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To cope with the current serious arsenate pollution problem, a new ternary layered double hydroxides (LDHs) containing Ni, Co and Mn with good performance was developed, guiding by DFT calculations. First, Ni, Co and Mn were screened as the metal sources to constitute the LDHs, due to their high ionic charge density. Then, Ni(II), Co(II) and Mn(III)-O octahedra were selected as the primary units for structuring the LDHs, because of their good chemical activity. Meanwhile, the ratio of metals in the ternary LDHs, favoring for arsenate removal, was optimized at 1:2:1. In addition, the synergistic effect among various metals in the LDHs was considered. The results suggested that in the case of single doping, all three metals can act as the center to promote chemical activity independently. On the contrary, when combined together, there is only one unilateral active center. Moreover, the existence of ligand covalent bonds between arsenate and LDHs was confirmed. Finally, a promising new NiCo 2 Mn-LDHs with the maximum adsorption capacity of 407.23 mg/g for arsenate removal had been prepared. [Display omitted] • A systematic computational design for the novel LDHs, from structure feedback to performance. • The synthesized NiCo 2 Mn-LDHs exhibited excellent arsenate removal capability of 407.23 mg/g, surpassing most adsorbents. • The intermetallic synergy between Ni, Co and Mn in LDHs was described. • The coordination covalent bond was found between arsenate and the -OH on the LDHs surface. [ABSTRACT FROM AUTHOR]

Millions of people in poor areas are still under the threat of fluoride contamination. How to effectively separate fluorine in water is an important step to reduce the ecological risk. In this paper, we performed a systematic DFT calculation focused on the defluorination behavior between the LiAl- and MgAl-LDHs. The results indicated that the LiAl-LDHs exhibited high chemical activity before the defluorination, because of the better electronic structure. After the defluorination, the LiAl-LDHs with adsorbed-F– were also more stable than the MgAl-LDHs. In addition, the existence of coordination covalent bond for the adsorbed-F– attached to the LiAl-LDHs was confirmed. This is an important reason for the high defluorination efficiency by the LiAl-LDHs. In addition, a series of weak interaction, including hydrogen bond and van der Waals interaction were also observed. Finally, a LiAl-LDHs with excellent fluoride removal properties were synthesized well by simple hydrothermal method. The results showed that our synthesized LiAl-LDHs with the capacity of 156.09 mg/g, could be effectively defluorinated in water. Notably, it surpasses most materials and has potential applications. [Display omitted] [ABSTRACT FROM AUTHOR]

Authentication of geographical indication (GI) is important for the protection of GI rice due to its unique quality characteristics and high economic value in the market. This paper compared the appearance quality, cooking quality and nutritional quality of four types of GI rice products (Luoding rice, Zhefang Tribute rice, Xijiang rice and Wanbaozhen rice) in China. Luoding rice was found to have the highest nutritional value with respect to protein and amino acid profile. The vitamin content of Xijiang rice was significantly higher than that of other types of GI rice. Principal component analysis showed that Luoding rice had a quite different protein, aspect ratio and amino acid profile from other GI rice samples. Zhefang Tribute rice had quite different cooking quality, fatty acid and sugar profile from Xijiang rice and Wanbaozhen rice. Geographical origin was predicted by using a multilayer perceptron artificial neural network model with quality characteristics as the input variables. It was found that all the samples were accurately predicted in both training and test sets, indicating the potential of using quality characteristics to discriminate GI rice samples from different geographical origins. • Appearance, cooking, nutritional quality of four GIs were investigated and compared. • LD possessed different protein, aspect ratio and amino acid profile from other GI rice. • ZF possessed different cooking quality and fatty acid, sugar profile from XJ and WBZ. • GI rice was predicted using quality characteristics as input variables. [ABSTRACT FROM AUTHOR]

Deep-sea mussels, one of the dominant species in most deep-sea ecosystems, have long been used as model organisms to investigate the adaptations and symbiotic relationships of deep-sea macrofauna under laboratory conditions due to their ability to survive under atmospheric pressure. However, the impact of additional abiotic conditions beyond pressure, such as temperature and light, on their physiological characteristics remains unknown. In this study, deep-sea mussels (Gigantidas platifrons) from cold seep of the South China Sea, along with nearshore mussels (Mytilus coruscus) from the East China Sea, were reared in unfavorable abiotic conditions for up to 8 days. Integrated biochemical indexes including antioxidant defense, immune ability and energy metabolism were investigated in the gill and digestive gland, while cytotoxicity was determined in hemocytes of both types of mussels. The results revealed mild bio-responses in two types of mussels in the laboratory, represented by the effective antioxidant defense with constant total antioxidant capability level and malondialdehyde content. There were also disparate adaptations in deep-sea and nearshore mussels. In deep-sea mussels, significantly increased immune response and energy reservation were observed in gills, together with the elevated cytotoxicity in hemocytes, implying the more severe biological adaptation was required, mainly due to the symbiotic bacteria loss under laboratory conditions. On the contrary, insignificant biological responses were exhibited in nearshore mussels except for the increased energy consumption, indicating the trade-off strategy to use more energy to deal with potential stress. Overall, this comparative study highlights the basal bio-responses of deep-sea and nearshore mussels out of their native environments, providing evidence that short-term culture of both mussels under easily achievable laboratory conditions would not dramatically alter their biological status. This finding will assist in broadening the application of deep-sea mussels as model organism in future research regardless of the specialized research equipment. [Display omitted] • Responses in antioxidant system suggested manageable oxidative stress in mussels • Nearshore and deep-sea mussels responded diversely in immunity and energy budget • Sub-lethal effects may be related to symbiotic loss in deep-sea mussels under stress • Huge adaptive potential of G. platifrons except depressurized adaption was inferred • G. platifrons can be short-term cultured in easily controlled laboratory conditions [ABSTRACT FROM AUTHOR]

To meet the challenges posed by global arsenic water contamination, the MgAlMn-LDHs with extraordinary efficiency of arsenate removal was developed. In order to clarify the enhancement effect of the doped-Mn on the arsenate removal performance of the LDHs, the cluster models of the MgAlMn-LDHs and MgAl-LDHs were established and calculated by using density functional theory (DFT). The results shown that the doped-Mn can significantly change the electronic structure of the LDHs and improve its chemical activity. Compared with the MgAl-LDHs that without the doped-Mn, the HOMO-LUMO gap was smaller after doping. In addition, the -OH and Al on the laminates were also activated to improve the adsorption property of the LDHs. Besides, the doped-Mn existed as a novel active site. On the other hand, the MgAlMn-LDHs with the doped-Mn, the increased of the binding energy, as well as the decreased of the ion exchange energy of interlayer Cl−, making the ability to arsenate removal had been considerably elevated than the MgAl-LDHs. Furthermore, there is an obvious coordination covalent bond between arsenate and the laminates of the MgAlMn-LDHs that with the doped-Mn. [Display omitted] [ABSTRACT FROM AUTHOR]

Rice flavor is one of the most important rice qualities, consisting of aroma and taste. In this paper, aroma- and sweetness-related compounds were investigated and compared in glutinous, japonica , and indica rice. More volatile compounds were found in glutinous rice, as compared with japonica and indica rice. Hexanal, nonanal, octanal, trans -2-octenal, trans -2-nonenal, heptanal, decanal, (E,E)-2,4-nonadienal, (E,E)-2,4-decadienal, 2-pentylfuran, 2-n-butylfuran, 1-octen-3-ol, 2-ethylhexyl acrylate, 2-decanone, and 2-nonen-4-one were important contributors to the aromatic profile, according to their relative odor activity values. Sucrose was found to be the main contributor to sweetness, while other soluble sugars had little sweetness contribution. During storage, the contents of fatty acids and soluble sugars decreased, except for fructose. The decrease in soluble sugar content had an adverse effect on the sweetness of cooked rice and the Maillard reaction during cooking, resulting in lower quality rice flavor. In addition, the content of volatiles, such as aldehydes, ketones, and furans, increased during rice storage and negatively impacted rice aroma. • Glutinous rice possessed volatile profile distinct from non-glutinous rice. • Glutinous rice showed green and fat odor due to high aldehydes and furans contents. • Aldehydes, ketones, furans increased during rice storage, deteriorating rice odor. • As the main rice sweetness contributor, sucrose decreased during rice storage. • Fatty acids decreased to some extent during rice storage. [ABSTRACT FROM AUTHOR]

• As(III) was effectively removed and stabilized via in-situ forming Zn-Fe layered double hydroxides (ZnFe-LDHs). • The factors influencing the ZnFe-LDHs formation and As(III) removal were investigated. • As(III) was removed and stabilized more effectively by in-situ formation of LDHs than adsorption onto pre-formed LDHs. • As(III) oxidation, removal and stabilization mechanisms were discussed. • An in-situ formation pathway for ZnFe-LDH via a three-stage process was revealed. In order to remove and stabilize As(III) simultaneously from wastewater, a novel and effective method based on the in-situ formation of As(III)-containing Zn-Fe layered double hydroxides (ZnFe-As-LDHs) was developed. The influence of pH, Zn/Fe, Fe/As and adding rate on the formation of ZnFe-As-LDHs were investigated. Under the optimal conditions, the concentration of As(III) decreased from 100 to 0.13 mg/L and As leaching concentration of the ultimate sludge was 1.87 mg/L, which could meet the arsenic leaching criteria (5 mg/L) regulated by US EPA. Compared with the "ex-situ" sludge obtained by As(III) adsorbed on the pre-formed ZnFe-LDHs, the As(III) removal efficiency increased by 21.6 % and the stability of the sludge increased by 94.2 % on the in-situ formation of LDHs, which mainly attributed to 55.06 % oxidation of As(III) and co-precipitation of As with Zn and Fe. Additionally, a possible in-situ formation pathway for ZnFe-As-LDHs was illustrated. At the beginning of the process, non-crystalline ferric arsenate formed and then transformed to amorphous ferrihydrite as precursors, followed by the formation of LDHs. This work demonstrated that co-precipitating As with Zn and Fe in the wastewater to in-situ form LDHs exhibited excellent potential for removal and direct stabilization of As(III). [ABSTRACT FROM AUTHOR]