4#265m2烧结机烟气脱硫工程运行参数分析与对策

通过对脱硫连续生产化验数据及烟气预处理效果的分析，总结出胺浓、pH值等参数的变化特性，研究参数变化及烟气预处理效果对脱硫效果的影响，找出了促进SO2减排的方法。

Degradation of aniline by Fe^(2+)-activated persulfate oxidation at ambient temperature

The aniline degradation by persulfate activated with ferrous ion (Fe2+ ) was investigated in batch reactor at ambient temperature. The experimental factors in aqueous solutions including persulfate concentration, Fe2+ concentration, pH and ionic strength level were discussed. It is demonstrated that, aniline degradation rate increases with increasing persulfate concentration, but much more ferrous ion inhibits the aniline degradation. When the aniline concentration is 0.10 mmol/L, the maximum aniline degradation occurs at the S2O82- to Fe2+ molar ratio of 250/5 at pH 7.0. In the pH range of 5.0-8.5, increasing pH causes higher aniline degradation. What's more, the increase of ionic strength in solution causes inhibiting in the reaction. Produced intermediates during the oxidation process were identified using gas chromatography-mass spectrometry (GC-MS) technology. And degradation pathways of aniline were also tentatively proposed.

Effects of Hypoxia on Dopamine Concentration and the Immune Response of White Shrimp (Litopenaeus vannamei)

Effects of hypoxia on the dopamme concentration and the immune response of White Shrimp Litopenaeus vannamei were studied. The results showed that hypoxia had significant effects on the concentration of dopamme （DA） in the haemolymph, haemocyte count, phenoloxidase activity, phagocytic activity of haemocytes and bacteriolytic and antibacterial activity in the haemolymph （P〈0.05）. The concentration of the dopamme in haemolymph reached its maximum in the 3.0 and 1.5 mgL^-1 DO groups at 12hand 6h, and then returned to normal after 24h and 12h, respectively. All munune parameters decreased with the reduction of dissolved oxygen. Total haemocyte count （THC）, the hyaline cells and semi-granular cells in the 3.0mgL^-1 DO group became stable after 12h, while granular cells did so after 24h. The THC and different haemocyte count （DHC） in the 1.5mgL^6-1 DO group became stable after 24 h. Phenoloxidase activity and bacteriolytic activity in the 3.0 and 1.5 mgL^-1 DO groups reached their stable levels after 24 h and 12h respectively, while phagocytic activity and antibacterial activity＂ became stable after 24 and 12, and 36 and 24h, respectively. It was also indicated that the changes of dopamme concentrations in haemolymph, haemocyte count and phenoloxidase activity were obviously related to the exposure ttrne under hypoxic conditions.

Effects of iron electrovalence and species on growth and astaxanthin production of Haematococcus pluvialis

To increase the cell concentration and the accumulation of astaxanthin in the cultivation of Haematococcus pluvialis, effects of different iron electrovalencies （Fe^2＋-EDTA and Fe^3＋-EDTA） and species （Fe-EDTA, Fe（OH）x^32x and FeC6H5O7） addition on cell growth and accumulation of astaxanthin were studied. Results show that different iron electrovalencies have various effects on cell growth and astaxanthin accumulation of H. pluvialis. Compared with Fe^3＋-EDTA, Fe^2＋-EDTA stimulate more effectively the formation of astaxanthin. The maximum astaxanthin content （30.70 mg/g biomass cell） was obtained under conditions of 18 μmol/L Fe^2＋-EDTA, despite the lower cell density （2.3×10^5 cell/ml） in such condition. Fe^3＋-EDTA is more effective than Fe^2＋-EDTA in improving the cell growth. Especially, the maximal steady-state cell density, 2.9×10^5 cell/ml was obtained at 18 μmol/L Fe^3＋-EDTA addition. On the other hand, all the various species of iron （EDTA-Fe, Fe（OH）x^32x, FeC6H5O7） are capable to improve the growth of the algae and astaxanthin production. Among the three iron species, FeC6H5O7 performed the best. Under the condition of a higher concentration （36 μmol/L） of FeC6H5O7, the cell density and astaxanthin production is 2 and 7 times higher than those of iron-limited group, respectively. The present study demonstrates that the effects of the stimulation with different iron species increased in the order of FeC6H5O7, Fe（OH）x^32x and EDTA-Fe.

Synthesis and Characterization of MgSb2O6 Trirutile-Type in Low Presence Concentrations of Ethylenediamine

The nanoparticles MgSb206 with trirutile-type structure were prepared by colloidal method using ethylanediamine （0.5 and 0.75 mL）, following a calcination at 800 ℃. After, those powders were analyzed by x-ray obtaining a tetragonal structure with cell parameters, a = 4.64 A and c = 9.25 A and special group P42/mnm. Using a scanning electron microscopy were analyzed the powders calcined at 800 ℃, showing the formation of micro-plates, micro-rods, nanoparticles and morphology as rice grains. Employing a transmission electron microscopy, were found nanostructures hexagonal shaped with sizes of- 33.6 nm （0.5 mL） and 28.6 nm （0.75 mL）.

Deactivation Kinetics of Nitrile Hydratase in Free Resting Cells

Nitrile hydratase (NHase) is an important industrial enzyme used for acrylamide production from acrylonitrile.The deactivation kinetics of NHases in free resting cells of Rhodococcus sp.was presented based on a bi-steady state assumption.Effects of hydration temperature,product concentration and substrate concentration on NHase deactivation were investigated experimentally and correlated with a first order deactivation kinetics.The results showed that the hydration temperature and product concentration were major factors governing the deactivation of NHases under substrate-feeding conditions.When acrylamide concentration was higher than 250 g·L1,the deactivation of NHases became serious and the bi-steady state assumption was not applicable.When the hydration temperature was controlled at a relatively higher level such as 28°C,the total deactivation rate constant was about 2.8-fold of that at 20°C.

Effects of Temperature and Concentration on the Rheological Behavior of Polyacrylamide-Based Polymers

Polymers are high molecular weight molecules that provide high viscosity at low concentrations to the media they are inserted. In the oil industry, they are used for enhanced oil recovery and for drilling fluids, where its viscosity is an important factor for a greater efficiency. From all the polymers used by industry, the polyacrylamide and the biopolymer xantham gum are those, which appear significantly in those applications. Taking that into consideration, this work intends to study the effects of the physical, chemical and structural parameters of those polymers in their rheological behaviour, by varying their concentrations from 400 ppm to 2,000 ppm and their temperatures from 298 K to 328 K, which are values similar to those found in the field. For that, a Brookfield Viscometer-Brookfield Engineering Labs rheometer was used. The results acquired showed that the increase on the polyacrylamides ionicity generates and increase on the medium viscosity. For the temperature, its increase causes a reduction of viscosity for the low ionicity polyacrylamides, while increases the viscosity for the high ionicity ones. In the comparative study between xantham gum and polyacrylamides, it was possible to notice that, even though the biopolymer is more complex, its viscosity still is lower when compared to the polyacrylamides.

An easily recoverable thermo-sensitive polyelectrolyte as draw agent for forward osmosis process

As a potential solution to the crises of energy and resources, forward osmosis(FO) has been limited by the development of draw agents. An ideal draw agent should be able to generate high osmotic pressure and can be easily recovered. In this study, a thermo-sensitive polyelectrolyte of poly(N-isopropylacrylamide-co-acrylic acid)(PNA)is developed as an efficient draw agent, and two easy and simple methods are proposed to effectively recover the polyelectrolytes. After adjusting the pH value of polyelectrolyte solutions to around 6.0, the polyelectrolyte can generate relatively high osmotic pressure, and induce average water fluxes of 2.09 and 2.95 L·m^(-2)·h^(-1) during12 h FO processes when the polyelectrolyte concentrations are 0.20 and 0.38 g·ml^(-1) respectively. After acidifying and heating to 70 °C, the PNA-10 polyelectrolyte can aggregate together because of hydrophobic association and separate from water, so it can be easily recovered by either simple centrifugation or gravitational sedimentation. The recovery ratios of PNA-10 polyelectrolyte in both methods are as high as 89%, and the recovered polyelectrolytes can be reused with almost the same FO performance as fresh ones. The results in this study provide valuable guidance for designing efficient and easily recoverable draw agents for FO processes.

The role of phosphatidylinositol signaling pathway in regulating serotonin-induced oocyte maturation in Mercenaria mercenaria

Serotonin (5-HT) has been found to stimulate meiotic maturation of oocytes in many molluscs. During maturation, several signaling pathways are involved, especially the phosphatidylinositol and cAMP pathways. In order to examine the possible role of the phosphatidylinositol signaling pathway in regulating oocyte maturation in Mercenaria mercenaria, the effects of the activator/inhibitor of phospholipase (PLC) and protein kinase C (PKC) on serotonin-induced maturation were studied. Results show that high-concentrations of neomycin (inhibitor of PLC) blocked oocyte maturation, while 9, 10-dimethyl-1, 2-benzanthracene (DMBA, activator of PLC) promoted oocyte maturation in the presence of serotonin. It was also found that in the presence of serotonin, phorbol 12-myristate 13-acetate (PMA, activator of PKC) inhibited oocyte maturation, while sphingosine (inhibitor of PKC) stimulated oocyte maturation. These results indicate that serotonin-induced oocyte maturation requires the activation of the phosphatidylinositol pathway. Decrease of PLC inhibited serotonin-induced oocyte maturation, whereas a decrease of PKC stimulated the maturation. Thus, our study indicates that serotonin promotes maturation of M. mercenaria oocytes through PLC stimulated increase in calcium ion concentration via inositol-1, 4, 5-trisphosphate (IP3) but not PKC.

Chromium Extraction from Sewage Sludge Using Polyepoxysuccinic Acid

An environmentally benign biodegradable chelant,polyepoxysuccinic acid(PESA),was used to separate heavy metals from sewage sludge from the Shanghai Taopu Wastewater Treatment Plant,China,based on chemical extraction technology.The extraction of chromium(Cr) from sewage sludge with an aqueous solution of PESA was studied under various conditions.It was found that the extraction of Cr using PESA was more efficient than that using ethylenediaminetetraacetic acid(EDTA) and S,S-ethylenediaminedisuccinic acid(EDDS) under similar conditions.PESA was capable of extracting Cr from the sewage sludge,and the extraction efficiency was obviously dependent on both the pH and the concentration of the chelating reagent.The extraction efficiency decreased gradually with increasing pH,and the dependence on pH decreased as the concentration of PESA increased.The extraction efficiency reached 58% under conditions of pH = 4 and a ratio of PESA to total heavy metals of 10:1.The extraction efficiency was maintained above 40% within the pH range from 1 to 7 at the high ratio of PESA to total heavy metals of 10:1.Comparing the contents of heavy metals in the sewage sludge before and after the extraction,it was found that the extracted Cr came mainly from the reducible and oxidizable fractions.