Occurrence,removal, and environmental risks of pharmaceuticals in wastewater treatment plants in south China

Pharmaceutically active compounds in wastewater released from human consumption have received considerable attention because of their possible risks for aquatic environments. In this study, the occurrence and removal of 10 pharmaceuticals in three municipal wastewater treatment plants in southern China were investigated and the environmental risks they posed were assessed. Nifedipine, atenolol, metoprolol, valsartan and pravastatin were detected in the influent wastewater. The highest average concentration in the influents was observed for metoprolol (164.6 ng/L), followed by valsartan (120.3 ng/L) in August, while median concentrations were higher in November than in August. The total average daily mass loadings of the pharmaceuticals in the three plants were 289.52 mg/d/person, 430.46 mg/d/person and 368.67 mg/d/person, respectively. Elimination in the treatment plants studied was incomplete, with metoprolol levels increasing during biological treatment. Biological treatment was the most effective step for PhACs removal in all of the plants studied. Moreover, the removal of PhACs was observed with higher efficiencies in August than in November. The WWTP equipped with an Unitank process exhibited similar removals of most PhACs as other WWTPs equipped with an anoxic/oxic (A/O) process or various anaerobic-anoxic-oxic (A²/O) process. The environmental risk assessment concluded that all of the single PhAC in the effluents displayed a low risk (RQ<0.1) to the aquatic environments.

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滇池近岸水体微塑料污染与富营养化的相关性

内陆淡水湖泊微塑料污染受到广泛关注,但与水体富营养化的相关性尚不明晰.在滇池沿岸布设24个采样点,研究了近岸表层水体微塑料丰度、聚合物成分、粒径、颜色及形态,同步测定富营养化相关水质指标并计算富营养化状态指数.结果表明,滇池近岸水体微塑料丰度在800~6000 n·m^-3之间,平均为2867 n·m^-3,检出的聚合物类型主要是聚对苯二甲酸乙二醇酯（polyethylene terephthalate,PET）、聚醚型聚氨酯（polyetherurethane,PEU）、聚丙烯（polypropylene,PP）、聚乙烯（polyethylene,PE）和聚醋酸乙烯酯（polyvinyl acetate,PVAc）.微塑料粒径以0.2~0.5 mm为主,纤维状微塑料是最主要的检出形态,其次为碎片和薄膜.24个监测点中,处于重度、中度、轻度富营养化和中营养水平的样点数分别占8.33%、58.33%、29.17%和4.17%,主要污染物为总氮（TN）.相关性分析发现滇池近岸水体微塑料丰度与TN质量浓度呈极显著正相关（P<0.01）,与叶绿素a（Chl-a）呈负相关,但未达到显著性水平（P>0.05）,靠近昆明市主城区的北岸水体中微塑料丰度和TN质量浓度均显著高于其他三岸,主要来源于污水处理厂尾水排放.     

Investigation of the effects of humic acid and H<Subscript>2</Subscript>O<Subscript>2</Subscript> on the photocatalytic degradation of atrazine assisted by microwave

A solution of atrazine in a TiO₂ suspension, an endocrine disruptor in natural water, was tentatively treated by microwave-assisted photocatalytic technique. The effects of mannitol, oxygen, humic acid, and hydrogen dioxide on the photodegradation rate were explored. The results could be deduced as follows: the photocatalytic degradation of atrazine fits the pseudo-first-order kinetic well with k = 0.0328 s^?1, and ·OH was identified as the dominant reactant. Photodegradation of atrazine was hindered in the presence of humic acid, and the retardation effect increased as the concentration of humic acid increased. H₂O₂ displayed a significant negative influence on atrazine photocatalysis efficiency. Based on intermediates identified with gas chromatography-mass spectrometry (GC-MS) and Liquid chromatography-mass spectrometry (LC-MS/MS) techniques, the main degradation routes of atrazine are proposed.     

Pyrolysis behaviors of oil sludge based on TG/FTIR and PY-GC/MS

Pyrolysis is an alternative technology for oil sludge treatment. Thermogravimetric Analysis-Fourier Transform Infrared Spectroscopy and Pyrolysis-Gas Chromatography/Mass Spectrometry were employed to investigate the pyrolysis process and products of oil sludge. The pyrolysis process was divided into five stages: drying and gas desorption, oil volatilization, main pyrolysis, semi-coke charring, and mineral decomposition. The main reaction temperatures ranged from 497.6 K to 753.2 K. The products were mainly composed of pairs of alkane and alkene (carbon number ranges from 1 to 27). The mechanisms consisted of random chain scission followed by end chain scission at high temperatures with volatilization occurring during the whole process. This study is useful not only for the proper design of a pyrolysis system, but also for improving the utilization of liquid oil products.     

近20年来黑河干流中游地区土地利用/覆被变化及驱动力定量研究

黑河干流水量统一调度实施后(即2000年以后),流域干流中游地区用水量在时空上进一步受到限制。为此,研究黑河干流中游地区土地利用/覆被变化过程及其驱动力,尤其是黑河水量统一调度以来的生态环境问题,对研究区可持续发展具有重要意义。研究表明:①研究区土地利用发生了较大变化,1985-2000年,耕地、林地、城乡工矿居民用地逐渐增加,而草地、水域、未利用土地不断减少,2000-2005年耕地、城乡工矿居民用地逐渐增加,而草地、林地、水域、未利用土地不断减少;②黑河流域干流水量统一调配以来,一方面研究区可用水量进一步减少,另一方面研究区耕地短时间增加较快,研究区生态环境有退化的迹象,草地、林地、水域面积呈现减少趋势,变化率分别为2.14%、7.36%和3.69%;③1985-2000年土地利用类型主要呈现耕地和城乡工矿居民用地、耕地和未利用土地之间的相互转换,草地转为耕地,2000-2005年,土地利用类型主要呈现未利用土地转为耕地,草地和耕地之间相互转换;④土地利用程度变化存在明显的区域差异,以甘州区变化最大;⑤研究区土地利用/覆被变化的主要驱动力为社会经济因子,包括人口增长、经济社会发展等,2000年黑河流域水量统一调配以后,中游可利用水量的约束直接影响着研究区的土地利用变化。     

丘陵山区耕作层覆土需求优先度评价研究——以福建省光泽县为例

论文基于GIS技术,采用层次分析法从土壤构型、交通便捷情况、地块立地条件和地块理化条件4个方面构建了丘陵山区耕地耕作层覆土需求优先度的评价指标体系,利用改进的特尔斐法确定其权重,建立了评价模型,并以福建省光泽县为例进行了评价。结果表明：① I级优先区面积占5.2%,该区54%的面积是质量较差的规划开发补充耕地,其余是质量较差而基础条件较好的现有低产水田,对其实施覆土工程成本较低、综合效益较高,属于优先覆土区;② II级优先区占49.1%,该区耕作层覆土效益仅次于I级区,属于备选覆土区;③ III级和IV级区占45.7%,暂可不安排覆土工程。评价结果较好地反映了光泽县的实际情况,将为该区移土培肥专项规划编制以及耕地保护工程实践提供科学依据。     

基于农户生计的乡村能源消费模式研究——以陕南金丝峡乡村旅游地为例

为探讨乡村旅游发展对农户生计转型及能源消费模式产生的影响,论文借鉴可持续生计理论,以陕南金丝峡乡村旅游地为例,通过入户调查与访谈,构建能源消费-生计多样性模型对农户分类,基于用能多样性矩阵与效益评估法,分析不同生计类型农户用能结构及其综合效益,继而依据灰色关联分析,识别影响农户能源消费的主要生计资本因子,并总结农户能源消费模式转变的驱动机制.结果表明:① 参与旅游经营与不参与旅游经营的两大类农户中,农户用能多样性水平随生计多样性水平的提高而上升;② 与非旅游经营户相比,旅游经营户商品能源消费大幅增加,新型能源迅速推广,传统能源消费有所降低,能源消费模式向优质化和商品化发展;③ 不同类型农户用能综合效益差异明显,旅游经营户用能综合效益(16.96 元/kgce)明显大于非旅游经营户(13.53 元/kgce),表明旅游经营户从能源消费中获益更多;④ 促使农户能源消费模式变化的主要影响因素是物质、人力和金融三大生计资本.乡村旅游业发展带来了农户生计资本与策略的变化,并成为农户能源消费模式转变的重要驱动力,最后为进一步改善环境政策和优化能源利用,提出了相应的对策和建议.     

广州市学龄儿童在校期间PM2.5暴露水平评价

采用便携式大气颗粒物采样器(MiniVol)和便携式颗粒物检测仪(pDR-1500)在2010年3月底至4月初对广州市某小学的室内外细颗粒物(PM2.5)浓度进行了监测,并对学龄儿童在校期间活动模式进行了跟踪调查,评价了学龄儿童在校期间PM2.5暴露水平.结果显示该小学室内外日均PM2.5浓度范围为25.1~145.9μg/m3,室内PM2.5浓度略低于室外,两者呈明显的正相关关系(R2=0.65);室内实时PM2.5浓度结果表明非假期与假期存在差异.使用离子色谱分析了PM2.5的阴离子成分,其中NO3-和SO42-占阴离子成分总量的73%~95%.研究显示道路交通源是采样地点PM2.5主要来源之一.学龄儿童在校期间单位体重PM2.5日均潜在暴露水平为7.6μg/(kg×d),个体日均潜在暴露水平为246.8μg/d.     

Effect of organic compositions of aerobically pretreated municipal solid waste on non-methane organic compound emissions during anaerobic degradation

Odor pollution caused by municipal solid waste (MSW) treatment plants has become a growing public concern. Although aerobic pretreatment of MSW has advantages in accelerating landfill stabilization, the property of non-methane organic compound (NMOC) emissions from aerobically pretreated MSW (APMSW) during landfilling is unknown. To investigate NMOC emissions from anaerobic degradation of APMSW and to study the impact of organic compositions of APMSW and their decomposition stages, five simulative anaerobic bioreactors (R1-R5) were filled up with APMSW of different original organic compositions in a laboratory. For NMOC analysis, samples were collected from the gas that accumulated separately during two successive independent stages of the whole experiment. The results showed that the cumulative quantities of NMOCs from R1 to R5 were 1.11, 0.30, 0.18, 0.28, and 0.31 mg/kg DM, respectively, when volatile solid was degraded by 34.8-47.2%. As the organic content of the original waste was lower, the proportion of NMOCs generated in the early stage of anaerobic degradation became higher. Multiple linear regression analyses of the relationship between the quantities of degraded organics and generated NMOCs showed that lipid and protein have a strong effect on NMOC amount. The effect of lipid on NMOC quantity lasts longer than that of protein. This observation suggests that controlling the lipid and protein contents in MSW can reduce the odor from landfills.     

利用TM图像逐级分类提取非点源信息

探讨了运用逐级分类从TM图像中提取与非点源污染有关的土地利用信息的方法.研究表明,逐级分类与一般的最大似然度分类相比效果更佳,具有简化复杂问题、突出研究重点和方法灵活等优点,能够快速有效地提取所需要的信息.