Advanced Materials Research Vols. 955-959

Abstract: In this study, Fe/C internal electrolysis was used to pretreat the wastewater of lead 2, 4, 6-trinitroresorcinate (LTNR) production. The influences of pH, acids, reaction time and Fe/C volume ratio on COD removal were investigated. The optimum condition of iron-carbon electrolysis was determined by orthogonal experiment. And the reaction kinetics of COD removal and mechanism of contaminant removal were preliminary explored. The results showed that wastewater pH adjusted by sulfuric acid was more economical and better for COD removal. The effect of pH is the greatest. Two processes programs (pH3, Fe/C volume ratio 1.0, reaction time 24hr; pH3, Fe/C volume ratio 1.2, reaction time 18hr) are advised in project. Under the two process conditions, COD removal rates are 73.78% and 72.42%, respectively. The COD removal could be well described by pseudo-second-order kinetic model, and the reaction rate constant is 2.804×10^-4 L/(mg·hr). Within the range of 0-24hr, film diffusion is the rate controlling step of the electrolysis process. The degradation process of trinitroresorcinate may be as follow: trinitroresorcinate→nitroaniline phenol or phenol aniline →nitrobenzene quinone or benzoquinone and ammonia→biodegradable or inorganics and nitrate.

Abstract: Coking coal of the Shanxi Lvliang mining area, enjoying a fame as the treasure of China, is one of the scarcest types in the world. A mining area in Lvliang willow mining area. Heavy coal under villages has affected the production of the mine. In order to maximize the benefits of local government, residents and enterprise, we analyzed several typical coal under villages mining methods, took account of the actual situation of this area and conducted evaluations on these mining plans of A mine area. Taking into consideration of all factors, Removal plan of villages above mining area was considered to be the most ideal mining scheme.

Abstract: Construction of a project at a proposed site requires understanding of the geological and hydrogeological conditions for the purpose of engineering design and environmental impact assessment. However, investigation and assessment of the site conditions may be challenging for limestone areas due to the irregular occurrence and development of karst. This paper presents a demonstration of the site investigation and assessment for the karst hydrogeological conditions through a case study of a site with complex lithology. A joint on-site surveying and mapping, drilling, geophysical exploration, supplemented by in-situ and laboratory tests, was implemented in the assessment. Results indicate the site area presents a multiplicity in lithology with steep attitude stratum. Northern part of the site distributed shales suffering different degree of weathering, while the rest areas were developed with carbonate rocks. Fracture zones with north-west and north-east trend were developed at the site, which are prone to form strong runoff zone of the groundwater. No shallow buried river, hall-or corridor-type karst caves were detected at the site, neither of large-scale well-connectivity karst channels. However, many small karst and soil caves were developed at the site, which suggest a post treatment of engineering measures for the purpose of engineering and environmental safety. Based on the distribution of karst ratio calculated from boreholes, the proposed site area can be divided into 3 zones of very-strongly developed zone with a karst ratio around 71.2%, strongly developed zone with a ratio around 26.3% and intermediate-slightly developed zone with a ratio of 15.0%. Characteristics of each sub-zones are analyzed regarding to the general layout and later engineering design of the power plant project. This study provides an example of a joint study for site condition assessment at karst areas with complex lithology. Such an assessment is crucial to the site selection, project layout, engineering design and to later environmental impact assessment.

Abstract: A section of Liaohe River in east of Shuangan bridge, Yingzhou District, Tieling City was selected as the experimental site to study ecological slope protection technique of riverbank in an agricultural catchment. Four ecological slope protection techniques, including combined biostabilization, Live stakes, Vegetation planting and Live stakes+vegetation planting were conducted. Results showed that through six and sixteen months growing, the highest shoot length and root length were observed in live stakes technology, while the lowest shoot length and root length were appeared in Vegetation planting technology. It indicated that Salix suchowensis is more suitable for the Liaohe river initially.

Abstract: To treat coking wastewater with A²O-MBR hybrid process, membrane pollution control has become an important factor affecting the long-term stable operation of the system. The experiment reported in this paper focused on the membrane fouling of this hybrid system and try to evaluate the effects of aeration intensity and flux on the membrane fouling. The results show that the optimal parameters of membrane module operation are: aeration 0.2 m3/h, membrane flux 11.5 L/(m²·h), and with the maintenance of cleaning measures the membrane module can be kept under long-term stable operation.

Abstract: Struvite crystallization is an efficient method for phosphorus recovery from animal manure wastewater. However, large amount of organic coexisting impurities, contained in animal manure wastewater, might influence struvite crystallization. In this study, the effect of typical organic matter contained in animal manure wastewater, such as butyric acid, fulvic acid, tetracycline, on phosphorus recovery was examined. The following conclusions were drawn: (1) with an increase in butyric acid concentration in animal manure wastewater, phosphorus recovery efficiency did not change significantly; (2) with an increase in fulvic acid concentration in animal manure wastewater, phosphorus recovery efficiency decreased obviously; (3) with an increase in tetracycline concentration in animal manure wastewater, phosphorus recovery efficiency decreased slightly.

Abstract: Car brings convenience to people's work and life, however, there are too many environmental issues such as energy shortages, atmospheric pollution and greenhouse effect have been caused by using a lot of traditional fuel cars, which threaten mankind survival. Pure electric vehicle (PEV) has its unique advantage for high efficiency, low noise, less environmental pollution and can use alternative energy sources, therefore, PEV has achieved rapid development with governments and automobile manufacturers support. Lithium-ion (Li-ion) batteries are considered to be the best choice of power batteries for electric vehicles due to their high energy density, high working voltage, long cycle life and low self-discharge rate. With the production, use and scrap of Li-ion battery, the recycling and the utilization of Li-ion will become the focus of attention.

Abstract: The experiments were performed by considering the upper loose porous media and lower fractured media as a typical structure of vadose zones, and by constructing the corresponding physical model to simulate water flow and solute transport processes in order to investigate water flow features and migration mechanism. It has been indicated that in the porous and fractured complex media, if the lower fracture structure remains unchanged, the structure and permeability of the porous media offer considerable impact on infiltration processes. Additionally, if the structure and permeability of the porous media remain unchanged, the overall permeability and flow features of the fracture structure are significantly controlled by fracture configurations. Furthermore, for the fracture structures with different fracture configurations, it is indicated that increasing of the density of the vertical fractures results in much more enhancement of the solute concentration decay rate than that caused by increasing the density of the horizontal ones. This investigation was expected to be of scientific significance and practical value for effective groundwater protection.

Abstract: The flue gas simultaneous desulfurization and denitrification was studied for its feasibility with the new gas-liquid medium by using Ca(OH)₂ as absorbent. The effects on key operating parameters were analyzed. They are pH, inlet temperature of flue gas and inlet concentration of air pollution. When pH is almost 5.5-6, and inlet temperature of flue gas is between 110℃ and 120℃, the results show that the removal efficiency of SO₂ and NO are above 85% and 80% using rotating biological technology (RDB), respectively, which can satisfy most requirements of industrial scale applications. Besides, When C_SO2 is more than 1500 (mg/m³), with the rising of imported pollutant concentration, desulfurization efficiency continues to increasing and denitrification efficiency was growing slowly.

Abstract: Surface discharge plasma was used to activate air to produce reactive oxygen species (ROS) for promoting the oxidation of ammonium sulfite by air forced oxidation method. The effect of applied voltage and the air speed in discharge reactor on the generation of ozone as well as the oxidation kinetic of ammonium sulfite were analyzed and discussed. The ozone concentration increased with the discharge voltage, but decreased with the air speed, and a maximum mass of generated ozone was obtained at air speed of 15 m/s. Compared with air forced oxidation, the oxidation kinetic constant of ammonium sulfite by ROS injection had an increase by 2.67-fold, and the oxidation of ammonium sulfite followed a pseudo zero order kinetics. An increase in air speed accelerated the oxidation of ammonium sulfite, and the oxidation kinetic constant of ammonium sulfite was increased by 5-fold when the air speed increased by 2-fold.