以再生水为补水的景观水体水华爆发特征调查和药剂应急控藻效果评价

Algal bloom investigation and control evaluation through algaecides in recreational water bodies supplemented by reclaimed water

采用现场调查和实验室验证的方法,对以再生水为景观补水的水华优势藻进行了分析。2年的现场调查表明,再生水在条件适合时极易发生水华,且水华的优势藻以小球藻为主。在实验室针对小球藻和铜绿微囊藻进行了竞争生长实验研究,在再生水的氮磷浓度范围内小球藻生长快于铜绿微囊藻,这也验证了再生水作为景观水补水时小球藻是优势藻现场调查结论。针对水华爆发初期和水华爆发验证时2种条件,比较研究了4种以化学成分为主的抑藻药剂对以小球藻为水华特征藻的控藻效果。结果表明,这4种药剂对水华的控制均具有一定的效果,并且水华初期实施药剂抑藻,药剂投加少,且效果好。对4种药剂进行急性毒性实验,只有S2一种药剂在安全浓度时对水华爆发初期有抑藻效果。

Combined site investigation and laboratory test, the algal bloom and its dominant alga species were analyzed in recreational or ornamental water use that the makeup water is from reclaimed water. Conducting two year site investigation, the results showed that the recreational or ornamental pond break out algal bloom easi- ly when the favorable conditions are available such as light, temperature and nutrient, etc, and the dominant al- ga is Chlorella vugaris. For further verifying the results in site investigation, the competitive growth test was made between Chlorella vugaris and Microcystis aeruginosa through the algal growth potential under different TN and TP concentrations that coined with the scope of reclaimed water effluent. The lab test showed that the propagation speed of Chlorella vugaris was faster than Microcystis aeruginosa＇ s, which is same as the results in site investiga- tion. To inhibit algal bloom with dominant Chlorella vugaris, four different chemical algaecides were selected, i. e. S1, S2, S3 and S4. The inhibiting abilities of the four algaecides were evaluated in the initial algal bloom outbreak （algal density： l07 cells/L or so） and after algal bloom outbreak （algal density： 109 cells/L or so）. It is found that the four algaecides all had a certain inhibition on algal bloom with different dosage levels. After a- cute toxicity tests of four algaecides, S2 showed better inhibiting algal bloom in initial algal bloom outbreak with safe level.