Taha R, Ba-Omar M, Pillay A E, Roos G, al-Hamdi A
Sultan Qaboos University, Department of Civil Engineering, P.O. Box 33, Al Khoud 123, Sultanate of Oman.
J Environ Monit. 2001 Aug;3(4):417-20. doi: 10.1039/b103750c.
The environmental impact of using petroleum-contaminated sand (PCS) as a substitute in asphalt paving mixtures was examined. An appreciable component of PCS is oily sludge, which is found as the dregs in oil storage tanks and is also produced as a result of oil spills on clean sand. The current method for the disposal of oily sludge is land farming. However, this method has not been successful as an oil content of < 1% w/w is required, and difficulty was encountered in reaching this target. The reuse of the sludge in asphalt paving mixtures was therefore considered as an alternative. Standard tests and environmental studies were conducted to establish the integrity of the materials containing the recycled sludge. These included physical and chemical characterization of the sludge itself, and an assessment of the mechanical properties of materials containing 0%, 5%, 22% and 50% oily sludge. The blended mixtures were subjected to special tests, such as Marshall testing and the determination of stability and flow properties. The experimental results indicated that mixtures containing up to 22% oily sludge could meet the necessary criteria for a specific asphalt concrete wearing course or bituminous base course. To maximize the assay from the recycled material, the environmental assessment was restricted to the 50% oily sludge mixture. Leachates associated with this particular mixture were assayed for total organic residue and certain hazardous metal contaminants. The results revealed that the organics were negligible, and the concentrations of the metals were not significant. Thus, no adverse environmental impact should be anticipated from the use of the recycled product. Our research showed that the disposal of oily sludge in asphalt paving mixtures could possibly yield considerable savings per tonne of asphalt concrete, and concurrently minimize any direct impact on the environment.
研究了将石油污染砂（PCS）用作沥青铺路混合料替代品对环境的影响。PCS的一个重要成分是含油污泥，它是储油罐中的残渣，也是干净沙子上发生石油泄漏产生的。目前处理含油污泥的方法是土地耕作。然而，这种方法并不成功，因为要求含油率低于1%（重量/重量），且难以达到这一目标。因此，考虑将污泥重新用于沥青铺路混合料作为替代方案。进行了标准测试和环境研究，以确定含有回收污泥的材料的完整性。这些研究包括对污泥本身的物理和化学特性进行表征，以及对含有0%、5%、22%和50%含油污泥的材料的力学性能进行评估。对混合后的混合料进行了特殊测试，如马歇尔试验以及稳定性和流动性能的测定。实验结果表明，含油污泥含量高达22%的混合料能够满足特定沥青混凝土磨耗层或沥青基层的必要标准。为了使回收材料的利用率最大化，环境评估仅限于含50%含油污泥的混合料。对与这种特定混合料相关的渗滤液进行了总有机残留物和某些有害金属污染物的检测。结果显示，有机物含量可忽略不计，金属浓度也不显著。因此，使用这种回收产品预计不会对环境产生不利影响。我们的研究表明，在沥青铺路混合料中处置含油污泥每吨沥青混凝土可能会节省大量成本，同时将对环境的任何直接影响降至最低。
