Advanced Materials Research Vols. 690-693

Abstract: Active carbon modified by hydrochloric acid was prepared with impregnation method. The synthesized material was characterized by scanning electron microscopy. It was proved that plenty of pores with diameter of about 5-10μm were exist on the surface of active carbon. The adsorption process with toluene was performed over the modified active carbon to investigate the adsorptive efficiency. For comparison, other porous materials were also performed the adsorption experiment. The results showed that active carbon modified by hydrochloric acid has high adsorptive efficiency for toluene. The results proved that adsorptive performance of active carbon increased with the hydrochloric acid concentration.

Abstract: Slag haydite made from steel slag and clay was used for phosphate adsorption, and adsorption characteristic was studied. Results showed that the uptake of phosphate was facilitated for pH 3-8, the adsorption process fitted with pseudo-second-order model and intra-particle diffusion model, and the equilibrium time was about 3h. Isotherm adsorption data on slag haydite were fitted by both the Freundlich and Langmuir models. It was found that the data follows the Langmuir model better, and the maximum adsorption capacity increased from 1.17mg·g^-1 to 2.42mg·g^-1 as temperature rose from 20°C to 40°C. Thermodynamic parameters G⁰, H⁰ andS⁰ showed that the adsorption was spontaneous, endothermic and entropy increase process and increasing temperature was favorable.

Abstract: The hydroxy-aluminum pillared bentonite(OH-Al-bent) and aluminum pillared bentonite(Al-bent) were synthesized and characterized by XRD and SEM analysis. The yield of products and the adsorbent capabilities for Cr(Ⅵ) from aqueous solution were investigated, and the optimal experimental conditions including adsorption time, reagent dosage, the initial concentration of Cr(Ⅵ) and PH that might influent the adsorption performance were also investigated. It was observed that the adsorption capabilities of OH-Al-bent was better than Al-bent. The efficiency of Cr(Ⅵ) removal were better when the dosage of the sorbent was higher. And a reagent dosage of 7g/L, adsorption time of 60min, PH of 4 were selected as an optimum conditions.

Abstract: SiO₂-coated Fe nanocomposites (Fe@SiO₂) were prepared without using any of surface-coupling agents. The outer SiO₂ coating offered new possibilities for the control of Fe core agglomeration. In order to investigate Cr (VI) reduction in open systems that simulated subsurface conditions, sand column experiments were conducted. When 10 mg/L of Cr (VI) was injected into the columns, the removal efficiencies of Cr (VI) by the Fe@SiO₂ were 65 mg Cr/g Fe. The transport tests in deionized water-saturated sand columns indicated that 88.03% of Fe@SiO₂ was eluted. Nonetheless, the mobility of Fe@SiO₂ decreased when encountering 10 mmol/L Na⁺ and Ca²⁺. Presumably, 15 mg/L humic acid enhanced the mobility of Fe@SiO₂. Overall, the results of this study indicate that Fe@SiO₂ has the potential to become an effective reactive material for in situ groundwater remediation.

Abstract: In this paper, the early strength behavior of Metakaolin and Palm Oil Fuel Ash (POFA) based geopolymer mortar was investigated for the purpose of exploring the utilization of POFA which is a waste material generated from production of palm oil. Geopolymer mortar was prepared by activating metakaolin combined with POFA at 0%, 30%, 40%, 50%, 60%, 70% and 80% replacement levels in NaOH and Na₂SiO₃ medium. The mortar specimens were tested for compressive strength at 3 and 7days. The maximum compressive strength at 3 and 7days are 65.264MPa and 68.863MPa respectively corresponding to a POFA replacement of 40%. A replacement of 80% POFA to 20% Metakaolin gave compressive strength as high as 26.174MPa and 30.791MPa for 3 and 7 days. It was also discovered that water demand of the system reduced with increase in POFA replacement. It is concluded that POFA addition to metakaolin can improve behavior of Metakaolin and POFA geopolymer system.

Abstract: Lignin-based anionic exchange resin was synthesized by modified alkali lignin after reaction with epichlorohydrin and triethylamine in the weak alkaline medium provided by pyridine in the organic medium of N,N-dimethylformamide (DMF). The influence of pyridine on synthesis process and yield of products were discussed. The product was characterized by FTIR spectroscopy analysis and the adsorbent capabilities for N from aqueous solution were also exploited. The factors that might influent the adsorption performance were investigated. An adsorbent dosage of 0.2g, adsorption time of 100min, pH of 4 and the initial concentration of nitrate concentration was 10mg/l were selected as optimum conditions.

Abstract: Waste generation from surface coating industries brings about worsening of the environmental scenery and human health in the world. The production of these wastes is detrimental to surrounding areas in landfill or dumping spaces, therefore necessary action is required to minimize the unpleasant situation. This research is aimed at using waste generated from the manufacture of paint known as vinyl acetate effluent as an admixture in concrete. The material is rinse water taken from the cleaning process reactor. Concrete of 0% vinyl acetate effluent cured in water with those of 2.5%, 5%, 10% and 20% by weight of cement were produced and cured using Japanese standard. The specimens were tested for compressive strength, splitting tensile strength and durability at 3, 7 and 28 days. Findings show that incorporating of 2.5% of Vinyl acetate effluent improves strength properties of concrete. Higher resistance of water absorption and sulfate conditions were observed in polymer modified concrete. The study has shown that incorporating vinyl acetate effluent in producing polymer modified concrete could bring lights of using the waste material for sustainable and environmental preservations.

Abstract: The paper wooden compound pallets are produced through the processing and assembly by using particle board, paper tubes and PE coated paper board as raw materials. Comparing with traditional wooden flat plate, the new type of green environmental protection pallets has many advantages such as high strength, light weight, low cost, waterproof, anti-moth-eaten, no need fumigation, etc. is an ideal green transport packaging materials for export commodities. The paper discusses and probes into the process and technology of paper wooden compound pallets.

Abstract: In the system of heteropoly acid [π-C5H5NC16H33]3[PO4(WO3)4], H2O2 (30 %, w/w), polyethylene glycol, 1,2-dichloroethane, soybean oil under went epoxidation reaction smoothly via reaction-controlled phase transfer catalysis. Effects of the amount of interfacial active agent, H2O2, catalyst and reaction time were investigated and the optimized reaction conditions were as follows: 10 g of soybean oil, 0.3 g of [π-C5H5NC16H33]3[PO4 (WO3)4],8 ml of H2O2 (30 %, w/w), 5.0 ml of PEG, 30 g of 1,2-dichloroethane, and the reaction temperature was 65 °C and reaction time was 3.5-4.0 h. Under these optimized conditions, an epoxy value of 6.30 % and a yield of 90 % were obtained. Hence, it is an environmental-friendly and effective way to synthesize epoxidized soybean oil.

Abstract: Tertiary treatment wascarried out to treat pulp and paper effluent from secondary treatment processby a three-dimensional electrode system equipped with modifiedbentonites as powdery electrode. The cetyl trimethylammonium bromide modified bentonite (CTAB-bent) and hydroxy-aluminum pillaredorganic bentonite (OH-Al-CTAB-bent) were synthesized and characterized by XRDand FTIR spectroscopy analysis.The impacts such as the dosage of particle electrode, electrolysis times,current density were on the COD removal efficiency and decolorization effect ofeffluent were also investigated. The results showed that the experimentscarried out by three-dimensional electrode system with OH-Al-CTAB-bent weresufficient for the COD and color removal efficiency. A current density of 30mA/cm², electrolysis time of 40min, and the particle electrodedosage of 1.6g/L were selected as an optimum conditions that allows fast andlow cost treatment. The effluent can achieve the discharge standard of waterpollutants for pulp and paper industry (GB3544-2008) after electrolysis.