Advanced Materials Research Vols. 881-883

Abstract: Pyrolysis appears to be a promising route allowing all-components recovery of the high value of potentially accessible products from waste printed circuit boards (WPCBs). However, bromine-containing pyrolysis oil must be dehalogenation, otherwise it will be a strong impact on thermal treatment. In the present study, an effective and environmental-friendly process using tri-iron tetroxide sorbent (Fe-O) to simultaneously degrade brominated epoxy resin from WPCBs was developed in pyrolysis process. The results show that brominated epoxy resins can be quickly decomposed under catalysis condition. Bromide concentration in pyrolysis oil decreases with the increase of the content of Fe-O. It can transfer the bromine from the gas phase and liquid phase to solid phase. When adding proportion to 1:1, bromine concentration of pyrolysis oil decreased by up to 98.2%. Fe-O can promote the decomposition of complex structure of benzene compounds to substance with simple structure. This study produces halogen free liquid products to recycle.

Abstract: In this study, a simple and effective method for the determination of organic phosphorus in environmental water samples using ionic liquid (1-butyl-3-methyl-imidazolium hexafluorophosphate, BmimPF₆) head space fiber liquid-phase microextraction combined with high-performance liquid chromatography (HPLC) has been developed. The effects on the extracting efficiency such as the pH of the sample solution, the concentration of NaCl, etc., were investigated. Under optimized conditions, the value of the extracting efficiency can reach 289 for parathion.

Abstract: The advanced pretreatment by electrolysis of Bohai seawater in Tianjin used a diaphragm electrolyzer in the experiment. Removal efficiency and influence factors of the method were analyzed. Results show that turbidity, organic compounds, SDI and chroma of seawater were effectively decreased by electrolysis. Removal efficiency was significantly increased by current density, operation time and inter-electrode distance, and the optimum electrolytic conditions was determined as inter-electrode distance of 2 cm, current density of 15.87 mA·cm^-2, operation time of 10 minutes. It was investigated that when the water quality after electrolysis was of pH 8.6, the chroma and turbidity decreasing trend slowed down, with chroma of 0.052 A, removal rate reached 88.4%; the residual turbidity reduced to 2.52 NTU, removal rate reached 90.71%. A PH of about 8.5, COD_Cr decreasing trend slowed down, and when COD_Cr < 750 mg/L, it conformed to the requirements of the reverse osmosis water.

Abstract: A new non-phosphorus composite water treatment agent m (PASP) : m (PESA) : m (HPMA) : m (BTA) = 8:12:10:5 was developed from polyaspartic acid (PASP), polyepoxysuccinic acid (PESA), hydrolyzed polymaleic anhydride (HPMA) and benzotriazole (BTA). The performance of corrosion and scale inhibition were evaluated by rotary hanging-piece, electrochemical and bubble experiments. The corrosion testing piece was characterized by SEM. The results show that the new environment-friendly composite water treatment agent has good performance of corrosion and scale inhibition. Further dynamic simulated test also indicates that the water treatment agent meet the use demand of circulating cooling water.

Abstract: Along with new urbanization, substantial debates have been triggered on whether urban ecological economic system of CO₂ balance relates to the sustainable urbanization. Based on the data of Nanjing city, China, in 2010, we calculate the total amount of CO₂ emission and CO₂ sequestration. Results show that CO₂ emission mainly comes from industrial production (63.19%) and transportation (33.44%). Moreover, industrial raw coal (51.69%) is the main source of the carbon emission, whereas cultivated land (68.62%) and forestland (27.59%) are the most important carriers of CO₂ sequestration. According to the calibrated results, we conclude that: (1) The relationship between the urban ecological subsystem and economic subsystem is uncoordinated; (2) Nanjing's economic development exerts particular influences on other regions ecological environment.

Abstract: Peroxynitrite can be highly efficient catalyzed to harmless products with a turnover frequency 34.5 s^-1 by micromolar concentration of water-soluble iron porphyrin, 5, 10, 15, 20-tetrakis-(4-carboxyphenyl)-porphyrin-Fe^(III)-chloride (T(p-COOH)PPFe^(III)Cl). Then we used spectroscopic and kinetic to study its decomposition mechanism and rate in bionic environment (25 mM sodium bicarbonate). The data reveal that this catalytic reaction is a recyclable reaction. Peroxynitrite is decomposed to nitrate (NO₃^-) and nitrite (NO₂^-) through forming [oxoFe^(IV)]⁺ intermediate. Moreover, the [oxoFe^(IV)]⁺ intermediate is reduced back to the starting porphyrin. It is noted that the oxidized iron porphyrin can be reduced by the reducing agent in the solution. In addition, we also find the catalytic rate constant is higher in the presence of sodium bicarbonate than the absence of sodium bicarbonate. They are 1.26×10⁶ M^-1s^-1 and 1.17×10⁶ M^-1s^-1, respectively.

Abstract: This study describes an analytical method employing capillary gas chromatography (GC) using flame ionization detection (FID) that has been developed for the simultaneous determination of acrylates (methyl acrylate (MA), methyl methacrylate (MMA), butyl acrylate (BA)) in wastewater. For this purpose, dispersive liquid-liquid microextraction (DLLME) was applied as a sample preparation technique. The DLLME conditions such as the types and volume of extraction solvent, the types and volume of the disperser solvent, pH value and salt addition were studied and optimized. The method was linear in the ranges from 4.3×10^-4 to 200.0 μg·mL^-1 for abovementioned acrylates with R² ≥ 0.9992. The DLLME procedure allowed efficient recovery of the investigated acrylates ranging between 81 % and 109 % with a relative standard deviation (RSD) ≤ 9.1 for the blank samples spiked with 10, 50 and 100 μg·mL^-1 of acrylates, respectively. These results showed the potential of this technique for acrylates monitoring in wastewater samples. Furthermore, the investigated methods are simple, reproducible, and inexpensive.

Abstract: A simple and reliable method combining dispersive liquid-liquid microextracion (DLLME) with gas chromatography (GC) using flame ionization detection (FID) was developed for the simultaneous determination of aniline (AL), o-toluidine (o-TLD), N,N-dimethylaniline (N,N-DAL), p-chloroaniline (p-CAL), and p-nitroaniline (p-NAL) in wastewater. For this purpose, dispersive liquid-liquid microextraction (DLLME) was applied as a sample preparation technique. The DLLME conditions such as the types and volume of extraction solvent, the types and volume of the disperser solvent, pH value and salt addition were studied and optimized. The method was linear in the ranges from 2.2×10^-3 to 100.0 μg·mL^-1 for aforementioned aromatic amines with R² ≥ 0.9968. The DLLME procedure allowed efficient recovery of the investigated aromatic amines ranging between 82 % and 92 % with a relative standard deviation (RSD) ≤ 3.4 for actual wastewater samples spiked with 5, 10 and 20 μg·mL^-1 of aromatic amines, respectively. These results showed the potential of this technique for aromatic amines monitoring in wastewater samples. Furthermore, the investigated methods are simple, reproducible, and inexpensive.

Abstract: The chemical compositions of waste cooking methyl ester (WCME) were analyzed by GC-MS, and the cold flow properties of WCME were studied by cold filer plugging point tester and viscosity tester. Through blending with petrodiesel and adding cold flow improver (CFI), the cold flow properties of WCME were improved efficiently. The study shows that WCME was mainly composed of saturated fatty acid methyl ester (SFAME) and unsaturated fatty acid methyl ester (UFAME), and contents of SFAME and UFAME were 27.63 and 71.81 w%, respectively. The cold filer plugging point (CFPP) of WCME was 0 °C, and the viscosity of it was 4.41 mm2·s-1 at 40 °C. Blending with 0 petrodiesel (0PD) and-10 petrodiesel (-10PD) decreased the CFPP of WCME to-4 °C and-13 °C, respectively. Meanwhile with WCME blending ratio increasing the viscosities of blending oils increased at the same temperature, and the viscosities increased gradually when the temperature decreased. Treating with CFI could significantly reduce the CFPP of blending oils which were composed of WCME and petrodiesel. The viscosities of blending oils with adding CFI were slightly higher than those with out CFI.

Abstract: The simultaneous desulfurization and denitrification performance from the N₂-SO₂-NO simulated flue gas using the urea solution as the reduction absorbent and piperazine as the additive was investigated. The influences of the concentration of urea solution and the concentration of piperazine solution on the simultaneous desulfurization and denitrification behavior were also discussed. The experimental results showed that the addition of piperazine in the urea solution could enhance the denitrification performance, which could result the desulfurization efficiency of 94.07% and the denitrification efficiency of 85.11%.