Gharibzadeh Farzaneh, Kalantary Roshanak Rezaei, Esrafili Ali, Ravanipour Masoumeh, Azari Ali
1Students' Scientific Research Center (SSRC), Tehran University of Medical Sciences, Tehran, Iran.
2Department of Environmental Health Engineering, School of Public Health, Tehran University of Medical Sciences, Tehran, Iran.
J Environ Health Sci Eng. 2019 Mar 7;17(1):171-181. doi: 10.1007/s40201-019-00338-1. eCollection 2019 Jun.
Prediction of polycyclic aromatic hydrocarbons (PAHs) desorption from soil to estimate available fraction regarding to initial concentration of the contaminant is of great important in soil pollution management, which has poorly been understood until now. In the present study estimation of fast desorption fraction which is considered as available fraction was conducted by evaluating desorption kinetics of phenanthrene (a three ring PAH) from artificially contaminated soils through the mathematical models.
Desorption rate of phenanthrene (PHE) was investigated by using the nonionic surfactant Tween80 in a series of batch experiments. The effects of reaction time from 5 to 1440 min and initial PHE concentration in the range of 100-1600 mg/kg were studied.
Available fractions of the contaminant were achieved within the first hour of desorption process as the system reached to equilibrium conditions. Experimental data were examined by using kinetic models including pseudo-first-order, pseudo-second-order in four linearized forms, and fractional power. Among the models tested, experimental data were well described by pseudo-second-order model type (III) and (IV) and fractional power equation. Fast desorption rates, as Available fractions were determined 79%, 46%, 40%, 39%, and 35% for initial PHE concentrations of 100, 400, 800, 1200, and 1600 mg/kg respectively. Among the evaluated isotherm models, including Freundlich, Langmuir in four linearized forms, and Temkin, the equilibrium data were well fitted by the first one.
Applying the nonionic surfactant Tween80 is a useful method to determine available fraction of the contaminant. This method will provide the management of contaminated sites by choosing a proper technique for remediation and predicting achievable treatment efficiency.
预测多环芳烃（PAHs）从土壤中的解吸情况，以估算与污染物初始浓度相关的有效部分，这在土壤污染管理中非常重要，但目前对此了解甚少。在本研究中，通过数学模型评估菲（一种三环PAH）从人工污染土壤中的解吸动力学，对被视为有效部分的快速解吸部分进行了估算。
在一系列批量实验中，使用非离子表面活性剂吐温80研究了菲（PHE）的解吸速率。研究了5至1440分钟的反应时间以及100 - 1600 mg/kg范围内的初始PHE浓度的影响。
随着系统达到平衡条件，在解吸过程的第一小时内就获得了污染物的有效部分。使用包括四种线性化形式的伪一级、伪二级动力学模型以及分数幂模型对实验数据进行了检验。在所测试的模型中，实验数据由伪二级模型类型（III）和（IV）以及分数幂方程很好地描述。对于初始PHE浓度分别为100、400、800、1200和1600 mg/kg时，快速解吸率即有效部分分别确定为79%、46%、40%、39%和35%。在评估的等温线模型中，包括四种线性化形式的弗伦德利希、朗缪尔以及坦金模型，平衡数据由第一个模型很好地拟合。
应用非离子表面活性剂吐温80是确定污染物有效部分的一种有用方法。该方法将通过选择合适的修复技术和预测可实现的处理效率来为污染场地的管理提供帮助。
