Hydraulic conductivity of compacted manufactured sand tailings–bentonite mixtures: a new hydraulic barrier material

Journal of Material Cycles and Waste Management - The valorization of manufactured sand tailings (MST) with annual production of 4 billion tons is crucial to the healthy development of manufactured...     

黑碳气溶胶研究概况

黑碳气溶胶是大气气溶胶的重要组成部分,由于其在全球气候变化和区域空气质量中的双重作用,黑碳已经成为目前全球气候变化研究中备受关注的焦点之一。在查阅近年国内外相关文献资料基础上,分析了黑碳气溶胶的来源和源强分布,结果表明工业源和居民生活消费源是大气中黑碳气溶胶最主要的贡献者,全球黑碳排放空间分布不均匀,与区域经济发展和人口密度相一致;总结了黑碳气溶胶的基本特性及其影响,重点探讨了黑碳对气候的影响机理,结果表明黑碳气溶胶既可以通过直接气候效应改变地-气系统的辐射平衡,又可以通过云反射效应、地表下垫面改变效应以及作为云凝结核间接影响区域或全球气候;随后对黑碳气溶胶的典型测量方法的优缺点进行了对比分析;最后介绍了黑碳研究领域中存在的主要问题,并对黑碳气溶胶研究的发展方向进行了展望。     

长江干流近三十年来水质变化探析

本文根据我国水利部水文年鉴中的水质监测资料和全球水质监测计划中长江站的水质监测资料,对长江干流六十至八十年代水质变化的三个问题：河水碱度降低及Ｃａ＾２＋和ＳＯ＾２－４含量增高与环境酸化的关系;     

进水氨氮浓度对静置/好氧/缺氧SBR脱氮除磷性能的影响

在4个序批式反应器(SBR)R1、R2、R3和R4中,以静置段代替传统厌氧段,采用后置缺氧,考察进水氨氮浓度分别为20,30,40,50mg/L对静置/好氧/缺氧SBR脱氮除磷性能的影响.结果表明,R1、R2、R3和R4长期运行中磷去除率分别为82.3%、92.8%、92.6%和89.1%,总氮(TN)去除率分别为97.2%、88.6%、84.5%和72.6%.静置段省却搅拌,但仍起厌氧段作用,仍可实现生物强化除磷.4个反应器好氧段均发生同步硝化-反硝化(SND),分别贡献14.7%、16.6%、17.8%和14.8%的进水后TN量,且后置缺氧段利用糖原驱动反硝化,脱氮效果较好,出水TN分别为0.57,4.43,6.61,13.70mg/L.研究表明,进水氨氮浓度可影响静置释磷、好氧摄磷、反硝化除磷.静置段代替厌氧段的后置缺氧工艺可取得较好脱氮除磷效果,且节约成本,简化工艺.     

Mercury concentrations in the surface sediments of the intertidal area along the west coast of Peninsular Malaysia

Total mercury (Hg) levels in the intertidal surface sediments along the west coast of Peninsular Malaysia were analysed by using heat vaporization method. Total Hg levels in these sediments ranged from 3.00 to 201?µg?kg^?1 dry weight with a mean concentration of 60.0?µg?kg^?1 dry weight. More than 90% of the samples studied have the total Hg concentrations less than 150?µg?kg^?1 dry weight. Compare with the regional data and sediment quality guidelines, the Hg contamination in the intertidal area along the west coast of Peninsular Malaysia was not serious, except for a few sites that might have received anthropogenic Hg in the samples collected between 1999 and 2000. It is suggested that a similar study of heavy metals in the sediments of the west coast of Peninsular Malaysia be conducted regularly.     

感悟大海

我从小生活在平原的黄土地上。厚重的土地,滋养了我憨厚、负重的一面,但又缺少了水的灵性和感悟。因此,向往大海,走近大海,成了我多年的梦想。     

生物接触氧化+混凝沉淀工艺处理医院综合污水

利用生物接触氧化、混凝沉淀工艺改造原处理工艺,处理中型医院综合污水,设计能力100 m3/d,处理效果显著且稳定达标。废水进水水质ρ(COD)为408~594 mg/L、ρ(SS)为211~280 mg/L;调试稳定后,出水水质ρ(COD)为12~40 mg/L、ρ(SS)为11~18 mg/L,COD、SS去除率分别为90.2%~97.9%、91.5%~96.1%,出水水质达山东省DB37/596-2006《医疗污染物排放标准》的二级排放标准。     

高位钻孔采空区瓦斯抽采技术应用效果分析

本文以贵州发耳煤矿10102采煤工作面作为研究对象,对采空区高位钻孔抽放瓦斯原理进行论述,并且结合此原理设计高位钻孔的抽放参数。为有效快捷地评价高位钻孔的抽放效果,本文通过单元法对其进行评价,最终找到存在的问题及其解决方法。该技术的应用实践解决了该工作面瓦斯超限的问题,获得了有价值的技术参数,积累了宝贵的实践经验。     

Effects of Al3+ on pollutant removal and extracellular polymeric substances (EPS) under anaerobic,anoxic and oxic conditions

The highest removal efficiencies of COD and TN were achieved under 10 mg/L of Al³⁺. The highest TP removal efficiency occurred under 30 mg/L of Al³⁺. EPS, PS and PN concentrations increased with the addition of Al³⁺. Sludge properties significantly changed with the addition of Al³⁺. Aluminum ions produced by aluminum mining, electrolytic industry and aluminum-based coagulants can enter wastewater treatment plants and interact with activated sludge. They can subsequently contribute to the removal of suspended solids and affect activated sludge flocculation, as well as nitrogen and phosphorus removal. In this study, the effects of Al³⁺ on pollutant removal, sludge flocculation and the composition and structure of extracellular polymeric substances (EPS) were investigated under anaerobic, anoxic and oxic conditions. Results demonstrated that the highest chemical oxygen demand (COD) and total nitrogen (TN) removal efficiencies were detected for an Al³⁺ concentration of 10 mg/L. In addition, the maximal dehydrogenase activity and sludge flocculation were also observed at this level of Al³⁺. The highest removal efficiency of total phosphorus (TP) was achieved at an Al³⁺ concentration of 30 mg/L. The flocculability of sludge in the anoxic zone was consistently higher than that in the anaerobic and oxic zones. The addition of Al³⁺ promoted the secretion of EPS. Tryptophan-like fluorescence peaks were detected in each EPS layer in the absence of Al³⁺. At the Al³⁺ concentration of 10 mg/L, fulvic acid and tryptophan fluorescence peaks began to appear, while the majority of protein species and the highest microbial activity were also detected. Low Al³⁺ concentrations (<10 mg/L) could promote the removal efficiencies of COD and TN, yet excessive Al³⁺ levels (>10 mg/L) weakened microbial activity. Higher Al³⁺ concentrations (>30 mg/L) also inhibited the release of phosphorus in the anaerobic zone by reacting with PO₄^3-.     

上海室内外降尘磁学空间变化特征

采用磁学方法分析上海市室内外降尘样品的磁学参数在不同功能区和不同行政区的变化特征,探讨影响室内外降尘磁学性质的影响因素。研究结果表明:上海市大气降尘污染有自然和人为2种影响因素;室内外降尘样品的磁性特征均受磁铁矿控制,主要以假单畴和多畴颗粒为主;低频磁化率在功能区上呈现出工业区(553.464×10~(-8)m~3/kg)交通区(484.302×10~(-8) m~3/kg)商业区(443.216×10~(-8) m~3/kg)居住区(320.849×10~(-8) m~3/kg)清洁区(269×10~(-8) m~3/kg)的空间变化趋势在行政区上整体呈现出宝山区(558.104×10~(-8) m~3/kg)、杨浦区(464.263×10~(-8) m~3/kg)的磁化率偏高,崇明区(218.673×10~(-8) m~3/kg)、奉贤区(218.868×10~(-8) m~3/kg)、松江区(218.689×10~(-8) m~3/kg)磁化率较低。室内外降尘的低频磁化率(χ_(if))、饱和等温剩磁(SIRM)和非磁滞剩磁磁化率(χ_(ARM))的相关系数分别为0.777、0.504、0.547,有较好的正相关关系表明室内外降尘来源很可能存在一定的趋同性。对比分析不同磁学参数,可以更好地反映降尘污染状况。研究发现χ_(lf)、SIRM和χ_(ARM)可以作为上海市大气降尘磁性特征的有效参考指标。在不同行政区大气降尘磁化率和PM_(10)浓度表现出相似的空间变化趋势。降尘样品的磁学参数测量速度快,方便用于监测城市空气污染的状况,在一定程度上可以对空气污染指数有一定的指代作用。