城市面源污染控制工程技术的应用及进展

城市面源污染已成为危害我国城市水体的重要污染源，而我国对城市面源污染的控制还处于起步阶段。详细介绍了国内外城市面源污染控制的工程技术，系统阐述了工程性控制技术的类型、研究重点、应用现状等情况，指出城市面源污染控制技术应尽量采用组合系统，充分利用各种技术的优势；同时在工程设计时，可将工程措施景观化、小型化，以达到效益最优化。     

沉淀池—草坪系统控制城市初期暴雨径流污染研究

为控制城市不透水下垫面的径流污染,构建了沉淀池—草坪系统,考察了该系统对初期暴雨径流污染的控制效果。结果表明,沉淀池—草坪系统对暴雨径流中TSS、COD、TP、TN和水量的平均截留效率分别为96．24％、96．66％、94．15％、85．24％和61．92％;沉淀池对暴雨径流中TSS、COD、TP和TN的截留作用分别是草坪的12．0、9．6、2．8、1．6倍。沉淀池对径流中TSS的去除起主要作用,草坪对径流中溶解态氮、磷的去除起主要作用。沉淀池—草坪处理系统不仅能有效控制径流污染,而且能充分利用径流中的营养盐和水资源,实现雨洪资源化。     

Determination of penicillin G and its degradation products in a penicillin production wastewater treatment plant and the receiving river

To investigate the fate of penicillin G (PEN G) in the wastewater from a PEN G production facility and the receiving river, an analytical method was developed for the simultaneous detection of PEN G and five degradation products using liquid chromatography-electrospray ionization mass spectrometry (LC-ESI/MS). PEN G had already undergone transformation before entering into the wastewater treatment plant (WWTP), with concentrations of 153+/-4 microg/L in raw wastewater. Most of the PEN G could be eliminated following successive treatments of anaerobic, hydrolysis, and two aerobic units under a hydraulic residence time (HRT) of 30 h, and the final concentrations were 1.68+/-0.48 microg/L in treated water. In the receiving river, the concentration of PEN G decreased from 0.31+/-0.04 microg/L at the discharging point to under the detection limit (0.03 microg/L) at the last sampling site (about 30 km from the discharging point). The main PEN G degradation products in surface water were found to be penilloic acid, penicilloic acid and isopenillic acid, which occupied 65.8%, 20.4% and 12.9%, respectively, of the total concentration at the last site. This is the first study on the behaviors of PEN G and its main degradation products in wastewater treatment processes and the aquatic environment.     

Historical records of heavy metal accumulation in sediments and the relationship with agricultural intensification in the Yangtze-Huaihe region, China

The extensive use of fertilizers on farmlands during the past several decades in China has led to a rapid deterioration of environmental water quality in recent years. An agricultural watershed with high-yield grain production and characterized by multipond systems in the Yangtze-Huaihe region of China was selected to establish the historic records of heavy metal pollution by (137)Cs-dated sediment cores. The experimental results indicated that the contents of most of the heavy metals investigated, such as Cd, Cr, Cu, Ni, Pb, and Zn, continuously increased in the multipond sediments throughout the past three decades. An inflection point appeared in the 1980s, prior to which all heavy metal contents showed little or no increase with time. Thereafter, the heavy metal contents increased dramatically due to the extensive application of phosphate fertilizers. The mean Cd content in 1980 was 0.13 microg/g which increased rapidly to 0.33 microg/g in 2004, but prior to 1980, the level was only 0.08 microg/g. Similar trends were also found for other heavy metals. The enrichment factor (EF) values indicated that Cd was not only the most anthropogenic metal in the multipond sediments but also aggravated anthropogenic impacts on the watershed environment during the past two decades. The high proportion of chemical reactive forms of Cd (10%-30%) implied a moderately high ecological risk. Our results clearly reveal that the extensive use of fertilizers has resulted in significant heavy metal pollution in this watershed, which threatens the water quality of the watershed and downstream water bodies.     

AutoPrep离子色谱法检测饮用水中痕量NO3-和NO2-

利用戴安公司全新的AutoPrep自动样品前处理技术，首次提出将OnGuard SPE前处理小柱在线使用的概念，对饮用水中的大部分氯离子进行在线去除的同时，还可对其中的亚硝酸盐和硝酸盐进行快速、准确的定量。该方法选用了自动在线水纯化装置CIRA和OnGuard Ag小柱，运用阀切换技术实现自动进样；适宜的色谱条件为：高容量氢氧化物选择性IonPac AS18阴离子交换色谱柱，淋洗液自动发生装置在线产生KOH进行梯度淋洗，抑制型电导检测；相关方法参数：对于自来水和瓶装水，亚硝酸盐和硝酸盐的检出限（S／N=3）分别为17．8μg/L和25．6μg/L，线性相关系数分别为0．9997和0．9999，RSD〈5％，加标回收率〉92％。该方法具有自动化程度高、操作简单、重现性好、节约时间、成本低廉和对环境友好的特点。此外，研究了前处理小柱的连续使用次数，并对在线和离线的除氯效果进行了比较，认为在线除氯可节约检测成本，且对除氯效果无太大影响。     

Adsorption of cadmium onto Al(13)-pillared acid-activated montmorillonite

The optimal preparation conditions for Al(13)-pillared acid-activated Na(+)-montmorillonite (Al(13)-PAAMt) were (1) an acid-activated Na(+)-montmorillonite (Na(+)-Mt) solution of pH 3.0, (2) a OH(-)/Al(3+) molar ratio of 2.4 and (3) Al(3+)/Na(+)-Mt ratio of 1.0 mmol g(-1). The effects of OH(-)/Al(3+) and Al(3+)/Na(+)-Mt ratios on the adsorption of Cd(2+) onto Al(13)-PAAMt were studied. A comparison of the adsorption of Cd(2+) onto Al(13)-PAAMt, Al(13)-pillared Na(+)-montmorillonite (Al(13)-PMt) and Na(+)-Mt suggested that Al(13)-PAAMt had higher adsorption affinity for Cd(2+) than the other two adsorbents. A pseudo-second-order model described the adsorption kinetics well. Cadmium adsorption followed the Langmuir two-site equation, while desorption was hysteretic.     

Fe-USY zeolite catalyst for effective decomposition of nitrous oxide

Zeolite matrix FAU is applied as an effective support that can be readily exchanged with ferric ions simply by wet ion exchange. The high exchange degree in this zeolite (USY) probably benefits from its larger channel dimension, which makes the diffusion of hydrated ferric ions into the channels easier. The as-prepared and subsequently calcined Fe-USY samples contain various kinds of iron species, which enable Fe-USY to efficiently decompose N2O to N2 and O2. The presence of O2 (20%), H2O (2%), or both reduces the N2O conversion only to a small extent at the same temperature. To test the feasibility and the catalytic activity in a practical situation, we prepared a monolithic Fe-USY/cordierite sample and investigated the N2O conversion under similar conditions. Such a cordierite-supported Fe-USY catalyst (approximately 9 wt % USY and 0.5 wt % Fe) shows the catalytic performance in N20 decomposition similar to the pure Fe-USY catalyst. Remarkably, both the pure Fe-USY and Fe-USY/cordierite catalysts demonstrate a very good durability because there is no activity lost after 100 and 144 h tests. Thus, the Fe-USY zeolite shows its potential as a cost-effective catalyst for N2O elimination in future applications.     

Source identification of PCBs in sediments from the Milwaukee Harbor Estuary,USA

This work focuses on the determination of PCB source profiles and their contributions to sediments in the Milwaukee Harbor Estuary by a principal component analysis (PCA) model. The model was recently developed and, for the first time, applied to apportion pollutant sources in sediments. Factor loadings and scores were computed, rotated via nonnegative constraints, and matched with candidate Aroclor profiles. Contamination by Aroclors 1016, 1242, 1254, and 1260 were identified for cores VC 6, 9, and 12 based on a log Q² criterion. The majority of PCB contribution was from a combination of Aroclors 1016 and 1242. Similarity between Aroclors 1016 and 1242 obscured resolution between the two profiles. Results from a chemical mass balance (CMB) model with known Aroclor profiles were in good agreement with the prediction from the PCA model.     

Preliminary evaluation of the performance of new pre-polymerised inorganic coagulants for lowland surface water treatment

This paper is concerned with the performance of relatively new kinds of pre-polymerised inorganic coagulants, poly-alumino-iron-sulphate (PAFS) and polyferric sulphate (PFS). Laboratory experiments were undertaken to evaluate the PAFS and PFS, in comparison with conventional coagulants such as ferric sulphate (FS) and aluminium sulphate (AS), for the coagulation of algal-type model waters and a lowland surface water containing algae and natural organic matter (NOM). Experimental results demonstrated that under the conditions studied, the performance of pre-polymerised coagulants were consistently superior to conventional coagulants (i.e., FS and AS). This is attributed to the presence of a range of pre-formed polymerised species. The coagulation mechanism of PAFS and PFS has been discussed in the paper.