不同胁迫条件下芦苇对污染物的去除及其生长响应研究

芦苇是常见的挺水湿地植物,研究其对不同类型的污染环境修复能力以及生长响应具有重要意义.本实验通过模拟受到重金属、富营养化及营养匮乏胁迫的芦苇湿地系统,对芦苇的鲜重变化、污染物去除、根际微生物种类及多样性,以及污染净化与芦苇蒸腾之间的关系进行研究.结果表明,芦苇是一种优良的重金属去除植物,对Mn—Ni—Cu—Zn—Cd复合金属污染的去除比例平均达到77.15%(其中Mn 90.01%,Ni 59.03%,Cu 90.17%,Zn68.37%,Cd 78.16%),总的去除效率达到2.015 mmol m-2d-1(其中Mn 1.001mmol m-2d-1、Ni 0.063 mmol·m-2·d-1、Cu 0.224 mmol·m-2·d-1、Zn 0.718 mmol·m-2·d-1、Cd 0.009 mmol·m-2·d-1);对营养类污染物(TN、NH3-N、TP)的去除比例平均达到27.36%(其中P 17.43%,TN 37.29%,NH3-N 70.08%),对氮—磷的总去除效率达到15.892 mmol·m-2·d-1(其中TN 15.539 mmol·m-2·d-1、TP 0.353 mmol·m-2·d-1,另外对NH3-N的去除效率为10.689 mmol·m-2·d-1);无论是氮、磷还是重金属的去除,都与芦苇蒸腾呈正关联.通过对芦苇根际水样的PCRDGGE分析,发现在不同的胁迫生境中,芦苇根际的优势细菌在种类上差异明显,在多样性指数上也有较大差别:营养匮乏胁迫(蒸馏水培养)生境的多样性指数最高(1.538),富营养化生境处理次之(1.517),重金属胁迫生境最低(1.498).

Study on the Pollutant Removal and Growth Response of Phragmites australis Cultured in Habitats Under Different Stress Conditions

Phragmites australis is a common emergent wetland plant,and research on its ability to repair different types of contaminated environment as well as growth response is of great significance.By way of simulating Phragmites wetland ecosystems under stress of heavy metal pollution,eutrophication and nutrition deficient（distilled water culture）,the fresh weight change of P.australis,the pollutant removal by P.australis,the species and diversity index of rhizosphere bacteria,and the relationship between pollutant removal and Phragmites transpiration were investigated.It was revealed that P.australis was an excellent plant to purify heavy metals.For compound heavy metal contamination,the percentage of heavy metals removal by P.australis averagely reached 77.15%（Mn 90.01%,Ni 59.03%,Cu 90.17%,Zn 68.37%,Cd 78.16%）,the corresponding removal efficiency for the five heavy metals reached 2.015 mmol m-2d-1（Mn 1.001 mmol m-2d-1,Ni 0.063 mmol m-2d-1,Cu 0.224 mmol m-2d-1,Zn 0.718 mmol m-2d-1,Cd 0.009 mmol m-2d-1）.For nutritional pollutant,the percentage of TN,NH 3-N,TP removal by P.australis reached 37.29%,70.08% and 17.43% respectively,and the corresponding removal efficiency for nitrogen and phosphorous reached 15.892 mmol m-2d-1（TN 15.539 mmol m-2d-1,TP 0.353 mmol m-2d-1）,the removal efficiency for NH 3-N reached 10.689 mmol m-2d-1.Either the heavy metal removal or the nitrogen and phosphorous removal were positively related with the transpiration of P.australis. By analyzing the rhizosphere bacteria of P. australis through PCR-DGGE methods,it was revealed that the dominant rhizosphere bacteria species of P. australis showed obvious difference when cultured in habitats with different stress and their diversity indexes varied correspondingly： that of P. australis cultured in nutrition deficient habitat was the highest（1. 538）,followed by that in eutrophication habitat（1. 517）,and then by heavy metal contaminated habitat（1. 498）.