Advanced Materials Research Vols. 726-731

Abstract: In order to know the characteristic of spatial and temporal distribution of heavy metal concentrations in urban stormwater runoff, rainfall runoff from impervious underlying surfaces in urban region was observed during rain events. Results showed that during the precipitation process, heavy metal concentrations decreased gradually temporally (except Cd); concentrations of Fe, Cu and Zn meet Class III standard of Environmental Quality Standards for Surface Water in terminal runoff, but concentrations of Cd and Pb go beyond this standard far. Heavy metal concentrations in runoff from different types of landuses were significantly different. The arithmetic average concentrations of Fe, Cd, Cu and Zn in stormwater runoff from roof (e.g.,34.4mg/L, 0.15mg/L, 1.25mg/L and 1.23mg/L, respectively) were obviously higher than that in stormwater runoff from road (e.g., 11.8mg/L, 0.05mg/L, 0.13mg/L and 0.69mg/L, respectively).

Abstract: With the acceleration of urbanization, dust composed of solid particles has become one of the major air pollutants in urban areas. The dust-retention capacity and its spatial distribution of 8 greenbelt types are discussed. The results show that the dust-retention capacity of Cedrus deodara is the highest, and the total dust-retention capacity is (2.85±0.28) g/m², in contrast, only (0.48±0.04) g/m² for Ligustrum quihoui. Moreover, the dust-retention capacity of outside of 7 greenbelt types is higher than that of inside, except Osmanthus fragrans. The dust-retention capability of outside indicates an order of lower section, middle section and upper section, and an order of middle section, lower section and upper section of inside.

Abstract: To find out the heavy metal pollution condition from the Beng River sediment, we see the region from Beng River Rubber Dam to the Yimeng Road Bridge as research object.We monitored and surveyed on the three kinds of metal components (Cu, Zn, Cd) in the sediments from eight sectionsthe. With reference to the relevant domestic standards, we established sediment pollution evaluation criteria suitable for the region., We conducted the evaluation of ecological risk and pollution levels with the detection results by standard index of the potential ecological risk index and Nemerow France France. The results showed that: the heavy metals ecological risk index in Sediment from Beng River Rubber Dam to the Yimeng Road bridge section, Nemerow pollution index was 6.95, It was heavily polluted. This showed that the heavy metals in river sediment pollution was very serious.

Abstract: An atmospheric tracer dispersion study known as Urban Meteorological and Tracer Experiment was carried out in Yuzhong County, Gansu province in northwest of China, during October of 2011. By using the observational data, the applicability of CALPUFF model based on Gaussian formula was verified within urban area. The results show that (i) CALPUFF model can reasonably reflect the actual observations on the whole, and the high value centers of tracer concentration was changed with wind direction over the urban canopy layer. (ii) The simulated plume central axis has a bias of 10-15° with observations, and the simulation error is very much big at the single point, especially at the ground.

Abstract: This paper reviewed the development of bioretention systems with a focus on its abilities to control phosphorus in stormwater. Bioretention systems takes full advantage of the matrix-microbes-plant system with simultaneous removal of organic matter, nitrogen, phosphorus, total suspended solids (TSS), heavy metal, and pathogens. But phosphorus removal has been found inconsistent in bioretention systems, which can be observed phosphorus leaching in some systems. The phosphorus forms in stormwater, the distribution and transfer pathways of phosphorus in bioretention system need to be figured out and simulated in order to solve the phosphorus leaching. Some new matrix materials, such as aluminum-based water treatment residual, were also employed to adsorb and trap the phosphorus in stormwater. The latest study progress and further research needs of bioretention systems were summarized.

Abstract: The degradation of atrazine in UV/H₂O₂ advanced oxidation process was studied. The combined UV/H₂O₂ process could effectively degraded atrazine, which is attributed to the strong oxidation strength of hydroxyl radical produced. Results show that atrazine degradation rate was affected by H₂O₂ concentration and initial atrazine concentration. The degradation rate constant (k) increased with H₂O₂ concentration from 20 to 80 mg/L and decreased when H₂O₂ concentration exceeded 120 mg/L. The degradation rate of atrazine decreased with increasing atrazine concentration. NO₃^-¡¢Cl^-¡¢HCO₃^- have inhibitory action on atrazine degradation. The higher inorganic anions concentration was, the stronger inhibitory action would be. When their concentrations were 0.5¡¢5 and 20 mmol/L, respectively, their inhibitory action order is HCO₃^- > NO₃^->Cl^- all the time.

Abstract: Fir sawdust, a low-cost residual agricultural material, was used as adsorbent for the removal of Cu²⁺from aqueous solutions. Factors affecting the adsorption behavior of Cu²⁺, such as pH, initial metal concentration, contact time and temperature, have been carried out. The Cu²⁺ removal was pH-dependent, reaching a maximum at pH 5. The adsorption capacity of the fir sawdust from Langmuir adsorption isotherm was 38.6 mg/g at 25°C. The adsorption process followed pseudo-second-order kinetics. The equilibrium data fitted very well to the Freundlich isotherm. The negative ΔG^o values at various temperatures confirm that the adsorption processes are spontaneous.

Abstract: The purpose of this paper is to construct a dynamic comprehensive optimization simulation model to forecast the net load of water pollutant and economic growth rate of Beijing. Our results propose an optimal policy for helping to achieve the goal of sustainable development. We performed a linear optimization modeling by using LINGO software to simulate a socio-economic model and an environmental model with input-output table. The socio-economic model represents the relationship between socio-economic activities and water pollutant emissions. The environmental model represents the changes in the amount of water pollutants generated.

Abstract: Polymeric Aluminum Chloride (PAC) is the most commonly used wastewater treatment of flocculant, with PAC sewage will PAC itself with the heavy metal ion (Cd^{2 +}, Hg^{2 +},Cu^{2 +}, Cd^{6 +} etc.) is introduced into the water cause secondary pollution. The adsorption method to remove one of the Cr (VI). The first was determined by spectrophotometry PAC in Cr (VI) content,then the coal ash, PVA entrapping activated carbon microsphere and activated carbon powder three adsorbent, under the same conditions were removed PAC of Cr (VI). The results have shown that the activated carbon had the highest effect on treatment of waste water of Cr (VI). But the carbon price is quite high. After the removal of trace Cr (VI), choose activated carbon as adsorbent. After the removal of a large number of Cr (VI) , choose coal ash as adsorbent.

Abstract: To control environment pollution by exploitation of asbestos mine and forming of tailing pond effectively and provide decision-making basis to competent authorities, the paper analyzed the causes for asbestos powder pollution in course of exploitation of asbestos mine and tailing pond of asbestos through field investigation and research. Slow exploitation and grading process of asbestos mine and shortage of management were the root causes for environment pollution by asbestos, and the tailing pond of asbestos resulted in resources waste and pollution of the atmosphere, water and land. The government should regulate in terms policy, industrial planning etc. offer economic support, change the backward exploitation process, perform comprehensive resources utilization and utilize asbestos properly.