Advanced Materials Research Vols. 881-883

Abstract: An IC reactor volume 6m³ was used to treat the straw-washing water produced in a pulping and papermaking mill in experiment. When loading rate was 3.34~6.28kgCOD/(m³·d) COD average removal rate was 28.14%, that was lower than COD average removal rate of sludge waking up stage (47.30%) and acclimation stage (51.14%), and also lower than COD removal rate (50~80%) of IC running well. Gas production rate of the reactor was 1.53~32.17L/h, and effluent VFA was 746.0~1211.0mg/L. So hydrolysis-acidification process was more appropriate than anaerobic process when treating the straw-washing water. Due to low concentration of the wastewater and less gas production, the inner circulatory system of the reactor produced discontinuous ascending flow. When gas production rate of the reactor was 12.00~54.55L/h, flow rate of lifting pipe was 1.20~12.86L/h, and the ratio of flow rate and gas production rate was 0.08~0.36. Down pipe produced intermittent backflow, backflow rate reached 518.4~725.1L/h.

Abstract: In this paper, by introducing carbon production and Baking process and equipment, the channel for SO₂ to generate from Baking fume is explained, sulfur content control requirements for various materials in production are expressed; after analyzing inspection data, it is summed up that SO₂ in Baking fume mainly comes from fuel gas, calcined petroleum coke and coal tar pitch do not contain SO₂ basically, metallurgical coke has great influence on SO₂ concentration in the fume only in the first application, and the influence shall disappear after repeated use, which provides theoretical basis to solve the environmental problems generated because of SO₂.

Abstract: In this paper, NaHSO₃/LiBr/SDS dissolution system was used to deal with waste wool to prepare non-toxic stable keratin solution with higher dissolving rate and higher molecular weight. Effects of component use levelspH valuereaction temperature and reaction time were critically investigated in detail. Based on the above results, the optimal reaction conditions were obtained. That is, 94 % wool dissolution rate (WDR) and 50.2% keratin extraction rate (KER) reached under the best conditions (NaHSO₃: 0.5 mol/L, LiBr: 0.1 mol/L, SDS: 0.02 mol/L, temperature: 90°C, reaction time: 4 h, pH=12). IR spectra showed that the extracted keratin from solution system with the addition of LiBr was dominated by a-helical conformation, which can be used as textile materials or to develop novel functional fibers.

Abstract: Rainwater utilization system using green technology, not only can reduce the pressure of rainstorm on the city drainage system, and replenish groundwater resources, but also control urban non-point source pollution. At present, rainwater indirect utilization is widely used. This research explored the Kunming urban green space system typical for each pollutant runoff reduction effect, purifying regularity and removal mechanism in order to provide a theoretical basis for its application.

Abstract: The paper proposes application of municipal solid waste CFB gasification as well as of the possible plant configurations and the environmental performances of the main commercially available gasifiers for municipal solid wastes. The case indicates that gasification is a technically viable option for the solid waste conversion, including residual waste from separate collection of municipal solid waste. It is able to meet existing emission limits and can have a remarkable effect on reduction of landfill disposal option. However, the operational difficulties experienced at several pilot and demonstration plants indicate that long-term operating results from a large industrial plant are needed before gasification can be considered a reliable alternative to combustion.

Abstract: Copper smelting gas producing sulfuric acid process produces contaminated acid which contains high concentration of fluorine, chlorine, arsenic and copper, zinc, lead, cadmium and other metals. The sulfide precipitation and lime neutralization methods have been used at present. Those methods have some deficiencies as which produces a lot of hazardous and unwieldy solid wastes, spends huge processing cost, reuse difficultly the water after treatment. In this paper, according to characteristics of this kind of smelting contaminated acid, evaporation condensing process and the feasibility of recycling arsenic, sulfuric acid and valuable metals were studied. Under the condition of atmospheric heating evaporation, this study explored the distribution characteristics of fluorine, chlorine, sulfate radical, arsenic in condensate and in concentrate and the crystallization removal rates of arsenic trioxide in concentrate at different temperatures and different enrichment ratios. The results show arsenic, fluorine and chloride have good removal rates from contaminated acid by evaporation condensing process. Temperature at 130°C, enrichment multiple in 6~7, the removal rate of arsenic, fluorine and chlorine reached 62%, 88%, 77%. The results also show evaporation condensing process has good application prospects to treat smelting contaminated acid.

Abstract: In this work adsorption of heavy metal ions (Cu²⁺, Pb²⁺, Zn²⁺ and Ni²⁺) from aqueous solution by chitosan was investigated in a batch reactor. Three commercially different viscosity chitosans were used as adsrobents. pH value, adsorption temperature, time and initial concentration had affected adsorption efficiency of metal ions. The results showed that low viscosity chitosan has the highest adsorption capacity among the low, middle and high viscosity chitosans. The amounts of adsorbed metal ions decreased with increased adsorption temperature and decreased pH value. The highest adsorbed amount at the equilibrium time (7.5mg/g) of Cu²⁺ was observed among Cu²⁺, Pb²⁺, Zn²⁺ and Ni²⁺.

Abstract: Vitrification is considered to be an attractive technology for municipal solid waste incineration. The main components of the vitrified bottom ash slag are SiO₂, CaO, Al₂O₃, Fe₂O₃, Na₂O and MgO, accounting for more than 90% of the total mass. The phase relations and thermodynamic properties of the CaO-Al₂O₃-SiO₂-FeOx-MgO-Na₂O oxide system is highly required, and is of great significance for optimization of vitrification processing and sustainable resource utilization of melting slag. Thermodynamic properties of the vitrified bottom ash slag were investigated in the present work. A study on the phase equilibria of CaO-SiO₂-Na₂O system was carried out with modelling method.

Abstract: Activated carbons (AC) were produced by chemical activation with potassium hydroxide (KOH) at 800°C from chars that were carbonized from reedy grass leaves at 450°C in N₂ atmosphere. The effects of the weight ratio of KOH/char ( impregnation ratio), activation temperature and duration time were examined. Adsorption capacity was demonstrated with iodine number. BET surface area, pore volume and pore size of activated carbons were characterized by N₂ adsorption isotherms. The maximum surface area and iodine number of the AC was 1100 m²/g and 1080 mg/g produced at 800°C for2h and impregnation ratio is 4:1.The characteristics of activated carbons were determined by Infrared spectroscopy (FT-IR) and X-ray diffraction (XRD). Thermal gravimetry (TG/DTA) analysis of raw material was carried out.

Abstract: As an agricultural waste available in large quantity in China, Orange peel was utilized as low-cost adsorbent to remove furadan from aqueous solution by adsorption. The FTIR spectrum of OP (Figure 2 and Table 1) showed that some peaks were shifted or disappeared and new peaks were also appeared. The value of q_t (mg.g^-1) increased with an increase in initial furadan concentration and remained constant after reaching equilibrium time. The contact time needed for furadan solutions with initial concentrations of 20-60 mg.L^-1 to reach equilibrium was less than 30 min. But for furadan solutions with initial concentrations of 80-120 mg.L^-1, equilibrium time of 40 min was required. Finally, the effects of adsorbent (OP, OPC and OPA) on the furadan adsorption were carried out in this study. After reaching equilibrium time the removal percentage of 40.12% acquired for OP, while OPA adsorbed about 43.34% and OPC adsorbed about 57.93%. The results in this study indicated that orange peel was an attractive candidate for removing furadan from the aqueous solution.