Impact of Field Application of Treated Wastewater on Hydraulic Properties of Vertisols

Fifteen soil profiles were taken from Ar-Ramtha wastewater treatment plant, 65 km north of Amman. Twelve of them represent soil planted with barley and irrigated with wastewater for the past 2, 5, and 15 years. The remaining three profiles represented a control area that has been only rainfed. Soil samples were collected in four replicates from each depth in each soil profile. Field and laboratory experiments were conducted to study the effect of irrigation with treated wastewater on hydraulic properties of surface and subsurface vertisols. Soil infiltration rate (IR), hydraulic conductivity (HC), and water retention (at 33 kPa and 1.5 MPa) were measured. The application of wastewater for 2, 5, and 15 years reduced soil hydraulic conductivity, whereas the infiltration rate decreased for 2 and 5 years, compared with non-irrigated area. Sites irrigated for 15 years with treated wastewater are characterized by higher percentages of large cracks, therefore revealed the highest infiltration rate. Soil available water changed due to wastewater application in decreasing order of: control (rainfed), 15, 5, 2 years of wastewater application.     

不同温度对苜蓿与苜蓿菟丝子种子发芽的影响

观测了８个不同温度下（５，１０，１５，２０，２５，３０，３５和４０℃）３种苜蓿和苜蓿菟丝子种子的发芽率和发芽势。结果表明，苜蓿菟丝子种子的最适发芽温度为３０℃，此时发芽率为９％，３ｄ发芽势为６％，３种苜蓿种子的最适发芽温度为２５℃，此时种子的发芽率为８１％～８４％，３ｄ发芽势与发芽率相同。从生态学角度分析了苜蓿菟丝子种子的发芽特点与其寄生生活之间的关系     

不同热身程度对伊犁马血气指标的影响

【目的】 研究不同热身程度对伊犁马1 000 m速度赛机体状态及运动性能的影响,为伊犁马1 000 m速度赛赛前最佳热身程度条件的确立提供数据支持及理论基础。【方法】 试验选取10匹速度型伊犁马为研究对象,控制马匹心率稳定在70%~80% HRmax、60%~70% HRmax、50%~60% HRmax分别在10、5、3 min时间区间,共9个热身程度组内热身后进行1 000 m速度赛。并对各组热身程度热身后血气指标进行差异性分析。【结果】 9组热身程度中,Ⅱ组热身后血液Glu浓度极显著高于Ⅸ组(P<0.01),显著高于Ⅴ组、Ⅵ组和Ⅷ组(P<0.05);Ⅱ组Hct,Hb浓度极显著高于Ⅴ组(P<0.01);Ⅵ组Cl^-浓度极显著高于Ⅱ组和Ⅳ组(P<0.01),Ⅸ组Cl^-浓度显著高于Ⅱ组和Ⅳ组(P<0.05);Ⅵ组和Ⅶ组Na⁺浓度显著高于Ⅱ组和Ⅲ组(P<0.05);Ⅵ组K⁺浓度极显著高于Ⅲ组(P<0.01),Ⅰ组K⁺浓度显著高于Ⅲ组(P<0.05);Ⅱ组pO₂极显著高于Ⅲ组和Ⅷ组(P<0.01),显著高于Ⅵ组和Ⅸ组(P<0.05);Ⅶ组TCO₂极显著高于Ⅱ组(P<0.01),Ⅳ组TCO₂显著高于Ⅱ组和Ⅲ组(P<0.05);Ⅱ组SO₂极显著高于Ⅲ组、Ⅷ组和Ⅸ组(P<0.01);Ⅱ组pH值极显著高于Ⅴ组和Ⅸ组(P<0.01),显著高于Ⅷ组(P<0.05);Ⅶ组和Ⅸ组Lac浓度显著高于Ⅱ组、Ⅲ组和Ⅴ组(P<0.05);Ⅰ组、Ⅱ组、Ⅵ组和Ⅶ组BE(ecf)浓度显著于高Ⅴ组(P<0.05)。【结论】 伊犁马1 000 m速度赛竞赛马匹在Ⅱ组热身程度下热身,马匹肺功能良好,有氧代谢水平较好,提升马匹运动状态。     

Levels and Bioaccessibilities of Metals in Dusts from an Arid Environment

The elemental composition and bioaccessibility of trace metals have been determined in a variety of geosolids (soils, road dusts and house dusts) from an arid, coastal region (Dhahran, Saudi Arabia). Concentrations of many elements reflected those of the local geology, ascertained by analysis of desert sand. Several trace metals (e.g. Cu, Sb, Zn, Pb, Tl and Sn) were moderately enriched in both road and house dusts, reflecting external and internal (household) anthropogenic sources. For a given trace metal, bioaccessibilities, assessed using a physiologically based extraction test, were broadly similar across the range of geosolids. Median values for a simulated gastric phase ranged from less than 10% (Ba, Cu, Cr, Ni and V) to more than 50% (As, Cd, Sb, Sn and Tl), and for a subsequently simulated intestinal phase from less than 15% (Ba, Cr, Cu, Ni, V and Zn) to more than 50% (As, Cd, Sb, Tl and U). Results suggest that the levels and bioaccessibilities of trace metals in dusts from arid environments are controlled by the dilution of anthropogenic particulates by variable (but significant) proportions of fine, baseline sand.     

浅谈城市污水的深度处理技术

随着时代的发展,我国对城市污水的利用技术也在不断的加深,其处理方法、形式也在不断增多。本文介绍了深度去除城市污水中几种主要污染物的方法和相应的技术。