我国主要潮间带沉积物中磷的含量、形态及释放

Phosphorus content,fractionation, and desorption status in the sediments of major Chinese tidal flats

本研究分析了我国12个潮间带表层及柱状样的总磷(TP)含量,发现浙江慈溪以北样品,辽宁辽河口表层样(0.046%土0.013%)及柱样(0.047%±0.015%)和山东青岛的表层样(0.047%±0.009%)及柱样(0.055%±0.008%)为低值区,其余天津汉沽、东营黄河口、江苏盐城、上海崇明东滩和浙江慈溪等北部5地区TP均值在0.063% 0.074%,为沿海12个潮间带中的高值区.慈溪以南,除厦门九龙江口和珠江的表层样和柱样高外(0.051% 0.070%),福州闽江口、广西英罗湾和海南东寨港较低(0.019% 0.041%).北部滩地高值区与沉积物来源以高通量的河流悬浮质输送有关.磷酸钙盐(Ca-P)的含量高值点也出现在北部5地区(4.16 9.56 μmol g^-1).本研究柱样的铁结合态无机磷酸盐(Fe-P)含量低于表层样.Fe-P的高值点位于汉沽、青岛和九龙江口的表层样.通过两次连续和非连续加水培养,发现连续培养中,同一区域TP的释放速率有增有降,九龙江口(0.927土0.312 μmol kg^-1h^-1)释放率远高于其他区域.非连续培养,除了辽河口,其他11个区域TP释放速率显著增加(P<0.01),汉沽释放速率(1.437土0.325 μmol kg^-1h^-1)最高.

This study analyzed the content of total phosphorus (TP) in the sediments of major Chinese tidal flats.It found that the northern flats,separated by the Zhejiang Cixi sampling site,showed low TP content in the surficial and core samples of the Liaoning Liao River delta (0.046%±0.013% surficial,0.047%±0.015% core) and the Shandong Qingdao mud flats (0.047%±0.009%;0.055%±0.008%).The average TP in the rest of the northern flats,such as Tianjin Hangu,the Yellow River delta,Jiangsu Yancheng,Shanghai Chongming Dongtan,and Cixi,varied from 0.051% to 0.070%,the highest level in the 12 tidal flats.Except for the Xiamen Jiulong River and Guangdong Pearl River flats (0.051%?0.070%),the TP content values were found to be lower in the southern flats,especially in Fuzhou Minjiang,Gangxi Yingluo Bay,and Hainan Dongzhaigang (0.019%?0.041%).The high TP in the northern flats can be attributed to fluvial sediments carried by high discharge rivers.At the site of high measured TP values,large amounts of Ca-P also were detected (4.16-9.56 μmol g^-1).The concentration of Fe-P in the core samples was lower than the surficial samples.The tidal flats of Hangu,Qindao and Jiulong River exhibited the highest Fe-P levels.Two consecutive and non-consecutive incubation experiments showed various self-release velocities of TP.In the consecutive incubations,the largest release velocity occurred in the Jiulong River delta (0.927±0.312μmol kg^-1h^-1).The non-consecutive experiments showed a significant increasing trend of TP release velocities in 11 tidal flats,except for the Liao River delta (P<0.01).Among the sites,the Hangu,displayed the highest TP release velocity (1.437±0.325μmol kg^-1h^-1).