolved solids (TDS). Halite, calcium carbonate, and barium sulfate scales all can pose substantial production challenges. Trademarks of Bakken produced brine include elevated concentrations of sodium (>90,000 mg/L), chloride (>200,000 mg/L), and calcium (>30,000 mg/L), contrasted against low concentration of bicarbonate (50-500 mg/L). In the past 3 years, operators have experienced unexpected instances of severe calcium carbonate scale on surface where produced fluids from the production tubing commingled with the gas produced up the casing. Initially treated as one-off scale deposits despite the application of scale inhibitor, acid remediation jobs or surface line replacement were typical solutions. As time has passed, this issue has become more and more prevalent across the Bakken. Investigation of this surface issue discovered a most unexpected culprit: a low TDS, high alkalinity brine (up to 92,000 mg/L alkalinity measured to date) produced up the casing with the gas. When mixing with the high calcium brine typically produced in the Bakken, the resulting incompatibility posed remarkable scale control challenges. The uniqueness of this challenge required thorough analytical work to confirm the species and concentrations of the dissolved ions in the brine produced with the gas. Scale control products were tested to evaluate their abilities and limitations regarding adequate control of this massive incompatibility. The theory that corrosion contributed to this situation has been supported by a unique modelling approach. Once corrosion was identified as the likely source of the high alkalinity brine, corrosion programs were instituted to help address the surface scaling. This paper highlights the evaluations conducted to fully grasp the severity of the incompatibility, the theories put forth to date, work conducted to try to replicate the phenomena in the lab and in models, and chemical programs used in the field to address corrosion and scale. While not known to exist in other oilfield basins, conventional or unconventional, this discovery may have implications for the broader industry if similar situations occur. The possible explanations for why this may be happening may have implications for scale control, asset integrity, and potentially even the methods by which wells are produced.

Minerals ◽  
2021 ◽  
Vol 11 (11) ◽  
pp. 1261
Julia S. Kirchner ◽  
Karsten A. Lettmann ◽  
Bernhard Schnetger ◽  
Jörg-Olaf Wolff ◽  
Hans-Jürgen Brumsack

The reduction in CO2 emissions is a major task for the coming decades. Accelerated weathering of limestone (AWL) can be used to capture CO2 from effluent gas streams and store it as bicarbonate in marine environments. We give an overview of the fundamental aspects of AWL, including associated CO2 emissions during the operation of AWL, characteristics of the accumulating bicarbonate-rich product water, and factors influencing the outgassing of CO2 from the ocean back into the atmosphere. Based on these aspects, we identify locations where AWL could be carried out favorably. The energy demand for AWL reduces the theoretical CO2 sequestration potential, for example, by only 5% in the case of a 100 km transport of limestone on roads. AWL-derived product water is characterized by high alkalinity but low pH values and, once in contact with the atmosphere, passive outgassing of CO2 from AWL-derived water occurs. This process is mainly driven by the difference between the fCO2 in the atmosphere and the oceanic surface layer, as well as the sea surface temperature at the discharge site. Promising sites for AWL may be in Florida or around the Mediterranean Sea, where outgassing could be prevented by injections into deep water layers.

2021 ◽  
pp. 1-16
Peter Marchev ◽  
Raya Raicheva ◽  
Stoyan Georgiev ◽  
Ivan P. Savov ◽  
Danko Jelev

Abstract Generally all orogenic ultrapotassic rocks are formed after melting of metasomatized sub-continental lithospheric mantle via subducted crustal mica-bearing lithologies. Here we present another possible model, based on the study of the small Stomanovo ultrapotassic monzonite porphyry intrusion in the Central Rhodope Massif, Bulgaria. The monzonite dated at 30.50 ± 0.46 Ma is intruded into the voluminous Oligocene (31.63 ± 0.40 Ma) Bratsigovo–Dospat ignimbrite. The monzonite hosts both normally and reversely zoned clinopyroxene phenocrysts. The normally zoned clinopyroxene is characterized by gradually diminishing core-to-rim Mg no. (89–74), whereas the reversely zoned clinopyroxene has green Fe-rich cores (Mg no. 71–55) mantled by normally zoned clinopyroxene (Mg no. 87–74). Neither the core of the normally zoned clinopyroxene nor the Fe-rich green cores are in equilibrium with the host monzonite. This ultrapotassic monzonite shows more radiogenic Sr isotopes ((87Sr/86Sr)i = 0.71066) and ϵNd(t) = −7.8 to −8.0 that are distinct from the host ignimbrites with (87Sr/86Sr)i = 0.70917–0.70927 and ϵNd(t) = −4.6 to −6.5. The Sr–Nd isotopic data and the presence of copious zircon xenocrysts from the underlying metamorphic basement suggest extensive crustal assimilation. Our observations indicate that the Stomanovo ultrapotassic monzonite formed after extensive lower or middle crustal fractional crystallization from an evolved magma producing cumulates. The process was followed by hybridization with primitive mantle-derived magma and subsequent continuous crustal contamination. We suggest that instead of inheriting their high K2O and large-ion lithophile element enrichments from slab-derived/metasomatic fluids, the Stomanovo ultrapotassic monzonite may owe some of its unusually high alkalinity to the assimilation of potassium-rich phases from the Rhodope Massif basement rocks.

Siba Prasad Mishra ◽  
Madhurima Das ◽  
Saswat Mishra

The Red Mud has focused through major industrial and scientific research in industrial waste valorization. Red mud is the discarded produce of alumina extraction processes from its parent the bauxite ore. Its high alkalinity causes it to be kept in large quantities, resulting in increased deforestation. Annually, it is estimated that 64.2 MMT of red mud wastes are formed around the world, and India produces about 9MMT with less hope of being reused, posing a serious threat of pollution and contamination of both soil, ground water and the environment. Large numbers of research have shown that this bauxite solid waste can be refurbished to make construction bricks, pavement tiles, ceramic materials, but no full large-scale benign re-utilization have been made. The intent of the research is to probe in to the applications of red mud in the construction and various sectors, giving emphasis on Indian context. Other researchers' observations were considered and analyzed in terms of environmental, economic, and technical feasibility to fulfill zero waste demand due to red mud.

2021 ◽  
Vol 36 (2) ◽  
pp. 239-243
Y. Vinod Kumar ◽  
V. Gopi Naik ◽  
G. Veeraswamy ◽  
E. Balaji

The current study's goal is to discover the geochemical analysis of groundwater in the uddanam area of the Srikakulam district of Andhra Pradesh, India. In the current study area, 50 groundwater samples were collected and analyzed for physicochemical properties such as cations, anions, total hardness, conductivity, and alkalinity. This was assessed for its suitability for drinking and irrigation purposes by calculating pH, EC, TDS, hardness, and alkalinity in addition to major cations (Na+, K+, Ca2+, Mg2+) and anions (HCO3-, Cl-, SO42-, NO32-, F-). Chemical indices such as SAR, percent Na, permeability index, RSC, Kelly's Ratio, Magnesium Ratio, and Non-carbonate hardness (NCH) have been calculated based on the analytical results. Water with high alkalinity may be aesthetically unfit for drinking, whereas water with high TDS and TH may not be recommended for consumption by people suffering from kidney and related diseases. Geogenic, anthropogenic influence, agricultural activity, and mineral dissolution, Presence of high TDS and TH levels were the primary causes for chronic kidney disease (CKD), not suitable for drinking and irrigation purposes.

2021 ◽  
Vol 50 (7) ◽  
pp. 1827-1841
Nuruol Syuhadaa Mohd ◽  
Baoqiang Li ◽  
Shaliza Ibrahim ◽  
Rumana Riffat

Temperature phased anaerobic digestion (TPAD) systems with conventional sequences (first stage of 55 ℃ and second stage of 35 ℃) have been widely studied. However, very limited studies were available on TPAD system with the first stage operated at the intermediate zone of 45 °C, mainly due to the notion that limited microbial activity occurs within this zone. The objective of this research was to evaluate the performance, stability and the capability of 45 °C TPAD in producing class A biosolids, in comparison to a conventional TPAD. Four combinations of TPAD systems were studied, 45 ℃ TPAD 2.5/10 (1st stage solids retention time (SRT) 2.5 days/2nd stage SRT 10 days), 45 ℃ TPAD 7.5/10, 55 ℃ TPAD 2.5/10 and 55 ℃ TPAD 7.5/10. Among all, 45 ℃ TPAD 7.5/10 was found to have the best performances, attributed to its high volatile solids (VS) destruction (58%), minimal acetate accumulation (127 mg/L), high methane yield (0.58 m3 CH4/kg VS removed), high COD destruction solid COD (sCOD; 74% and total COD (tCOD) 54%) and minimal free NH3 content (67.5 mg/L). As for stability, stable pH distribution, high alkalinity content and low VFA to alkalinity ratio, indicated a well-buffered system. Additionally, the system had also able to produce class A biosolids. Therefore, proved that TPAD system operated at the intermediate zone of 45 ℃ can perform better than the conventional TPAD, hence, highlighting its economic advantage.

2021 ◽  
Ela Ofer-Rozovsky ◽  
Gabriela Bar-Nes ◽  
Amnon Katz ◽  
Michal Arbel Haddad

Abstract The use of fly ash as a precursor for geopolymer has been investigated during the last decades for various applications. The aim of this research was to study the effect of nitrate on the formation and evolution of fly ash-based geopolymers, in order to assess their applicability as waste immobilization matrices. These may be of interest in order to treat waste streams from agricultural runoff and various industries including the nuclear industry. Fly ash was alkali-activated using NaOH solutions of various alkalinities, to which nitrates were added as NaNO3. The samples were cured at 40֯C for different periods and characterized by X-Ray diffractometry, Fourier transform mid-Infrared spectroscopy, scanning electron microscopy (SEM), and compressive strength measurements. The content of neo-formed crystalline phases in fly ash-based geopolymers was found to be lower than in metakaolin-based systems studied previously. The nature of the minerals formed in nitrate-free samples differed from those obtained in corresponding metakaolin-based geopolymers. Nevertheless, the dominant phase formed in the presence of nitrate at sufficiently high alkalinity was nitrate-cancrinite, as reported for metakaolin-based geopolymers, regardless of the type of fly-ash used. Although the presence of nitrates was found to have a promoting effect on the geopolymerization process of metakaolin-based geopolymers, it was found to inhibit the processes in fly-ash-based geopolymers.The formation of crystalline phases in FA-based geopolymers suggests that these materials may be used for immobilizing various hazardous species, while FA-based geopolymers containing the nitrate-cancrinite can be considered as a promising candidate for immobilizing radionuclides from radioactive wastes.

2021 ◽  
Vol 3 ◽  
Mustapha Missbah El Idrissi ◽  
Omar Bouhnik ◽  
Salma ElFaik ◽  
Soufiane Alami ◽  
Hanane Lamin ◽  

In this work, we analyzed the diversity of the nodule-forming bacteria associated with Lupinus luteus and Lupinus cosentinii grown in the Maamora Cork oak forest acidic soils in Morocco. The phenotypic analysis showed the high diversity of the strains nodulating the two lupine's species. The strains were not tolerant to acidity or high alkalinity. They do not tolerate salinity or high temperatures either. The strains isolated from L. luteus were more tolerant to antibiotics and salinity than those isolated from L. cosentinii. The plant growth promoting (PGP) activities of our strains are modest, as among the 28 tested isolates, only six produced auxins, six produced siderophores, whereas three solubilized phosphates. Only two strains possess the three activities. The rrs gene sequences from eight representative strains selected following ARDRA and REP-PCR results revealed that they were members of the genus Bradyrhizobium. Six strains were then retained for further molecular analysis. The glnII, recA, gyrB, dnaK, and rpoB housekeeping gene sequence phylogeny showed that some strains were close to B. lupini LMG28514T whereas others may constitute new genospecies in the genus Bradyrhizobium. The strains were unable to nodulate Glycine max and Phaseolus vulgaris and effectively nodulated L. luteus, L. cosentinii, L. angustifolius, Chamaecytisus albidus, and Retama monosperma. The nodC and nodA symbiotic gene phylogenies showed that the strains are members of the genistearum symbiovar.

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