酵母融合菌对铬离子的吸附特性研究

酵母融合菌的完整细胞、细胞壁、细胞内含物富集水体中的铬,比较了各组分对铬离子的吸附能力差异,并进行了模型拟合.结果表明:细胞壁的去除率和吸附量都明显高于完整细胞;完整细胞及细胞壁对铬的吸附均符合Freundlich和Langmuir热力学方程,且细胞壁对Cr6 的最大吸附量和吸附亲和力都大于完整细胞,说明细胞壁是该吸附剂吸附重金属离子的主要部位.同时利用多种分析手段研究了各组分对铬的吸附行为:酵母细胞壁的特殊结构以及AFM图显示细胞壁可以为活性基团吸附、络合或螯合金属离子提供更为广阔的空间;X-射线衍射和FTIR分析检测表明吸附剂对铬的吸附并未破坏其本身的结构.     

不同AM真菌对三叶草耐油性的影响

在盆栽条件下研究了4个油浓度（0、5000、10000和50000w/mgkg^-1）下接种辽河油田污染土壤中分离出的3种AM真菌（Glomus mosseae，G.geospora，G.constrictum）对三叶草耐油性的影响。试验结果表明：1）随着油浓度的增加，侵染率亦增加，10000mgkg^-1时G.geospora和G.constrictum的侵染率分别为67.65％和82.86％；2）从侵染率、地上部生物量和菌根依赖性来看，随着油浓度的增加，最适的AM真菌亦不一样，油浓度为0、5000和10000mgkg^-1时，最适AM真菌分别是G.geospora、G.mosseae和G.constrictum；3）油污染土壤上接种AM真菌能促进植株的地下部和地上部的生长，接菌处理的茎干重比相应的对照增加62.2％-267.1％；4）随着油浓度的增加和植物的生育进程，AM真菌的接种效应在增强。图3表3参14     

碱矿渣胶凝材料固化重金属污泥的研究

主要原材料为高炉矿渣的碱矿渣胶凝材料(HAS)、掺3%沸石的HAS、掺5%沸石的HAS、水泥等4种固化材料被用来固化人工合成含铅、镉、铬等重金属的污泥。污泥固化体中污泥与固化材的掺和比例为4:1。实验结果表明,HAS固化剂对重金属污泥的固化效果要好于水泥,其污泥固化体的无侧限抗压强度高于水泥固化体,同时其固化体的重金属浸出量明显低于水泥。沸石的掺入使HAS固化体的重金属浸出量减小,且随着沸石掺加量的增大,HAS固化体的重金属浸出量相应的减少。     

Metropolitan Open-Space Protection with Uncertain Site Availability

Abstract:  Urban planners acquire open space to protect natural areas and provide public access to recreation opportunities. Because of limited budgets and dynamic land markets, acquisitions take place sequentially depending on available funds and sites. To address these planning features, we formulated a two-period site selection model with two objectives: maximize the expected number of species represented in protected sites and maximize the expected number of people with access to protected sites. These objectives were both maximized subject to an upper bound on area protected over two periods. The trade-off between species representation and public access was generated by the weighting method of multiobjective programming. Uncertainty was represented with a set of probabilistic scenarios of site availability in a linear-integer formulation. We used data for 27 rare species in 31 candidate sites in western Lake County, near the city of Chicago, to illustrate the model. Each trade-off curve had a concave shape in which species representation dropped at an increasing rate as public accessibility increased, with the trade-off being smaller at higher levels of the area budget. Several sites were included in optimal solutions regardless of objective function weights, and these core sites had high species richness and public access per unit area. The area protected in period one depended on current site availability and on the probabilities of sites being undeveloped and available in the second period. Although the numerical results are specific for our study, the methodology is general and applicable elsewhere.     

陕西省黄土崩塌隐患区宅基地选址方案研究

在对黄土崩塌所造成的伤亡、损失及灾害成因的调查的基础上,结合对黄土地形地貌、颗粒结构、岩土特征和力学特性的研究分析,提出了在黄土高原区内黄土崩塌隐患区居民宅基选址应注意的问题,变被动防灾为主动预防,这对地处黄土高原区山西、陕西、甘肃等省的居民宅基选址具有重要的指导意义和参考价值。     

几种螯合剂对污染土壤的重金属提取效率的研究

在Cd,Pb污染的土壤上,采用批提取实验(batchexperiment),研究了几种螯合剂和不同的水土比对重金属提取效率的影响。结果表明:螯合剂对Cd的提取效率随着各淋洗剂浓度的提高而逐渐提高,相同浓度下各淋洗剂的提取效率大小顺序依次为EDTA>DTPA>NTA>PA>CA>CD>HCl。随水土比提高,相应的提取效率也提高。几种淋洗剂中只有EDTA对Pb和Cd都能达到理想的淋洗效果。     

Laboratory scale studies on removal of chromium from industrial wastes

Chromium being one of the major toxic pollutants is discharged from electroplating and chrome tanning processes and is also found in the effluents of dyes,paint pigments,manufacturing units etc.Chromium exists in aqueous systems in both trivalent(Cr^3 )and hexavalent (Cr^6 )forms.The hexavalent form is carcinogenic and toxic to aquatic life,whereas Cr^3 is however comparatively less toxic.This study was undertaken to investigate the total chromium removal from industial effluents by chemical means in order to achieve the Pakistan NEQS level of 1 mg/L by the methods of reduction and precipitation.The study was conducted in four phase Ⅰ,the optimum pH and cost effective reducing agent among the four popular commercial chemicals was selected.As a result,pH of 2 was found to be most suitable and sodium meta bisulfate was found to be the most cost effective reducing agent respectively.Phase Ⅱ showed that lower dose of sodium meta hisulfate was sufficient to obtain 100% efficiency in reducing Cr^6 to Cr^3 ,and it was noted that reaction time had no significance in the whole process.A design curve for reduction process was established which can act as a tool for treatment of industrial effluents.Phase Ⅲ studies indicated the best pH was 8.5 for precipitation of Cr^3 to chromium hydroxide by using lime.An efficiency of 100% was achievable and a settling time of 30 minutes produced clear effluent.Finally in Phase Ⅳ actual waste samples from chrome tanning and electroplating industries,when precipitated at pH of 12 gave 100% efficiency at a settling time of 30 minutes and confirmed that chemical means of reduction and precipitation is a feasible and viable solution for treating chromium wastes from industries.     

煤渣填料固定化菌膜处理餐厅污水

以煤渣为填料,采用人工筛选优势菌挂膜固定化技术和直流式供水送风形式,对酒家、宾馆的餐厅污水进行生物接触氧化处理,COD和BOD的去除率可>90％,处理后排放水质可稳定达到COD≤100mg·1~(-1),BOD≤30mg·1~(-1),SS≤30mg·1~(-1),NH_3—N≤15mg·1~(-1)。推广应用结果表明,具有显著的经济效益和环境效益。     

铬渣的固化/稳定化研究

探讨了用水泥粘结剂对铬渣进行稳定化的方法。结果表明，把高炉矿渣和粉煤灰加入水泥基材中对铬渣进行固化，固化体抗压强度达到30MPa以上，浸出毒性大大降低，浸了同液中六价铬浓度在容许范围内，建议可以综合利用。     

堆肥法处理含油污泥研究进展

含油污泥是炼油厂和石油化工厂的日产固体废弃物 ,是当前石化行业所面临的污染问题。本文给出了近期国内外对含油污泥的处理方法 ,并对堆肥法处理含油污泥进行了综述。含油污泥的堆肥处理需提供氧气、菌种和营养 ,为保持油泥的疏松状态 ,还需加入填充剂。本文对高速生物反应器的结构、运行、调控进行了详细介绍 ,并从经济核算角度指出了其运营可行性