污泥热解残渣制备聚合氯化铝的实验研究＊

含铝污泥热解或焚烧残渣制备聚合氯化铝的研究,有利于实现污水处理过程投加的铝盐絮凝药剂的回收与高效循环利用,减少污染物排放和资源消耗。针对辽河油田欢三联稠油污水处理污泥的热解残渣具有较高铝含量的特点,开展采用盐酸进行铝溶出及制备聚合氯化铝的实验研究。结果表明:焙烧温度为700～750℃,焙烧时间控制在1h即可。将经过焙烧活化的残渣在常温下进行酸溶,酸溶时间为2～5h,选用25%～30%盐酸,氧化铝与盐酸的摩尔比为1∶1.0～1∶1.2为宜。将溶出的铝溶液制备聚合氯化铝,在常温下采用CaO粉末来调节pH值为3.5,聚合反应时间为1d,即可得聚合氯化铝溶液。     

利用废弃物衍生燃料的热化学处理法制富含氢气合成气

为了探讨利用热化学方式从城市垃圾中制取富含氢气合成气过程的要素影响,解析氢气发生特性及其与主要影响要素之间的关系。在分析了城市生活垃圾组分特性的基础上,将其加工成组分均一的废弃物衍生燃料(refuse de-rived fuel,RDF),并在700、800和900℃等3个温度条件下,分别开展了RDF的热解、气化及水蒸汽气化等实验。研究表明,RDF的加工不但可有效降低垃圾含水率,还可将垃圾热值提高近1倍。温度和添加水蒸汽是从RDF中制取富含氢气合成气过程中的关键影响要素。其中,温度对氢气生成起到至关重要的决定作用,温度的提高对促进H2浓度的提高有利,同时,在气化过程中添加水蒸汽,可有效促进CO和H2等有价气体组分生成。在900℃的高温水蒸汽气化处理过程中,可获得H2浓度最高为34.13%的合成气。另外,800℃热解过程所产生的合成气热值最高,达到14 509 kJ/Nm3。     

MFC-MBR耦合系统运行效果

膜生物反应器(MBR)是一种高效的污水处理工艺,而微生物燃料电池(MFC)能有效降解污泥中的胞外生物有机质(EBOM)并回收电能.将MFC与MBR联用,建立了一套能够有效抑制膜污染同时回收电能的新系统——MFC-MBR耦合系统,MBR的剩余污泥经MFC处理后回流.以传统MBR为对照,对耦合系统中污水处理效果、膜污染情况和污泥混合液的性质进行研究.研究表明,耦合系统的污水处理效果没有明显恶化,COD去除率为94％,NH4+-N的去除率为92％.耦合系统能够有效减缓膜污染的发生,清洗周期延长了28％.污泥混合液的MLVSS/MLSS稳定在80％ ～ 88％,系统内几乎没有无机颗粒积累.松散结合态胞外聚合物(LB-EPS)降低了48％,使污泥混合液性质得到改善.较低的污泥比阻(2.69×1012m/kg)和标准化毛细吸水时间(1.67 s·L/g MLSS),证明耦合系统污泥混合液脱水性能提高了.     

Impact of increased collection rates and the use of commingled collection systems on the quality of recovered paper. Part 1: increased collection rates

The recovery and utilization of recovered paper have increased over past decades all over the world due to economic, environmental, and social issues. However, it is well known that an extended recovered paper collection is detrimental to its quality, either by the exploitation of lower quality sources such as households, or the spreading of commingled systems instead of selective collection systems. The influence of these two factors was assessed by analyzing the quality of different recovered paper grades used as raw material in a mill located in Madrid (Spain) producing newsprint and light weight coated paper from recovered paper. Part 1 of the paper deals with the impact of increased collection rates on the quality of recovered paper and Part 2 with the use of commingled collection systems. Results of Part 1 show that increased collection rates have a large impact on the quality of the recovered paper. The quality, measured as total unusable material and moisture contents, had deteriorated very rapidly in only 4 years (2005–2008) as a consequence of increased collection rates. Collection rates increased in Spain from 58.5% to 68.6% during this period, resulting in more than 50% increase of total unusable material and 25% of moisture content. The downgrading of the quality of recovered paper is one of the major threats for extending the current limits of paper recycling. Therefore, future challenge is to increase its availability but maintaining its quality.     

Environmental assessment of garden waste management in the Municipality of Aarhus, Denmark

An environmental assessment of six scenarios for handling of garden waste in the Municipality of Aarhus (Denmark) was performed from a life cycle perspective by means of the LCA-model EASEWASTE. In the first (baseline) scenario, the current garden waste management system based on windrow composting was assessed, while in the other five scenarios alternative solutions including incineration and home composting of fractions of the garden waste were evaluated. The environmental profile (normalised to Person Equivalent, PE) of the current garden waste management in Aarhus is in the order of −6 to 8 mPE Mg⁻¹ ww for the non-toxic categories and up to 100 mPE Mg⁻¹ ww for the toxic categories. The potential impacts on non-toxic categories are much smaller than what is found for other fractions of municipal solid waste. Incineration (up to 35% of the garden waste) and home composting (up to 18% of the garden waste) seem from an environmental point of view suitable for diverting waste away from the composting facility in order to increase its capacity. In particular the incineration of woody parts of the garden waste improved the environmental profile of the garden waste management significantly.     

国外建筑废弃物循环利用的经验及对我国的启示

伴随着建筑废弃物产生量的迅速增长,建筑废弃物循环利用已成为循环经济发展的重点领域。从完善的法律法规、深度循环利用方式和产业化发展等方面,对国外发达国家废弃物循环利用的经验和做法加以总结和提升,并结合我国实际,提出建立健全我国建筑废弃物法律法规体系、构筑多级循环利用模式和培育废弃物利用产业体系的几点启示,以期为我国相关部门制定建筑废弃物的相关政策制度、提高建筑废弃物的循环再利用水平提供参考和依据。     

转变观念 突破思维——对供销社再生资源行业的冷思考

在我国转变经济发展方式、调整经济结构的转型期,供销社再生资源行业面临重大的机遇和挑战。对传统再生资源回收企业如何抓住机遇、转变观念、突破创新,进行了深入、全面的分析。     

把握机遇乘势而为全力推进再生资源回收体系建设——对温家宝总理关于建立废旧商品回收体系重要指示的理解

2011年9月22日,国务院总理温家宝主持召开国务院常务会议,部署建立完整、先进的废旧商品回收体系。在深刻学习、理解会议精神的基础上,提出了全力推动再生资源回收体系建设向纵深发展,必须要做到“四个坚持,一个加强”。     

浅议宣传培训在推动农村再生资源回收利用中的作用

介绍我国开展农村再生资源回收利用的背景,以及宣传培训在推动农村再生资源回收利用中的重要作用。阐述农村再生资源回收利用宣传培训的内容和方式,以及培养再生资源回收利用意识的途径。提出应加大宣传培训工作力度,丰富宣传培训内容并采取多样化的形式,推动相关理念和知识的传播,逐渐形成农村再生资源回收利用的长效机制。     

新制备生物炭的特性表征及其对石油烃污染土壤的吸附效果

生物炭作为一种绿色环保的功能材料因其在污水处理和污染土壤修复方面具有显著效果而受到极大关注.采用红外光谱、元素分析仪及微孔分析对不同温度(200、300、400、500和600℃)条件下制备的木屑和麦秆生物炭进行特性表征,并采用制备的生物炭净化石油污染土壤,分别考察了污染物性质、生物质原料和热解温度对其净化效果的影响.结果表明,随着热解温度的增高,生物炭芳香化程度增加,极性降低,微孔结构逐渐发育,表面积增大.加入生物炭33 d后,污染土壤中总石油烃及其组分烷烃的浓度比对照略有降低,而PAHs浓度下降显著.随着热解温度升高,2种生物炭对PAHs的吸附强度均逐渐增大,芳香度增高、表面积增大是强吸附的主要原因.2种生物炭在400℃及以下温度制备时对PAHs的吸附强度为:木屑生物炭＞麦秆生物炭;而400℃以上温度制备的生物炭吸附强度则相反,即麦秆生物炭＞木屑生物炭,说明生物炭原料对其吸附强度也具有显著影响.