Long-term engineering properties of recycled plastic lumber used in pier construction

Plastic lumber manufactured using post consumer waste plastic has been proposed as an acceptable material for use in the construction of docks, piers and bulkheads and is touted to outlast conventional wood products due to its strength, durability and resistance to rot. This study examines the long-term engineering properties of plastic lumber manufactured using post consumer waste plastic (TRIMAX, Ronkonkoma, NY). Plastic lumber profiles were used in the decking of a pier built in West Meadow Creek, Old Field, NY during December 1995. Samples of plastic lumber were removed from the deck of the pier periodically over a two-year period and returned to the laboratory for testing. Results of engineering tests showed the in-plane compression modulus (260±30 MPa), dimensional stability and the Shore D surface hardness (60±2) of plastic lumber removed from the pier remained similar to or greater than their pre-placement values. In contrast, significant changes in the modulus of elasticity of plastic lumber were measured with prolonged weathering. The modulus of elasticity of plastic lumber initially decreased from 1370 Pa to 750 Pa following 12 months weathering, a decrease equal to 45% of its pre-placement value and then increased during the second year to close to its initial value. The high variability in the modulus of elasticity should restrict the use of plastic lumber profiles to non-load bearing structural applications.     

含汞有害固体废弃物的固化/稳定化技术研究进展

总结了国外含汞有害固体废弃物固化技术的研究和应用发展现状。系统阐述了研究和应用较多的三种固化技术(水泥基、低温化学键磷酸盐陶瓷,硫聚合物)的固化过程原理、特征,研究和应用现状以及可得的操作数据。介绍了新兴的可能用于含汞固体废弃物的材料的研究数据。比较了各种技术的优缺点,应用上的局限性,为含汞固体废弃物的固化处理新技术的发展提供思路。     

多途径实现城市垃圾无害化处理

从多方面分析了城市垃圾对环境、对人类健康造成的危害,以及在垃圾处理过程中形成的二次污染。并提出了相应的对策,以实现城市垃圾的无害化处理。     

泰安市医疗废物的特性研究

通过实验分析了医疗废物的组成、灰分、水分、挥发分、固定碳和热值等特性参数,探讨其燃烧特性。研究表明,医疗废物具有高热值、高挥发分的特点,其热值远高于一般城市生活垃圾,而高挥发分的特点决定了其容易着火和稳定燃烧的特性。     

HNO_3─KI─MIBK萃取／原子吸收光谱法测定固体废物浸提液中的微量银

采用选择性较好的ＨＮＯ３—ＫＩ—ＭＩＢＫ萃取体系对铋渣和尾矿渣浸出液中的痕量银进行预分离富集后，用火焰原子吸收法（ＡＡＳ）进行测定。此法不仅变异系数小（约为３．１％），而且检出限比直接火焰ＡＡＳ法降低两个数量级，达０．５ｎｇ／ｍｌ．另外，还就作品细度对银测定结果的影响原因做了初步探讨。     

POPs废物处置技术多目标决策筛选研究

采用层次分析法对国际上较为成熟的9种POPs废物处置技术进行综合评价,筛选出适合我国的POPs废物处置技术. 从经济指标、环境指标和技术指标3个影响因素建立递阶层次结构模型,每个指标又细分为若干个子准则. 根据模型及评价指标体系设计专家咨询表,发放给POPs相关领域的专家打分. 采用matlab对评价结果进行数值分析,得到9种处置技术的总权重,其中分值最高的处置技术有:水泥窑共处置0.174 8,高温焚烧0.172 7;其次是安全填埋0.107 1,热解吸0.107 0,原位玻璃化0.103 0;最后是深井灌注0.086 9,超临界水氧化0.084 1,碱催化脱氯0.082 3,碱金属还原0.082 3.表明高温焚烧和水泥窑共处置是目前我国POPs废物处置技术的较佳之选.      

通风速率对烟草废料堆肥腐熟及元素变化影响

以烟草废料为原料堆肥,设置不同的通风速率,通过对堆肥中温度、营养元素和腐殖质等指标变化的研究,揭示了通风速率对堆肥腐熟和主要元素变化的影响。结果表明,通风速率为0.1和0.2 m3/(h·m3)的处理的高温期持续时间在5 d以上,满足堆肥无害化卫生标准要求,堆肥积温以0.2 m3/(h·m3)的处理最高;堆肥结束时,通风速率为0.2和0.3 m3/(h·m3)处理的总碳含量降低率、总氮含量增加率及NO3--N含量增幅均强于0.1 和0.4 m3/(h·m3)的通风处理,且两处理的NH4+-N含量至堆肥结束时降至400 mg/kg阈值以下;通风速率为0.2 m3/(h·m3)的处理的终产品的腐殖化质数为1.91,达到腐熟阈值1.90。综合以上结果表明,0.2 m3/(h·m3)的通风速率较适于烟草废料堆肥腐熟和营养转化。     

稳健GM(1,1)模型在工业固废产生量预测中的应用

本文提出了稳健灰色模型,并用该模型建立了山东省工业固体废物产生量数学模型。结果表明,稳健ＧＭ（１,１）模型比通常的ＧＭ（１,１）模型更具预测应用价值。     

高温蒸汽灭菌处理技术处置医疗废物工艺设计

高温蒸汽灭菌处理技术是近几年开发的新型医疗废物处置技术,并在全国部分地区得到了应用和推广。以西北某市医疗废物处置工程中高温蒸汽灭菌处理技术的应用为例,通过对其工程原理、系统组成、工艺流程等的分析论证共同探讨其工程原理和性能特点,为今后在工程实际中的运用提供参考。     

Building partnerships — the Ohio Materials Exchange

This paper discusses a method by which individuals working in government, private business, not-for-profit and educational organizations developed a collaborative statewide program involving the exchange of materials from manufacturers, commercial business and not-for-profit organizations in Ohio.