少根紫萍对湿地污染水体的修复研究

A Study of the Remediation of Wetland Waste Water by Spirodela punctata

大量含氮、磷的污水未经处理直接排放到当地河流湖泊等自然水体中,导致湿地环境越来越恶劣,水体富营养化程度加剧,对污染水体的修复已迫在眉睫。本实验以1/5的Hoagland溶液为培养液,设置0 mL·L^-1、20 mL·L^-1、40 mL·L^-1、80 mL·L^-1、160 mL·L^-1五个铜绿微囊藻接种浓度梯度与0 mg·m^-2、100 mg·m^-2、200 mg·m^-2、400 mg·m^-2、800 mg·m^-2 5个少根紫萍接种浓度梯度进行双因素正交试验。结果发现,在0~15 d内,所有少根紫萍接种浓度和铜绿微囊藻接种浓度处理下,水体中总氮(TN)、磷(TP)含量随着接种时间的增加而降低,且铜绿微囊藻和少根紫萍共培养比各自单独培养对污染水体具有更好的修复效果。15d后测定培养液中藻毒素和少根紫萍体内藻毒素含量,结果表明少根紫萍可有效吸收培养液中的藻毒素。以上结果表明,低浓度铜绿微囊藻可促进少根紫萍生长,高浓度铜绿微囊藻抑制少根紫萍生长,少根紫萍可有效吸收培养液中的TN、TP和藻毒素。在铜绿微囊藻浓度为20 mL·L^-1、少根紫萍接种浓度为400 mg·m^-2时,浮萍生长状况最好,对培养液中TN、TP及藻毒素的去除率也达到最高。综上所述,低浓度铜绿微囊藻和100%覆盖率的少根紫萍共培养用于湿地水体修复具有良好的修复效果。

A large amount of sewage containing nitrogen and phosphorus was directly discharged without treatment into natural water such as rivers and lakes,resulting in an increasing harsh situation of wetlands and an increasing degree of eutrophication of water bodies.So it was imminent to repair the polluted water and recover the environment.In this experiment,0 mL·L^-1,20 mL·L^-1,40 mL·L^-1,80 mL·L^-1,160 mL·L^-1 of Microcystis aeruginosa were co-cultured with 0,100,200,400 and 800 mg·m^-2 of Spirodela punctata in 1/5 Hoagland culture medium.The above-mentioned Microcystis aeruginosa and S.punctata were subjected to the two-factor orthogonal test.The results showed that the total nitrogen(TN) and phosphorus(TP) contents in the culture medium of all Microcystis aeruginosa concentration decreased in 0~15 days with the increase of time.Co-culture of M.aeruginosa and S.punctata had better repairing effect on polluted water than that in their respective cultures.After 15 days,the microcystin content in the culture was determined,which showed that the S.punctata was effective for absorbing the TN,TP and amicrocystin in the culture.To sum up,the concentration of S.punctata was 400 mg·m^-2,the growth reached its maximum value,removal rates(%) of TN,TP and microcystin in the culture medium were also up to the highest.Therefore,it was concluded that the low concentration of M.aeruginosa and 100% coverage of S.punctata had a potential effect on wetland water repairing.