锐劲特在菜地生态系统中的残留动态研究

建立了青菜、土壤中锐劲特及其代谢物的气相色谱毛细管柱残留分析的方法。对锐劲特及其降解产物在菜地生态系统中的残留动态进行了研究,明确了锐劲特在青菜和土壤中的残留和消解情况,锐劲特在土壤中的降解半衰期为7．88d,在青菜中的降解半衰期为2．58d。     

辽阳蔬菜种植畜禽养殖地土壤重金属污染及评价

为了解辽阳市蔬菜种植和畜禽养殖基地土壤中重金属状况,依据《环境监测分析方法》、《土壤元素的近代分析方法》的要求土壤采样分析。并根据土壤环境质量标准(GB15618-1995),采用Harkanson"潜在生态危害指数法"对土壤中重金属进行生态风险评价。结果表明,在蔬菜种植和畜禽养殖基地所选典型采样点中,重金属含量无超标现象,均属安全范围,对人体及生物无危害。     

重金属Cd在再生水—土壤—蔬菜体系中的迁移

通过小区试验种植了小白菜和萝卜,以再生水灌溉和污泥施肥,采用修正的BCR法测定了再生水、污泥、土壤、蔬菜中重金属Cd的5种形态含量,分析Cd在再生水(污泥)-土壤-蔬菜体系中的迁移和累积特征。结果表明:灌溉用清水和再生水中Cd的总量均未超出国家农田灌溉水质标准(GB5084-2005)的规定,但水样中的Cd主要以水溶态存在,生物有效性系数K≥0.85。经再生水灌溉和污泥施肥后土壤中Cd的形态和总量均发生了变化。蔬菜地上部分中Cd以水溶态B0和可氧化态B3的形式存在,B0>B3;而地下部分以B0、B2和B3为主,B0相似文献   

红霉素发酵菌湿渣烧制氧化锌烧渣研究

红霉素发酵菌湿渣中约含2．5％的锌,经直接烘干后灼烧实验表明,可获得ZnO含量高达87．15％的氧化锌烧渣。烧渣中铅铜镉铁含量远低于同位品的锌焙砂,是生产高纯氧化锌的最佳原料,有较高的经济价值。     

遥感指数在湖泊叶绿素a反演研究中的应用

借鉴陆地植被指数的算法,利用MODIS数据的波段组合对太湖叶绿素8浓度进行反演。探讨了差值植被指数DVI、比值植被指数RVI、归一化植被指数NDVI这三种遥感指数形式的反演效果及各自特点。MODIS数据蓝光波段和红外波段的组合是反演太湖叶绿素浓度的最佳波段组合,DVI适合于反演叶绿素浓度高的情况,RVI的反演结果两极分化明显而普适性较差,NDVI适合于反演浓度较低的情况。     

Nitrate leaching under vegetable field above a shallow aquifer in Slovenia

In the search for new technologies that would ensure optimum yield and environmental sustainability, various irrigation, nitrogen and cropping system management strategies for the production of vegetables with a shorter growing period were assessed at a benchmark site in Slovenia for the years 2006 and 2007. In the studied years four irrigation and fertilization treatments were applied: (1) 50% drip irrigation of plants water requirements ET_crop and the farmer's practice of fertilisation (broadcasting), (2) fertilisation and 100% drip irrigation (fertigation), (3) the farmer's practice of irrigation (sprinkler irrigation using water stored in plastic tanks) and fertilisation, and (4) control (the farmer's practice of irrigation but no fertilisation). An equivalent of 80, 80 and 200 kg ha⁻¹ of nitrogen (N), 50, 50 and 80 kg ha⁻¹ of phosphorous (P) and 120, 120 and 300 kg ha⁻¹ of potassium (K) was added for iceberg lettuce, endive and cabbage, respectively. Nitrogen (N) labelled fertilizer (¹⁵N) was applied to trace the movement of the applied N fertiliser. The tested irrigation and fertilisation techniques for the production of vegetables with a shorter growing period in the Slovenian climate showed that environmentally sustainable practices (split application of nutrients compared to broadcast incorporating fertilisation) should be a practice of choice in water protection zones. The results confirm that fertigation and improved irrigation scheduling can be an effective way of minimizing nitrate leaching, and should be considered for vegetable production in or close to groundwater protection zones.     

Safety issues related to the maintenance operations in a vegetable oil refinery: A case study

The present work was focused on maintenance hazards related to vegetable oil refining. An incident occurred in an Italian vegetable oil refinery was presented to evidence this safety criticality. The incident took place during a maintenance shut down, and was associated to the ignition of the solid residual in a packed column. No fatalities or injuries were reported, but the column was strongly damaged and removed from the plant. A specific experimental characterization of the solid residues accumulated in the column, sampled both from the damaged and undamaged parts of the column, was carried out in order to determine the conditions leading to unwanted combustion of the residues. At the same time, samples taken from the damaged column steelwork were subjected to metallurgical analysis aimed at the thermal and mechanical characterization of the steel, obtaining information about the incident duration and temperature reached during the combustion phenomenon. The study evidenced the need of adequate maintenance procedures and safety management in the generic framework of food industry, identified as key lessons learned.     

乙氧氟草醚在模拟稻田-鱼塘生态系统中残留动态的研究

在野外稻田-鱼塘模拟系统研究了乙氧氟草醚以规定剂量72g/hm2施用于田间后的残留分布及消解动态?结果表明,施药后4h该药在稻田表水和鱼沟中的浓度分别为29.4和19.6μg/L,在稻田土?鱼塘水和塘泥中的最大浓度分别为0.752,0.006和0.156mg/L?且在各介质中消解迅速,在田表水?塘水?田土中的半衰期分别为4.5,48.8h和7.2d?说明该药对水生生物虽有较高毒性,但在规定使用剂量下,其在稻田及邻近鱼塘中的残留浓度与毒性已降到对其中的水生生物不再有危害的水平?因此可认为该农药在稻田使用对水生生物无实际危害作用?      

香港近海沉积物中汞残留研究

研究是测定了从 2 0 0 0～ 2 0 0 1年 ,对香港近海 16个采样点所采集的沉积物中残留汞的含量。通过沉积物中汞含量对香港近海的汞污染分布状况进行研究。测量的结果中 ,沉积物中汞含量的范围是 (45 7～ 384 4ng g ,干重 )。     

气相色谱法测定人参中BHC残留量

本文研究了一种快速、简便、准确地测定人参中ＢＨＣ残留量的气相色谱法。人参样品经正己烷—丙酮冷浸泡,超声萃取,磺化法处理后,萃取液直接上机测定。本方法对人参中ＢＨＣ各异构体的回收率均在８５％以上。变异系数小于１０％。与其它方法相比,本法耗时少,价格廉,结果准确,适合批量样品测定。