Five year water and nitrogen balance for a constructed surface flow wetland treating agricultural drainage waters

The performance of a constructed surface flow wetland in reducing diffuse N pollution coming from croplands is being investigated in an ongoing experiment, begun in 1998 in NE Italy. The 0.32 ha wetland is vegetated with Phragmites australis (Cav.) Trin. and Typha latifolia (L.). It receives drainage water from 6 ha of land managed for an experiment on drainage systems, where maize, sugarbeet, winter wheat and soybean are cultivated. During the period 1998-2002, the wetland received from 4698 to 8412 mm of water per year (on average, about 9 times the environmental rainfall); its water regimen was discontinuous and flooding occurred on a variable number of days per year (from 13 to 126). Nitric nitrogen was the most important form of element load. Its concentration in the inflow water over time was rather discontinuous, with median values ranging from 0.2 (in 2001) to 4.5 (in 2000) mg L(-1). Inflow nitric N concentrations were occasionally in the 5-15 mg L(-1) range. Concentrations reduced passing through the wetland, with a more evident effect in the last year. Over 5 years, the wetland received slightly more than 2000 kg ha(-1) of nitrogen, 87% in nitric form mostly from farmland drainage. The remaining 13% of N was applied as organic slurry directly onto the wetland, with 5 distributions during 1998 to assess wetland performance in treating occasional organic loads. Field drainage loads had a discontinuous time pattern and occurred mostly during autumn-winter, with the exception of the 2001-2002 season which was a very dry. The wetland discharged 206 kg ha(-1) of N, over the 5-year period, with an apparent removal efficiency of about 90%. The disappearance was mostly due to plant uptake (1110 kg ha(-1)) and soil accumulation (570 kg ha(-1)), with the contribution of denitrification being estimated at around 7%.     

黄河兰州段湿地景观水体净化处理及循环再生利用研究

黄河流域仅短期内抑制污染物,无法彻底分解污染物,导致水体净化和循环再利用效果差,提出黄河兰州段湿地景观水体净化处理及循环再生利用方法。通过种植旱伞草与鸢尾等植物,添加65%炉渣、25%砖块、10%砾石的填料,布设湿地景观,净化处理水体;利用厌氧池与缺氧池等一系列装置分解废水污染物,完成水体循环再生利用。试验表明,布设黄河兰州段湿地景观,有效净化处理水体内的化学需氧量、总磷、硝态氮,夏季指标的去除率高于冬季;布设黄河湿地景观,有效净化处理水体内的氨氮,冬季氨氮去除率高于夏季。水力负荷对化学需氧量、总磷的净化处理效果影响小;水力负荷越小,硝态氮的净化效果越佳;当水力负荷超过10 m3/（m2〖KG-*2〗·〖KG-*3〗d）时,氨氮的净化效果越佳。     

新型转鼓式一体化装置+人工湿地组合工艺的运行特性与效果

为研究改造优化后的新型转鼓式一体化装置+人工湿地组合工艺的处理效果,结合锦溪镇红霞村分散型农村生活污水处理示范工程,对新型组合工艺处理出水水质指标及其去除率进行了分析。结果表明,组合工艺可实现COD、NH3-N、TP、SS的总去除率最高达到90.20%、94.40%、91.82%、95.80%,出水COD、NH3-N、TP、SS浓度分别小于等于30.0、40.0、0.32、8.0 mg/L,水质长期稳定达到《城镇污水处理厂污染物排放标准》中一级A标准;组合工艺处理污水所需能耗仅接近常规能耗的50%。     

P-S-R模型在海河流域湿地生态安全评价中的应用

以生态安全理论为基础,基于湿地普查和重点湿地调查结果,应用P-S-R模型,从压力、状态、响应3个方面对海河流域10个重要湿地进行生态安全评价。结果表明:海河流域重要湿地生态安全状况不容乐观,10个重要湿地中有9个处于预警状态,1个处于中度预警状态。其中生态安全指数最高的是大黄堡洼,为5.995 0,最低的为大浪淀湿地,为3.834 0,海河流域湿地整体生态安全状况近年来有向中度预警甚至极度预警状态恶化的趋势;指出必须重视海河流域湿地的生态安全建设。     

某小城镇综合生活污水CASS工艺及人工湿地工艺的方案比选

小城镇综合污水处理是我国许多城镇发展面临的急待解决的问题,文章通过CASS工艺及人工湿地工艺方案比选,人工湿地是一种投资低、建设运营成本低、工艺简单的新型生态处理系统。该工艺成熟可靠,去除N、P能力强,出水各污染指标均能达到排放要求。在解决小城镇综合污水处理方面具有广阔的应用前景。证明了人工湿地工艺是一种适合小城镇污水处理的新型工艺,适合在小城镇推广应用。     

东平湖湿地景观演变对人类活动的响应机制

为探索南水北调工程通水前后湿地景观格局变化,采用决策树分类法,对2000年、2009年和2014年3期Landsat影像进行分类;在分类结果的基础上,应用转移矩阵和景观指数等方法,分析不同时期景观格局的特点及驱动因素;最后应用马尔科夫模型,对研究区景观格局演变进行预测。结果表明:水域周边出现了更多的建筑用地,景观指数INP由7 174增长至10 334,蔓延度指数IC由64.594 4减少至63.651 5,景观格局总体呈破碎趋势,景观破碎度增加,景观异质性增强;2009—2014年香农均匀度指数ISHE和香农多样性指数ISHD指数小幅上升,景观格局集聚度水平提高,但是与2000年的景观格局水平存在较大差距,部分天然湿地被人工湿地取代,导致湿地生态功能退化。     

河北省湖泊型湿地水环境状况及保护建议

湿地是水陆相互作用形成的独特生态系统,是自然界最富生物多样性的生态景观和人类最主要的生存环境之一。河北省湿地资源类型多样,分布广泛,其中湖泊型湿地以其特殊的性能,在经济社会发展中发挥着不可替代的作用,但随着人类的不合理开发利用及污染物的大量排放,湖泊型湿地出现了缺水干涸、富营化加剧、泥沙淤积、生物多样性受损等一些问题,现旨在针对湖泊型湿地存在的水环境问题,提出修复的对策建议,借以呼吁全社会重视湿地保护。     

中国湿地面面观——兼论湿地保护的重要性及其策略

介绍我国湿地概况,探讨我国湿地的消减原因、保护措施和可持续利用策略;阐述湿地保护对水土资源可持续利用的重要作用;以促进流域水土资源保护及湿地保护工作,挽救湿地生态危机。     

Wetland use and impact on Lake Victoria, Kenya region

This article reports on a study of wetland use and impact on Lake Victoria conducted in March and April 1995. A field survey and interviews were used to study wetland use and their impact on Lake Victoria. This article identifies management issues and establishes a broad vision for the future. It also addresses the need to balance the competing demands for wetland use and development with the need to conserve a healthy and functional Lake Victoria. Investment proposals are made that would minimize destruction of the wetlands and negative impacts on the lake. General recommendations for planning and management issues, as well as suggestions of specific research needs that should form the basis of action and investment initiatives, are given.     

湿地保护范围的量化确定方法

本文探讨了一种定量确定湿地保护范围的方法。首先根据区域地形地貌和水环境等自然条件初选数个可能的湿地保护规模的方案，然后计算各方案表征社会经济、生态环境和水环境条件的6个特征指标：湿地初级生产力产值、淹没投资、环境影响指标、蓄滞洪水量、湿地补水难度系数和湿地水体更新难度系数。最后采用灰色系统关联度法和权重图解法量化确定整体效益相对最佳的湿地保护规模的方案。文中以吉林省查干湖湿地为例进行了计算，取得了较符合实际的计算结果。