Quantitative determination of organic priority pollutants in the composts of sewage sludge with rice straw by gas chromatography coupled with mass spectrometry.
In order to investigate the occurrence and distribution of organic contaminants in the compost of sewage sludge with rice straw, four different composting treatments at a low carbon/nitrogen (C/N) ratio (13:1) were conducted. Thirty semi-volatile organic compounds (SVOCs) listed as priority pollutants by both China and the US Environmental Protection Agency (EPA) were Soxhlet-extracted, separated and analyzed by gas chromatography coupled with mass spectrometry (GC-MS). The results showed that after composting (56 days) most of SVOCs were detected in the final composts. The total concentrations of polycyclic aromatic hydrocarbons (PAHs) and phthalic acid esters ranged from 1.8 to 10 mg/kg dry weight (d.w.) and from 9.8 to 18 mg/kg d.w., respectively, being significantly higher than those of chlorobenzenes and nitroaromatic compounds which were generally less than 1.0 mg/kg d.w. The concentrations and predominant compounds of organic contaminants in the different composts varied, and were affected by their physico-chemical properties and the composting processes. Concentrations of SVOCs in the static aerated composting processes especially intermittently aerated composting treatment were considerably lower than those in the manual-turned composting treatments. Concentrations of organic contaminants especially PAHs and di(2-ethylhexyl) phthalate in the final composts were in agreement with the maximum permissible limits for agricultural purposes proposed by the European Union and by the EPA.
Cai
Quan-Ying
QY
College of Resources and Environment, South China Agricultural University, Guangzhou 510642, China. cai_quanying@yahoo.com
Mo
Ce-Hui
CH
Wu
Qi-Tang
QT
Zeng
Qiao-Yun
QY
Katsoyiannis
Athanasios
A
D002722:Chlorobenzenes / Q000032:analysis; D004785:Environmental Pollutants / Q000032:analysis*; D008401:Gas Chromatography-Mass Spectrometry / Q000379:methods*; D012275:Oryza; D010795:Phthalic Acids / Q000032:analysis; D011083:Polycyclic Compounds / Q000032:analysis; D012722:Sewage / Q000737:chemistry*
D002722:Chlorobenzenes; D004785:Environmental Pollutants; D010795:Phthalic Acids; D011083:Polycyclic Compounds; D012722:Sewage