Advanced Materials Research Vols. 518-523

Abstract: The removal of elemental mercury (Hg⁰) with the reactive species produced by gas phase surface discharge plasma was studied. The effects of several operational parameters, such as applied voltage, inlet Hg⁰ concentration and gas humidity, were investigated. The removal of Hg⁰ was significantly promoted by an increase in the applied voltage of the reactor system. Hg⁰ oxidation efficiency decreases with increasing inlet Hg⁰ concentration. Furthermore, with the addition of H₂O, Hg⁰ oxidation is remarkably restrained.

Abstract: Coal fly ash (CFA) was modified by hydrothermal treatment using NaOH solutions for zeolite synthesis. The XRD patterns of zeolite and coal fly ash are presented. The synthesized zeolite was investigated for adsorption of heavy metal ions in aqueous solution. It was shown that fly ash and the modified forms could effectively absorb heavy metals. The adsorption isotherm could be described by Freundlich isotherm equations. The pseudo second-order kinetics would be better for fitting the dynamic adsorption of Cu2+ and Cd2+.

Abstract: A newly modified resin can be impregnated with hydrated ferric oxide on the base of D301 resin. The article involved batch experiments to investigate the effect of concentration, contact time, pH and temperature. The results showed that the maximum adsorption was found at 6 h,3.0 pH and 298 K temperature. The maximum adsorption capacity was 961.95 mg/g at 1200 mg/L initial β-naphthalenesulfonic acid concentration. The equilibrium adsorption was fitted by Temkin isotherm.

Abstract: The paper adopted Coagulation-Fenton Oxidation Method on treating the wastewater of 6-nitro-1,2 diazonium oxygroup naphthalene-4-sulfoacid production process (i.e. 6-nitry wastewater), introduced the treatment effect of the combined technology used on 6-nitry wastewater, and studied the factors influencing the treatment effect, to determine the reasonable parameters of the technology on treating 6-nitry wastewater. The results showed that Using polyaluminium chloride (mass fraction 2%) as flocculant for treating 6-nitry wastewater, the COD removal rate reached up to 48.7%; Making Fenton reagent oxidation treatment on coagulation yielding water, under the best conditions for solution acidity controlled at pH3 or so, in the 100 mL wastewater, 30% hydrogen peroxide was 5.0 mL, 0.5 mol/L ferrous sulfate solution was 4.0 mL, reaction time was 60 min, the COD removal rate could reach 98% or more.

Abstract: Bake-out exhaust method was used to significantly accelerate the release of VOCs from building materials. This paper studies the bake-out technology with dilution ventilation for indoor air pollution by experimental works. The baking effectiveness of formaldehyde, benzene, toluene and xylene ranged from 3 to 7.6, 7.6 to 25, 5.1 to 17 and 6 to 22 for the six cases, respectively. Baking effectiveness would become higher at longer baking time and higher baking temperature for formaldehyde and VOCs released from decorative materials. However, considering the possible deformation of building materials, 40°C and 10 hr would be the best choice for a suitable bake-out.

Abstract: Based on the strong regularity of public transit, this paper presents analysis of influencing factors of buses gaseous pollutants emission at first. Then through separating the bus running process into several parts, a quantitative forecasting model of gaseous pollutants emission of diesel buses and a validity test of this model are manifested.

Abstract: Groundwater is an important component of water resources. Compared with surface water, groundwater has slower flow rate and lower capacity of diluting and self-purification. It is difficult to treat the groundwater pollution. Therefore, it is important to protect the groundwater from being polluted for planning and management of groundwater resources. It is considered as an effective method for decision makers and administrators to identify the high risk level of groundwater pollution through groundwater pollution vulnerability assessment. In this study, the most widely used DRASTIC model and GIS software were used to evaluate the groundwater vulnerability of Chengting new district in Shijiazhuang, china. The groundwater vulnerability grades of the study area were divided by the model. The research results could provide scientific basis for the new district planning and construction.

Abstract: Contaminant transportation is an important environment factor of tailings. Discharge pollutants that exceed the stipulated standards will cause serious problems of environmental water pollution. Quantitative analysis of the rules of contaminant transportation will be helpful to quantitative evaluating the environment factors of tailings and making out corresponding control schemes. In this paper, a numerical simulation method is adopted to a certain tailing dam to quantitatively analyse the rules of contaminant transportation. Results show that absorption of the tailing pool is the key factor to contaminant.

Abstract: This article studied the effects of chemical fixation with magnesium oxide, calcium oxide, aluminum oxide, ferrous sulfate+calcium oxide in situ on Arsenic and Cadmium combined contamination soils. The results indicate: Four agents have well fixation effects, and the fixation effect of ferrous sulfate and calcium oxide mix- restoration is the best. However, it increases the leaching toxicity of Cadmium; Aluminum oxide also has a certain fixation effect on Arsenic, but it strengthens the leaching toxicity of Cadmium in acidity condition; the fixation in situ effects of magnesium oxide and calcium oxide on Arsenic and Cadmium combined contamination soils, which dramatically decreases the leaching toxicity of Arsenic and Cadmium and makes two pollution elements co-stabilized.

Abstract: Silicon metal is known as a metalloid or semi-metal with several characteristics of metals. Silicon metal also has a large influence on the modern world economy. But the production of the silicon metal consumes high energy and discharges huge furnace fume. According to the technical demands of the fume cleaning and micro-silicon powder recovery system to the silicon metal furnace, this paper studies the control scheme with the structure mode of Schneider PLC and the Kingview software, develops the relevant control program and monitor program, and optimizes the control strategy through the on-line debugging. The practical application indicates that the control system is stable and reliable with the best effect of dust extraction and the longest service life to the dust settling bag.