生物炭对几类常见新兴污染物去除的研究进展

近年来药物和个人洗护用品（PPCPs）以及内分泌干扰物（EDCs）等新兴污染物频频检出,引起人们高度关注。众多研究表明,这些新兴污染物已经广泛分布在河流、湖泊、海洋、土壤、沉积物和地下水等环境介质中,而这些物质具有不易降解特性,加之不断排入水体环境,在水体环境中呈现“假持续存在”状态,对生态环境和人体健康造成诸多的不良影响。本文首先简述了以PPCPs和EDCs为代表的新兴污染物在环境中的来源、传播、分布和去除技术,并以表格形式综述了PPCPs和EDCs在各地区的污染现状。最后介绍了生物炭在去除PPCPs和EDCs上的研究现状和进展,分别通过生物炭制备原料、热解温度、改性或活化方式、溶液pH、离子强度和干扰物等因素综述了其对生物炭吸附PPCPs和EDCs的影响,并在最后做出总结和展望,以期能给今后生物炭在去除PPCPs和EDCs等新兴污染物上的相关研究和实际应用提供更多思路。     

Fate of pharmaceuticals in contaminated urban wastewater effluent under ultrasonic irradiation

The application of sonolysis (US) for remediation of wastewater is an area of increasing interest. The aim of this study was to evaluate the ultrasonic (US) process on the degradation of pharmaceuticals (diclofenac (DCF), amoxicillin (AMX), carbamazepine (CBZ)) in single solutions and also in three mixtures spiked in urban wastewater effluent. Several operating conditions, such as power density (25-100 W L⁻¹), initial substrate concentrations (2.5-10 mg L⁻¹), initial solution pH (3-11), and air sparging were varied for the evaluation and understanding of the process. The degradation (as assessed by measuring UV absorbance), the generation of hydroxyl radicals (as assessed measuring H₂O₂ concentration), the mineralization (in terms of TOC and COD removal), and the aerobic biodegradability (as assessed by the BOD₅/COD ratio) were monitored during sonication. Ecotoxicity to Daphnia magna, Pseudokirchneriella subcapitata and Lepidium sativum before and after treatment was also evaluated. It was found that the pharmaceuticals conversion is enhanced at increased applied power densities, acidic conditions and in the presence of dissolved air. The reaction rate increases with increasing initial concentration of single pharmaceuticals but it remains constant in the mixtures, indicating different kinetic regimes (i.e. first and zero order respectively). Mineralization is a slow process as reaction by-products are more stable than pharmaceuticals to total oxidation; nonetheless, they are also more readily biodegradable. The toxicity of the wastewater samples before and after contamination with pharmaceuticals both in mixtures and in single substance-containing solutions was observed more severely on P. subcapitata; a fact that raises concerns in regards to the discharge of such effluents. D. magna displayed less sensitivity compared to P. subcapitata because it belongs in a lower taxonomic species than D. magna. The germination index of L. sativum in the presence of the drugs' mixture was stimulated instead of inducing any toxicity effect and this might be attributed to the fact the sample, laden with very low drug concentrations was able to act as a provider of additional nutrient elements.     

水环境中药物类PPCPs的赋存及处理技术进展

药品和个人护理品(PPCPs)类新兴污染物在水环境中被广泛检测出,因其生物累积性和潜在的生态危害性,近年来受到高度关注。文中总结了水环境中PPCPs的赋存状况,解析了水环境中PPCPs的来源和迁移、转化路径,发现传统污水处理厂尚不能彻底、有效地去除PPCPs,污水厂的尾水排放是水环境中PPCPs的重要来源。同时,比较了污水厂常规处理和三级处理工艺对PPCPs的去除效果,指出污水处理厂基于宏量常规污染物和微量新兴污染物的同步去除技术或复合去除技术是削减水环境新兴污染物浓度的核心途径,开发能够经济、高效地去除各类PPCPs的深度处理技术仍然十分必要。     

Occurrence and loss over three years of 72 pharmaceuticals and personal care products from biosolids–soil mixtures in outdoor mesocosms

Municipal biosolids are in widespread use as additives to agricultural soils in the United States. Although it is well known that digested sewage sludge is laden with organic wastewater contaminants, the fate and behavior of micropollutants in biosolids-amended agricultural soils remain unclear. An outdoor mesocosm study was conducted in Baltimore, Maryland, to explore the fate of 72 pharmaceuticals and personal care products (PPCPs) over the course of three years in that were placed in plastic containers made from polyvinylchloride and kept exposed to ambient outdoor conditions. Of the 72 PPCPs tested for using EPA Method 1694, 15 were initially detected in the soil/biosolids mixtures at concentrations ranging from low parts-per-billion to parts-per-million levels. The antimicrobials triclocarban and triclosan showed the highest initial concentrations at 2715 and 1265 μg kg⁻¹, respectively. Compounds showing no discernable loss over three years of monitoring included diphenhydramine, fluoxetine, thiabendazole and triclocarban. The following half-life estimates were obtained for compounds showing first-order loss rates: azithromycin (408–990 d) carbamazepine (462–533 d), ciprofloxacin (1155–3466 d), doxycycline (533–578 d), 4-epitetracycline (630 d), gemfibrozil (224–231 d), norfloxacin (990–1386 d), tetracycline (578 d), and triclosan (182–193 d). Consistent with other outdoor degradation studies, chemical half-lives determined empirically exceeded those reported from laboratory studies or predicted from fate models. Study results suggest that PPCPs shown in the laboratory to be readily biotransformable can persist in soils for extended periods of time when applied in biosolids. This study provides the first experimental data on the persistence in biosolids-amended soils for ciprofloxacin, diphenhydramine, doxycycline, 4-epitetracycline, gemfibrozil, miconazole, norfloxacin, ofloxacin, and thiabendazole.     

药物和个人护理用品在水环境中的现状与去除研究

未经处理或在城市污水处理工艺中未被去除的药品及个人护理用品(PPCPs)会进入水环境污染地表水和地下水。通过对现有研究结果分析,归纳了当前国内外水环境中PPCPs的污染现状、预测和检测方法。结合城市给水厂常规工艺和深度处理技术对PPCPs的去除情况分析,指出我国开展相关研究的必要性及方向。     

Ozonation and advanced oxidation technologies to remove endocrine disrupting chemicals (EDCs) and pharmaceuticals and personal care products (PPCPs) in water effluents

Advanced oxidation processes (AOPs) constitute a promising technology for the treatment of wastewaters containing pharmaceuticals and personal care products (PPCPs) and especially endocrine disrupting chemicals (EDCs). Data concerning the degradation of PPCPs and EDCs by means of AOPs reported during the period January 2000-May 2007 are evaluated in this work. Ozonation was the oxidation process most studied, gives the best expectatives to be applied with successful results.     

膜处理和活性炭吸附去除水环境中的PPCPs

近年来,药物和个人护理品(PPCPs)在环境中的污染正引起环境工作者的关注.传统污水处理工艺不能有效去除水中的PPCPs,其随出水进入地表水环境中,需要进一步深度处理.膜处理技术由于空间排斥作用,能有效截留比膜孔小的PPCPs;疏水性相互作用和静电排斥也会影响PPCPs的去除.由于活性炭和PPCPs的疏水性作用,PPCPs能够被有效吸附去除,且不产生副产物,但活性炭需要再生处理.虽然深度处理能有效去除出水中的PPCPs,但是源头控制策略相对于末端处理来说是更有意义的选择.     

北极地区水环境中PPCPs的污染现状研究进展

药物及个人护理产品(PPCPs)是一种国内外广泛关注的新污染物，其在北极地区水环境中的出现引起了多国政府与环保组织的高度重视。通过归纳北极地区水环境中PPCPs的来源、浓度、分布及归趋，发现近北极地区的河流输送、大气与海洋长距离传输、废液的直接排放和污水处理厂排放是PPCPs进入北极地区水环境的主要途径。北极地区水环境中典型的PPCPs为抗癫痫药、非甾体抗炎药(NSAIDs)、抗抑郁药、兴奋剂和增塑剂，其具有“假性持久性”,相似于非北极地区水环境中PPCPs的环境行为。目前，有关北极地区PPCPs污染控制技术、北极地区淡水环境中PPCPs污染水平的调查、北极地区水环境中PPCPs的性质以及环境行为等方面的研究有待加强。     

A2/O—MBR组合工艺去除城市污水中PPCPs

对某城市污水处理厂采用A2/O—MBR组合工艺去除几种典型药品及个人护理品(PPCPs)的效果进行了长期检测.结果表明,部分目标物的进水浓度呈现一定的季节性变化规律,对大部分目标物的去除效果相对稳定,其中对咖啡因、硫氰酸盐和避蚊胺的去除率达到80％以上,而舒必利、卡马西平和双氯酚酸等物质在工艺中几乎不能被去除.通过考察各种目标物沿工艺流程的浓度变化,发现目标物的迁移行为呈现出一定的规律性,根据这种规律性可将目标物划分为3类:在厌氧段迅速得到去除的物质(如咖啡因、避蚊胺、佳乐麝香和吐纳麝香)、沿程均匀去除的物质(如美托洛尔、甲氧苄安嘧啶和硫氰酸盐)以及在工艺中不易被去除的物质(如舒必利、卡马西平和双氯酚酸).