Heavy metals immobilization of ternary geopolymer based on nickel slag, lithium slag and metakaolin.

To solve heavy metals leaching problem in the utilization of various industrial solid wastes, this work investigated the heavy metals immobilization of ternary geopolymer prepared by nickel slag (NS), lithium slag (LS), and metakaolin (MK). Compressive strength was measured to determine the optimum and appropriate mix proportions. The leaching characteristics of typical heavy metals (Cu (Ⅱ), Pb (Ⅱ), and Cr (Ⅲ)) in acid, alkali, and salt environments were revealed by Inductively Coupled Plasma (ICP). The heavy metals immobilization mechanism was explored by Mercury Intrusion Porosimetry (MIP), X-ray Diffraction (XRD), Fourier Transform Infrared Spectroscopy (FTIR), and Scanning Electron Microscopy (SEM) tests. The experimental results show that the group with a mass ratio of NS, LS and MK of 1:1:8 exhibits the highest compressive strength, which reaches 69.1 MPa at 28 d. The ternary geopolymer possesses a desirable capacity for immobilizing inherent heavy metals, where the immobilization rates of Cu and Pb reach 96.69 %, and that of Cr reaches 99.97 %. The leaching concentrations of Cr and Pb increase when the samples are exposed to acidic and alkaline environments. Cu and Pb are mainly physically encapsulated in geopolymer. Additionally, immobilization of Cr mainly involves physical encapsulation and chemical bonding.

Exploration of the Compressive Strength and Microscopic Properties of Portland Cement Taking Attapulgite and Montmorillonite Clay as an Additive.

The effects of attapulgite and montmorillonite calcinated at 750 °C for 2 h as supplementary cementing materials (SCMs) on the working properties, mechanical strength, phase composition, morphology, hydration and heat release of ordinary Portland cement (OPC) were studied. The results show that pozzolanic activity increased with time after calcination, and with the increase in content of calcined attapulgite and calcined montmorillonite, the fluidity of cement paste exhibited a downward trend. Meanwhile, the calcined attapulgite had a greater effect on the decrease in the fluidity of cement paste than calcined montmorillonite, and the maximum reduction was 63.3%. Within 28 days, the compressive strength of cement paste with calcined attapulgite and montmorillonite was higher than that of the blank group in the later stage, and the optimum dosages of calcined attapulgite and montmorillonite were 6% and 8%, respectively. In addition, the compressive strength of these samples reached 85 MPa 28 days later. The introduction of calcined attapulgite and montmorillonite increased the polymerization degree of silico-oxygen tetrahedra in C-S-H gels during cement hydration, thereby contributing to accelerating the early hydration process. In addition, the hydration peak of the samples mixed with calcined attapulgite and montmorillonite was advanced, and the peak value was lower than that of the control group.

The impacts of sodium nitrate on hydration and microstructure of Portland cement and the leaching behavior of Sr2.

Immobilization and solidification of low-level and intermediate-level radioactive waste liquid from nuclear power station involves the interaction between highly concentrated sodium nitrate solution and cement paste. This study aims to clarify the influence of sodium nitrate on the hydration kinetics of cement matrices, hydration products and microstructure. The hydration heat evolution in the first 28 days are tested by calorimetry. The hydration products are examined by XRD and DTG while the structure of C-S-H is characterized by NMR, FTIR and XPS. The results indicate that sodium nitrate reduced the degree of hydration and reduced the degree of the polymerization of C-S-H gel. The C-S-H of solidified cement matrices that contained the highest concentration of sodium nitrate is predominantly composed of Q2 and Q1 Si, while more Q3 units are found in the matrices without sodium nitrate. The decomposition temperature of Ca(OH)2 decreased with the increasing concentration of sodium nitrate solution because of the geometrical transformation of Ca(OH)2. Sodium nitrate in solidified cement matrices mainly existed in the form of granular crystalline phase. The cumulative leaching fraction of Sr2+ increases with the increasing concentration of NaNO3 solution.

[Meta-analysis on influence of different exercise intervention modes to blood glucose related indexes of pre-diabetes].

OBJECTIVE: To assess the influence of the different exercise intervention mode, aerobic exercise training(AET), resistance training(RT) and AET RT, on blood glucose of pre-diabetes. METHODS: Literatures were identified from the PubMed, EMBASE, EBSCO, CNKI and Wanfang databases. Relevant journals or conference proceedings were also searched manually. The qualities of randomized con-trolled trials that conformed to inclusion criteria were evaluated. Meta-analysis of the obtained related data was completed utilizing RevMan 5.2 statistical software. Mean difference of index related in exercise intervention groups and control group were calculated across the studies. RESULTS: Eight original literatures enrolled in this study. Compared with control group, combined effect of different exercise interventions on fast-ing blood glucose showed no significant, consistent with different intervention subgroups analysis. RT group and AET + RT group showed a sig-nificantly reduced role on 2 h postprandial blood index (P < 0.05). AET group showed a significantly reduced role on insulin resistance in-dex. CONCLUSIONS: To pre-diabetic, effects of exercise on postprandial 2 h blood glucose and insulin resistance index are related to modes of ex-ercise. Effects of exercise on fasting blood glucose, but still could not be determined.

[Determination of octreotide in human plasma by HPLC-MS with solid-phase extraction and study on the relative bioavailability of domestic and imported octreotide injections].

AIM: To establish an HPLC-MS method for determination of octreotide in plasma and study the relative bioavailability of domestic and imported octreotide injections. METHODS: Octreotide in plasma samples were extracted with a Waters solid-phase extraction mini column. HPLC-MS was carried out using a Waters Xetrra C18 column and a mobile phase consisting of CH3 OH-1% HAc (80 : 20), the flow rate was 0.2 mL x min(-1), and the internal standard was 6, 7, 4'-OH-isoflavone, the SIR ions for quantification were m/z 1 014.4 for octreotide and m/z 317.6 for internal standard. A single dose of 200 microg of domestic or imported preparations was intramuscularly given to 18 healthy volunteers in a randomized crossover study. Octreotide concentration in plasma was determined by LC-MS method. The pharmacokinetics and bioavailability were studied. RESULTS: The regressive curve was linear (r = 0.9997) within the range of 0.5 - 40 microg x L(-1) for octreotide. The pharmacokinetics parameters of domestic and imported injection were reply to one compartment model. The mean C(max) were (19 +/- 10) microg x L(-1) and (19 +/- 11) microg x L(-1), T(max) were (0.50 +/- 0.15) h and (0.52 +/- 0.20) h, T1/2 were (1.5 +/- 0.8) h and (1.5 +/- 0.8) h, AUC(0-7 h) were (50 +/- 25) h x microg x L(-1) and (50 +/- 25) h x microg x L(-1), respectively. The relative bioavailability of domestic to imported injection was 101% +/- 10%. CONCLUSION: The method is accurat and sensible for assay of plasma octreotide concentration. The results of statistics showed the two preparations were bioequivalent.