青萍生长特征及其对受污染河水的修复效果

以浮萍优势品种青萍（Lemna minor）为研究对象,开展受污染河水修复。分析了青萍在不同营养盐浓度条件下的生长特征,探讨了青萍对受污染河水的修复效果。在表面积为0.0095 m2的限制空间条件下,青萍在1、2和5 mg总氮（TN）/L营养液中的生长特征都能较好地服从Logistic生长模型,受制约的临界鲜重（FW）分别为1.20、1.36和1.36 g;青萍对受污染河水中氮磷污染物具有较好的去除效果,氨氮（NH＋4-N）的平均去除率、平均去除量和平均去除速率分别为56.87%、1.22 mg/d和0.0466 mg/（g FW·h）,正磷酸盐（PO3-4-P）的平均去除率、平均去除量和平均去除速率分别为66.95%、0.25 mg/d和0.0088 mg/（g FW·h）。根据相关性分析,进水NH＋4-N和PO3-4-P浓度与其对应去除量之间极显著相关;青萍FW与NH＋4-N去除速率之间显著负相关,但与PO3-4-P去除速率之间不存在显著相关性;NH＋4-N进水浓度与去除速率相关性不显著,但PO3-4-P进水浓度与去除速率显著正相关。

Growth characteristics and purification efficiencies of Lemna minor to polluted river water

As an advantage variety of duckweed,Lemna minor was used to purify polluted river water.Growth characteristics under different nutrient concentrations were analyzed,and the purification efficiencies to polluted river water were investigated.Cultured with 1,2 and 5 mg / L total nitrogen（TN） concentrations,the growth characteristics of L.minor could be well illustrated with the Logistic growth model,and the restricted fresh weight（FW） of L.minor were 1.20,1.36 and 1.36 g,respectively,when the growth space was limited to 0.0095 m2.L.minor had acceptable removal abilities to nitrogen and phosphorus pollutants.The average removal rate,average removal quantity and average removal velocity to ammonium（NH＋ 4-N） were 56.87%,1.22 mg / d and 0.0466 mg /（g FW·h）,respectively,and those were 66.95%,0.25 mg / d and 0.0088 mg /（g FW ·h） to orthophosphate（PO3 4-P）.According to the results of correlation analyses,extremely significant positive correlations between influent concentration and removal quantity to NH＋ 4-N and PO3 4-P were observed in this study.The FW was significant negative correlated with removal velocity of NH＋ 4-N,but insignificant correlated with the removal velocity of PO3 4-P.The relationship between influent concentration and removal velocity was insignificant to NH＋ 4-N,which was significant positive to PO3 4-P.