造纸废水对离体鱼头呼吸运动的影响

EFFECT OF WASTE WATER OF PAPER MILLS ON THE RESPIRATORY MOVEMENT OF THE ISOLATED FISH'S HEAD

本文采用离体鱼头灌注法,以两个造纸厂的制浆造纸废水对147个鲤鱼头进行了人工灌流。结果表明:废水在低浓度(如4%以下)体积稀释液时,鱼头呼吸速率基本未产生影响,而以较高浓度的废水(如5%以上)稀释液灌流与不含废水的鸭绿江水源地水灌流的对照组鱼头比较,几乎均发生了显著性变化,即对鱼鳃盖运动产生了抑制作用,出现了Biot氏呼吸。以往学者们认为,造纸废水主要是由于水中溶解氧(DO)减少而使鱼类致死的,但本工作灌注液中已人工给予足够的DO,提示:有毒物质本身似已直接危及延髓呼吸中枢。 实验同时表明,离体鱼头灌注法可供环境保护部门应用于含多种有机毒性物质的制浆造纸废水的现场监测。

By means of the improved method of perfusing isolated fish's head, 147 carp's heads were perfused with the waste water of different concentration of the Yalujiang Paper Mill (YPM) and the Dandong Paper Mill (DPM). The results were that the respiratory frequency was not affected as the waste water concentration of YPM was less than 4 % (waste water (V) /physiological perfusing liquid of carp), and it was obviously inhibited as the waste water concentration was more tnan 5%. The waste water of DPM gave a similar result.The control test was done with 10% water of upper reaches of Yalujiang river, and it didn't result in affection on the respiratory frequency of isolated fish's head.Predecessors reported that discharge of the waste water of paper mill poisoned fish because the dissolved oxygen (DO) in the water decreased that affected the fish rather than the toxicant itself in the waste water. In our study, the perfusing liquid had enough DO (10mg/l), however, appearance of Biot's respiration and the inhibited respiration occurred that the toxicant action had effect on the respiratory center of medulla oblongata. According to predecessors' report and our previous work that indicated that the phenol at very low concentration (0. 005 ppm) seriously inhibited respiration of isolated fish's head, and the waste water of YPM had 3. 6 ppm phenol and DPM 22. 84 ppm, so the toxicant of waste water of paper mill was also the reason for poisoning fish. Our result suggests a suspicion of the sole reason of fish poisoning i. e. lack of DO. , and it needs to be further studied.