Advanced Materials Research Vols. 113-116

Abstract: In order to control stormwater runoff and reduce water pollution, stormwater management planning was carried out in Futian River watershed of Shenzhen city, China. Major rain harvesting methods for different land use, including roof rainwater collection, road rainwater collection and green space rainwater infiltration were investigated. Respective harvesting methods in mountain areas and urban areas were conducted. The instantaneous unit hydrograph (IUH) method and the EPA Storm Water Management Model (SWMM) were recommended for flow routing in mountain areas and urban areas. The runoff coefficient of Futian River watershed reduces from 0.6 to 0.52 after stormwater management. The result shows Futian River watershed has great potential in rain harvesting. The planning practice has a significant effect on runoff reduction. This case of stormwater utilization planning provides useful information to stormwater managers and site designers, and can serve as example for other cities with similar situation.

Abstract: The concentration of dissolved oxygen (DO) and organics in biological aerated filters (BAFs) changes with the height. Due to the different microbiologic property distributions in different heights, biomass and bioactivity also vary with the height. By monitoring biomembranes at different heights in a laboratory simulation reactor, we found that owing to the decrease of organic substance concentration, biomass decreased with the change of height; bioactivity showed V shaped changes with the height, and due to the influence of intercepted suspended substance, bioactivity in the middle and lower levels were the lowest. Observation on the biomembrane biofacies showed that biomembrane became thinner along with the flow direction, i.e. from 700μm to 100μm, and the colour became lighter. Biofacies changed from lower level to higher level, forming a complete biosystem.

Abstract: To overcome the difficulties, because of the unpredictability, uncertainty and randomicity of the urgent accident, in addition to randomness and fuzzy attribute of personnel behavior, during doing the quantitative analysis for reaction time of people in emergency condition. In this paper, by using the results of widespread questionnaire, trained the Adaptive Neural Fuzzy Inference System (ANFIS), and conducted the research of reaction time for evacuating of the students in school in the typical coal chemical industry region of China. The research discovered that the ANFIS method may be use to forecasting the personnel reaction time for evacuating. Regarding many questions, whose internal regulations are very indistinct and complex, such as personnel evacuating action influenced by uncertainty of human's thought and the feared state of mind in the state of emergency, using ANFIS is one effective method.

Abstract: N-Nitrosodimethylamine(NDMA) is known as a carcinogenic and mutagenic compound ,and in recent years, it has been found to be a novel disinfection by-product of the chloramination process.The NDMA precursors are considered as dimethylamine(DMA) and tertiary amines with dimethylamine functional groups. There are four pathways to NDMA formation: nitrosation, unsymmetrical dimethylhydrazine(UDMH) oxidation, chlorinated UDMH oxidation and hydroxylamine pathway. Formation of NDMA is affected by the presence of free chlorine and bromide, and pH is also a sensitive fator.The detection and analytical methods of NDMA are usually spectrophotometry，thin-layer chromatography, GC, LC and GC/MS.To improve the detection precision, GC/MS/MS and GC/HRMS are applied in detecting the trace NDMA. The methods of NDMA removal are UV degradation, the resin and several types of zeolite adsorption, UV/ozone and UV/hydrogen peroxide advanced oxidation technologies. Ozone also can oxidate percursors,so it can control the NDMA yield indirectly.

Abstract: Organic wastewater pollution control was one of the focus researches for environmental workers. In this study, high active electrode was made and hydrogen peroxide production via cathodic reduction of oxygen was studied, the H2O2 generated in the optimization of research and the effect of dye wastewater degradation under the typical conditions were explored. The effects of mass ratio between graphite and PTFE, Na2SO4 concentration, cathodic potential, pH and gas flow rate on hydrogen peroxide output were investigated. The optimized operational parameters were as follows: graphite and PTFE 5:1, pH=6, Na2SO4 concentration 0.5 mol/L, oxygen flow rate 450mL/min, and cathodic potential -1.2 V (vs SCE). Hydrogen peroxide concentration could reach 66.17 mg/L after 2h at optimized condition. Meanwhile, dye removal could reach about 70% at the same time. Therefore, the use of active electrode as cathode has shown promising prospect in dye wastewater treatment.

Abstract: Water quality is more and more important for people all over the world. But there are many problems in ordinary monitoring system for water quality such as untimely data processing, the lack and weakness of early warning mechanism for water quality change and so on. In this paper, one new remote water quality monitoring system was designed based on GPRS technology, after that the modules of the system were mentioned. Especially including the design and the working process of GPRS module, the design of the two main subsystem of the remote water quality monitoring system was described. The test of the remote water quality monitoring system based on GPRS proved that the system has the qualities of stable performance, reliability, well-maintain and low cost.

Abstract: Environmental management is based on environmental theory, Game theory and control theory. Facing three major scientific issues that called population, resources and environment, we will strengthen environmental management of theory, progressively form new comprehensive field of science and technology. We can regard it as game problem. Here, we provide a Game model about environmental management，it give us a methods and scientific basis to solve the practice problem.

Abstract: Five classrooms in a Primary School in Xuanwu District of Beijing were chosen for investigation of indoor air quality. In the autumn measurement period and in the winter measurement period, various dust particle fractions (PM10 and PM2.5) were monitored indoors and outdoors continuously by portable monitors and samplers. Applying statistical software, the impact of different parameters on particulate matter (PM10 and PM2.5) mass concentration was then quantitatively analyzed. The main conclusions were included as follows: (1) Exposure to PM10 and PM2.5 in the indoor air of classrooms in autumn and in winter was high, especially that of PM2.5 in autumn. (2) The indoor PM10 and PM2.5 mass concentrations were related to different parameters including relative humidity, temperature, carbon dioxide, area of opened windows or louver windows, number of students and room volume/student and so on. (3) No marked differences in indoor PM10 and PM2.5 mass concentrations were observed between autumn and winter (p>0.05). However, a statistically significant influence of class level on the indoor PM10 and PM2.5 mass concentrations was apparent in both measurement periods (p<0.05).

Abstract: Recent trend for membrane bioreactor (MBR) operation was to apply a low sludge retention time (SRT) to decrease the fouling propensity and simplify the overall maintenance. However, the correct control and operation of MBRs under low SRT conditions were not well-established. In this study, modeling of MBR system for municipal wastewater treatment was evaluated using hybrid Activated Sludge Models 3 (ASM3), which helped in determining the control and operating strategies. The experiment-based, manual trial-and-error approach used to calibrate the hybrid ASM3 was verified to be useful for MBR modeling at 30 d sludge retention time (SRT). Furthermore, the consistency relationships among carbon oxygen demanded (COD), soluble microbial products (SMP) and mixed liquor suspended solids (MLSS) were established in the process of modeling, implying that the accurate simulation of MLSS were the prerequisites for the COD and SMP prediction.

Abstract: The workability of excessively wet subgrade can be effectively improved by using a “green materials” based entirely on industry byproduct of combination of fly ash (FA) with carbide lime (CL) and flue gas desulfurization gypsum (FGDG). This paper presents the results of a further systematic investigation on the mechanical behavior and durability of FA/CL/FGDG treated silt from Dezhou in Shandong province. FA, CL and FGDG were added at 3 levels in percentages of 8%-24%, 2%-6% and 1%-3% by dry weight of the soils, respectively. The unconfined compressive strength as well as splitting tensile strength (STS), volumetric expansion (VE), California bearing ratio (CBR), dry-wet cycles test and freeze-thaw cycles test were performed. The best strength of 0.802MPa was achieved for 24%FA/6%CL/1%FGDG treated soil, while the 16%FA/6%CL/1%FGDG treated soil also produce good strengths of 0.742MPa, after 7 days curing. STS keeps increasing with curing period in the first 8 weeks throughout the investigation. According to the VE test, a mellowing period may help prevent swelling from ettringite precipitation by letting these minerals form and hydrate before compaction. The FA/CL/FGDG treated soil has a better durability with strength loss ratio less than 15% after 10 wet-dry cycles, and the maximum weight loss around 25% after 10 freeze–thaw cycles. CBR decreases with decrease of compaction degree, but the values are still around 70 even in a poor compaction degree of 93%, meeting the general requirements of subgrade. So, if the silt subgrade is in excessively wet state and could not be compacted to the required density, the modified subgrade would still serve as a strong platform and could provide necessary support for pavement.