Alkali Sodium Research Articles

Alkali metal ion passivation of lead-free perovskite film for high responsivity self-powered broadband photodetectors

All-inorganic lead-free bismuth-based perovskites have attracted great interest in the optoelectronic applications due to their low toxicity and excellent stability. However, the inherent polycrystalline (PC) of perovskite films suffers severe charge recombination due to the large numbers of trap density. Herein, high-quality Cs3Bi2I9 (CBI) PC thin films are prepared by solution process with alkali sodium (Na+) cation doping strategy, resulting large grain size and lower trap density. Afterward, the photoelectrochemical-type detectors based on Na+ doped CBI thin film is constructed for the first time. The photodetector displays a broadband photoresponse covering ultraviolet (UV), visible and near-infrared (NIR) ranges. Significantly, by precisely controlling Na+ doping concentration, the performance of photodetector can be largely enhanced with the highest responsivity of 53.38 mA/W and detectivity of 5.99 × 109 Jones without bias, and these results exceed the performance of most reported CBI PC thin film based photodetectors. In addition, the photodetector exhibits an obvious increase in photoresponse and outstanding photo-stability after more than 150 on/off cycles. Finally, the mechanism of Na+ doping is further discussed. These results provide an outstanding example for the preparing high-quality CBI PC thin film and also demonstrate the great potential of CBI in the application of self-powered broadband photodetectors.

Na3Ge2P3: A Zintl Phase Featuring [P3Ge-GeP3] Dimers as Building Blocks.

Recently, ternary lithium phosphidotetrelates have attracted interest particularly due to their high ionic conductivities, while corresponding sodium and heavier alkali metal compounds have been less investigated. Hence, we report the synthesis and characterization of the novel ternary sodium phosphidogermanate Na3Ge2P3, which is readily accessible via ball milling of the elements and subsequent annealing. According to single crystal X-ray structure determination, Na3Ge2P3 crystallizes in the monoclinic space group P21/c (no. 14.) with unit cell parameters of a = 7.2894(6) Å, b = 14.7725(8) Å, c = 7.0528(6) Å, β = 106.331(6)° and forms an unprecedented two-dimensional polyanionic network in the b/c plane of interconnected [P3Ge-GeP3] building units. The system can also be interpreted as differently sized ring structures that interconnect and form a two-dimensional network. A comparison with related ternary compounds from the corresponding phase system as well as with the binary compound GeP shows that the polyanionic network of Na3Ge2P3 resembles an intermediate step between highly condensed cages and discrete polyanions, which highlights the structural variety of phosphidogermanates. The structure is confirmed by 23Na- and 31P-MAS NMR measurements and Raman spectroscopy. Computational investigation of the electronic structure reveals that Na3Ge2P3 is an indirect band gap semiconductor with a band gap of 2.9 eV.

Selective extraction of potassium from raw nepheline materials

The global aluminium industry is ever-changing and primarily relies on bauxite as its traditional source. However, due to the finite reserves of processed bauxite, alternative sources need to be found. Nephelines have emerged as potential alumina sources. In addition to alumina, nepheline processing can yield marketable products such as soda, potash, cement, and rare metals.The objective of this study was to identify the ideal conditions for selectively extracting potassium from alkaline leaching solutions while separating it from sodium alkali, aluminium, and silicon during the comprehensive processing of nepheline syenites from the Kubasadyr deposit. This approach involved a two-stage hydrothermal leaching process with an incremental calcium addition. Under optimal conditions, the potassium extraction in the alkaline solution reached 93.91 %. The resulting leaching solution served as a feedstock for potassium sulfate production through the crystallization method. The preliminary selective separation of potassium played a crucial role in mitigating its adverse effects on the extraction of aluminium, which is the primary processed product; thus, the economic viability of production was enhanced.

Preparation and characterization of a novel high barrier mulching film with tunicate cellulose nanocrystals/sodium alginate/alkali lignin

In this study, the base film (CSL) was prepared by blending tunicate cellulose nanocrystals (TCNCs) extracted from tunicate shells, with sodium alginate (SA) and alkali lignin (AL). Then, the mulching film (CSL-WK) was prepared using water-borne polyurethane (WPU) as binder to install low-energy Kaolin on the surface of CSL film. The influences of composition with different concentrations on mechanical properties were studied. The tensile strength and elongation at break of CSL-WK film could reach 86.58 MPa and 50.49 %, respectively. The mulching films were characterized by degradability test, SEM, FTIR, and TGA. TCNCs had good compatibility with SA and AL, and a rough structure was formed on the surface of the film to improve the hydrophobicity. The barrier properties, including ultraviolet resistance, water contact angle, water vapor permeability, water retention, and flame retardancy, were tested. The results showed that CSL-WK films could block 97 % of ultraviolet light, reduce about 25 % of soil water loss, and self-extinguish within 7 s of open flame ignition. Note that the secondary spraying method significantly improved the barrier property of films. This study lays a foundation for the preparation of ecologically friendly, biodegradable, and high barrier mulching film, and expands the application of marine resources.

Pretreatment of alkali/surfactant/polymer (ASP)-flooding produced wastewater by electron beam radiation to improve oil-water separation

The management of wastewater produced from alkali/surfactant/polymer (ASP) flooding, known for its considerable volume and high emulsion stability, poses a challenge in oilfields globally. This study has demonstrated that ionizing irradiation is a promising pretreatment method for ASP wastewater to improve oil-water separation. After a settling time of 1 h, approximately 69.5% of oil remained in the raw ASP wastewater, while only 20–29% of the oil persisted in the liquid phase following radiation at absorbed doses ranging from 0.1 to 5.0 kGy. A noticeable increase in the size of oil droplets and reduction in turbidity was observed after irradiation. Further analysis revealed that the combination of surfactant, sodium dodecyl sulfate (SDS) and alkali exhibits a synergistic impact, leading to a substantial reduction in interface tension of ASP wastewater. Notably, ionizing irradiation induces several key changes that are crucial for efficient demulsification. The transformation of the wastewater's rheological behavior from pseudoplastics to a Newtonian fluid accompanied by a reduction in viscosity, the increased interfacial tension at both liquid-air and liquid-oil interfaces, along with the degradation of organic components such as partly hydrolyzed polyacrylamide (HPAM) and SDS, all contribute to the coalescence and floatation of oil droplets.

Inorganic intumescing alkali silicate particles

New generation intumescent coatings apply self-intumescing particles to induce expansion in a controlled manner. Various studies have investigated alkali silicate-based coatings due to their inherent expansion with the release of H2O. The presented work investigated the self-intumescing concept of alkali silicates as particles. A thorough study of inorganic alkali silicate particles as potential intumescent ingredients in passive fire protection systems was carried out by applying HSDM, TGA, FTIR, XRD, and SEM. Herein, particles of lithium-, sodium-, and potassium silicates were synthesized with varying silica-to-alkali oxide molar ratios and curing humidity. Subsequently, the hydration chemistry and thermal behavior were examined. The results revealed increased expansion potential with decreasing SiO2/M2O molar ratio (M = Na, Li, or K) in the range 3.1–7.4 and increasing curing humidity in the range 35, 50, and 90% RH. Previous studies have emphasized the effect of solid-bound H2O to induce intumescence. In this study, the influence of the softening of the silicate matrix and H2O release is highlighted to allow increased expansion potential. Here, the coupling of thermal analysis with microscopy suggests an intumescence mechanism in the order of 1) initial shrinkage due to loss of free and physical bound H2O, 2) sphere formation to minimize surface energy, 3) expansion as a result of H2O evolution and viscoelastic melt formation, and 4) second shrinkage due to sintering before 5) melting. The sodium alkali silicate particles with a SiO2/M2O molar ratio of 3.4 exhibited a timely softening of the silicate matrix from about 155 °C to provide a distinct spherical particle followed by ionic H2O evolution. As a result, hereof, hollow, spherical particles with relative solid expansions of up to 550% were obtained and maintained until a second shrinkage at 650 °C with a subsequent melting at 950 °C. In comparison, the imbalance in viscoelastic melt formation and H2O release of lithium- and potassium silicate particles resulted in less expansion. Considering the expansion potential and thermal behavior of the alkali silicate particles, it is suggested as a possible, sustainable intumescence ingredient.

Co-hydrothermal carbonization of pretreated sludge and polyethylene terephthalate for the preparation of low-nitrogen clean solid fuels.

In this work, polyethylene terephthalate (PET) and sewage sludge (SS) were co-hydrothermally carbonized to produce low-nitrogen solid fuels. To minimize the effect of nitrogen, this work introduces a co-hydrothermal carbonization method involving alkali (A), ultrasonic cell disruptor (UCC), and sodium dodecyl sulfate (SDS) for both individual and combined pretreatment of SS and PET. Comparative analysis of the products shows that the combined pretreatment with sodium dodecyl sulfate (SDS) and alkali (A) effectively disrupts the SS cell structure, leading to the loosening of stable extracellular polymeric substances (EPS). This condition is conducive to the release and hydrolysis of proteins during hydrothermal carbonization. Moreover, under conditions where PET serves both as an acid producer and a carbon source, and through parameter optimization at a temperature of 240 °C, reaction time of 2 h, PET addition of 20 wt%, and water addition of 0.6 g cm-3, a high-quality, low-nitrogen clean solid fuel was produced (N: 0.51 wt%, C: 19.10 wt%).

Synthesis and application of super absorbent polymers synthesized with ammonia solution and diatomaceous earth with low toxic residues

Water-soluble harmful components that remained in SAPs pose potential risks to crop growth, resulting in decreased seed germination rate, reduced yield, and inhibited root system growth. These factors restrict its widespread use in agriculture and forestry. In this study, a new type of super absorbent polymers (AD-SAP) with low residual acrylic acid and sodium ions was synthesized by using ammonia solution instead of strong alkali sodium hydroxide for neutralization and adding modified diatomaceous earth to improve the grafting efficiency. The prepared samples were characterized by Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), and energy-dispersive X-ray spectroscopy (EDS), and the influence of the dosage of acrylic acid and ammonia solution used for preparation on the residual content of water-soluble harmful components in AD-SAPs was investigated. When 28% of acrylic acid, 24% of ammonia solution, and 5% of diatomaceous earth were used for synthesis, the residual acrylic acid content in AD-SAP was 0.03%, and the sodium ion content was reduced to 0.12 g/kg, which is much lower than the three commercially available SAPs. However, its water-absorption capacity has not decreased and its salt resistance has improved. The water absorption ratio of AD-SAP is 578g/g, and the salt-absorption ratio is 87 g/g. Pot experiments showed that AD-SAP eliminated the adverse effects of commercial SAPs on crop growth. The research provided technical support for the production of SAPs, and offer scientific guidance for how to mitigate the adverse effects of SAPs on crop growth.

Concentration of sodium chloride solutions in the processing of concentrates for reverse osmotic water desalification

The paper examines the processes of concentrating sodium chloride solutions by the electrodialysis method. Given the shortage of reagents and their high prices, this electrodialysis method can be implemented to obtain acid and alkali from solutions of sodium sulfate, alkali, aluminum and iron coagulants. Today, the technologies that, as a result of the process, allow us to obtain valuable materials, substances, products, coagulants as a secondary product, are very justified, economically feasible and, most importantly, allow us to successfully implement the principles of low-waste production. The essence of the process is the use of sodium chloride solutions, which are formed during the desalination of water by reverse osmosis in the form of concentrates. The concentration process was implemented in a three-chamber electrolyzer, in the cathode, anode and working areas, a sodium chloride solution with a concentration of 360 mmol/dm3 was placed. An alkali solution with a concentration of 480 mg-eq/dm3 was used in the anode area. During electrolysis, alkali was formed in the cathode area, due to the diffusion of sodium in the working area and the cathodic reduction of water. Chlorides from the working area moved to the anode area. Hydroxide anions on the anode were oxidized to oxygen, chlorides with sodium formed sodium chloride, the concentration of which increased to 660 mg-eq/dm3. Alkalinity decreased to 68-70 mg-eq/dm3. When changing cathodes and anodes, the process was repeated in some places until the alkalinity in the cathode zone and the concentration of chlorides in the anode zone increased. . A solution of sodium chloride with a concentration of 360 mmol/dm3 was added to the working area where water desalination took place. After nine cycles of electrolysis, a sodium chloride solution with a concentration of 100-150 g/dm3 was obtained. The residual content of sodium chloride in desalinated water reached 50-100 mg/dm3. Sodium chloride solutions with a concentration of 4 to 30 g/dm3 can be used for concentration. It should be noted that after conducting nine cycles of the experiment, we can state that the process of concentration by this electrodialysis method does not lead to an increase in system resistance and energy consumption.

Development of a Robust Self-Healing Biomass Composite Gel Material for Spontaneous Combustion Prevention in Coal Mines

ABSTRACT The research in this paper focuses on the development of a recyclable, efficient and environmentally friendly fireproofing material for mining applications. Therefore, we formulated a novel composite gel named sodium alginate composite gel (PBSL-3) with sodium alginate, alkali lignin and polyvinyl alcohol as raw materials and borax as cross-linking agent. The success of the synthesis of PBSL gel material was verified by scanning electron microscopy and infrared spectroscopy experiments. The good self-healing and ability of PBSL-3 was verified by self-healing, thermal stability and rheological performance experiments; The material has a moderate viscosity and exhibits suitable rheological properties at different shear rates, making it suitable for pipeline transportation; In addition, the weight loss of the gel material was only 64.43% at the programmed warming to a temperature of 160°C, presenting a lesser rate of weight loss, and the material lost only 58% of its weight at temperatures up to 800°C. The flame retardancy of the PBSL-3 gel material was verified by programmed warming experiments and small-scale fire extinguishing experiments. The experimental results showed that the material critical temperature of the coal samples treated with the material was delayed from 100°C to 130 °C, and the CO and C2H4 gas inhibition was 41.98% and 58.12%, respectively, and the flame retardancy was 56.41% at a temperature of 200°C. Small-scale fire extinguishing experiments show that the overall fire extinguishing effect of PBSL gel material is better, and it can effectively extinguish spontaneous coal combustion fires.

PHYSICAL PROPERTIES OF GEOPOLYMERS MADE FROM MINERAL WASTE

Geopolymer is an alumino-silicon gel consisting of tetrahedral SiO 4 and AlO 4 sections, polycondensed in a spatial structure as a result of the reaction between aluminosilicates and an alkaline activator.The report is a part of the complex research plan for geopolymers, in which information is given about the experimental results in the preparation of geopolymers from natural and man-made mineral components characteristic of Latvia (clay, sand, wood ash, brick waste).The aim of the study was to find out the dependence of the geopolymer formation process on the composition of the reacting components at constant exposure factors. Sodium alkali solution and sodium silicate was used in the experiments. The raw materials used are red and gray clay, sand, wood ash.The composition of the clay, ash and sand composition was changed with an interval of twenty percent. The obtained geopolymer samples were subjected to physical and technical tests. The compositions that are perspective in terms of properties in the studied modes of exposure have been determined.

Correlation-driven metal-insulator transition in unconventional magnetic metal superoxides

We have extensively studied the electronic and magnetic properties of alkali sodium superoxide (NaO2) in comparison with that of potassium superoxide (KO2) both at high and low temperatures, using first-principles electronic structure calculations. The unpaired electron donated by the alkali atoms Na and K to the O atoms, forming dimers in NaO2 and KO2 respectively, control their properties. In both cases, this unpaired electron is the cause of orbital fluctuations in the O-π* manifold. Both undergo several structural phase transitions to minimize orbital fluctuations. As a result, the O2− dimers undergo several rotational configurations. This leads to a complex linking of their orbital and spin degrees of freedom. Therefore, as the orientation of the O2− dimers changes, so do the magnetic properties that were found to be controlled by this unpaired electron. Simultaneously the alkali ion cages surrounding the O2− dimers change from square in the pyrite phase to rhombus and rectangle in the orthorhombic phase for NaO2 and square in the tetragonal phase to a parallelogram in the monoclinic phase for KO2 on the plane cutting through the dimers. The different degree of the lifting of degeneracy in the O-π* manifold is owing to an intrinsic difference in the electrostatic interaction between the K/Na cages and the O2− dimmers, as shown by the band structures of NaO2 in the low-temperature orthorhombic phase and that of KO2 in the monoclinic phase. This, along with electron correlation among the localized O-π* electrons, establishes complete orbital ordering (OO) and thereby metal-insulator transition (MIT) in both systems. Correlation-induced MIT also occurs upon K doping for Na in NaO2 but is predicted to take place at a temperature higher than that in pure NaO2. This makes MIT in Rb/Cs-doped NaO2 a possibility at higher temperatures.

Correction to: A Method to Extract Vanadium from HIsmelt Reduction Slag: In Situ Sodium Salt Oxidation and Alkali Leaching

Correction to: A Method to Extract Vanadium from HIsmelt Reduction Slag: In Situ Sodium Salt Oxidation and Alkali Leaching

Nano cristobalite embedded Er3+ doped multi-functional silica phosphate composite glasses for optoelectronic applications

Composite silica-based glasses were synthesized with varying concentrations of Er3+ by sol-gel route. The presence of alkali sodium ions reoriented the silica tetrahedra, eventually forming the cristobalite phase in the glasses. The addition of Er3+ reduces the crystallite size from 23.8 nm to 6.9 nm, while retaining the fractional ceramic attribute for effectuating mechanical stability and ductility. Band gap energy increases with Er3+ doping by the principles of the Burstein-Moss shift, increasing transmittance to 90% in the glasses. The density of the glasses increases with erbium content, with a subsequent increase in ionic bonding as validated by the metallization criterion. Judd OFelt (JO) parameters were evaluated from the oscillator strengths of absorption transitions, identifying decreasing covalency in the glass systems. Broad bandwidth and lifetime of 79.9 nm and 6.2 ms respectively were obtained for near-infrared (NIR) transmission at 1.47 μm, suitable for an S-band telecommunication window. The material has potential red lasing performance corresponding to the transition: 4F9/2→4I15/2. Low dielectric constants and decreasing activation energy of the glass material at higher frequencies, as derived from Arrhenius plots, is suggestive of a cost-effective inter-layer dielectric substrate for microwave signal propagation. This could be favorably capitalized for micro-fabrication in integrated electronic industries, employing the Low-Temperature Co-fired Ceramic (LTCC) technology as a strategic alternative to the ceramic substrates devised otherwise using high sintering temperatures.

Fabrication of Synthetic Zeolite from Sinabung Mountain Volcanic Ash via Sol-Gel Method

Fabrication of synthetic zeolite from Sinabung Mountain volcanic ash by Sol-Gel method. The zeolite is obtained by extraction of alkalis sodium silicate and sodium aluminate. At first volcanic ash was characterized using XRF and XRD analyses. The XRF analysis shows that silica is 44.8%. In contrast, XRD analysis showed a sharp peak at a 2Ѳ corner area of 27.55o to express bonded with silica mineral salt. At the same time, the silica characterization is done by FT-IR analysis. The FT-IR analysis shows the presence of Si-O-Si groups at wave numbers 1064.71 cm-1, 786.96 cm-1 and Si-OH at wave 3749.62 cm-1 and 3448.72 cm-1, identifying the presence of silica. The synthetic zeolite characterization analysis obtained is FT-IR, XRD, SEM-EDX, and BET analysis. In the FT-IR analysis, the O-Si-O group was obtained at wave 987,85 cm-1 and O-Al-O at wave 447,89-585,30 cm-1, identifying X zeolite. Diffractogram XRD showed a sharp peak at 66.8°, 28.12°, and 45.84°, forming mixed crystalline X and zeolite A. SEM-EDX analysis shows that zeolite morphology is tight and homogeneous and has a high aluminium content of 24.79 and Si 16.12. While for nitrogen desorption, adsorption analysis on pore size, surface area and pore volume are 3,22 nm, 61,86 m2/g and 0,095 cc/g. The result of synthetic zeolite isotherm adsorption-desorption shows type V showing mesoporous size.

Functionalized Halloysite Nanotubes as Potential Drug Carriers

The aim of the work was to examine the possibility of using modified halloysite nanotubes as a gentamicin carrier and to determine the usefulness of the modification in terms of the effect on the amount of the drug attached, its release time, but also on the biocidal properties of the carriers. In order to fully examine the halloysite in terms of the possibility of gentamicin incorporating, a number of modifications of the native halloysite were carried out prior to gentamicin intercalation with the use of sodium alkali, sulfuric and phosphoric acids, curcumin and the process of delamination of nanotubes (expanded halloysite) with ammonium persulfate in sulfuric acid. Gentamicin was added to unmodified and modified halloysite in an amount corresponding to the cation exchange capacity of pure halloysite from the Polish Dunino deposit, which was the reference sample for all modified carriers. The obtained materials were tested to determine the effect of surface modification and their interaction with the introduced antibiotic on the biological activity of the carrier, kinetics of drug release, as well as on the antibacterial activity against Escherichia coli Gram-negative bacteria (reference strain). For all materials, structural changes were examined using infrared spectroscopy (FTIR) and X-ray diffraction (XRD); thermal differential scanning calorimetry with thermogravimetric analysis (DSC/TG) was performed as well. The samples were also observed for morphological changes after modification and drug activation by transmission electron microscopy (TEM). The conducted tests clearly show that all samples of halloysite intercalated with gentamicin showed high antibacterial activity, with the highest antibacterial activity for the sample modified with sodium hydroxide and intercalated with the drug. It was found that the type of halloysite surface modification has a significant effect on the amount of gentamicin intercalated and then released into the surrounding environment but does not significantly affect its ability to further influence drug release over time. The highest amount of drug released among all intercalated samples was recorded for halloysite modified with ammonium persulfate (real loading efficiency above 11%), for which high antibacterial activity was found after surface modification, before drug intercalation. It is also worth noting that intrinsic antibacterial activity was found for non-drug-intercalated materials after surface functionalization with phosphoric acid (V) and ammonium persulfate in the presence of sulfuric acid (V).

Thermal and acoustic insulation properties in nanoporous geopolymer nanocomposite

In building and construction sector, seeking for high thermal and sound insulation materials is crucial to reach lower carbon footprints and also for curtailed consumption energy either for heating or for cooling. Nowadays, geopolymer nanocomposites, an alternative binder to Ordinary Portland Cement (OPC), are drawing considerable attention for their great prospective to withstand heat and sound exposure beside to their outstanding properties including high early strength, little creep and shrinkage and a good resistance to corrosion and abrasion. To advance geopolymer insulating properties, a nanoscale analysis has been investigated here to consider porosity, nanopore size, moisture as well as chemical composition and alkali agents impacts. Our findings conclude that a better thermal isolation is predicted for a high-silicon content geopolymer nanostructure with the presence of sodium alkali activators. The lowest thermal conductivity values of 0.08 W/m.K and 0.10 W/m.K are obtained for a porosity of 30.8% for Na+ and K+ samples, respectively. Considering humidity, results indicate that residual water enhances 4.5 times the thermal insulation of a highly nanoporous metakaolin geopolymer rich on silicon and in the presence of NaOH alkali activator. Nanoscale investigation has finally shown a promising acoustic insulation behavior than OPC material when pore size and porosity are higher than 12 Å and 20% respectively, making nanoporous geopolymer paste as a great challenge for cementitious materials.

Eco-friendly salt/alkali-free exhaustion dyeing of cotton fabric with reactive dyes

The textile-wet process enormously consumes a large volume of water and chemicals, and thus awareness of cleaner production has been growing to protect the environment from the industrial effluents. In this context, reactive dyeing of cellulosic materials such as cotton fabrics is a major sector of textile coloration that necessitates the use of a large amount of sodium sulfate or sodium chloride and alkali to exhaust and fix the dye molecules with cellulosic macromolecules, respectively. However, the remaining salt and alkali in the effluent badly affect the environment. For this purpose, the use of trisodium nitrilotriacetate (TNA) in reactive dyeing of cotton fabrics was hypothesized to have a double benefit, one as an exhausting agent (organic salt) and the second as a fixing agent (organic base). Thus, the exhaust dyeing characteristics of cotton fabrics using C.I. Reactive Yellow 145 (RY145) was optimized under different conditions of TNA concentration, alkali concentration, temperature, and dyeing time. The color strength and the primary and secondary exhaustion values were also investigated with an eye on those values obtained using the conventional dyeing method. The characterization of effluent samples with RY 145 taken after dyeing using TNA compared with conventional dyeing indicated an efficient reduction of COD, BOD, and TDS values by 99, 97, and 97%, respectively. The new dyeing method was implemented using C.I. Reactive Black 5 (RB5), C.I. Reactive Blue 160 (RB160), and C.I. Reactive Red 24 (RR24) to reveal good dyeability and fastness properties comparable with those obtained using the conventional method. The overall results obtained suggest the suitability of TNA as an environmentally friendly agent suitable as an exhausting and fixing agent of cellulosic fabrics.

New mechanisms for the kidney-protective effect of alkali in chronic kidney disease.

Worldwide, more than one in ten adults are estimated to have chronic kidney disease (CKD). As CKD progresses, both the cost of treatment and associated risk of morbidity and mortality increase exponentially. As such, there is a great need for therapies that effectively slow CKD progression. Evidence from several small clinical trials indicates that alkali therapy may slow the rate of CKD progression. The biological mechanisms underlying this protective effect, however, remain unknown. In their recently published manuscript, Pastor Arroyo et al. (Clin Sci (Lond) (2022) 136(8): https://doi.org/10.1042/CS20220095) demonstrate that the alkali sodium bicarbonate protects against loss of renal function in a crystal nephropathy model in mice. Using unbiased approaches in both mice and human tissue, the authors go on to identify two novel mechanisms that may underly this protection. The first pathway is through promoting pathways of cell metabolism, which they speculate helps the remaining functional nephrons adapt to the greater metabolic needs required to maintain kidney filtration. The second pathway is by restoration of α-Klotho levels, which may limit the expression of adhesion molecules in the injured kidney. This, the authors speculate, may prevent inflammation from driving the functional decline of the kidney. Identifying these novel pathways represents an important step forward harnessing the potential benefits of alkali therapy in CKD.

ASSESSMENT OF IRRIGATION WATER QUALITY AS DETERIORATED BY EFFLUENT DISCHARGED FROM MAJOR SHRIMP PROCESSING INDUSTRIES OF RUPSHA UPAZILA, KHULNA, BANGLADESH

A Comparative study was carried out in different shrimp processing industries at Rupsha Upazila under Khulna district from January 2010 to December 2010. In the experiment, some water quality parameters were determined to sketch out the nutrient dynamics of the experimental area. The nutrient contents of water were analyzed for measuring temperature, pH, EC, salinity, sodium adsorption ratio (SAR), soluble sodium percentage (SSP), hardness and some major ionic concentrations. The temperature of the water samples were ranged from 29.1°C to 29.3 °C and the pH varied from 8.0 to 8.12 which reflected neutral to alkaline in nature. The values of SAR, SSP and hardness were ranged from 4.28 to 8.65, 71.24 to 81.847 percent and 239.1 to 312.3 mg L-1, respectively. Among the five industries the hazardous classes of the four industries reflected High sodium (alkali) content with medium salinity hazard. So, from the result, it may be concluded that appropriate sustainable management technologies need to be incorporated to control pH, hardness and salinity of that water.