污泥干化芦苇床芦苇中多环芳烃的含量分布

通过现场试验,考查了多环芳烃（PAHs）从污泥向芦苇的转移以及PAHs在芦苇各部位的分布情况。受试芦苇植于污泥干化芦苇床内,芦苇床规格3m×1m×1.3m,其中高度含0.65m填料层和0.65m超高。试验进行了3a,包括2a的污泥负荷期和1a的闲置期。2a负荷期内共进泥8.4m（含水率99.14%）,污泥PAHs含量平均5.69mg·kg-1。原生芦苇茎和叶中的PAHs含量相对较高,达到2.198和2.583mg·kg-1（DW）,分别是芦苇根PAHs含量的2.44和2.87倍,且以低环PAHs为主。运行结果表明,受试芦苇对污泥中的PAHs产生了明显的富集作用。运行第2年9、10和11月取污泥干化芦苇床芦苇样品并进行检测,发现芦苇根茎叶内PAHs含量呈逐月升高趋势;第3年11月芦苇根茎叶所含PAHs总量分别为7.642、7.713、7.946mg·kg-1（DW）,相对原生芦苇分别提高了8.50、3.52和3.08倍,且以低环PAHs为主,根茎叶低环PAHs含量占PAHs总量的55.14%、56.96%和44.59%。芦苇中PAHs的含量与植物含脂率具有显著的正相关关系,而与芦苇的含水量无关。

Distribution of PAHs in Phragmites australis in Sludge Drying Reed Bed

The transfer of polycyclic aromatic hydrocarbons （PAHs） from sewage sludge to Phragmites australls and the distribution of PAHs in Phragmites australis were investigated in a field experiment. Tested phragmites australis were planted in a sludge drying reed bed （SDRB） with the size of 3 m× 1 m× 1.3 m （0.65 m media layer and 0.65 m extra height）. The experiment lasted three years including two years＇ sludge loading and one year＇s resting period. Totally 8. 4 meters surplus activatied sludge with 99.14% of moisture content wa~ feed into the SDRB during loading time, and raw sludge contained 5.69 mg/kg （DW） of total PAHs. Native Phragmites australis contain higher PAHs in the stems and leaves, averaged 2. 198 and 2. 583 mg/kg （DW） which are 2.44 and 2.87 times of that in the roots, respectively. The results showed that Phragmites australis accumulated PAHs from sludge obviously. Lower molecular weight PAHs are the dominant contents in which of Phragmites australis. According to the experimental results in September, October and November of the second year, the PAHs contents in the roots, stems and leaves of tested Phragmites australis have the trend of increasing with plant growing time; the total PAHs in the roots, stems and leaves are averaged 7. 642, 7. 713 and 7.946 mg/ kg （DW） in November of the third year, which are 8.5, 3.52 and 3.08 times of that in native ones, and also lowermolecular weight PAHs are dominant with the percentages of 55.14%, 56.96% and 44.59%, respectively. PAHs contents in Phragmites australis are observed to be significant positive relations with their coarse fat contents and have no relationship with lipid percentages.