不同回流位置对潜流人工湿地氮分布及去除效果的影响

通过脱氮实验比较了不同回流位置（进水口、前部、中部、后部）对潜流人工湿地的氮浓度空间分布状况和氮去除效果的影响。结果表明：4种回流与未回流处理相互之间的氨氮（NH4＋-N）空间分布无明显差异,而回流位置越靠近进水口,湿地中总氮（TN）分布浓度越低。将湿地出水按1/3的回流比回流到湿地进水口,对NH4＋-N去除率的影响差...     

围填海工程的生态环境价值损失评估——以江苏省两个典型工程为例

围填海工程对近海生态系统的影响一直是生态学和生态经济学领域广泛关注的焦点。运用直接市场法和替代性市场法（如市场价值法、影子工程法、碳税法、替代成本法、成果参照法等,第Ⅰ类方法）、条件价值评估法（第Ⅱ类方法）两类方法,选取江苏省连云港市海滨新区和南通市通州区滨海新区两个典型的围填海工程为案例,从潮滩湿地生态系统服务功能视角进行了围填海工程生态环境价值损失评估。结果表明：（1）两个典型案例第Ⅰ类方法的评估结果分别为0818 2×10⁸元/a和0696 2×10⁸元/a;（2）第Ⅱ类方法的评估结果分别为1273 9×10⁸元/a和1186 0×10⁸元/a;（3）用两类方法的评估结果作为生态环境损失值区间,可以提高评估结果的准确性。研究结果可为围填海工程生态补偿标准和生态补偿政策制定提供参考     

Removal of antibiotics from urban wastewater by constructed wetland optimization

Seven mesocosm-scale constructed wetlands (CWs), differing in their design characteristics, were set up in the open air to assess their efficiency to remove antibiotics from urban raw wastewater. A conventional wastewater treatment plant (WWTP) was simultaneously monitored. The experiment took place in autumn. An analytical methodology including HPLC-MS/MS was developed to measure antibiotic concentrations in the soluble water fraction, in the suspended solids fraction and in the WWTP sludge. Considering the soluble water fraction, the only easily eliminated antibiotics in the WWTP were doxycycline (61 ± 38%) and sulfamethoxazole (60 ± 26%). All the studied types of CWs were efficient for the removal of sulfamethoxazole (59 ± 30-87 ± 41%), as found in the WWTP, and, in addition, they removed trimethoprim (65 ± 21-96 ± 29%). The elimination of other antibiotics in CWs was limited by the specific system-configuration: amoxicillin (45 ± 15%) was only eliminated by a free-water (FW) subsurface flow (SSF) CW planted with Typha angustifolia; doxycycline was removed in FW systems planted with T. angustifolia (65 ± 34-75 ± 40%), in a Phragmites australis-floating macrophytes system (62 ± 31%) and in conventional horizontal SSF-systems (71 ± 39%); clarithromycin was partially eliminated by an unplanted FW-SSF system (50 ± 18%); erythromycin could only be removed by a P. australis-horizontal SSF system (64 ± 30%); and ampicillin was eliminated by a T. angustifolia-floating macrophytes system (29 ± 4%). Lincomycin was not removed by any of the systems (WWTP or CWs). The presence or absence of plants, the vegetal species (T. angustifolia or P. australis), the flow type and the CW design characteristics regulated the specific removal mechanisms. Therefore, CWs are not an overall solution to remove antibiotics from urban wastewater during cold seasons. However, more studies are needed to assess their ability in warmer periods and to determine the behaviour of full-scale systems.     

Waterbird Population Changes in the Wetlands at Chongming Dongtan in the Yangtze River Estuary,China

We studied the changes in wetland habitats and waterbird communities between the 1980s and the 2000s at Chongming Dongtan, a Ramsar site in the Yangtze River estuary, an ecologically important region. This region is an important stopover site for shorebirds along the East Asian–Australasian flyway and is extensively used by waterfowl. A net loss of 11% of the wetland area was estimated during study periods at Chongming Dongtan. The change was dependent on wetland types: while the area of artificial habitats such as paddy fields and aquacultural ponds more than doubled, more than 65% of natural habitats including sea bulrush (Scirpus mariqueter) and common reed (Phragmites australis) marshes were lost over the two decades. An exotic plant species introduced from North America, smooth cordgrass (Spartina alterniflora), occupied 30% of the vegetated intertidal zone by the 2000s. Although waterbird species richness did not change between the 1980s (110) and the 2000s (111), 13 species found in 1980s were replaced by 14 newly recorded species. Moreover, there were more species with declining trends (58) than with increasing trends (19). The population trends of species were affected by residential status and habitat types. Transients, wintering migrants, and habitat specialists were more likely to show declining trends compared to those breeding at Dongtan (including year-round and summer residents) and habitat generalists. Furthermore, species associated mainly with natural wetlands were more likely to decline than those associated mainly with artificial wetlands. These patterns suggest that the loss and change of wetland habitats at Chongming Dongtan adversely affected local population dynamics and might have contributed to the global decline of some waterbird species. Because Chongming Dongtan provides stopover and wintering habitats for many migratory waterbirds, protection and restoration of natural wetlands at Chongming Dongtan are urgently needed.     

农村家园污水人工湿地处理示范工程研究

近年来国内农村家园和乡镇建设了不少人工湿地,但常出现渗漏、堵塞、短流、恶臭、去除效率低、管理粗放、资源未综合利用等问题,能长期正常运行的少,缺乏可靠运行的范例。为此,我们开展了农村家因污水、雨水人工湿地处理及综合利用研究,取得了一定的进展并在四川省成都市安德镇安龙村建设了示范工程。     

污水生物生态处理工艺中的脱氮机理研究

通过水解池-美人蕉湿地、水解/接触氧化池-菖蒲湿地现场实验装置考察了生物-生态工艺深度净化分散生活污水的效果。结果表明,水解池-美人蕉湿地尽管湿地停留时间达到7 d,出水NH⁺₄-N仍难以达到一级A（GB18918-2002）标准;而增加接触氧化池后,湿地停留时间仅2 d,组合工艺出水水质远优于一级A出水要求。美人蕉湿地脱氮的主要途径是湿地微生物的硝化/反硝化,植物吸收约占28%。对经接触氧化处理,NH⁺₄-N、NO^-₃-N浓度均较高的进水,菖蒲湿地可在C/N小于2时高效脱氮。菖蒲湿地对TN的去除占组合工艺TN去除量的79%,其中植物吸收仅占湿地除氮总量的8%。湿地介质的厌氧氨氧化活性试验表明,菖蒲湿地介质表面的微生物在无有机碳源存在的条件下,可使培养液中的NH⁺₄-N与NO^-₃-N、NO^-₂-N短期内发生同步脱氮,厌氧氨氧化可能是菖蒲湿地在进水低碳源条件下脱氮的主要原因。     

碳氮比对人工湿地污水处理效果的影响

采用表面流人工湿地系统静态小试装置,考察了低、中、高3组不同进水COD/N(2,5,10)对系统中氮、磷及COD去除效果的影响。结果表明:进水C/N的变化对COD的去除率影响不大,平均去除率达到94.6%。TN的去除率随着COD/N的增大而逐渐升高,在C/N=5时达到63.8%,继续提高COD/N,TN的去除率变化不大。NH4+-N去除率随着COD/N的增加而降低。随着碳源的增加,释磷菌能够从进水中获得充足的碳源,从而可以比较充分地释磷,因此,磷的去除率随COD/N的增加而提高。     

利用混合水体指数模型(CIWI)提取滨海湿地水体的信息

根据对滨海湿地区域光谱特性分析和背景信息的反射特点,对主要的水体信息提取方法进行比较分析,将混合水体指数模型（CIWI）应用于TM遥感影像,针对滨海湿地区域水体信息进行提取实验,并与近年得到广泛应用和承认的水体指数模型：归一化差异水体指数（NDWI）、改进的归一化差异水体指数（MNDWI）等进行比较。实验证明CIWI的区分度最高,水体与植被、水体与城镇、植被与城镇之间的区分度分别为505%、292%与267%;水体、植被、城镇像元之间的差异比NDWI和MNDWI增大,减少了混淆信息的影响,对江苏盐城滨海湿地研究区的水体信息提取精度达到949%,实现了滨海湿地区域水体信息的准确快速提取。     

The Role of Wetlands for Mitigating Economic Damage from Hurricanes

Coastal communities along the United States coast often experience significant economic damage resulting from the impacts of tropical storms and hurricanes. Research suggests that certain factors that affect economic damages are increasing the vulnerability of coastal communities. Population growth, which increases vulnerability by placing valuable lives and assets in the path of storms, is expected to increase. Climate change has the potential to cause more frequent and intense storms, and coastal wetland loss is contributing to the vulnerability of coastal populations. Wetlands conservation and restoration is often advocated for as a means of reducing the impacts of coastal storms. The relationship between wetlands and storm surge energy is understood relatively well in physical terms, but very little economic analysis has been conducted to estimate the degree to which wetlands reduce economic impacts. Using factor analysis, the relationships among coastal populations, wetlands, storm intensity, and economic damage are explored. The factor analysis suggests that wetland presence is associated with a reduction in economic damages from coastal storms. Factor score analysis suggests that the proportion of damage explained by wetland presence is smaller for more intense storms. These results are consistent with those found in the physical science literature and have potentially large consequences for how wetlands are used in risk reduction.     

水平潜流人工湿地处理太原市城市再生水的运行效能

以山西省太原市某污水厂的高氮低碳尾水为研究对象,开展基于3床并联的水平潜流人工湿地处理尾水的中试研究。研究结果表明,该人工湿地系统启动2个月进入稳定运行期;稳定运行期3个床体的出水水质除TN外其余指标均满足《地表水环境质量标准》（GB3838—2002）中Ⅳ类水体标准,TN指标满足《城镇污水处理厂污染物排放标准》（GB18918．2002）中一级A标准,该湿地系统出水可直接用于补充景观用水;稳定运行期3床的植物与基质的配置更适合处理同类尾水,3个床体对各污染物的去除效果均为3床〉2床〉1床;本系统中填料对污染物处理效果的影响大于植物对污染物处理效果的影响,最优填料顺序依次为沸石、砾石和钢渣,最适植物栽种顺序为芦苇、香蒲、美人蕉、黄菖蒲和芦苇。