Advanced Materials Research Vols. 779-780

Abstract: The distribution and accumulation of heavy metals in the planting base soils in Shenyang, northeast of China, were investigated. Sixty soil samples were collected and characterized for heavy metals contents (AsCdCrPbHgNiCu and Zn). Concentration data were processed using correlation analysis and soils pollution assessment was carried out using geoaccumulation and PI. The results revealed that eight heavy metals contents of planting base all reached pollution level, which Pb and Hg pollution relatively serious, reached 2.41 and 2.1 respectively. The order of heavy metal pollution levels are: Pb> Hg> Zn = Cu> As> Ni> Cd> Cr. A significant correlation exists in Pb-Cd, Pb-Cu, Cd-As, Cu-Ni, while an extremely significant correlation exists between Zn-Cu. In addition to the parent material soil, the sources of soil heavy metals are mainly by the industrial, agricultural, transportation or other human activities and the effect of atmospheric transport and deposition. KEYWORDS: soil, heavy metal pollution, assessment, pollution index

Abstract: Pulsed SBR process is a new type of SBR operation mode proposed against the traditional SBR process with poorer denitrification effect. This experiment is carried out at laboratory of sewage treatment, Beijing University of Technology, using real sewage for study, to study denitrification efficiency of pulsed SBR in nitration add raw water - denitrification this repeated and cycled process (with the same amount of water). The experimental results show that the effluent TN is less than 2 mg/L, removal efficiency is more than 96%.Keywords: pulsed SBR; domestic sewage; denitrification; experimental study

Abstract: this article has analyzed the quality of water, air and soil in Mt. Longhushan Scenic Area in recent three years. It turns out that although the environmental quality is good and complies with the national standards, various indexes are increasing year by year. And meanwhile, the disordered development has affected the environment, hence, the cultural pollution cannot be neglected. According to the investigation results, the tourism development for scenic area has brought negative effect to the environment. Therefore, we must take the active actions, quicken the pace on completing the management system, make a reasonable plan so as to promote the sustainable development to the scenic area.

Abstract: Biodiesel from microalgae provides a promising alternative for biofuel production. Microalgal biodiesel can be produced under three major cultivation modes, namely, photoautotrophic, heterotrophic, and mixotrophic cultivation. Studies of biodiesel production from microalgae have been reported mostly focusing on photoautotrophic cultivation, mixotrophic cultivation has rarely been researched. This paper compared the biomass productivity, lipid content, and lipid productivity of Chlorella sorokiniana under photoautotrophic, heterotrophic, and mixotrophic cultivation. Glucose was adopted as organic carbon source at five concentrations (0.1, 0.5, 1.0, 2.0, 5.0% glucose w/v). Results displayed that microalgal growth was significantly improved in glucose supplied cultures. Synergetic effect of photoautotrophy and heterotrophy existed in mixotrophic cultivation except for 5.0% culture. Highest biomass productivity of 1.178 g·L^-1·d^-1 and highest lipid productivity of 582 mg·L^-1·d^-1 was observed under mixotrophic cultivation with 2.0% (w/v) glucose addition. Lipid content of C. sorokiniana was mostly higher in stationary phase than in exponential phase. Highest lipid content of 49.37% was observed in 2.0% mixotrophic culture, followed by 47.09% in 2.0% heterotrophic culture.

Abstract: An analysis of 170 simples acquired monthly from August 2011 to December 2012 in the closed waterbody suggests that the concentration of algae bloom (Cyanophyta) is dependent on the nutrient dynamics. Without the overlying of nitrate concentrations carried by the external algae bloom, the enclosed waterbody isolated by the flexible enclosure maintains a lower nitrate level. Algae bloom tends to dominate (TN: TP < 12) and to rare (TN: TP>12). Cyanophyta is dominant for the whole year.

Abstract: Coagulation-photocatalytic oxidation process was used for pretreatment of simulated seawater, which had moderate turbidity and more organics. The optimal conditions of PAC/PAM coagulation and TiO₂ photocatalytic oxidation were investigated by simple variable method, coagulation and photocatalytic oxidation were combinated under optimal conditions finally. Results showed that when the dosage of polyacrylamide (PAM) and polyaluminium chloride (PAC) was 20mg/L and 0.5 mg/L respectively, the pH of simulated seawater was 8.0, the amount of TiO₂ photocatalyst was 1.8g/L and UV radiation time was 1h, the removal ratio of the turbidity and COD_Mn in simulated seawater was 97.5% and 72% respectively. Synergistic effect between coagulation and photocatalytic oxidation eventually made turbidity and organics in the effluent water meet the requirements of reverse osmosis system.

Abstract: This paper conducts in-depth discussion to influence factor of shoals refloating change through analysis. According to analysis, run of upper trench in the Xinzhou south channel and change of north channels inflow is the major cause of confluence refloating; the article also discusses and illustrates relative thoughts issues in the process of regulating shoal at confluence.

Abstract: Total phosphorus is an much important key water quality parameter . In view of the technical defects of existing detection methods and instruments for in situ monitoring total phosphorus, a new detection method based on ultrasonic assisted sample digestion and spectrum analysis was put forward in this paper, and the automatic monitoring system prototype based on such detection method had been developed. Aiming at wastewater treatment, the spot experiment had been carried out to contrast prototype with Chinas national standard analysis method for on line measuring total phosphorus in the water, and the results of the comparative experiment showed that the automatic monitoring instrument prototypes had good repeatability (10%) and high accuracy (±10%), which met the technical qualifications of Chinas environmental protection industry standards.

Abstract: S element is essential nutrient element of the crop and has spatial variability in soil. It is the base of managing soil S nutrition and reasonable fertilization to understand spatial variability of soil S element fully. Distribution of available S for Baiyao base was studied in this paper. Results show that the available S content of Baiyao base soil was 18.39 mg/kg on average, but the variation range was larger, and 80.84% SAI value of the soil samples were lower than 14, so the base soil had a greater risk of S. The higher available S content were mainly distributed in the middle, east and south areas of Baiyao base, but there were wide areas with lower S content in Baiyao base. In addition, OM had low linear correlation with available S. Nutrient division management was recommended to improve the reasonable application of S.

Abstract: This article analyzes bank collapse characteristics of different river types on the basis of previous research and stable bank slope by combining typical bank collapse samples of the middle and the lower reaches of the Yangtze and other rivers. In combination with the years of statistics of measured data on Daijiazhou section, it also analyzes status, types and features of bank collapse of right edge of Daijiazhou. It analyzes cause and mechanism of bank collapse at right edge of Daijiazhou and predicts bank collapse trend of Daijiazhou by combining the characteristics of bank geology, river regime, local topography of bank slope and hydrology, etc.