Gondek Krzysztof, Baran Agnieszka, Kopeć Michał
Department of Agricultural and Environmental Chemistry, University of Agriculture in Krakow, Al. Mickiewicza 21, 31-120 Krakow, Poland.
Chemosphere. 2014 Dec;117:33-9. doi: 10.1016/j.chemosphere.2014.05.032. Epub 2014 Jun 13.
The aim of the study was to determine the influence of the process of low-temperature transformation and the addition of plant material to sewage sludge diversifying the content of mobile forms of heavy metals and their ecotoxicity. The experimental design included: sewage sludge+rape straw, sewage sludge+wheat straw, sewage sludge+sawdust, sewage sludge+bark and sewage sludge with no addition. The mixtures were subjected to thermal transformation in a chamber furnace, under conditions without air. The procedure consisted of two stages: the first stage (130°C for 40 min) focused on drying the material, whereas in the second stage (200°C for 30 min) proper thermal transformation of materials took place. Thermal transformation of the materials, caused an increase in total contents of heavy metals in comparison to the material before transformation. From among elements, the cadmium content changed the most in materials after thermal transformation. As a result of thermal transformation, the content of water soluble form of the heavy metals decreased significantly in all the prepared mixtures. Low toxicity of the extracts from materials for Vibrio fischeri and Lepidium sativum was found in the research, regardless of transformation process. L. sativum showed higher sensitivity to heavy metals occurring in the studied extracts from materials than V. fischeri, evidence of which are the positive significant correlations between the content of metals and the inhibition of root growth of L. sativum.
本研究的目的是确定低温转化过程以及向污水污泥中添加植物材料对重金属可移动形态含量及其生态毒性的影响。实验设计包括：污水污泥+油菜秸秆、污水污泥+小麦秸秆、污水污泥+锯末、污水污泥+树皮以及未添加任何物质的污水污泥。这些混合物在箱式炉中于无空气条件下进行热转化。该过程包括两个阶段：第一阶段（130°C 持续40分钟）着重于干燥材料，而在第二阶段（200°C 持续30分钟）进行材料的适当热转化。材料的热转化导致与转化前材料相比重金属总含量增加。在元素中，热转化后材料中镉含量变化最大。热转化的结果是，所有制备混合物中重金属水溶性形态的含量显著降低。研究发现，无论转化过程如何，材料提取物对费氏弧菌和水萝卜的毒性都很低。水萝卜对研究的材料提取物中存在的重金属表现出比费氏弧菌更高的敏感性，金属含量与水萝卜根生长抑制之间的正显著相关性证明了这一点。
