Ji Song Yang

Heavy Metals Accumulation and its Environmental Risk in Sediments of Xihe River, Shenyang City

Heavy metal accumulation in Xihe River sediments was studied, and also its potential environmental risk was evaluated using geoaccumulation index (Igeo). The results showed that mean concentrations of Hg, Cd, Zn, Pb, Ba, Bi, Sn and Sb were 2.73, 18.42, 1066.1, 128.8, 366.9, 7.76, 24.70 and 8.53 mg/kg, respectively. The values of examined heavy metals, except for Ba, were higher than the reference of deep soil. There were different accumulation characteristics for heavy metals at different river sections. Cadmium and Pb concentrations in sediment dropped from upper to lower reaches along river, but Ba was quite the reverse. The potential environmental risk of heavy metals in sediments was in order: Cd > Hg > Bi > Zn > Sb > Sn > Pb > Ba. The river was subjected to a higher potential risk by Hg, Cd, Zn and Bi, a medium-high risk by Sn and Sb, and a lower risk by Pb and Ba.

Synthesis of Silicalite-1 Membrane with High-Thermal Stability on Silica Tubes by In Situ Hydrothermal Synthesis

Silicalite-1 membranes with high-thermal stability were prepared on silica tubes by two-step hydrothermal synthesis after filling the tubes with water and glycerol mixtures. It was found that the filling method can improve the membrane separation performance effectively. After filling the silica tubes with mixed solution, the average flux of silicalite-1 membranes was improved by 23% while keeping the separation selectivity nearly unchanged. The results showed that the silicalite-1 membrane still showed high separation performance towards ethanol/water mixture after the repeated calcination at 400°C for 5 h, even with a calcination rate of 4 °C/min, which suggested that silica tubes may be very suitable to synthesize high-performance silicalite-1 membranes in large area.

Effect of Mushroom Residue Used in Washed Soil on the Growth of Tomatoes

In order to reveal the regulating capacity of mushroom residue on washed soil, pots experiments were carried out. The growth of tomatoes planted on washed soil amended by mushroom residue were measured. Mushroom residue can be helpful to improve the plant height, stem diameter, the aerial parts fresh weight, root fresh weight, leaf photosynthetic rates and photosynthesis, and lay a good foundation for the growth of tomatoes. The effect of mushroom residue is the most significant. Among all the treatments of adding 2.5%, 5%, 10% mushroom residue, adding 10% mushroom residue is the best. It can significantly enhance the growth and photosynthesis of tomatoes, and is among the best of these three soil treatments for washed soil.

Pollutions of Nutrient Salts and Heavy Metals of Groundwater in Xihe River Basin in Shenyang

In order to evaluate the groundwater quality in the Xihe River Basin, the concentrations of fluoride (F-), chloride (Cl-), nitrite (NO2-), nitrate (NO3-), mercury (Hg), cadmium (Cd), zinc (Zn), lead (Pb) and barium (Ba) of the groundwater were investigated in the three sections, Section I, II and III for the upstream, midstream and down stream, respectively. A method of Nemero composite index was used to evaluate the groundwater quality. The concentrations of nutrient salts of groundwater in the Xihe River basin decreased from the upstream to the midstream and downstream. The values of heavy metals were higher in the midstream than in the upstream and downstream. The groundwater had obvious nutrient-salt pollutions in the upstream and midstream. According to the Nemero composite index the F-values of groundwater were 9.5, 5.7 and 0.3 in the up-, mid-and downstream, respectively, indicated that the groundwater in the midstream and the upstream of Xihe River basin was polluted and extremely polluted, respectively. KEYWORDS: Groundwater quality, Nutrient salts, Heavy metals, Xihe River

Preparation of Silicalite-1 Membranes with Seeding Method and its Separation Performance for Low Ethanol/Water Mixture

High performance silicalite-1 membranes were successfully synthesized on silica tubes by seeding method after filling the tubes with water and glycerol mixtures. After seeding the silica tubes with 200 nm seeds, all the silicalite-1 membranes show acceptable separation performance towards ethanol/water mixture after 4-12 h hydrothermal synthesis, and the highest flux of membrane with 8 h hydrothermal synthesis reaches about 0.98 kg/m2.h and the separation factor reaches about 60 towards 3 wt.% ethanol/water mixture. This result shows that the as-synthesized silicalite-1 membrane can concentrate the ethanol from 3% to about 65%, and the ethanol can be obtained over 600 g/m2.h by using the silicalite-1 membrane, which shows that seeding method and suitable control of synthesis conditions is possible for preparing high-performance silicalite-1 membranes.

Cadmium Migration and Distribution Process

The significant pollution accidents which not only threaten public health and public property safety, but also bring major disaster, have become the world concerning environmental problems. The migration process and feature of CdCl2 in the vertical and horizontal profiles of soil were studied by the stimulating experiment to present the theory for the treatment of significant pollution accident. The column leaching device was taken to simulate the vertical and horizontal migration of CdCl2 in the soil profile under two-phase rainfall during 16 days. The portable manual control negative pressure pump was taken to extract soil solution sample and the CdCl2 concentration was determined by the atomic absorption spectrophotometer. Results showed that during the whole experiment, the obvious horizontal and vertical migration features of CdCl2 appeared. The CdCl2 covered the whole horizontal profile in 0.5 h and the whole vertical profile in 146 hours. The relative variation rate of CdCl2 in the different depth of bulk showed that the rapid passing time differed in the different depths. The simulating device used in this paper could well investigate the vertical and horizontal distribution and migration of contaminant. Under the condition of greater rainfall, the CdCl2 gave priority to the horizontal runoff in the surface soil, followed by the vertical migration.

Simulated Study on the Migration of Petroleum Hydrocarbons in the Soil

Spills and leaks of petroleum hydrocarbons such as gasoline, diesel, motor oils, and similar materials have caused widespread contamination in the environment. The migration and distribution of petroleum hydrocarbons in the vertical and horizontal profiles of soil were studied by the stimulating experiment. Results showed that the soil pollutions could diffuse in vertical and horizontal directions after petroleum hydrocarbons leaks. The petroleum hydrocarbons mainly spread vertically in the soil and the horizontally migration was relatively slowly. The migration distances were increased with a logarithmic growth dependence on the time both in horizontal and in vertical direction.

Application of Principal Component Analysis (PCA) for the Estimation of Source of Heavy Metal Contamination in Sediments of Xihe River, Shenyang City

Source estimation of heavy metals of Hg, Cd, Zn, Pb, Ba, Bi, Sn and Sb in Xihe River sediment was studied using PCA. The results showed that there were three principal components extracted. Hg, Zn, Bi, Sn and Sb were controlled by Componet1 explaining the sources of material, chemical and pharmacy industries, Cd and Pb controlled by Component2 explaining the sources of smelting and machinery manufacturing industries and also automobile exhaust, and Ba controlled by Component3 explaining the effect of geochemical compositions changes on in the sediments. The results indicated that industry sewage and rock weathering and erosion process were the main sources of heavy metals in the Xihe River sediment.

Preparation of Silicalite-1 Membranes on α-Al2O3 Tubes and its Concentration Performance of Low Ethanol/water Mixtures

Silicalite-1 membranes were successfully synthesized on α-Al2O3 tubes by in-situ hydrothermal synthesis after filling the tubes with water and glycerol mixtures, and all the membranes show high concentration performance towards ethanol/water mixtures after pretreating tubes with different NaOH solution. The results show that the flux enhances with the enhancement of NaOH solution concentration, but the separation selectivity decreases with the enhancement of NaOH solution concentration. After pretreating the α-Al2O3 tubes with different NaOH solution, the weight of all the α-Al2O3 tube decreases, but the Si/Al ratio increases, which shows that suitable pretreatment of α-Al2O3 is useful for improving the hydrophobicity of silicalite-1 membranes.

Decomposition Analysis of Energy Ecological Footprint Change in Bohai Rim Region

Using ecological footprint and decomposition analysis models, energy ecological footprint (EEF) from 2000 to 2008 in Bohai Rim Region was calculated. The EEF change and the impact factors were also analysed. The results showed that the EEF increased continuously from 2000 to 2008. The total values of EEF increased to 4.578×108 hm2 in 2008 from 2.159×108 hm2 in 2000, and the values per capita increased to 1.946 hm2 from 0.974 hm2. These contributed 50-60 percent of regional total ecological pressure. In all contribution factors, GDP growth was highest, energy structure and population size were inferior, and energy strength was lowest. Though the energy strength was decreased continuously, this was not enough to counteract the ecological impact derived from immoderate energy structure and consumption level. This led to energy ecological footprint in Bohai Rim Region increasing continuously.