Jönsson K, Aspichueta E, de la Sota A, Jansen J C
Department of Water and Environmental Engineering, Lund Institute of Technology, P.O. Box 118, SE-221 00 Lund, Sweden.
Water Sci Technol. 2001;43(1):201-8.
A screening method for nitrification-inhibition determination has been evaluated at two laboratories, one in Sweden and one in Spain. Allyl-thiourea (ATU), methanol, chromium and zinc were used as reference toxicants in combination with different kinds of full-scale sludge and sludge produced in the laboratory. Different results were obtained with different combinations of activated sludge and toxicants. It was found that activated sludge often exposed to small amounts of a variety of toxic substances may build up a general resistance to toxic substances. Specific adaptation to certain substances was also observed. Domestic activated sludge responded in the same way to ATU regardless of whether it originated from Sweden or Spain. Synthetic sludge and domestic sludge exhibited the same inhibition of nitrification when tested with ATU as a toxicant. Synthetic activated sludge from two laboratory-scale plants run in parallel did not exhibit exactly the same sensitivity to certain toxicants. The variation in repeated tests with the synthetic sludges was about the same as for repeated tests with full-scale sludge and for other biological toxicity tests. Limits of detection were calculated to be about 5% for a single sample with three blanks as references at both the laboratories.
瑞典和西班牙的两个实验室对一种用于测定硝化抑制作用的筛选方法进行了评估。烯丙基硫脲（ATU）、甲醇、铬和锌被用作参考毒物，与不同种类的实际规模污泥和实验室产生的污泥相结合使用。活性污泥和毒物的不同组合得到了不同的结果。研究发现，经常接触少量各种有毒物质的活性污泥可能会对有毒物质产生普遍抗性。还观察到对某些物质的特异性适应。无论来自瑞典还是西班牙，生活活性污泥对ATU的反应方式相同。当用ATU作为毒物进行测试时，合成污泥和生活污泥对硝化作用的抑制表现相同。两个并行运行的实验室规模工厂的合成活性污泥对某些毒物的敏感性并不完全相同。合成污泥重复测试中的变化与实际规模污泥的重复测试以及其他生物毒性测试的变化大致相同。两个实验室以三个空白作为参考时，单个样品的检测限计算约为5%。
