Advanced Materials Research Vols. 781-784

Abstract: A new method has been developed to detect the residues of the binary mixed pesticides of prometryne-acetochlor in soil-water system by high performance liquid (HPLC). The study compared two pre-treatment ways: direct injection and solid-phase extraction. The results showed that the method of direct injection is better than that of solid-phase extraction. In the linear from 0.35 μg·mL^-1 to 15 μg·mL^-1 of prometryne-acetochlor, the correlation coefficients for prometryne and acetochlor were 0.9993 and 0.9999, and the limits of quantification were 0.011 μg·mL^-1 and 0.106 μg·mL^-1 respectively. The recoveries ranged from 91.2% to 109.7% with the relative standard deviations of 0.42% -0.78%. This method provides a dependable approach to determine the residues of prometryne and acetochlor in the soil-water system.

Abstract: Several surface sediment samples (JL1, JL2, YZ1~YZ3) were collected from different sites of Yangtze River and Jialing River in Chongqing downtown area. Sorption behavior of fluoranthene (Fluo), one of the typical PAHs, onto humic acid (HA) extracted from the samples and the effect of the clay minerals (Kaolinite and Montmorillonite) on sorption performance of Fluo were carried out. The results showed that addition of clay minerals was significantly enhanced Fluo adsorption properties of sediments. Montmorillonite gave a better enhancing performance than Kaolinite. The adsorption effects of the inorganic minerals of the sediment for Fluo could not be neglected. The unit Freundlich model was applied to describe the adsorption isotherms of HA samples to Fluo. The modified coefficient of K_f ́ were in order: YZ2>JL2>YZ1>YZ3>JL1. The adsorption performance was comparatively highly correlated with the polarity of HA, element contents and characteristics of functional groups.

Abstract: This paper presents a comparative study of the performance of ferrate (VI) towards wastewater treatment. The ferrate was produced by microwave irradiation-assisted hypochlorite-oxidation method. And the concentration of the prepared ferrate was determined by UV-Vis spectrum. Domestic wastewater collected from Longting lake of Kaifeng city was treated with ferrate (VI). Samples were analyzed for COD and ammonia-nitrogen removal. Results demonstrated that low addition of ferrate (VI) leads to good removal of COD and ammonia nitrogen. So ferrate (VI) is an effective reagent for wastewater treatment.

Abstract: Soil moisture plays an important role in agricultural drought monitoring. However, the traditional observed soil moisture data from meteorological stations has not been able to meet the demands for large-scale drought monitoring temporally and spatially. The microwave remote sensing is a new effective way for obtaining near surface soil moisture. The temporal and spatial variation in soil moisture in arid regions in northern China is examined based on the soil moisture data retrieved from AMSR-E (Advanced Microwave Scanning Radiometer-EOS), with which the observed soil moisture data at 10 cm depth from meteorological stations are compared. The results show that there is a small change in soil moisture with seasons for the central and west areas, while a large change for the east areas of the study region and the soil moisture in summer and autumn is greater than that in spring and winter. And that it decreases from southeast to northwest spatially, as is agree with the spatial distribution of precipitation in the study area. Moreover, there is a great difference in spatial distribution between the soil moisture retrieved from AMSR-E and the observed soil moisture data from meteorological stations for the central and west areas, while a small difference for the east areas of the study region.

Abstract: The objective of this study is to compare organic and inorganic coagulants in coagulation-flocculation and sedimentation, using a jar test apparatus. Six types of coagulants, namely extract solution of moringa oleifera seed with distillation water (Moringa-H), extract solution of moringa oleifera with sodium chloride (Moringa-N), Micro-nice^® bio separator A from Technogreen Limited, aluminium sulfate (alum), ferric chloride (FeCl₃) and polyaluminium chloride (PAC) were investigated using three types of synthetic wastewater, kaolin suspension, soymilk solution and oily wastewater for determination of the optimum dosage and coagulation mechanism. The results indicated that PAC was able to remove turbidity of 90-94%, pH in the range of 6-7 in the kaolin suspension concentration range of 20-100 mg/L, while the Moringa-H showed turbidity removal of 66-91% which was better than Moringa-N and dry sediment using Micro-Nice^® gave minimum sludge. The Micro-Nice^® also showed high turbidity removal in colloid and oily wastewater. The optimum dosage of Micro-Nice^® was in the range of 80-120 mg/L for colloid removal of 89-96% and COD removal of 37-73% at the colloid concentration range of 100-1000 mg/L, while 10 g/L oily wastewater showed that the optimum dosage of Micro-Nice^® was 200 mg/L for turbidity removal of 99%, COD removal of 73% and oil removal of 97%.

Abstract: The purification of polyether polyols with low unsaturation was studied. The removal effect of residual double metal cyanide in the polyols by the methods of adsorption and precipitation-filtration is characterized by the residual concentration of the zinc and cobalt ions which is measured by Inductively Coupled Plasma Atomic Emission Spectrometry (ICP-AES). Compared with precipitation-filtration, the method of adsorption was more practical and efficient for the purification of the polyols. And the optimum kind and amount of the adsorbent were obtained. The results showed that the combination of chelating fiber and attapulgus clay was the most favorable for the removal of zinc and cobalt ions and the appropriate weight ratio of chelating fiber and attapulgus clay was 1:1. The total concentration of zinc and cobalt ions can be reduced to lower than 1×10^-6. And the amount of the adsorbent added was 3.33% by the weight of the polyether polyols. And through Scanning Electron Spectroscopy (SEM) the morphology of the chelating fiber was characterized before and after adsorption.

Abstract: Taguchi method has been applied to evaluate the effects of operational parameters on the efficiency of vacuum membrane distillation (VMD) in the desalination of water. It was observed that permeate increases with an increase in feed temperature and vacuum pressure. However, feed salt concentration adversely affected the amount of the collected permeate due to the reduction of vapour pressure as a result of the presence of the solute in water. Flow rate, however, could only increase the permeate if it was increased from 37.5 to 50 ml/s. Any further increase in flow rate to 100 ml/s, negatively lowered the permeate due to the limited feed/membrane contact time. We observed that at very high salt concentration (300 g/l) the permeate reduces accordingly, highlighting the fact that VMD should be used with care due to the presence of membrane fouling and/or other simultaneous flux-lowering effects present at concentrated feeds.

Abstract: The chemical compositions of cottonseed oil biodiesel (CSME) are analyzed by using the gas chromatograph-mass spectrometer (GC-MS). The cold flow properties of CSME is studied by cold filer plugging point (CFPP) tester and crystallization mechanism of biodiesel, three approaches for enhancing cold flow properties of CSME are put forward: crystallization fractionation; blending with winter petrodiesel; and treating with cold flow improver (CFI) additives. A significant correlation model is proposed for predicting CFPP by CSME blending ratio. The study shows that the CSME is mainly composed of saturated fatty acid methyl esters (SFSMEs): C_14:0~C_24:0 and unsaturated fatty acid methyl esters (UFAMEs): C_16:1~C_22:1, C_18:2 and C_18:3. The mass fraction of SFAME and UFAME is 32.12 and 66.19%, respectively. The CFPP of CSME is 6 °C. Crystallization fractionation and blending with-10PD decrease the CFPP of CSME to-1 °C and-12 °C, respectively. Adding Flow Fit, Flow Fit K and T818 additives 1.5 v% decreases the CFPP of CME and CME/-10PD to 0 and-26 °C, respectively. This study has effectively enhanced cold flow properties of CSME and provides technical support for using CSME.

Abstract: Thermal treatment of an inferior residue in the presence of a potential industrial hydrogen donor was conducted in a continuous flow reactor. Properties of liquid products and SARA compositions of residuals were analyzed. Moreover, stability of residuals was characterized by colloidal stability index. The results showed that in the presence of the hydrogen donor, the viscosities of product oils were reduced to a much lower point, the asphaltene formation of residuals was supressed and the stability of residuals was improved.

Abstract: The chemical compositions of biodiesel are analyzed by gas chromatograph-mass spectrometer (GC-MS), and theirs molecular structure are investigated on the basis of the hybrid orbital theory. Cold filter plugging point (CFPP) of biodiesel is studied by CFPP tester, the solution crystallization theory and the similarity-intermiscibility principle. Good correlation models are proposed for prediction biodiesel CFPP by chemical compositions and CFPP of biodiesel-petrodiesel blends by biodiesel ratio. The study shows that biodiesel is mainly composed of SFAME (C_14:0C_24:0) and UFAME (C_16:1C_22:1, C_18:2 and C_18:3). Carbon atoms of the alkyl for SFAME arrange in a zigzag pattern by CCC=109.5°. C-C carbon atoms of the alkyl arrange in a zigzag pattern by CCC=109.5°, too, carbon chain is curved by C=C in CCC=122.0°, and curved degree increases with increasing unsaturated degree. CFPP of biodiesel is mainly determined by chemical compositions. CFPP increases with the amount and carbon chain length of SFAME. CFPP of biodiesel-petrodiesel blends is mainly determined by chemical compositions and ratio of biodiesel. To lower SFAME_C20 biodiesel, such as PME, CSME, WME, SBME and RME, it blending with-10PD can formed a eutectic mixture. CFPP of the eutectic mixture is-12 °C. The biodiesel ratio for the lowest CFPP rang increases with decreasing SFAME. Such as, SFAME contents in PME, CSME, WME, SBME and RME are 35.86, 32.12, 31.04, 18.29 and 14.69 w% respectively, and the range of biodiesel ratio is 520, 1020, 2030, 3050 and 4060 v% respectively. To higher SFAME_C20 biodiesel, such as PNME, CFPP increases with PNME ratio.