增蓝剂停留时间及对水质和浮游植物影响分析

Retention time and effects on water quality and phytoplankton of water shade agent-True Blue

水体遮光剂能干扰水下光照,抑制藻类生长。为了探讨水体遮光剂-增蓝剂在自然水体的作用情况,对围隔内增蓝剂的停留时间及水质、浮游藻类和沉水植物的变化特征进行分析。结果表明,当围隔水体中增蓝剂浓度为1 mg/L时,5周内其降解超过50%,9周后降解超过95%。与对照组相比,增蓝剂对围隔内总氮、总磷浓度无明显影响,易氧化成分的存在导致CODMn浓度升高至8.60 mg/L,但CODMn浓度随增蓝剂的降解逐步降至7.81 mg/L。在增蓝剂作用下水下光照度衰减明显,水深0.2 m处仅占水表面光强的21.16%,光衰减系数(k)为0.7 m-1。增蓝剂对藻类生长抑制作用明显,抑制率高达56.24%,但对金鱼藻生长无显著影响。

Water shade agents can interfere with underwater light to inhibit the growth of algae. To evaluate the effects of water shade agent-True Blue （TB） on natural waters, the investigations of the TB retention time and changing characteristics of water quality, phytoplankton and submerged plant in enclosures were carried out. The results showed that 1 mg/L concentration of TB had degraded over 50% in 5 weeks, and over 95% after 9 weeks in the enclosure water. Compared with the control groups, there were no obvious effects found on total ni- trogen and total phosphorus concentration by the TB. The permanganate index increased to 8.60 mg/L was caused by the oxidation composition in TB, and permanganate index gradually dropped to 7.81 mg/L along with the degradation of TB. Underwater light intensity attenuated obviously by the affecting of TB, the light intensity in 0.2 m depth was only 21.16% that of the water surface, and the diffuse attenuation coefficient （k） was 0.7 m-1. The growth of algae was obviously inhibited by the TB, which inhibition rate reached 56.24% , and no significant influence on the growth of Ceratophyllum demersum was found.