Field investigation of pavement rehabilitation utilizing cold in-place recycling

Despite the widespread field and laboratory research works there are still a lot of unknown aspects about the cold in-place recycling. This paper presents the outcomes of a five year evaluation of a major highway in Iran which had been rehabilitated by cold in-place recycling. Before starting the rehabilitation process, a comprehensive field survey was performed. During the pavement surveying, type, severity and reason of distresses were investigated and PCI parameter was calculated. Furthermore, both destructive and nondestructive tests were carried out to evaluate the pavement condition and estimate the remaining life. On the basis of these investigations studied highway was divided to six design sections. Based on technical analysis four sections were recycled whereas two other sections were rehabilitated with the conventional cold milling and overlay method. Afterwards, the pavement performance was monitored during the next 5 years. After about six months of monitoring, structural failures were detected in about 10% of recycled areas. Based on field surveying, low compaction and load bearing of subgrade materials and lack of high quality unbound pavement layers accompanied by some shortcomings in recycled layer resulted in undesirable results in these areas. Based on obtained results and performed analysis a practical flowchart was presented which could be used as a project selection guideline.     

乳化液膜法处理石油石化废水的研究

炼厂酸性汽提净化水中酚含量高，限制了汽提净化水回用效率，需进行脱酚处理。本研究采用煤油、span-80、液体石蜡、磷酸三丁酯和NaOH构建乳化液膜，探究其对酸性水汽提净化水的脱酚效率。运用以响应曲面法（RSM）为依据的Box-Behnken设计，以span-80投加量、液体石蜡投加量、油相/内相比和制乳转速为影响因素，建立了汽提净化水中苯酚去除率的二次回归预测模型，并优化了处理条件。结果表明，液体石蜡投加量对苯酚去除率的影响最为显著，其次是span-80投加量。通过RSM分析得到汽提净化水脱酚的最佳实验条件为：span-80投加量2wt%，液体石蜡投加量15%v/v，油内比为1:1，制乳转速取6000r/min，此时苯酚去除率为98.65%。反应后的液膜易于破乳，破乳率达98.33%，且回收油相可循环利用，从而大大节约成本实现资源化。     

反相乳液聚合制备阳离子聚丙烯酰胺及其絮凝性能评价

研究了单体浓度、单体配比、反应温度、引发剂用量等因素对所制备的阳离子聚丙烯酰胺特性粘度、转化率、阳离子度的影响,并对产品的污水絮凝性能进行了评价。较佳的制备条件为:单体浓度为45%,单体配比为7∶3,引发剂用量m(引发剂)/m(单体)为0.5%,引发温度为45℃。用红外光谱对共聚物进行了结构表征,结果表明聚合物中有六元氮杂环的存在,达到预定要求。对共聚物进行了油田污水絮凝性能评价,研究表明单独使用自制阳离子聚丙烯酰胺(CPAM)时浊度的去除率为86.22%,COD去除率为87.95%,与聚合氯化铝复配使用时浊度去除率提高到92.91%,COD去除率提高到92.68%。