Applied Mechanics and Materials Vols. 170-173

Abstract: Removal of perchlorate from drinking water in an ion exchange membrane bioreactor (IEMB) was investigated at different influent ClO₄^- concentrations when the hydraulic retention time was 5h. Except the 49th day and the 51st day, the effluent ClO₄^- concentrations met standard of the U.S. Environmental Protection Agency (USEPA) required 18µg/L. In the initial stages of the influent ClO₄^- concentration increase, the ClO₄^- concentration in the anaerobic bioreactor, the effluent Cl^- concentration and the effluent electrical conductivity increased suddenly. As the operating time increased, the ClO₄^- concentration in the sludge supernatant kept below 10µg/L after steady operation; the effluent Cl^- concentration declined slowly and finally stabilized at about 90 mg/L; the effluent electrical conductivity decreased gradually and finally stabilized at about 279µs/cm.

Abstract: Simultaneous powdered activated carbon(PAC) adsorption and dominant bacteria biodegradation process was evaluated for the aniline pollution accident existing in source water. The jar test results showed the aniline adsorption capacity and adsorption rate of the PAC were represented by the Freundich adsorption isotherm model. The aniline adsorption ability of the PAC was high when the temperature was low; the biological activity of dominant bacteria was high when the temperature was at 25°C and pH value was at 6. The poly-aluminum-chloride in combination with PAC and potassium permanganate in combination with PAC were compared with the simultaneous adsorption and biodegradation.

Abstract: Pot experiments were conducted under different status of soil moisture potential during different stages of rice. The results show that soil moisture potential regulation and control is able to increase the rice yield at each growth stages after returning green, the suitable soil water potential criteria for middle-season rice in Liaoning province at different stages is 5~10kPa in tillering initial stage, 35kPa at most in tillering final stage, 5~10kPa in jointing and heading stages, not more than 20kPa in Milk maturity stage; re-watering post drought has a compensation effect to rice whose soil suction potential is controlled in 5~10kPa at tillering initial stage according to the results that its tillers number, output, final root dry biomass and leaf dry weight were significant exceeding contrast; The research on rice quality indicates that water stress in jointing stage increase protein content but reduce eating quality.

Abstract: Two different kinds of water were treated with aeration-contact oxidation filtration process. One was groundwater containing iron and manganese (GIM), the other was GIM polluted by ammonia (GAIM). The results showed that ammonia has almost no influence on iron removal, but has great influence on manganese. Under the condition of 1m/h filter velocity and 10 mg/L average ammonia nitrogen concentration of inlet，the outlet manganese concentration for GAIM was less than 0.1 mg/L after 315 days. When temperature dropped to 18°C below, the manganese concentration of effluent exceeded 0.1 mg/L. When average ammonia nitrogen concentration of inlet for GAIM dropped to 3.27 mg/L, the manganese concentration of outlet for GAIM was less than 0.1 mg/L in winter. And for GIM, the manganese concentration of outlet was less than 0.1 mg/L only after 52 days. Although the filter velocity increased gradually from 1 to 7 m/h, the manganese concentration of effluent was always less than 0.1 mg/L. Therefore, ammonia pollution in the groundwater greatly increases the difficulty of water treatment.

Abstract: Most of the metropolis faces the water supply and demand management problem including the surface water pollution, groundwater overdraft, deficiency of water supply, and low efficiency water resource in the past decades. As the Chinese capital, Beijing has been trying to solve the unbalance. This paper describes the water resources equilibrium related with the urban population and the primary method is the equilibrium analysis of the water supply and demand. The elastic scenario output means the water consumption of ten thousand Yuan output value of the primary industry is most sensitive. The case shows building equilibrium equation may be a succinct and practical estimation method for the metropolis.

Abstract: The urgency of renovation the water mains from Malong Chemical Limited Company is analyzed. And the operation process with high density polyethylene pipe linings is described in this paper. The commentary on their respective advantages and the costs will be presented. It has been proved that the HDPE linings renovation technology has many advantages including shorter operation time, higher efficiency and lower cost with smaller and simpler operating equipments over conventional trenchless and replace pipe technology.

Abstract: This article presents the design of the air conditioning system in the building. In the project, ice storage for cold source and electric boiler thermal storage for heat source are taken while variable primary flow is used for water system. Taking into account the functions of each part, all air and fan coil unit with fresh air system are applied in ventilation system. The design of air exhaust system is introduced. A detail scheme about the annual operational regulation for energy saving is proposed. During the designing process, energy conservation is given enough attention, and the reliability of operation is also ensured.

Abstract: The refrigerating system is a very important part of marine conditioner. Through introducing the basic structure of refrigerating system and the process of failure, the root cause is found, the problem is solved, and some suggestions are put forward.

Abstract: The recover of condensation heat in fossil fuel power plant in summer was difficult. In this paper, a scheme that using condensation heat for cooling was proposed. Firstly, cooling water was used as low temperature resource to produce mid-temperature hot water, and mid-temperature hot water could be used as heat source in the absorption refrigerator. At the same time, the condensing heat of refrigeration system was transmit to saturated air from cooling tower and made air leaved far from saturation area thereby to control the visible plume. Thermodynamic analysis shows that this scheme is feasible, and economical analysis also shows that this scheme is feasible when heat resource of absorption-type heat pump using waste heat.

Abstract: Discuss the flame burning velocities of biomass gasification gases and the methods of increasing them by calculating and programming through MATLAB. The results display that the flame burning velocities of biomass gasification gases are relatively low, and they increase when adding hydrogen, which has a higher flame burning speed. Satisfying effects are achieved under different equivalence ratios, initial temperatures and pressures. Research shows that flame burning velocities improve with the fraction of hydrogen volume increasing. It also suggests that with the rise of equivalence ratio, the velocities increase first, and then decrease, and they reach the highest when equivalence ratio is stoichiometric; an increase in initial temperature accelerates the burning velocities, while the velocities drop by enhancing the pressures.