COIMed Research Group, Instituto de Recursos Naturales y Agrobiología de Sevilla (IRNAS-CSIC), Avda. Reina Mercedes 10, 41012 Sevilla, Spain.
COIMed Research Group, Instituto de Recursos Naturales y Agrobiología de Sevilla (IRNAS-CSIC), Avda. Reina Mercedes 10, 41012 Sevilla, Spain.
Sci Total Environ. 2020 May 1;715:136986. doi: 10.1016/j.scitotenv.2020.136986. Epub 2020 Jan 28.
Sewage sludge generated by Waste Water Treatment Plants (WWTPs) are frequently used as organic amendments in agriculture, but they contain pollutants such as Potentially Toxic Elements (PTEs) and organic contaminants which contaminate the agricultural soils. The study presented here is part of a larger study based on the application of environmentally friendly chemical and biological techniques to decrease the content of organic pollutants in sewage sludge before agricultural application. The aim of this study was to evaluate the performance of biodegradable extractants, such as some cyclodextrins (CDs), β-cyclodextrin (BCD), hydroxypropyl-β-cyclodextrin (HPBCD) and randomly methylated-β-cyclodextrin (RAMEB), and a biosurfactant (rhamnolipid, RL) on the removal and availability of pyrene (PYR), phenanthrene (PHE) and nonylphenol (NP) from several biosolids samples in order to improve their subsequent biodegradation. The influence of pollutants retention time on biosolids was studied, as well as the effect of each extractant on PTEs solubilization. Results obtained were pollutant and extractant-dependent. BCD extracted similar amounts of pollutants compared to water, whereas HPBCD and RAMEB actually increased the availability of the three pollutants in most of the samples and aging times. RL seems to be the best election for Polycyclic Aromatic Hydrocarbons (PAHs) extraction from biosolids, with percentages of extraction multiplied by more than 80 and 40 times for PHE and PYR, respectively, relative to water extraction. The extraction enhancement was the highest for NP, the most hydrophobic pollutant, reaching more than 500-fold higher with HPBCD and RAMEB. PTEs extractability was not affected by the different CDs used, but RL caused an increment in their soluble content what could endanger a subsequent biodegradation of the organic pollutants.
污水处理厂（WWTPs）产生的污水污泥经常被用作农业中的有机肥料，但它们含有污染物，如潜在有毒元素（PTEs）和有机污染物，这些污染物会污染农业土壤。本研究是基于应用环保化学和生物技术在农业应用前降低污水污泥中有机污染物含量的更大研究的一部分。本研究的目的是评估可生物降解提取剂（如某些环糊精（CDs）、β-环糊精（BCD）、羟丙基-β-环糊精（HPBCD）和随机甲基化-β-环糊精（RAMEB））和生物表面活性剂（鼠李糖脂，RL）对几种生物固体样品中芘（PYR）、菲（PHE）和壬基酚（NP）的去除和有效性的影响，以改善它们随后的生物降解。研究了污染物停留时间对生物固体的影响，以及每种提取剂对 PTEs 溶解的影响。结果取决于污染物和提取剂。BCD 与水相比提取了相似量的污染物，而 HPBCD 和 RAMEB 实际上增加了大多数样品和老化时间下三种污染物的有效性。RL 似乎是从生物固体中提取多环芳烃（PAHs）的最佳选择，与水提取相比，PHE 和 PYR 的提取百分比分别增加了 80 倍和 40 倍。对于疏水性最强的污染物 NP，提取增强度最高，使用 HPBCD 和 RAMEB 可达到 500 倍以上。不同 CDs 的使用并未影响 PTEs 的可提取性，但 RL 会增加其可溶性含量，这可能会危及随后对有机污染物的生物降解。
