Chi Jie, Gao Jing
School of Environmental Science and Engineering, Tianjin University, Tianjin 300072, China.
Chemosphere. 2015 Jan;119:59-64. doi: 10.1016/j.chemosphere.2014.05.058. Epub 2014 Jun 24.
To investigate the mechanism of submerged macrophyte-bacteria interactions on the removal of phthalic acid esters from surface water, experiments with and without Potamogeton crispus L. were performed. A two-compartment (i.e., water and plant) kinetic model was developed. The model adequately described the variation of dibutyl phthalate (DBP) and di-2-ethylhexyl phthalate (DEHP) in the plant-water system by providing the first-order rate constants of plant uptake (k1) and release (k2), microbial degradation in water (k3) and plant degradation (k4). During 10-d incubation, the presence of P. crispus enhanced the removal of DBP and DEHP from water by 6.3% and 22.4%. Compared with the experiment without P. crispus, biodegradation of DBP in water with P. crispus decreased by 8.3% because of plant uptake even though k3 increased by 30%. 21.4% of DBP transferred from water to plants, of which only small amount (5.1%) retained in the plant and the rest (94.9%) was degraded. Different from DBP, biodegradation of DEHP in water with P. crispus was a slightly higher than that without P. crispus. 25.5% of DEHP transferred from water to plants, of which a large portion (73.3%) retained in the plant and the rest (26.7%) was degraded. This finding reveals that the enhancement of DBP removal from surface water is mainly related to faster degradation in the plant, whereas it is mainly related to higher plant accumulation for DEHP.
为研究沉水植物与细菌相互作用对去除地表水中邻苯二甲酸酯的机制，进行了有无菹草参与的实验。建立了一个双室（即水和植物）动力学模型。该模型通过给出植物吸收（k1）和释放（k2）、水中微生物降解（k3）以及植物降解（k4）的一级速率常数，充分描述了植物 - 水系统中邻苯二甲酸二丁酯（DBP）和邻苯二甲酸二（2 - 乙基己基）酯（DEHP）的变化情况。在10天的培养期间，菹草的存在使水中DBP和DEHP的去除率分别提高了6.3%和22.4%。与无菹草的实验相比，有菹草时水中DBP的生物降解由于植物吸收而降低了8.3%，尽管k3增加了30%。21.4%的DBP从水转移到植物中，其中只有少量（5.1%）保留在植物中，其余（94.9%）被降解。与DBP不同，有菹草时水中DEHP的生物降解略高于无菹草时。25.5%的DEHP从水转移到植物中，其中一大部分（73.3%）保留在植物中，其余（26.7%）被降解。这一发现表明，从地表水中去除DBP的增强主要与植物中更快的降解有关，而对于DEHP则主要与更高的植物积累有关。
