广州市流花湖表层底泥磷的形态与生物可利用性

应用经改进的Psenner连续提取法对广州市流花湖表层底泥中的磷进行了连续提取和测定。结果表明,流花湖底泥中总磷含量在1.28~2.15 mg/g,流花湖总磷含量最高在L2点,最低在L3点。湖泊表层底泥总磷主要由金属氧化物结合态磷、有机磷和钙结合态磷组成,可还原态磷和弱吸附态磷仅占很少部分。不同形态磷的含量顺序是金属氧化物结合态磷NaOH-P>有机磷Org-P>钙结合态磷HCl-P>可还原态磷BD-P>弱吸附态磷NH4Cl-P。底泥中生物可利用性磷的含量达0.76~1.00 mg/g,平均含量为0.91 mg/g,占总磷的45.47%~64.71%。说明流花湖底泥的磷有较好的生物可利用性,将为水体藻类大量繁殖提供潜在的有利条件,因此在湖泊治理恢复过程中,应该采样有效的措施来控制底泥磷的内源释放。

Characteristics and Fractionation of Phosphorus in the Sediments of Lake Liuhuahu in Guangzhou

The forms of phosphorus in the surface sediments of lake Liuhuahu in Guangzhou,Guangdong Province,China were investigated by sequential chemical extraction according to the improved scheme proposed by Psenner.The results showed that the contents of total phosphorus forms in the surfaces sediments ranged from 1.28?mg/g to 2.15?mg/g in lake Liuhuahu.The total sediment phosphorus consisted mainly of NaOH-P,OrgP and HCl-P.The concentration of different phosphorus forms followed the order: NaOH-P > Org-P > HCl-P > BD-P > NH_4Cl-P.Moreover,the bio-available phosphorus(BAP) contents ranged from 0.79?mg/g to 1.00?mg/g,and the average value was(0.91)(mg/g).Therefore,the potential phosphorus released from sediments to the overlying water and the availability of phosphorus for algal uptake in sediments of lake Liuhuahu were high.The effective methods should be taken to control phosphorus release from the sediments during the lake restoration.