多聚磷酸复配体系处理PBO纤维改善表面性能的研究

采用80%的多聚磷酸与98%硫酸、67%硝酸及37%盐酸的复配体系处理PBO纤维,结果其纤维强力大幅下降。用硫酸和硝酸与多聚磷酸复配后处理PBO纤维,纤维失去服用价值。选择多聚磷酸、盐酸进行复配处理PBO纤维,并采用正交试验分析浓度、处理时间以及复配比对PBO纤维强力的影响。进一步测试纤维的毛细效应,采用扫描电子显微镜分析其表面形态,最终选出能较好保持纤维强力的最适宜的工艺:20%多聚磷酸与25%盐酸以体积比1∶1进行复配,处理时间4h。经处理后纤维强力保持率为84.01%,纤维表面有轻微刻蚀,毛细管效应有所提升。

Predicting the Degradability of Bioceramics through a DFT-based Descriptor

Bioceramics have attracted extensive attention for bone defect repair due to their excellent bioactivity and degradability.However,challenges remain in matching the rate between bioceramic degradation and new bone formation,necessitating a deeper understanding of their degradation properties.In this study,density functional theory(DFT)calculations was employed to explore the structural and electronic characteristics of silicate bioceramics.These findings reveal a linear correlation between the maximum isosurface value of the valence band maximum(VBM_(Fmax))and the degradability of silicate bioceramics.This correlation was subsequently validated through degradation experiments.Furthermore,the investigation on phosphate bioceramics demonstrates the potential of this descriptor in predicting the degradability of a broader range of bioceramics.This discovery offers valuable insights into the degradation mechanism of bioceramics and holds promise for accelerating the design and development of bioceramics with controllable degradation.

Thermodynamic study on phosphorus removal from tungstate solution via magnesium salt precipitation method

The thermodynamic equilibrium diagrams of Mg2＋- 3-4PO - ＋4NH -H2O system at 298 K were established based on the thermodynamic calculation. From the diagram, the thermodynamic conditions for removing phosphorus from the tungstate solution by magnesium salt precipitation were obtained. The results show that when the concentration of total magnesium increases from 0.01 mol/L to 1.0 mol/L, the optimal pH for the phosphorus removal by magnesium phosphate decreases from 9.8 to 8.8. The residual concentration of total phosphorus almost keeps the level of 4.0×10-6 mol/L in the system. MgHPO4, Mg3（PO4）2 and the mixture of Mg3（PO4）2 and Mg（OH）2 are stabilized in these system, respectively. However, increasing the total concentration of magnesium has little effect on phosphorus removal by magnesium ammonium phosphate, while it is helpful for phosphorus removal by increasing the total ammonia concentration. The calculated results demonstrate that the residual concentration of total phosphorus can decrease to 5.0×10-7 mol/L as the total concentration of ammonia reaches 5.0 mol/L and the optimal pH value is 9-10. Finally, verification experiments were conducted with home-made ammonium tungstate solution containing 50 g/L WO3 and 13 g/L P. The results show that when the dosage of MgCl2 is 1.1 times of the theoretical amount, the optimum pH for removing phosphorus is 9.5, which matches with the results of the theoretical calculation exactly.

Microbially induced deposition of barium phosphates and its ingredient,morphology and size under different pH values

A phosphate-mineralization microbe was used to induce barium phosphates precipitation, and the precipitates with different types were obtained under different pH values. The average crystallite size of the barium phosphates was calculated by particle size distribution curves, and the size of the products was 33.40, 29. 37, 24. 13, 47.76 and 96. 53 μm when the pH values of the mixed solution are 7, 8, 9, 10 and 11, respectively. The results of X-ray diffraction （XRD） show that the structures of the particles controlled by the mixed solution are mainly BaaPO4 when pH 〈 10; the barium phosphates are synthesized by biological deposition which is the mixture of BaHPO4 and Ba5 （PO4）3OH when pH = 10; when pH = 11, the barium phosphates are also the mixtures, which are Ba5 （PO4）3OH and BaNaPO4. The above results indicate that the phosphate-mineralization microbe can produce a certain enzyme which constantly hydrolyzes phosphate monoester in the mixed solution, and then PO4^3- ions are obtained.

花生壳吸附剂的制备及其对废水中Cr(Ⅵ)的吸附性能研究

为了提高花生壳对废水中Cr(Ⅵ)的吸附能力,实现农林废弃物资源化利用。用重铬酸钾溶液模拟废水,通过单因素吸附实验,探究了不同改性方法、吸附剂投加量、溶液pH、吸附时间、Cr(Ⅵ)初始浓度、温度对花生壳吸附Cr(Ⅵ)性能的影响。实验表明,采用磷酸/盐酸双组分改性的花生壳对Cr(Ⅵ)的吸附效果最佳。当溶液中Cr(Ⅵ)初始浓度为15 mg/L时,投加改性花生壳0.3 g,调节溶液pH为1.4,在温度为30℃条件下吸附120 min, Cr(Ⅵ)的去除率可达97.75%。

Double-blinded, Controlled, Randomized Study of Dihydrocodeine Tartrate vs Codeine Phosphate in Treating Cancer Pain

To compare the effects and adverse reactions of dihydrocodeine tartrate andcodeine phosphate in treating moderate cancer pain. Methods: Sixty-nine cases of cancer patientswith moderate pain were treated with dihydrocodeine tartrate or codeine phosphate respectively bydouble-blind, controlled randomized methods and the effects and adverse reactions were observed.Results: After administration of dihydrocodeine tartrate or codeine phosphate, in treatment group orcontrol group, the total effective rate was 86.6% and 93.6%, and common adverse symptoms includedconstipation (31.3%/12.9%), nausea (18.8%/19.7%), gastric trouble (18.8%/19.7%), skin pruritus(12.5%/10%), vomit (9.3% and 6.5%) with the difference being not significant. Conclusion: Theeffects of dihydrocodeine tartrate in treating moderate cancer pain are similar to codeinephosphate. Both them can be used to treat moderate cancer pain.

Leaching kinetics of calcium molybdate with hydrochloric acid in presence of phosphoric acid

Calcium molybdate(CaMoO4)is the main component of powellite and is a predominant intermediate in the pyrometallurgical and hydrometallurgical process of molybdenum.The extraction of Mo from CaMoO4 by a combination of phosphoric acid and hydrochloric acid was investigated.For further understanding of the leaching mechanism,the effects of five key factors were studied to describe the leaching kinetics.The results indicated that the dissolution rate of CaMoO4 was independent of the stirring speed.Mo extraction significantly increased with increasing HCl concentration and temperature,but decreased with increasing particle size.A shrinking core model with surface chemical reaction was found to withstand the dissolution of CaMoO4.The apparent activation energy was calculated to be 70.879 kJ/mol,and a semi-empirical equation was derived for the rate of reaction.

Synthesis of phosphate-embedded calcium alginate beads for Pb(Ⅱ) and Cd(Ⅱ) sorption and immobilization in aqueous solutions

The phosphate-embedded calcium alginate beads were successfully synthesized based on sodium alginate, calcium dihydrogen phosphate and sodium hydrogen carbonate. Scanning electron microscopy, Fourier transformed infrared (FTIR) spectroscopy and X-ray diffraction (XRD) were conducted to characterize the morphology and structure of the phosphate-embedded calcium alginate beads. The effects of pH and the initial concentration of the metal ions on Pb(II) and Cd(II) sorption by the beads were investigated. The optimal pH values for Pb(II) and Cd(II) sorption are 4.0 and 5.5, respectively. The optimal initial concentrations of Pb(II) and Cd(II) are 200 mg/L and 25 mg/L, correspondingly, and the removal efficiencies are 94.2% and 80%,respectively. The sorption mechanism is that the heavy metal ions accessed the beads firstly due to the large surface area, combinedwith OH?, and then precipitated with phosphate radical, which was proven by FTIR and XRD. The sorption of Pb(II) and Cd(II) isfitted to Langmuir isotherm model with R2 values of 0.9957 and 0.988, respectively. The sorption capacities of Pb(II) and Cd(II) are263.16 mg/g and 82.64 mg/g, respectively. The results indicate that the phosphate-embedded calcium alginate beads could be appliedto treating Pb(II)/Cd(II)-containing wastewater and it could be implied that the synthesized beads also could be used as a kind of soil ameliorant for remediation of the heavy metal contaminated paddy soil.

Response of Microbial Community to Petroleum Stress and Phosphate Dosage in Sediments of Jiaozhou Bay, China

The dynamic microcosms were used to evaluate the effect of oil spills on microbial ecological system in marine sediment and the enhancement of nutrient on the oil removal. The function and structure of microbial community caused by the oil pollution and phosphate dosage were simultaneously monitored by dehydrogenase activity assay and PCR-denaturing gradient gel electrophoresis(DGGE) techniques. The results indicated that the amount of total bacteria in all dynamic microcosms declined rapidly with incubation time. The number of petroleum-degrading bacteria and the activity of sediment dehydrogenase were gradually enhanced by petroleum in the oil-treated microcosms, while they both showed no obvious response to phosphate dosage. In comparison, phosphate spiked heterotrophic bacteria and they showed a significant increase in amount. DGGE profiles indicated that petroleum dosage greatly changed community structure, and the bacteria belonged to class Deltaproteobacteria, and phyla Bacteroidetes and Chlorobi were enriched. This study demonstrated that petroleum input greatly impacted the microbial community structure and consequently the marine sediment petroleum-degrading activity was enhanced. Phosphate dosage would multiply heterotrophic bacteria but not significantly enhance the petroleum degradation.

Effect of Competing Anions on Arsenate Adsorption onto Maghemite Nanoparticles

This paper reports the effect of several competing anions on arsenate adsorption with maghemite nanoparticles. Sulphate （as SO4）, nitrate （as NO3-N）, phosphate （as PO4-P） ions and silicate-（as SiO2） were-studied in dual solution with arsenate. Moreover, the combined effect of ions and other water characteristics were examined with a natural groundwater sample which was spiked with a certain amount of arsenate. Arsenate batch adsorption experiments were carried out with two different kinds of maghemite-a commercially, available one and a homemade one using the sol-gel orocess. Sulohate （≤250 mg.L-1） and nitrate （≤ 12 mg.L-1） had a neglivible effect onthe arsenate （0.5 mg.L-1） adsorption at pH 3. However, both phosphate （42.9 mg·L-1） and silicate （450 mg.L-j） had an adverse impact on arsenate （43 mg.L-1） adsorption at pH 7. Phosphate （41.5 mg.L-1） showed minimal competition with arsenate （0.5 mg.L-1）, while silicate （410 mg.L-1） inhibition was insignificant for all studied As（V） concentrations at p.H 3. The removal of arsenate from the groundwater sample was as efficient as from labo-ratory water tor 0.3 mgL -1 AS（V） botll at pH3 and pH7.

Distributions of Inorganic Nutrients in the Bohai Sea of China

To study the contents and distribution of inorganic nutrients in the Bohai Sea of China, two cruise surveys were undertaken in August (summer) 2000 and January (winter) 2001, respectively. A total of 595 water samples were collected from 91 stations and five nutrients, i.e., nitrate, nitrite, ammonia, phosphate and silicate, were analyzed for each sample. The results show that the average concentration of dissolved inorganic nitrogen (DIN) in the Bohai Sea in winter (6.529 μmol L -1) is significantly higher than that in summer (3.717 μmol L -1). The phosphorus concentration in winter (0.660 μmol L -1) is also significantly higher than that in summer (0.329 μmol L -1). Mean silicate concentration in winter (7.858 μmol L -1) is, however, not significantly different from that in summer (7.200 μmol L -1). Nutrients also vary considerably in different areas in Bohai Sea. DIN concentration in the Laizhou Bay (4.444 μmol L -1), for example, is significantly higher than those in the Bohai Bay (2.270 μmol L -1) and Bohai Strait (2.431 μmol L -1), which is caused by the discharge of large amounts of nitrogen into Laizhou Bay via Yellow River. The nutrients show different vertical distribution patterns. In summer, nutrients in bottom layer are generally richer than those in surface and middle layers. In winter, however, nutrients are not significantly different in different layers. Compared with historic data, DIN contents have increased continually since the early 1980 s. Based on atomic ratios of different nutrients, nitrogen is still the limiting factor for algal growth in the Bohai Sea.

Adsorption of Acid Phosphatase on Minerals and Soil Colloids in Presence of Citrate and Phosphate

The aim of this work was to study the influence of phosphate and citrate, which are common inorganic and organic anions in soils, on the adsorption of acid phosphatase by kaolin, goethite and the colloids separated from yellow-brown soil (YBS) and latosol (LS) in central-south China. The YBS colloid has the major clay mineral composition of 1.4 nm mineral, illite and kaolinite while the LS colloid mainly contains kaolinite and oxides. The adsorption isotherm of acid phosphatase on the examined soil colloids and minerals fitted to the Langmuir model. The amount of enzyme adsorbed in the absence of ligands was in the order of YBS colloid > LS colloid > kaolin ≈ goethite. In the presence of phosphate or citrate, the amounts of the enzyme adsorbed followed the sequence YBS colloid > kaolin > LS colloid > goethite. The presence of ligands also decreased the binding energy between the enzyme and soil colloids or minerals. With the increase of ligand concentration from 10 mmol L-1 to 400 m mol L-1, different behaviors for the adsorption of enzyme were found in the colloid and mineral systems studied. A sharp decrease in enzyme adsorption was observed on goethite while gradual decreases of enzyme adsorption were recorded in the two soil colloid systems. However, no any decrease was found for the amount of enzyme adsorbed on kaolin at higher ligand concentrations. When phosphate or citrate was introduced to the system before the addition of enzyme, the ligands usually enhanced the adsorption of enzyme. The results obtained in this study suggested the important role of kaolinite mineral in the adsorption of enzyme molecules in acidic soils in the presence of various ligands.

Influence of anions in phosphate and tetraborate electrolytes on growth kinetics of microarc oxidation coatings on Ti6Al4V alloy

The growth kinetics of microarc oxidation(MAO)coatings on Ti6Al4V alloy was studied by designing an electrolyte with low PO_(4)^(3−)content and high B_(4)O_(7)^(2−)content,using scanning electron microscopy,transmission electron microscopy,X-ray diffraction,and potentiodynamic polarization.The results showed that B_(4)O_(7)^(2−)increased the spark intensity and dissolved most of the oxides at high temperatures.Then,a thicker barrier layer at the coating/substrate interface was produced,which increased the polarization resistance of the coating.PO_(4)^(3−)at a low concentration also promoted the uniform growth of the MAO coating and the formation of hat-shaped holes in the outer deposition layer.The thickness of the MAO coatings obtained in Na_(2)B_(4)O_(7) electrolytes exhibited an exponential increase with time at spark discharge stage,while that of the MAO coating obtained in phosphate–tetraborate electrolytes showed a linear trend as the PO_(4)^(3−)content increased.

Plasma electrolytic oxidation behavior and corrosion resistance of brass in aluminate electrolyte containing NaH2PO4 or Na2SiO3

Plasma electrolytic oxidation(PEO) of brass was carried out in aluminate electrolytes with the addition of NaH2PO4(S1) and Na2SiO3(S2), respectively, with the aim to investigate the effect of additives on the coating formation and corrosion resistance. For the PEO in S1 electrolyte, a mixed layer of AlPO4and Al2O3is formed at the initial stage, which leads to fast plasma discharges and formation of black coatings with the compositions of Al2O3,CuO, Cu2O and ZnO. However, in S2 electrolyte, plasma discharges are delayed and the coatings show a reddish color due to more Cu2O. Mott-Schottky tests show that the S1 coatings are p-type semiconductors;while the S2 coatings can be adjusted between n-type and p-type. Potentiodynamic polarization and electrochemical impedance spectroscopy(EIS) tests show that the PEO treatment can significantly improve the corrosion resistance of brass, with protection efficiency up to 91.50% and the largest charge transfer resistance of 59.95 kΩ·cm^(2) for the S1 coating.

Phosphate Rock Fertilizer in Acid Soils: Comparing Phosphate Extraction Methods for Measuring Dissolution

Three phosphate extraction methods were used to investigate the dissolution, availability and transformation of Kunyang phosphate rock (KPR) in two surface acid soils. Dissolution was determined by measuring the increase in the amounts of soluble and adsorbed inorganic phosphate fractions, and did not differ significantly among the three methods. Significant correlations were obtained among P fractions got by the three extraction methods. Dissolution continued until the end of the 90 day incubation period. At the end of the period, much of the applied phosphate recovered in both soils were in the Al and Fe P or in the hydroxide and bicarbonate extractable inorganic P fractions. The dissolution of KPR in the two soils was also similar: increased addition of phosphate rock resulted in decreased dissolution. The similarity in the order and extent of dissolution in the two soils was probably due to the similarity in each soil of several factors that are known to influence phosphate rock dissolution, namely low CEC, pH, P level, and base status; and high clay and free iron and aluminum oxide contents. The results suggested that KPR could be an alternative P source in the long, if not the short, term in the soils, provided that those factors influencing P availability in the soils are not limiting.

The Inhibitory Degree Between Skeletonema costatum and Dinoflagllate Prorocentrum donghaiense at Different Concentrations of Phosphate and Nitrate/Phosphate Ratios

Interactions between Skeletonema costatum (S. costatum) and Prorocentrum donghaiense (P. donghaiiense) were inves-tigated using bi-algal cultures at different concentrations of phosphate (PO4-P) and nitrate/phosphate (N/P) ratios. Experiments were conducted under P-limited conditions and the Lotka-Volterra mathematical model was used to simulate the growth of S. costatum and P. donghaiense in the bi-algal cultures. Both of these two species were inhibited significantly in bi-algal culture. The results of the simulation showed that the inhibitory degree of S. costaum by P. donghaiense was high when the concentration of PO4-P was low (0.1μmolL-1/2 d), but that of P. donghaiense by S. costaum was high with increased PO4-P supply (0.6μmolL-1/2 d). At low concen-tration of PO4-P (0.1μmolL-1/2 d), or high concentration of PO4-P (0.6μmolL-1/2 d) with high N/P ratio (160), the interactions be-tween S. costatum and P. donghaiense were dependent on the initial cell densities of both species. At high concentration of PO4-P (0.6μmolL-1/2 d) with low N/P ratio (25 or 80), S. costatum exhibited a survival strategy superior to that of P. donghaiense. The de-gree of inhibition of P. donghaiense by S. costaum increased with elevated N/P ratio when the medium was supplemented with con-centration 0.1μmolL-1/2 d of PO4-P. The degree of inhibition to P. donghaiense by S. costaum increased with elevated N/P ratio at low concentration of PO4-P (0.1 μmolL-1/2 d). This trend was conversed at high concentration of PO4-P (0.6μmolL-1/2 d). However, the degree of inhibition of S. costaum by P. donghaiense increased with the increased N/P ratio at different PO4-P concentrations (0.1μmolL-1/2 d and 0.6μmolL-1/2 d). These results suggested that both phosphate concentration and N/P ratio affected the competition between S. costaum and P. donghaiense: P. donghaiense is more competitive in environments with low phosphate or high N/P ratio and the influence of N/P ratio on the competition was more significant with lower phosphate concentration.

Effect of Compost Amendment on Heavy Metals, Nitrogen and Phosphorus in a Peat-Based Container Medium

A laboratory study was conducted to evaluate the effect of compost amendment on mobility and leaching potential of heavy metals, nitrogen （N） and phosphorus （P） from a peat-based commercial container medium containing 700 g kg^-1 peat, 200 g kg^-1 perlite and 100 g kg^-1 vermiculite at varying amendment rates of compost （0, 0.25, 0.50, 0.75 and 1.00 L L^-1）. Increasing compost amendment significantly and linearly increased the pH （P 〈 0.01）, the total concentrations of organic carbon （P 〈 0.05）, copper （Cu） （P 〈 0.01）, cadmium （ca） （P 〈 0.01）, and lead （Pb） （P 〈 0.01）, and increased the bulk density （P 〈 0.01） of the medium. The electrical conductivity （EC）, and total N and P of the medium increased significantly （P 〈 0.01） and quadratically with increasing compost amendment. The relationship of the C/N ratio of the medium with the compost amendment rate was decreasing, significant （P 〈 0.01） and cubic, while that of the total Zn was increasing, significant （P 〈 0.01） and cubic. Extractable P, NO3-N, and NH4-N increased initially with an increasing compost amendment of up to 0.50 L L^-1 and then decreased with further increasing compost rate. Increasing compost rates resulted in a highly significant （P 〈 0.01） and linear increase in total Cd, Cu, and Pb, and a highly significant （P 〈 0.01） and cubic increase in total Zn in the medium. Increasing compost rates also significantly （P 〈 0.01） increased extractable Cu （linearly） and Zn （quadratically）, but significantly （P 〈 0.01） decreased extractable Pb （linearly）. There was no significant effect of compost amendment on the extractable Cd concentration in the medium. However, with increasing compost rates from 0.25 to 1.00 L L^-1, extractability of P, Cd, Cu, Pb and Zn （extractable concentration as a percent of total） was decreased, indicating that compost amendment could lower the leachability of these elements from the medium.

Characterization of tricalcium phosphate solubilization by Stenotrophomonas maltophilia YC isolated from phosphate mines

The phosphate solubilizing characteristics of a strain YC, which was isolated from phosphate mines (Hubei, China), were studied in National Botanical Research Institute’s phosphate (NBRIP) growth medium containing tricalcium phosphate (TCP) as sole phosphorus (P) source. The strain YC is identified as Stenotrophomonas maltophilia (S. maltophilia) based upon the results of morphologic, physiological and biochemical characteristics and 16S rRNA sequences analysis. The results show that the strain S. maltophilia YC can solubilize TCP and release soluble P in NBRIP growth medium. A positive correlation between concentration of soluble P and population of the isolate and a negative correlation between concentration of soluble P and pH in the culture medium are observed from statistical analysis results. Moreover, gluconic acid is detected in the culture medium by HPLC analysis. It indicates that the isolate can release gluconic acid during the solubilizing experiment, which causes acidification of the culture medium and then TCP solubilization. S. maltophilia YC has a maximal TCP solubilizing capability when using maltose as carbon source and ammonium nitrate as nitrogen source, respectively, in NBRIP growth medium.

Phosphate Distribution and Movement in Soil－Root In－terface Zone：I． The Influence of Transpiration Rate

The experiments were conducted in the artificial climate laboratory using ￣(32)P labelled soil and soil-rootplane system to investigate phosphate distribution and its movement in the soil-root interface zone andtheir relations with phosphate uptake by plant as well as transpiration rate (atmosphere humidity). It wasfound that although the phosphate in the soilroot interface zone was of depletive distribution as a functionC/Co = ax￣b(C/Co is the relative content of fertilizer phosphate in a distance from the root surface x, aand b are the regression constants), and a relative accumulation zone of phosphate within 0.5 mm near theroot surface was often observed especially in the heavier texture soils because of root phosphate secretion.The depletion intensity of phosphate in the soil-root interface zone was in agreement with the phosphateuptake by plants under two humidities very well. However, the effects of air humidity on characteristics ofthe phosphate distribution near wheat or maize root surface were different. Wheat grew better under loweratmosphere humidity while maize, under higher humidity, which caused a more intensive uptake and thusa stronger depletion of phosphate in the rhizosphere. Moreover, the depletion intensity was greater by thebottom or the middle part of wheat roots and by the top or the middle part of maize roots. The depletivedistribution of phosphate in the rhizosphere soil and the relative contribution of phosphate diffusion to plant,which was more than 98% in the cultural experiments, indicated that diffusion was a major process forphosphorus supply to plants.

Alkaline treatment kinetics of calcium phosphate by piezoelectric quartz crystal impedance

Calcium phosphate film was prepared by electrochemical deposition technology. Subsequently, the alkaline treatment process of calcium phosphate film in 0.1 mol/L NaOH solution was monitored on real time by the piezoelectric quartz crystal impedance （PQCI） technique. The variations of morphology and composition for the alkaline treatment products were characterized by scanning electron microscopy （SEM）, Fourier transform infrared （FT-IR） and X-ray diffraction （XRD）, respectively. The dynamic variations of calcium phosphate can be characterized by the change of equivalent circuit parameters. The results show that the forming process of hydroxyapatite （HA） is composed of three stages： （1） acidic calcium phosphate dissolution; （2） phase transformation; and （3） HA formation. Furthermore, the correlative kinetic equations and parameters are obtained by fitting the static capacitance （C8）-time curves.