中文摘要：

为了探讨不同pH条件下水葫芦与紫根水葫芦生长特性与净化效能的差异，以滇池草海原水为实验用水，利用HCl和NaOH稀溶液调节水体pH，设置3个pH处理，分别是8．00、9．50和11．00，开展了为期30d（重复3个周期）的静态模拟实验，结果表明，在实验条件下，pH过高会对水葫芦和紫根水葫芦的生长发育产生抑制作用，紫根水葫芦受到的抑制效果更为明显；水葫芦和紫根水葫芦的生长也会使水体pH降低至接近中性，水葫芦调节水体pH的能力更强；pH为8．00、9．50时，水葫芦和紫根水葫芦对水体氮磷污染物具有净化作用，水葫芦的净化能力更强；pH为11．00时，水葫芦和紫根水葫芦处理的水体氮磷浓度均表现起伏，表示在高碱度条件下，两者的净化能力减弱。

英文摘要：

In order to discuss the difference of grow characteristics and purification efficiency of water hya- cinth and water hyacinth with purple root under the conditions of different pH, a 30-day static simulation experi- ment with three cycles was carried out. The experimental water was taken from Caohai of the Dianchi Lake and pH values of the water were adjusted to 8.00, 9.50 or 11.00 by the dilute solution of HC1 or NaOH. Results showed that the growth and development of water hyacinth were inhibited and water hyacinth with purple root was significant inhibited at too high pH value, while the pH values of water decreased close to neutral with the growth of the two plants and water hyacinth had more powerful capability of adjusting pH. At pH 8.00 and pH 9.50, the two plants could purify the pollution of N and P in water and purification capability of water hyacinth was stronger. At pH 11.00, the concentrations of N and P in water of the two plants treatments showed fluctuation, while indicated purification capability of the two plants was limited at too high pH value.