Papers by Keyword: Soil

Abstract: This work regards the three main soil types in local area of eastern China as the research objects, that is, cinnamon, fluvo-aquic and brown soils are conducted corresponding investigations. In order to analyze the effects which Cu and Zn exert on urease’s and catalase’s activity as well as the microbial biomass carbon, the exogenous Cu and Zn were added to the gathered surface soil with the depth of 0-20cm.

Abstract: The soil is a brittle material compared to other engineering materials such as steel, concrete and wood. The clayey nature of the soils of western Paraná causes them to be chemically reactive towards certain compounds, thereby improving their engineering properties, especially its mechanical strength. The study involved treating the typical soil of the region with two residues from industrial and human activities: rice husk ash (RHA) at doses 0; 2.5; 5; 7.5 and 10%; and burned sewage sludge (BSS) at doses 0; 5; 10; 15 to 20%; in the dry soil mass. The test samples were compacted in Mini-MCV equipment and broken in triaxial compression tests of consolidated undrained type, with confining pressures of 25; 50 and 100 kPa. The results showed that both the RHA change dramatically as the BSS which passes viscoelastic plastic-linear mechanical behavior of the composites. There was a significant increase in deviator tension and elasticity modulus, implying a gain in strength and stiffness of the composite compared to the natural soil. The most striking effect was observed in the RHA cohesion parameter; while the substantial effect of BSS was observed in the interparticles friction angle. These results suggest that RHA promoted the formation of new products filling the pore space of the composite, changing the clayey material in a nature of a continuum, while the BSS promoted a substantial aggregation of the particles, wherein the soil reinforcement transformed clay in a particulate material coarser grain size.

Abstract: The paper deals with the determination of corrosion rate to the natural gas pipeline API 5L X60 in Trnava region. Linear polarisation resistance method (exposure time 1 hour) was used for investigation the corrosion rate of exposed samples in the environment (top, middle and lower part of soil excavation and distilled water). The corrosion rate was also determined by measuring the weight loss of the steel samples. The exposure time for the measurement method of the weight loss of metallic materials accounted 120, 288, 528 hours. These outputs helped to identify the most suitable environment for the tested metallic material. Top and middle part of soil excavation was situated in the least aggressive environment. On the other hand, the lower part of soil excavation was situated in the most aggressive environment for API 5L X60.

Abstract: Now most of the living garbage is transported to landfill. After soaking, waste water come from garbage will flow to the ponds, rivers and farmland. So living garbage is one of the main reasons of agricultural pollution. To solve this problem, a new type machine for compressing and packing garbage was designed, which is composed with brace, steering wheel, hopper, transmission, compression, banding, etc. The machine disposed garbage dispersedly. When the operator stamps the pedal, the gear will roll, and the rack, and slide piston will be moved. So the garbage will be compressed , packed , stacked, and can be air-dried. So the water and soil could not be polluted. This treatment of garbage can effectively reduce soil and water pollution

Abstract: A field experiment was conducted to identify the risk associated with Zinc (Zn) accumulation in leafy vegetable irrigated with final (FSTW) and biological (BSTW) secondary treated wastewater under soil and soilless culture. For purposes of analysis, the Inductively Coupled Plasma Optical Emission Spectrometry (ICP-OES) was used to determine the concentrations of Zn in wastewater, soil and plant samples followed by risk assessment. The results revealed that Zn concentrations of secondary treated wastewater were significantly higher in BSTW as compared to FSTW. Meanwhile, the Zn concentrations were found higher in plants grown under soilless culture as compared to soil culture. Besides, the daily intake metals for Zn were found to be higher in soilless culture as compared to soil culture. In addition, children were exposed to higher health risks than adults since the daily intake metals of Zn via consumption of plants was found to be significantly higher for children as compared to adults. However, the health risk index values were found to be less than 1. Thus, the risk associated with Zn contamination through consumption of plants irrigated with secondary treated wastewater by adults and children was no consequences and assumed to be safe in general. Yet, continuous monitoring is required in order to access possible detrimental effects to the human and environmental associated with secondary treated wastewater.

Abstract: This paper collected 18 soil samples in the Chin-sha River basin, and analyzed residues of organochlorine pesticides (OCPs) in soil using gas chromatographic method, revealing the organochlorine pesticide residues, the distribution and sources in the river basin. The results show that, the relatively high sampling residues of organochlorine pesticide distribute in the industrial area. The composition and characteristics of organic chlorine pesticide show that the organochlorine pesticide residues in soil mainly come from the historical use. Compared with the domestic similar research, residual organochlorine pesticides in Chin-sha River basin were lower.

Abstract: Batch equilibrium adsorption was conducted to study the adsorption of copper in the black soil and the effect of 2, 4-dichlorophenoxyacetic acid (2, 4-D) on adsorption of copper was probed by soils. The results showed all of the adsorption isotherms of copper in the absence and presence of 2,4-D could be described by Freundlich equation (R²>0.99), the adsorption coefficients K_f increased with increasing concentration of 2,4-D.The In kinetic modeling, the pseudo-first order equation was considered as the most celebrated model. The pseudo-second order equation in copper was depressed in the presence of 2, 4-D. 2,4-D diminished the adsorption of copper on the black soil.

Abstract: Based on smoothed particle hydrodynamics (SPH) and FEM method, the dynamic simulation of rigid cylindric plate's sinking process on soil is studied with LS-DYNA software, and MAT 147 material model is used to describe soil's attributes. The stress distribution and flowing trend of the soil are compared at different period. The simulation results show that the SPH/FEM method is useful to analyze large deformation of soil, and our findings can give helps to the mechanical design of the components interacting with soil.

Abstract: The removal of persistent organic pollutants (POPs) in soils at initial concentrations ranging from 20.00 to 321.05 mg·kg^-1 was investigated under different planting patterns, and enhancement mechanisms were analyzed. Results showed that the dissipation of POPs in soils growing Brassica campestris and Medicago sativa significantly exceeded those vegetating single species. During 70-day experiment, about 75.06% of Pyr and 68.22% of BaP was removed from the soils under mixed cropping; while only 31.8% and 64.03% of Pyr and 27.84% and 51.93 of BaP were removed under single rape and alfalfa cropping, respectively. Of all pathways enforcing POPs removal, plant-microbial interactions is the most predominant. These results suggested a feasibility of the establishment of multi-species phytoremediation for improvement of the remediation efficiencies of POPs, which may decrease accumulations of POPs in crops and thus reduce their risks.

Abstract: In last ten years, significant sedimentation has occurred, particularly in the lower portions of riparian zone of the Three Gorges Reservoir. However, the sediment and related environment effect did no explore well. In this study, sediment and soil in situ were collected in riparian zone, Three Gorges Reservoir, and heavy metals were analyzed and assessment. Results demonstrated:(1) concentration of heavy metals (except Cr and Ni) in sediment were significantly higher than those in soil; (2) sediment was moderately polluted by Cu and Pb, while soil were unpolluted-moderately polluted by As and Cu; (3) all of heavy metals both from sediment and soil are a potentially minor risk. Enrichment of heavy metals in riparian sediment is probably of formation regime and anthropogenic activities related pollutant emission. Therefore, enhanced control of water and soil, and pollution in the upper stream of the Yangtze River and the Three Gorges Reservoir area are recommended.