北运河下游典型灌渠沉积物有机磷形态分布特征

采用Bowman-Cole有机磷分级修正体系,分析了北运河下游典型灌渠泗村店干渠上游至下游7个采样区柱状沉积物中有机磷的赋存形态、分布及其垂向变化特征.结果表明,干渠沉积物总磷(TP)平均含量介于654.9～1 285.4 mg.kg-1,有机磷(TOP)平均含量则为241.6～501.1 mg.kg-1,占TP的34.08%～41.86%,TOP/TP较其他区域明显偏高.垂直分布上看,不同形态有机磷变化趋势迥异,活性有机磷(LOP)随着深度的变化呈先递增后递减的趋势,中活性有机磷(MLOP)则呈逐渐减少趋势,而稳性有机磷(NOP)却变化不大.MLOP是TOP的主要存在形态(39.03%～85.72%),高于LOP(7.73%～24.13%)和NOP(10.14%～35.64%).MLOP是该区域沉积物P的重要储备,其向LOP的转化过程及其对上覆水体富营养化效应值得关注.

Organic Phosphorus Forms in the Sediments in the Downstream Channel of North Canal River Watershed

Bowman-Cole modified organic phosphorus fractionation system was used for the analysis of the phosphorus (P) forms in the sediments in North Canal River. The results showed that the average concentrations variation of total phosphorus (TP), and total organic phosphorus (TOP) in the sediments were 654.9-1285.4 mg x kg(-1) and 241.6-501.1 mg x kg(-1), respectively. TOP accounted for 34.08%-41.86% of TP which was much higher than other regions. The vertical distribution of OP forms changed greatly with the depth in the sediments. Labile organic P (LOP) increased at first (0-10 cm depth) but decreased gradually (10-40 cm). On the contrary, moderately labile organic P (MLOP) showed a degressive trend and nonlabile organic P (NOP) was no change with the depth. MLOP was the major part of TOP which was about 39.03%-85.72% of TOP, and was much higher than LOP (7.73%-24.13%) and NOP (10.14%-35.64%). The dynamic of MLOP in the sediments should be attended because it's easy to transform to LOP resulting in a strong influence on the water quality.