在不同质地土壤中重金属的运移积累研究

随着污水灌溉面积的持续扩大,研究污水灌溉带来的重金属污染问题,特别是重金属污染物对土壤—作物系统的影响显得尤为重要。通过室内土柱模拟试验,以铅、镉两种常见的重金属为例,研究这两种重金属在不同土壤质地（砂土和砂壤土）条件下的运移积累规律。     

污水灌溉对水土及农作物的影响研究

选取邯郸市主城区周边生活污水、工业污水、混合污水、中水和井水5种灌溉区的样点,对不同水质灌溉农田后重金属对土壤、小麦、玉米、蔬菜以及地下水的影响进行了分析.结果表明:不同灌区土壤中各种重金属的含量依次为工业污水灌区>混合污水灌区>生活污水灌区>中水灌区>井水灌区;不同灌区小麦、玉米体内各种重金属含量分布规律为井水灌区和中水灌区含量较少、生活污水灌区次之、混合污水灌区和工业污水灌区较多;蔬菜体内各种重金属含量分布规律为井水灌区较少、工业污水灌区较多;污灌区的地下水已经受到污染.     

污灌条件下农田土壤中重金属的运移规律研究

污水灌溉对土壤环境的影响,特别是污水灌溉中的重金属对作物、土壤和地下水的研究受到人们的广泛关注。通过对呼市近郊污灌区试验研究,探讨了污灌条件下主要4种重金属在土壤中的运移规律。     

两种絮凝工艺去除污水中金属元素的对比试验

分别采用化学生物絮凝与化学絮凝两种工艺处理同一低浓度城市污水,对比分析污水中金属元素的去除效果。试验结果表明,在相同加药量的条件下,化学生物絮凝工艺在增加絮凝产物中铝元素含量的同时,对部分有害重金属的控制也优于化学絮凝工艺。但该工艺在处理高浓度污水时,处理效果会受重金属浓度的制约。     

污泥活性炭的制备及其用于重金属废水处理的研究进展

城市污水处理厂在处理污水的同时会产生大量的污泥,其含有大量有机物和有害物,性质不稳定,易腐化,如果处理不当,将会造成严重的环境污染和资源浪费.用城市污水处理厂污泥制备活性炭是20世纪80年代后期出现的一种新型利用途径,因其制备成本低,活性炭用途广泛,可以用于污水处理去除有毒有害物质,具有良好的环境效益和社会效益,引起国内外研究人员的关注.而有毒重金属对环境的严重威胁正逐渐成为全球性问题,活性炭吸附法是一种常用来处理重金属废水的方法.综述了国内外污泥制备活性炭的工艺方法,及在这些制备方法基础上对重金属废水的处理研究.     

不同pH值条件下重金属捕集剂有效性的研究

采用高分子有机捕集剂与废水中的多种重金属离子发生螯合反应,生成稳定且不溶于水的金属螯合物来去除废水中的重金属离子。对4种捕集剂在不同pH值的条件下对含有汞、铜、镉、铅等重金属污水的去除效果进行了试验研究。结果表明,利用重金属捕集剂方法处理重金属废水的效率较高,有很好的应用前景。     

水泥潜入河道底泥对重金属锌阻截作用的研究

基于水泥随入渗污水潜入河床淤泥模拟试验,分析了水泥潜入对污水中重金属锌的阻截作用,揭示了污水所含重金属锌沿深度方向的变化特性。结果表明:水泥潜入河道淤泥可以有效阻截重金属锌在土壤中的纵向迁移;在一定范围内,土壤阻截重金属锌的作用随着水泥潜入量的增大而增大;在水泥潜入的条件下,重金属锌的表聚作用明显,即土壤阻截重金属锌的作用随深度的增大而减小。     

南四湖表层底泥重金属污染的风险评

为定量评价南四湖表层底泥的重金属污染程序和潜在生态危害性,在实地采样分析表层底泥重金属污染浓度和空间分布特征的基础上,将地质积累指数与潜在生态风险指数相结合对南四湖表层度泥重金属的污染。程度进行了潜在的生态风险评价,两种方法相互补充和验证。结果表明：汞是南四湖高生态风险元素,应予特别关注;南四湖底泥的重金属污染从北到南重金属污染由重到轻,来自济宁的城市生活污水和工业废水是南四湖上级湖污染的主要来源最后基于评价结果提出了合理化的对策与建议。     

北京市东南郊灌区土壤和农产品重金属含量水平评估

为明确北京东南郊典型灌区土壤和作物重金属含量和污染水平,２０１５年对该灌区３１个监测点位土壤样品和６２个作物样品的６种重金属进行了检测,利用单因子污染指数法、综合污染指数法和综合潜在生态风险评估法对土壤污染状况和生态风险进行了评估,利用皮尔逊相关分析、主成分分析和地统计学分析对土壤重金属来源进行了分析。研究结果表明灌区土壤重金属含量属于安全级别,潜在生态风险较低,农产品重金属含量满足国家食品标准,灌区土壤重金属的主要来源是农业施肥、污水灌溉和大气沉降。     

土壤对重金属离子的吸附

介绍了土壤对重金属离子的吸附机理,并就影响土壤对重金属离子吸附的主要因素进行了论述,对水源地保护及污水土地处理中研究重金属离子的迁移转化规律有一定的参考作用。     

污水灌溉区土壤镉的高光谱遥感监测研究

以石家庄多年污水灌溉区为对象,通过对污灌土壤的可见-近红外波段光谱信息进行测量和处理,利用相关分析和多元逐步回归分析,建立土壤镉含量与反射光谱变量之间的回归模型。结果表明,土壤镉在研究区土壤中有一定程度的积累,镉含量与其原始光谱、倒数对数光谱在多数光谱波段达到极显著相关水平,与连续统去除光谱相关性不显著。逐步回归模型中,倒数对数模型拟合精度最高,均方根误差为0.020,预测精度达到92.71%,说明倒数对数光谱变量模型可有效预测土壤镉含量,是估算研究区土壤镉含量较理想的预测模型。     

Reuse of treated wastewater and sewage sludge for fertilization and irrigation

The objective of the present work was to assess the short-term potential of treated wastewater and sewage sludge for ornamental lawn fertilization and irrigation. A field experiment was performed and the following treatments were considered: sewage sludge application + irrigation with public water; sewage sludge application + irrigation with treated wastewater; irrigation with public water; irrigation with treated wastewater (TW). Irrigation with treated wastewater showed a positive effect on lawn installation through higher growth of grass (1,667 cm) and higher dry matter yield (18,147 g m(-2)). These results represent a significant increase in the grass yield compared with public water irrigation. The grass height (2,606 cm) and dry matter yield (23,177 g m(-2)) increased even more, when sewage sludge produced in the wastewater treatment plant (WWTP) was applied to soil, which proves once more its benefits as an organic fertilizer. At the end of the experiment, an increase of some soil parameters (pH, electrical conductivity, organic matter, Ca2+, Na+, K+, Mg2+ and NH4+) was observed, indicating that treated wastewater irrigation can cause a soil sodization. This short-term study indicated that use of treated wastewater and sewage sludge for ornamental lawn fertilization and irrigation is an environmentally sustainable option for re-use of the WWTP by-products.     

再生水灌溉对土壤质量的影响研究

再生水灌溉是解决水资源短缺的有效途径,在北京市选取新河再生水灌区,对土壤质量情况进行研究分析。结果表明：再生水灌区土壤中重金属含量未对土壤产生不利影响：再生水灌溉对土壤碱性的危害性较低;再生水灌区土壤阴离子含量相比井灌区含量变化要稳定,对作物影响程度小;再生水灌溉可以提高土壤有机质含量,对土壤具有较好的保肥能力。     

聚丙烯纤维土受力性能试验研究

为了解决由煤层采动和重载车辆导致的路基砂土大变形问题,依据三轴压缩试验,研究了4种纤维长度和4种纤维掺量下砂土的强度和抗变形能力。结果表明:纤维土的应力-应变关系近似呈双曲线关系,主要破坏形式为鼓胀破坏;纤维土的力学性能随纤维掺量和长度的增加而增大,但对内摩擦角影响很小。最后在试验基础上通过1stOpt进行多因素回归分析得到黏聚力与纤维长度和掺量的拟合公式,并通过与实测值比较,认为其能够满足工程需要。     

Approach of water–salt regulation using micro-sprinkler irrigation in two coastal saline soils

This study aimed to investigate whether saline silt and sandy loam coastal soils could be reclaimed by micro-sprinkler irrigation. The experiments were run using moderately salt-tolerant tall fescue grass. Micro-sprinkler irrigation in three stages was used to regulate soil matric potential at a 20-cm soil depth. Continued regulation of soil water and salt through micro-sprinkler irrigation consistently resulted in an increasingly large low-salinity region. The application of the three stages of soil water–salt regulation resulted in an absence of salt accumulation throughout the soil profile and the conversion of highly saline soils into moderately saline soils. There were increases in the plant height, leaf width, leaf length, and tiller numbers of tall fescue throughout the leaching process. The results showed that micro-sprinkler irrigation in three soil water and salt regulation stages can be used to successfully cultivate tall festuca in highly saline coastal soil. This approach achieved better effects in sandy loam soil than in silt soil. Tall fescue showed greater survival rates in sandy loam soil due to the rapid reclamation process, whereas plant growth was higher in silt soil because of effective water conservation. In sandy loam, soil moisture should be maintained during soil reclamation, and in silt soil, soil root-zone environments optimal for the emergence of plants should be quickly established. Micro-sprinkler irrigation can be successfully applied to the cultivation of tall fescue in coastal heavy saline soils under a three-stage soil water–salt regulation regime.     

Modeling the Effect of Cistern Size,Soil Type,and Irrigation Scheduling on Rainwater Harvesting as a Stormwater Control Measure

Urban stormwater runoff could have negative impacts on water resources and the environment. Rainwater Harvesting (RWH) can serve both as a stormwater control and water conservation measure. Cistern size and irrigation scheduling are two of the factors that directly impact the total runoff from a residential unit with a RWH system and the amount of potable water used for irrigation. The effectiveness of RWH was evaluated for four soil types; Sand, Sandy Loam, Loamy Sand, and Silty Clay, with a root zone of 15.2 cm using three irrigation scheduling methods (Evapotranspiration (ET)-based, soil moisture-based, and time-based), and five cistern sizes. Total runoff volumes and total supplemental potable water used were compared among the three irrigation scheduling systems and a control treatment without RWH. A model was developed to simulate the daily water balance for the treatments. Irrigation and runoff volumes were compared for the various scenarios. Silty clay soil resulted with 83 % more runoff than Sandy soil, while Sandy soil required on average 58 % more supplemental water than Silty Clay soil. On average, the 833 L cistern resulted with 41 % savings in water supply and 45 % reduction in total runoff. Results showed that the greatest volumes of runoff predicted were for the silty clay soil Control Treatment using a time-based irrigation scheduling method, while the least volumes calculated were for the sandy loam soil time-based irrigation scheduling treatment with 833 L cistern size. The greatest volumes of total supplemental water predicted were for sandy loam soil Control Treatment, while the least volumes were for silty clay soil ET-based irrigation scheduling treatment with 833 L cistern size. Regression equations were developed to allow for users to select a RWH cistern size based on the amount of water they want to save or runoff to reduce.     

渗灌对樱桃园土壤环境的影响效果试验研究

渗灌是一种新型节水灌溉技术,为了探讨渗灌对果园土壤环境的影响,促进渗灌节水技术在山区旱地果园中的推广应用,以代表北方土石山区典型区域的鲁中南山地果园为研究区域,通过对樱桃园渗灌和漫灌两种灌溉方式下土壤水分、土壤温度、土壤物理性状的测定,较为系统地研究了渗灌对樱桃园土壤环境的影响效果。结果表明,灌溉后7 d,渗灌土壤水分下降幅度为5.23%,而漫灌为7.13%,漫灌土壤水分损失较大;渗灌与漫灌相比,0~20 cm土壤层平均温度比漫灌高0.47℃,地上20 cm平均气温比漫灌高0.43℃;漫灌在1~0.05 mm范围内的土壤粒径分布由灌溉前的56.01%下降到43.69%,而渗灌没有明显变化;漫灌土壤容重增加了6.57%,总孔隙度减少了6.75%;漫灌土壤板结厚度达8.3 cm,灌溉4 d后,地面裂缝宽度5.0 mm,渗灌没有出现土壤表层板结和裂缝现象。     

开封市污水灌溉费用效益分析

利用开封市用水资料,计算了开封市区农业灌溉、市政用水、工业用水可利用的回用水量。由于污水的农业回用涉及到许多环境问题,因此根据开封市具体实例分析了污水的农业回用对灌区土壤中As、Pb含量、小麦品质、地下水水质和居民健康的影响。同时,运用费用效益基本理论,选择了市场价值法、影子工程法和人力资本法对灌溉带来的直接效益和间接效益进行了计算,并折算为单方水的效益。最后对比单方水灌溉费用,得到污水灌溉的单方水净效益,以此分析了开封市污水农业回用的费用效益。     

污灌对大同市农业生态环境的影响

大同市污水大都未经处理或处理不达标,直接排入河道用于灌溉农田,对农业生态环境造成严重的影响。文中着重分析了污灌对土壤、作物、地下水的危害,提出了加强对污灌的管理,达到对农业生态环境的有效保护,实现农业的可持续发展。