粘胶纤维无锌纺丝酸浴分析方法的探讨

对含硫酸、硫酸铝、硫酸钠三组份粘胶纺丝酸浴的分析方法进行了试验探讨。结果表明,本试验所采用的分析方法具有操作简便、快速、准确等特点,对以铝代锌的粘胶纤维无锌纺丝试验及生产有一定应用价值。

以国产块孔式石墨加热器取代引进的酸浴闪蒸装置的H列管式加热器

以块孔式加热器代替酸浴闪蒸装置的H列管式加热器,生产应用效果良好。块孔式加热器密封性能好,耐温耐压性能好,传热效率高,且投资省、安装方便。

Effect of arsenopyrite on thiosulfate leaching of gold

Arsenopyrite was artificially added into the thiosulfate leaching solution to clarify the role of arsenopyrite on the thiosulfate leaching of gold.The effect of arsenopyrite on the thiosulfate leaching of gold was studied by the thermodynamic calculation,mineral dissolution test,leaching test and XPS analysis.The results show that the thiosulfate consumption slightly increases with increasing the concentration of arsenopyrite,but the gold dissolution is obviously hindered.This may mainly attribute to the catalytic effect of arsenopyrite on the thiosulfate decomposition and the formation of passivation layer on the gold foil surface.The passivation layer likely consists of Cu2S or Cu（S2O3）35-,element S,FeOOH and iron arsenate,which is deduced from the XPS analysis.However,the negative effect of arsenopyrite can be eliminated by adding additives.It is found that both additives of sodium carboxymethyl（CMC） and sodium phosphate（SHPP） can not only decrease the thiosulfate consumption but also improve the gold dissolution.

Production of Biotechnology Fulvic Acid from Fermented Corn Straw by Microbial Community LCM9 and Its Application Effect

[Objective] The aim was to evaluate the feasibility of biotechnology fulvic acid produced by microbial community LCM9 by the use of corn straws as substrate and its application effect.[Method]Microbial community was obtained from the nature samples,and corn straws were used as fermentation substrate.The yield of biotechnology fulvic acid and its application effect was evaluated.[Result]The yield of biotechnology fulvic acid was up to 15.7% when the water content was 75.0% and fermented after 7 d using corn straws as the only source of nutrition.After 500 mg/kg of biotechnology fulvic acid was added for 5 d,the root length and bud length could be increased by 59.1% and 97.1%,respectively.[Conclusion]A higher yield of biotechnology fulvic acid could be obtained by the method in this experiment and the product could enhance the growth of wheat seedlings.

Decomposition mechanism of pentlandite during electrochemical bio-oxidation process

Electrochemical measurements were carried out to elucidate decomposition mechanism of pentlandite using modified powder microelectrode with Acidithiobacillus ferrooxidans attached or without on the mineral powder surface.Cyclic voltammetry（CV） results show that at a low potential of about-0.2 V（vs SCE）,the pentlandite was transformed to an intermediated phase like Fe4.5-yNi4.5-xS8-z when Fe and Ni ions were evacuated from mineral lattice;when the potential was changed from-0.2 V to 0.2 V,the unstable violarite（Fe3Ni3S4） and FeNi2S4 were formed which was accompanied by element sulfur formed on the mineral surface;when the potential increased over 0.2 V,the unstable intermediated phase decomposed entirely;at a higher potential of 0.7 V,the evacuated ferrous ion was oxidized to ferric ion.The presence of Acidithiobacillus ferrooxidans made the oxidation peak current increase with initial peak potential negatively moving,and the bacteria also contributed to the sulfur removing from mineral surface,which was demonstrated by the reduction characteristic at potential ranging from-0.75 to-0.5 V.Leaching experiments and electrochemical results show that the solution acidity increasing when pH2 may impede the oxidation process slightly.

Photocatalytic activity and kinetics for acid yellow degradation over surface composites of TiO_2-coated activated carbon under different photocatalytic conditions

TiO2-coated activated carbon surface （TAs） composites were prepared by a sol-gel method with supercritical pretreatment. The photocatalytic degradation of acid yellow （AY） was investigated under UV radiation to estimate activity of catalysts and determine the kinetics. And the effects of parameters including the initial concentration of AY, light intensity and TiO2 content in catalysts were examined. The results indicate that TAs has a higher efficiency in decomposition of AY than P25, pure TiO2 particles as well as the mixture of TiO2 powder and active carbon. The photocatalytic degradation rate is found to follow the pseudo-first order kinetics with respect to the AY concentration. The new kinetic model fairly resembles the classic Langmuir-Hinshelwood equation, and the rate constant is proportional to the square root of the light intensity in a wide range. However, its absorption performance depends on the surface areas of catalysts. The model fits quite well with the experimental data and elucidates phenomena about the effects of the TiO2 content in TAs on the degradation rate.

Effects of Different Application Amounts of Potassium Fulvate on Yield and Quality of Tomato and Soil Physical and Chemical Properties

This study was conducted to study the optimum dosage of potassium ful- vate （PF） on greenhouse tomato, the effects of different amounts of PF on yield and quality of greenhouse tomato and soil physical and chemical properties were investigated by a field plot experiment. The results showed that the bottom applica- tion of PF increased tomato yield, plant dry matter weight and root dry matter weight by 14.0%, 14.4 and 50.6%, respectively; Vc and soluble sugar content of tomato increased by 1＆5% and 10.0%, respectively; and soil bulk density de- creased by 3.6%, and CEC increased by 5.0%. All the indexes increased with the increase of PF application amount, and reached the maximum value when the PF application rate was 4 500 kg/hm2. In consideration of the cost of fertilizer and all indexes, the optimum dosaqe of PF fertilizer was 4 500 kg/hm2.

Comparison of electrochemical dissolution of chalcopyrite and bornite in acid culture medium

The electrochemical dissolution process of chalcopyrite and bornite in acid bacteria culture medium was investigated by electrochemical measurements and X-ray photoelectron spectroscopy（XPS） analysis. Bornite was much easier to be oxidized rather than to be reduced, and chalcopyrite was difficult to be both oxidized and reduced. The relatively higher copper extraction of bornite dissolution can be attributed to its higher oxidation rate. Covellite（CuS） was detected as the intermediate species during the dissolution processes of both bornite and chalcopyrite. Bornite dissolution was preferred to be a direct oxidation pathway, in which bornite was directly oxidized to covellite（CuS） and cupric ions, and the formed covellite（CuS） may inhibit the further dissolution. Chalcopyrite dissolution was preferred to be a continuous reduction-oxidation pathway, in which chalcopyrite was initially reduced to bornite, then oxidized to covellite（CuS）, and the initial reduction reaction was the rate-limiting step.

日、英、汉环境资源词汇

(大肠菌种) Escherichia coli(E.coli) 大肠杆菌,大肠埃希氏菌 EGR制御装置 exhaust gas recirculation EGR控制装置,废气再循环控制器 yellow cake 黄滤饼、黄滤渣硫黄回收法 sulfur recoverv process 硫黄回收法硫黄酸化物 sulfur oxides (SO_x) 硫氧化物(SO_x) 硫黄税(米国) Sulfur Oxides Emission Charge 脱硫税(美国) ion

Effect of pH values on extracellular protein and polysaccharide secretions of Acidithiobacillus ferrooxidans during chalcopyrite bioleaching

The effect of pH values on the extracellular protein and polysaccharide secretions of Acidithiobacillus ferrooxidans was comparatively investigated in different phases of bacterial growth during chalcopyrite bioleaching. The results indicate that the extracellular protein is always more than the extracellular polysaccharide secreted by attached cells on the chalcopyrite, on the contrary, and is always less than the extracellular polysaccharide secreted by free cells in the solution at bacterial adaptive phase, logarithmic phase and stationary phase whenever pH value is at 1.0, 1.5, 2.0 or 2.5; free cells are mainly through the secretion of extracellular polysaccharide rather than the extracellular protein to fight against disadvantageous solution environment, such as high concentration of metal ions and unsuitable pH solution; both amounts of polysaccharide and protein secreted by attached cells are mainly positively related to the solution acidity rather than the total concentration of soluble metal ions. The experimental results imply that bacteria are mainly through secreting more extracellular polysaccharide to fight against disadvantageous environment and the extracellular protein perhaps plays an important role in oxidation？reduction reactions in the bioleaching system.

Synthesis of glycerine-xanthate and its depressing mechanism in separation of marmatite from arsenopyrite

A small molecular organic depressor glycerine-xanthate was synthesized. The effect of glycerine-xanthate on the flotation of sulfide minerals was investigated based on a function of pH value and concentration of glycerine-xanthate through flotation experiments in the presence and absence of Cu^2＋. The results show that glycerinee-xanthate has a strong dressing effect on marmatite at pH〉6 and on arsenopyrite in weak acid and base conditions with butyl-xanthate as collector. In the presence of glycerine -xanthate, marmatite is activated by addition of Cu^2＋, but arsenopyrite cannot be activated and remains unfloatable. So the selective separation can be achieved for two minerals. The depression of glycerine-xanthate on sulfide minerals was discussed based on the radical electronegative calculation and the theory of HSAB. Infrared spectrum shows that there are some -OH and-CSS-in glycedne-xanthate molecule, which competes with butyl-xanthate on the mineral surface. As a result of many hydrophilic groups in glycerine-xanthate, the surfaces of marmatite and arsenopyrite become hydrophilic, thus the flotation of marmatite and arsenopyrite is depressed. The collector is adsorbed preferentially on the surface of marmatite and it shows a better floatability in the presence of Cu^2＋, whereas, the surface of arsenopyrite absorbs glycerine-xanthate and the flotation of arsenopyrite is depressed by glycerine-xanthate.

Acid-base buffer effect of fulvic acid and barium fulvate from weathered coal

The acid-base buffer characteristics of fulvic acid (FA) and barium fulvate (BaFA)were analyzed. Each share of the sample or model agents (phthalic acid and salicylic acid)were separately mixed into a series of shares of dilute solutions of HCI or NaOH with a series of concentration. The original pH values of the solutions were arranged from 2 to 13.Final balanced pH of each share was measured. The pH changes show that FA and BaFApossess buffer ability, whereas the model agents do not. The tendency of balanced pHvalues was 5.4 for FA and 7.4 for BaFA, whereas the original pH was 4.0-8.5; balancedpH changed little. At room temperature, the maximum buffer capacities were as follows:18.11 mmol hydroxyl per gram FA, 11.25 mmol hydroxyl per gram BaFA, 1.19 mmol protonper gram FA, and 1.45 mmol proton per gram BaFA. Mathematics analysis shows thatlogarithm of buffer capacities of FA and BaFA is linearly dependent on original pH. Compared with BaFA and model agents, it is concluded that FA buffer capacity against hydroxylrelies not only on its acidic groups, BaFA buffer capacity against hydroxyl does not rely onits acidic groups, and FA buffer capacity against proton is not related with its carboxyl andphenolic hydroxyl group. The pH values of FA-water solutions with different concentrationsfrom 1 to 10 grams per liter were measured. Their pH values were slightly affected by itsconcentration. Thus, FA possesses a much stronger buffer ability against water dilutionthan common buffer agent. All the pH values of FA water solutions were very nearby 5.4,just the same as the balanced pH tendency for adding FA.

Formation of arsenic−copper-containing particles and their sulfation decomposition mechanism in copper smelting flue gas

The heat recovery steam generator(HRSG)of copper smelting generates a large number of arsenic−coppercontaining particles,and the in-situ separation of arsenic and copper is of importance for cutting off environmental risk and realizing resource recovery.The formation of arsenic−copper-containing particles was simulated,the method of in-situ decomposition of arsenic−copper-containing particles by pyrite was proposed,and the decomposition mechanism was confirmed.It was found that particles with high arsenic content were formed in the simulated HRSG,and copper arsenate was liable for the high arsenic content.Pyrite promoted the sulfation of copper,leading to the in-situ decomposition of copper arsenate.In this process,gaseous arsenic was released,and thus the separation of arsenic and copper was realized.

Catalytic effect of visible light and Cd^2+on chalcopyrite bioleaching

The effects of visible light and Cd^2+ion on chalcopyrite bioleaching in the presence of Acidithiobacillus ferrooxidans(A.ferrooxidans)were studied by scanning electron microscopy(SEM),synchrotron radiation X-ray diffraction(SR-XRD),and X-ray photoelectron spectroscopy(XPS).The results of bioleaching after 28 days showed that the copper dissolution increased by 4.96%with only visible light,the presence of Cd2+alone exerted slight inhibition effect on chalcopyrite dissolution and the concentration of dissolved copper increased by 14.70%with visible light and 50 mg/L Cd^2+.The results of chemical leaching showed that visible light can promote the circulation of iron.SEM results showed that Cd^2+promoted the attachment of A.ferrooxidans on chalcopyrite surface under visible light.SR-XRD and XPS results indicated that visible light and Cd^2+promoted chalcopyrite dissolution,but did not inhibit the formation of passivation.Finally,a model of synergistic catalysis mechanism of visible light and Cd2+on chalcopyrite bioleaching was proposed.

pH-dependent leaching mechanism of carbonatitic chalcopyrite in ferric sulfate solution

The dissolution of a carbonatitic chalcopyrite(CuFeS2)was studied in H_(2)SO_(4)−Fe_(2)(SO_(4))_(3)−FeSO_(4)−H_(2)O at varying pH values(0.5−2.5)and 25℃ for 12 h.Experiments were conducted with a size fraction of 53−75μm.Low Cu recoveries,below 15%,were observed in all pH regimes.The results from the XRD,SEM−EDS,and optical microscopic(OM)analyses of the residues indicated that the dissolution proceeded through the formation of transient phases.Cu_(3.39)Fe_(0.61)S_(4) and Cu_(2)S were the intermediate phases at pH 0.5 and 1.0,respectively,whereas Cu_(5)FeS_(4) was the major mineral at pH 1.5 and 1.8.The thermodynamic modelling predicted the sequential formation of CuFeS_(2)→Cu_(5)FeS_(4)→Cu_(2)S→CuS.The soluble intermediates were Cu_(5)FeS_(4) and Cu2S,whilst,CuS and Cu_(3.39)Fe_(0.61)S_(4) were the refractory phases,supporting their cumulating behaviour throughout the dissolution.The obtained results suggest that the formation of CuS and Cu_(3.39)Fe_(0.61)S_(4) could contribute to the passive film formed during CuFeS_(2) leaching.

The inhibitory effect of lotus leaf extract on hyperuricemia and its potential mechanism

Objective:Lotus leaf is a traditional Chinese herb that has been used successfully for centuries for relieving edema by inducing diuresis.Based on its good clinical evidence and anti-hypertensive effectiveness,this study aimed to investigate the potential mechanism of the hyperuricemic inhibitory effects of lotus leaf crude extract(LL)and lotus leaf total alkaloids fraction(LA).Methods:The xanthine oxidase(XOD)inhibitory effect of LL and LA was analyzed in vitro by determining mRNA expression and protein expression levels of hepatic XOD.The hyperuricemic inhibitory effect of the lotus leaf was analyzed in vivo in a potassium oxonate(PO)-induced rat model by determining mRNA expression for renal urate transporters.Results:At a concentration of 40mg/mL,LL and LA suppressed XOD enzymatic activity by 37.35%±9.50%and 47.73%±8.32%,respectively.Both LL and LA administration significantly reduced the concentration of uric acid in the serum and liver of PO-induced hyperuricemic rats.Both LL and LA administration could inhibit XOD mRNA and protein expression,activate renal organic anion transporter 1/3 mRNA expression,and inhibit renal urate reabsorption by decreasing renal GLUT9 and renal urate transporter 1.Conclusions:Insight was gained into the mechanism behind the hyperuricemic inhibitory effects of LL and LA.Our results suggest that they act on two targets:decreasing the production of uric acid by inhibiting mRNA and protein expression of XOD in the liver,and regulating the mRNA expression of renal urate transporters in the kidneys.

Iron Phosphate Coating: A Novel Approach to Controlling Pyrite Oxidation

A novel coating technique was developed for controlling Pyrite oxidation. The technique invo1ved leachingpyrite particles with a solution containing low concentrations of phosphate and hydrogen peroxide. Duringthe leaching process, the iron released from pyrite by hydrogen proxide was precipitated by phosphate as aferric phosphate coating. This coating was shown to be able to effectively prevent Pyrite from oxidation and itcould be established at the expense of only surface portions of Pyrite. The emergence of this technique couldprovide a unique potential route for abating acid mine drainage and reclaiming sulfide-containing degradedmining land.

Degradation of n-butyl xanthate using fly ash as heterogeneous Fenton-like catalyst

Heterogeneous Fenton-like process using fly ash as a catalyst was studied to degrade n-butyl xanthate form aqueous solution. The different reaction parameters on the degradation efficiency of the process were investigated. The fly ash/H2O2 catalyst possesses a high oxidation activity for n-butyl xanthate degradation in aqueous solution. It is found that both the dosage of catalyst and initial solution pH significantly affect the n-butyl xanthate conversion efficient. The results indicate that by using 1.176 mmol/L H2O2 and 1.0 g/L fly ash catalyst with mass fraction of 4.14% Fe(III) oxide at pH 3.0, almost 96.90% n-butyl xanthate conversion and over 96.66% COD removal can be achieved within 120 min with heterogeneous catalysis by fly ash. CS2 as an intermediate of n-butyl xanthate oxidation. Finally, it is demonstrated that the fly ash/H2O2 catalytic oxidation process can be an efficient method for the treatment of n-butyl xanthate containing wastewater.

Iron Monosulfide Distribution in Three Coastal Floodplain Acid Sulfate Soils, Eastern Australia

The distribution of iron monosulfide (quantified as acid volatile sulfur: SAV) was compared with geo- chemical properties that are known to affect its formation and accumulation in three coastal Holocene acid sulfate soils (ASS) at Tuckean Swamp, McLeods Creek and Bungawalbyn Swamp respectively. These properties included PH, reactive iron (FeR), pore-water sulfate (SO:42-) and organic carbon (OC). Iron monosulfide was concentrated at the oxic/anoxic boundary. The Tuckean Swamp and McLeods Creek sites are Holocene sediments, whereas the Bungawalbyn Swamp is a Holocene peat. The concentration of SAV averaged 0.2 g kg-l in a 0.5 m thick soil layer at the Tuckean Swamp, but was an order of magnitude lower in the oxic/anoxic transition layers at McLeods Creek and Bungawalbyn Swamp. The SAV mineral greigite (Fe3S4) was identified in the Tuckean Swamp by X-ray diffraction and scanning electron microscopy with quantitative energy dispersive X-ray analysis (SEM-EDX). Very small concentrations of greigite were also observed in the McLeods Creek, based on crystal morphology and elemental composition. The concentration of SAV was a small fraction of the total reduced sulfur, representing at most 3% of the Pyrite sulfur. However, the presence of this highly reactive sulfide mineral, distributed within pores where oxygen diffusion is most rapid, has important implications to the potential rate of acid production from these sediments.

Effect of TongFengNing Decoction on Uric Acid Levels and Xanthine Oxidase Activity in Hyperuricemia Rats

Objective To observe the effect of TongFengNing Decoction （TD） on uric acid levels, xanthine oxidase （XOD） activity, and XOD mRNA expression of hyperuricemia （HUA） model rats. Methods： 90 rats were randomly divided into 6 groups （n=15）, and the HUA model in all groups except the blank group was established by administering hypoxanthine （HX） by gavage and injecting potassium oxonate （OAPS） intraperitoneally. Rats in all TD groups and allopurinol group were administered multiple doses of TD and a single dose of allopurinol by gavage twice daily for 21 days, while the blank group and the model group were administered normal saline. On the 7th, 14th, and 21st days of drug intervention, serum uric acid （SUA）, urine uric acid （UUA）, intestinal uric acid （IUA）, as well as XOD activity and mRNA expression in the liver and small intestine were measured in randomly selected 5 rats of each group. Results： On the 14th and 21st days of intervention, all TD dose groups and the allopurinol group showed decreased SUA and IUA levels, increased UUA levels, as well as decreased XOD activity and mRNA expression in the liver and small intestine, compared with the model group （P 〈 0.05）. The low- and high-dose TD group and the allopurinol group showed increased SUA and IUA levels, as well as XOD activity and mRNA expression in the liver and small intestine, and decreased UUA levels, compared with the moderate-dose TD group （P〈0.05）. Upon extending the drug intervention time of each TD dose group, SUA and IUA levels, XOD activity, and XOD mRNA expression in the liver and small intestine decreased and UUA levels increased （P 〈 0.05）. Conclusion： TD reduces SUA levels in HUA model rats, which promotes uric acid excretion and inhibits XOD activity and XOD mRNA expression to reduce uric acid production. The reduction in uric acid level by the intermediate dose of TD was better than that by allopurinol and the low and high doses of TD.