The presence of antinutrients and undesirable flavours in kidney bean flour poses challenges to consumer acceptance. Although extrusion can mitigate antinutrients to some extent, its impact on reducing beany flavour in bean flour remains underexplored. This study investigated the effects of injecting acetic acid or sodium carbonate solutions at three concentration levels (0.05, 0.1, 0.15 mol/L), in conjunction with three temperature profiles (40/60/80/80/90, 40/60/80/90/110, 50/70/90/110/130 °C) and two feed moisture levels (25, 30 %), on the removal of antinutrients (condensed tannins, trypsin inhibitor activity, phytic acid, raffinose family oligosaccharides) and reduction of volatile compounds that contribute to beany flavour in whole kidney bean flour. The results showed that all concentrations of acetic acid and sodium carbonate solutions effectively reduced condensed tannins compared to water, especially at 130 °C extrusion temperature. Introducing acetic acid and sodium carbonate solutions at a concentration of 0.15 mol/L led to 72 and 90 % reduction of total raffinose family oligosaccharide content, respectively, in contrast to the 17 % reduction observed with water alone. The incorporation of sodium carbonate solution reduced the total volatile compounds by 45-58 % as compared with water (23-33 %) and acetic acid (11-27 %). This reduction was primarily due to the reduction of aldehydes, alcohols, and aromatic hydrocarbons. These results indicate that injecting sodium carbonate solution during extrusion can effectively reduce antinutrients and beany flavour compounds in kidney bean flour.

Microbially induced carbonate precipitation (MICP) is a common biomineralization method, which is often used for remediation of heavy metal pollution such as hexavalent chromium (Cr(VI)) in recent years. Calcium sources are essential for the MICP process. This study investigated the potential of MICP technology for Cr(VI) remediation under the influence of three calcium sources (CaCl2, Ca(CH3COO)2, Ca(C6H11O7)2). The results indicated that CaCl2 was the most efficient in the mineralization of Cr(VI), and Ca(C6H11O7)2 could significantly promote Cr(VI) reduction. The addition of different calcium sources all promoted the urease activity of Sporosarcina saromensis W5, in which the CaCl2 group showed higher urease activity at the same Ca2+ concentration. Besides, with CaCl2, Ca(CH3COO)2 and Ca(C6H11O7)2 treatments, the final fraction of Cr species (Cr(VI), reduced Cr(III) and organic Cr(III)-complexes) were mainly converted to the carbonate-bound, cytoplasm and cell membrane state, respectively. Furthermore, the characterization results revealed that three calcium sources could co-precipitate with Cr species to produce Ca10Cr6O24(CO3), and calcite and vaterite were present in the CaCl2 and Ca(CH3COO)2 groups, while only calcite was present in the Ca(C6H11O7)2 group. Overall, this study contributes to the optimization of MICP-mediated remediation of heavy metal contaminated soil. CaCl2 was the more suitable calcium source than the other two for the application of MICP technology in the Cr(VI) reduction and mineralization.

Sponge bioerosion is an important process on many carbonate reef ecosystems. Eutrophication has been linked with an increase in boring sponge abundance and biomass in coral reefs, yet the impacts on sponge bioerosion rates remain largely unexplored within oyster reef communities. The present study evaluated the impacts of nitrate and phosphate addition on the bioerosion of Cliona celata inhabiting carbonate substrates in the subtropical southeastern U.S. Using in situ and aquarium manipulations, sponge bioerosion rates were compared among control and nutrient addition treatments in three experiments. Overall, there were no differences in loss of calcium carbonate substrate among treatments in any of the experiments, though very high rates of bioerosion (up to 0.11 g CaCO3 day-1) were observed in the field experiments. Future research should consider the impacts of both inorganic and organic nutrient loading to fully understand the impacts of eutrophication on boring sponge ecology in subtropical oyster reefs.

Membrane distillation (MD) offers promise for recycling shale gas produced water (SGPW), while membrane fouling is still a major obstacle in standalone MD. Herein, sodium percarbonate (SPC) oxidation was proposed as MD pretreatment, and the performance of the single MD, SPC-MD hybrid process and Fe(II)/SPC-MD hybrid process for SGPW treatment were systematically evaluated. Results showed that compared to raw SGPW, the application of SPC and Fe(II)/SPC led to the decrease of the fluorescent organics by 28.54 % and 54.52 %, respectively. The hydrophobic fraction decreased from 52.75 % in raw SGPW to 37.70 % and 27.20 % for SPC and Fe(II)/SPC, respectively, and the MD normalized flux increased from 0.19 in treating raw SGPW to 0.65 and 0.81, respectively. The superiority of SPC oxidation in reducing the deposited membrane foulants and restoring membrane properties was further confirmed through scanning electron microscopy observation, attenuated total reflection fourier transform infrared, water contact angle and surface tension analyses of fouled membranes. Correlation analysis revealed that hydrophobic/hydrophilic matters and fluorescent organics in SGPW took a crucial role in MD fouling. The mechanism of MD fouling mitigation by Fe(II)/SPC oxidation was attributed to the decrease in concentrations and hydrophobicity of organic by synergistic oxidation, coagulation and adsorption.

Groundwater contamination by nitrates presents significant risks to both human health and the environment. In groundwater characterized as oligotrophic-low in organic carbon, but abundant in carbonate and phosphate-chemolithoautotrophic bacteria, including nitrate-reducing Fe(II)-oxidizing bacteria (NRFeOB), play a vital role in denitrification. The chemoautotrophic nitrate reduction is sensitive to environmental factors, including widespread iron oxides like hematite in nature. However, the specific mechanisms of this influence remain unclear. We examined the mechanism of how hematite impacts autotrophic nitrate reduction in a model NRFeOB community known as culture KS. We found that hematite enhances the rate of autotrophic nitrate reduction by promoting Fe(II) oxidation. Mössbauer spectroscopy detected a significant amount of adsorbed Fe(II) when hematite was present, leading to a reduction in dissolved ferrous iron. In conjunction with XRD data, it can be inferred that the formation of vivianite decreased, thereby increasing the Fe(II) activity in the reaction system. Within the culture KS bacterial consortium, hematite fosters the proliferation of autotrophic microorganisms, specifically Gallionellaceae, and amplifies the presence of denitrifying microbes, notably Rhodanobacter. This dual enhancement improves Fe(II) utilization and nitrate reduction capabilities. Our findings highlight intricate interactions between hematite and a model NRFeOB community, offering insights into groundwater nitrate removal mechanisms and the ecological strategies of autotrophic bacteria in mineral-rich environments.

The study of Na-carbonates stability and their transformations in aqueous carbonate fluid under high P-T conditions is relevant from the point of view of the understanding geochemical processes of the Na-assisted carbon circulation in the Earth\'s crust and subduction zones. In situ Raman study of Na-bearing carbonate-water-Fe-metal system in diamond anvil cell (DAC) at high P-T conditions revealed that carbonates decompose with abiogenic formation of formates and other organic compounds that differs from behavior of carbonates in dry system. XRD and FTIR methods have been used additionally to determine the phase composition. Na-bearing carbonates (nahcolite NaHCO3, shortite Na2Ca2(CO3)3 and cancrinite Na7Ca[(CO3)1.5Al6Si6O24]⋅2H2O) in aqueous fluid decompose to form simple carbonates and formates (as dominant organic molecules) at moderate P-T parameters (above ∼0.2 GPa, 200 °C). Our experimental results directly confirm the hypothesis of Horita and Berndt (Science, 1999) about possible yield of organic formates in the carbonate-water-metal system. Nahcolite NaHCO3 in aqueous fluid in the presence of Fe metal decomposes into anhydrous phases: natrite γ-Na2CO3, siderite, magnetite (due to dissolution of Fe steel gasket), Na-formate and likely organic molecular crystalline solvate of Na-formate and methyl formate. Shortite decays into anhydrous phases: aragonite CaCO3, Na-Ca-formates and an amorphous phase. Cancrinite decomposes to unidentified carbonate-alumonosilicate phases, Na-Ca-formates and unknown organic molecular crystal. Magnetite is also formed in this system due to dissolution of Fe steel gasket used in DAC. The present study provides a new insight in processes of abiogenic formation of organic matter from carbonates in the crust and upper mantle.

BACKGROUND: Tungiasis is a cutaneous parasitosis caused by the female flea Tunga penetrans. Two-component dimeticone (NYDA) is the only treatment for tungiasis recommended by the World Health Organization; however, this topical drug is not available in Kenya. In Western Kenya, sodium carbonate is commonly used in the treatment of tungiasis. This study evaluated the 7-day cure rates for tungiasis by comparing sodium carbonate and NYDA treatments in Homa Bay County, Kenya.
RESULTS: This was a randomized, observer-blinded, parallel-treatment cohort trial. Twenty-three eligible children with 126 flea infections were matched and randomized. All participants received both treatments, with one treatment on each foot. We recorded all health conditions/information, including inflammation scores and adverse events. Observations were performed on days 3, 5, and 7 using a digital microscope to confirm dead or live fleas based on the viability signs. Twenty-three children aged 3-13 years were analyzed. The proportion of dead fleas on day 7 was higher after NYDA treatment than after 5% sodium carbonate treatment (87% versus 64%, respectively, P = 0.01) NYDA. Median survival was 5 days for both treatments; NYDA had significantly higher trend of flea non-viability rate than 5% sodium carbonate (P<0.01). There were no significant differences in the inflammation score or pain/itchiness between the two treatments. On the last day, 14 children indicated their preference for NYDA in future treatment of tungiasis, whereas nine children preferred the 5% sodium carbonate solution.
CONCLUSIONS: NYDA was significantly more effective than 5% sodium carbonate for tungiasis treatment. Both treatments were safe but the children preferred NYDA more. Future studies with more participants and an extended observation period are warranted to confirm our findings. The findings suggest that NYDA should be made more available in tungiasis endemic area.
BACKGROUND: UMIN-CTR; UMIN 000044320.

Adsorption methods offer efficient recovery of phosphorus from water bodies. Modification adsorption materials combining lanthanum (La) and zirconium (Zr) dual-metal immobilized via co-precipitation method have been widely applied in the adsorption and recovery of phosphate. Meanwhile, sodium carbonate (Na2CO3) is gradually replacing sodium hydroxide (NaOH) as the mainstream co-precipitant for immobilizing metals into supporting matrices due to its excellent performance and environmental friendliness. However, the adsorption mechanisms of materials synthesized with different co-precipitants and the synergistic effects between dual-metal components are not well understood, which is not conducive to the further optimization of dual-metal adsorption materials. In this study, anion exchange resin was utilized as the supporting matrices, and La&Zr dual-metal-modified materials, La&Zr-CO32- and La&Zr-OH-, were prepared using Na2CO3 and NaOH as co-precipitants, respectively. The results indicate that La&Zr-CO32- exhibits superior performance in phosphate adsorption and recovery, with adsorption capacity and recovery efficiency reaching 36.28 mg/g and 82.59%, respectively. Additionally, this material demonstrates strong stability in reuse, phosphate selectivity, and a wide pH applicability range. La&Zr-CO32- achieves phosphate adsorption through surface electrostatic affinity, ligand exchange, and intraspherical complexation, whereas La&Zr-OH- primarily relies on electrostatic adsorption on the surface and interior of the material. Synergistic effects between La and Zr result in enhanced adsorption performance of the dual-metal material compared to individual metals. Specifically, phosphate adsorption is predominantly governed by La, while the presence of Zr further enhances ligand exchange between lattice oxygen and metals. Simultaneously, Zr doping enhances the phosphate recovery capacity and reusability of the materials. Continuous flow adsorption results from actual water bodies demonstrate that La&Zr-CO32- is more suitable for the removal and recovery of phosphate in water treatment engineering. This study provides a theoretical basis and technical support for the adsorption and recovery of phosphate using dual-metal-modified materials.

Soil improvement techniques utilizing the metabolic functions of microorganisms, including microbially induced carbonate precipitation (MICP), have been extensively researched over the past few decades as part of bio-inspired geotechnical engineering research. Given that metabolic reactions in microorganisms produce carbonate minerals, an enhanced understanding of microbial interaction with soils could improve the effectiveness of MICP as a soil improvement technique. Therefore, this study investigated the effects of sands on MICP by denitrification to employ MICP for geotechnical soil improvement. Under the coexistence of natural sand and artificial silica sand, nitrate-reducing bacteria were cultured in a mixed liquid medium with nitrate, acetate, and calcium ions at 37 °C. Nitrate reduction occurred only in the presence of natural sand. However, the lack of chemical weathering of the composed minerals likely prevented the progress of bacterial growth and nitrate reduction in artificial silica sands. For natural sand, artificial chemical weathering by acid wash and ferrihydrite coating of the sand improved bacterial growth and accelerated nitrate reduction. The calcium carbonate formation induced by denitrification was also influenced by the state of the minerals in the soil and the nitrate reduction rate. The observed MICP enhancement is due to the involvement of coexisting secondary minerals like ferrihydrite with large specific surface areas and surface charges, which may improve the reaction efficiency by serving as adsorbents for bacteria and electron donors and acceptors in the solid phases, thereby promoting the precipitation and crystallization of calcium carbonate on the surfaces. This crystal formation in the minerals provides valuable insights for improving sand solidification via MICP. Considering the interactions between the target soil and microorganisms is essential to improving MICP processes for ground improvement.

Sulfide-carbonate-mineralized functional bacterial consortium was constructed for flue gas cadmium biomineralization. A membrane biofilm reactor (MBfR) using the bacterial consortium containing sulfate reducing bacteria (SRB) and denitrifying bacteria (DNB) was investigated for flue gas cadmium (Cd) removal. Cadmium removal efficiency achieved 90%. The bacterial consortium containing Citrobacter, Desulfocurvus and Stappia were dominated for cadmium resistance-nitrate-sulfate reduction. Under flue gas cadmium stress, ten cadmium resistance genes (czcA, czcB, czcC, czcD, cadA, cadB, cadC, cueR, copZ, zntA), and seven genes related to sulfate reduction, increased in abundance; whereas others, nine genes related to denitrification, decreased, indicating that cadmium stress was advantageous to sulfate reduction in the competition with denitrification. A bacterial consortium could capable of simultaneously cadmium resistance, sulfate reduction and denitrification. Microbial induced carbonate precipitation (MICP) and biological adsorption process would gradually yield to sulfide-mineralized process. Flue gas cadmium could transform to Cd-EPS, cadmium carbonate (CdCO3) and cadmium sulfide (CdS) bioprecipitate. The functional bacterial consortium was an efficient and eco-friendly bifunctional bacterial consortium for sulfide-carbonate-mineralized of cadmium. This provides a green and low-carbon advanced treatment technology using sulfide-carbonate-mineralized functional bacterial consortium for the removal of cadmium or other hazardous heavy metal contaminants in flue gas.