广西木圭锰矿区复垦效果及生态恢复治理对策

广西木圭锰矿历经数十年露天开采,生态环境遭到严重破坏。通过对复垦区的桉树林、水稻田、花生地、木薯地的土壤进行营养状况和重金属含量的检测分析,总结了前阶段取得的复垦效果,探讨了复垦区的重金属污染情况及生态恢复途径。结果表明,复垦区土壤为强酸性土壤,土壤肥力较低,土壤中镉的含量为2.30~4.46 mg·kg-1,超过了土壤环境质量三级标准的2~4倍。针对该矿区的环境现状,提出了生态恢复治理对策和建议。     

张集矿区复垦土壤养分变化研究及评价

煤炭开采引发土地沉陷,耕地资源严重破坏,土地复垦是恢复耕地的重要措施。开展矿区复垦土壤养分变化研究及评价,对于指导矿区土地复垦工作有着重要意义。以淮南张集矿区不同复垦年限的土壤为对象,系统研究了土壤养分的变化。结果表明：随着复垦时间的增加,土壤的有机质、全氮、速效磷和速效钾呈现增加趋势;复垦土壤在垂直层次上表现出随深度的增加,土壤有机质、全氮、速效磷和速效钾有下降的趋势;以正常耕地土壤养分水平作为评价标准时,复垦土壤养分恢复指数呈现增加趋势。     

生物复垦技术在钟山排土场的研究与应用

马钢姑山矿钟山排土场靠近居民区及马芜高速,对周围生态环境带来严重破坏。研究依据生物复垦技术原理,在马钢姑山矿钟山排土场进行实际应用,通过合理的结构设计以及乔灌草优化配置,采取相应的工程措施,建立合理的功能分区,取得了良好的效果。     

黑岱沟露天煤矿不同复垦模式效益分析与评价

本研究以黑岱沟露天煤矿为研究对象,通过研究草灌乔结合、草灌、灌木、牧草和农田复垦模式,对不同复垦模式进行了投资效益分析与评价。结果表明:牧草复垦模式投资成本最低,草灌乔复垦模式和欧李复垦模式投资成本较高;对不同复垦模式综合分析对比,不同复垦模式各具特点;综合分析生态效果、投资成本、土地条件要求、生物价值和财务能力,认为牧草复垦模式和欧李复垦模式优势明显,农作物复垦模式劣势明显;考虑到在可利用耕地的作用效果,农作物复垦模式优势明显,直接增加了可利用耕地面积;草灌乔复垦模式提升复垦区生态系统稳定性上效果最佳。因此,各种复垦模式优缺点明显,需要根据实际情况斟酌使用。     

Technical and Economic Advantages of Producing and Applying Ozone At High Concentration

Today ozone can be produced in concentrations up to 3.5 wtJ (12 g/Nm³) in air and 7 wt% (92 g/Nm³) in oxygen with simultaneously low specific energy consumption. The high concentrations improve the transfer efficiency and the reaction kinetics of ozone. This is demonstrated with reference to the design basis of the water treatment plants of Los Angeles, Dordrecht and Jeddah. In all cases the overall costs per kilogram of ozone are minimized by choosing the appropriate ozone concentration between 2 wt% (24 g/Nm³) and 6 wt% (79 g/Nm³).     

一种提高凝固数值模拟计算速度的方法

用显式差分法进行铸件凝固数值模拟时，通过存贮，引用预先计算好的离散方程系数，使模拟计算速度大大提高。     

水利水电机械疏浚工程综述

本文简述了机械疏浚专业范畴，用于机械疏浚的作业船分类，辅助船舶及陆上机械，国内外机械疏浚发展简况，重点叙述了国内用于水利水电工程水下开挖，水下开采砂石料，清淤清渣，吹填等工程及行业联系管理概况，根据近年国内外机械疏浚发展水平和国内的需要，提出当前水利水电系统疏浚机具的发展方针和建议。     

Water Reclamation At South Caboolture,Queensland, Australia

The 10 ML/d South Caboolture Water Reclamation Plant was designed to reduce riverine pollution and to provide water to industry and community consumers for non-potable uses. Whilst the plant will provide water for non-potable uses it has been designed to meet drinking water standards. The unique physical-chemical/biological treatment process incorporates biological denitrification, preozonation, coagulation/flocculation, dissolved air flotation/sand filtration, ozonation and biological activated carbon treatment. The Caboolture process, with its unique integrated physical-chemical/biological treatment ensures continuous sustainable production with low operational and chemical cost. Some demineralization (denitrification) is achieved biologically and expensive activated carbon life is prolonged almost indefinitely also by biological means, encouraged by prior ozonolysis of retractable compounds. Water can be supplied well below the cost of water from conventional sources. Minor operational problems have been overcome and the experience will be valuable for further implementation of this approach to water reclamation. Once again, the value of a combination of ozonation and activated carbon has proved its value in this World's first production application. This paper compares the Caboolture plant with some other well-known water reclamation plants in the US and southern Africa.     

Organic amendment effects on crop productivity and nutrient uptake on reclaimed natural gas wellsites

Restoration of productivity on agricultural soils disturbed by industrial activity is important for agronomic and environmental reasons. Because of the role of organic matter in soil health and quality, organic amendments have been widely used in the reclamation of disturbed soils such as those on abandoned oil and natural gas wellsites. This study examined the effects of one-time applications of alfalfa (Medicago sativa L.) hay or beef cattle (Bos taurus) feedlot manure compost on wheat (Triticum aestivum L.) yield and nutrient uptake on two abandoned natural gas wellsites that had recently been reclaimed in southern Alberta, Canada. The base amendment rate (1×) [dry wt.] was 5.3 Mg ha⁻¹ for compost and 3.1 Mg ha⁻¹ for alfalfa. The five treatment amendment rates of 0, 1×, 2×, 4×, and 8× were soil-incorporated at the wellsites. Yields and plant nutrient uptake were generally higher at Hussar than at Turin, reflecting the higher inherent fertility of the soil at Hussar. Grain yields were similar for alfalfa and compost amendments, indicating that either amendment can be used depending on availability and/or transportation costs. Our results show that spring wheat yields on these reclaimed soils can be optimized at alfalfa and compost rates of no more than 6 and 10 Mg ha⁻¹, respectively. Continued monitoring of crop productivity and soil properties may provide insight into the long-term benefits of alfalfa and compost amendments in wellsite reclamation schemes. Lethbridge Research Centre contribution no. 387-07030.     

Nutrient removal potential of emergent ( Scirpus articulatus ) and floating ( Lemna major ) macrophytes

Nutrient removal capacity of Lemna major (floating macrophyte) was compared with Scirpus articulatus (emergent macrophyte) in hypertrophic mesocosms held in situ . While Lemna removed orthophosphate mainly from waterphase, Scirpus on the other hand, took up their phosphorus exclusively from the sediment. Plant recovery of both nitrogen and phosphorus was high in emergent macrophyte than in floating macrophyte. Introduction of macrophyte resulted in decline of denitrifying bacteria, but increase in heterotrophic bacterial populations. Counts of heterotrophic bacterial population were significantly higher in case of Lemna than in Scirpus . Decline of phytoplankton number was more pronounced in case of Lemna due to its shading effect compared to Scirpus . It'is concluded that reclamation ability of floating Lemna was short lived because of nutrient removal mainly from water phase whereas, the nutrient removal mechanism in emergent Scirpus was primarily through the root system from the sediment. Differential rates of nutrient storage was responsible for short term nutrient uptake by Lemna , whereas, it was reverse in case of Scirpus .