Liang Y, Wong M H
Department of Biology, Institute for Natural Resources and Environmental Management, Hong Kong Baptist University, Kowloon Tong, Hong Kong, PR China.
Chemosphere. 2003 Sep;52(9):1647-58. doi: 10.1016/S0045-6535(03)00505-8.
An intensive monthly sampling of water and sediments from 12 sites over 8 months covering wet and dry seasons at Mai Po Marshes Nature Reserve was conducted during June 1997-February 1998. Major organic (C, N and P) and heavy metal pollutants (Cd, Cr, Cu, Ni, Pb, Zn) water and sediment samples were examined. The results showed that Mai Po Marshes were severely polluted by organic matter and heavy metals, and the water from Deep Bay appeared to be the source of pollution. Up to 13-55% chance that the sediments of Mai Po Marshes were classified as moderately to seriously metal contaminated materials, according to the guideline set by Hong Kong Government. Empirical models describing organic matter and heavy metal spatial and seasonal dynamics in the water and sediments were formulated, based on data analysis. During wet season (June-October), more than 58% variations of total P can be explained by ortho-P in water, while ammonia-N explained up to 90% variations of total Kjeldahl nitrogen in water. Throughout the whole sampling period (June-February), there were significant correlations (p<0.01) between total organic C in water. pH in the sediments and salinity in water appeared to be important factors determining heavy metal mobility in sediments, while potential metal release from the sediments is a concern when any oxidizing processes such as flooding or dredging are imposed on sediments.
1997年6月至1998年2月期间，在米埔自然保护区对12个地点进行了为期8个月的密集月度水和沉积物采样，涵盖了雨季和旱季。对水和沉积物样本中的主要有机污染物（碳、氮和磷）以及重金属污染物（镉、铬、铜、镍、铅、锌）进行了检测。结果表明，米埔沼泽受到有机物和重金属的严重污染，后海湾的水似乎是污染源。根据香港政府制定的指导方针，米埔沼泽沉积物被归类为中度至重度金属污染物质的可能性高达13%-55%。基于数据分析，建立了描述水和沉积物中有机物和重金属空间及季节动态的经验模型。在雨季（6月至10月），水中总磷超过58%的变化可由正磷酸盐解释，而氨氮可解释水中凯氏氮总量高达90%的变化。在整个采样期（6月至2月），水中总有机碳之间存在显著相关性（p<0.01）。沉积物中的pH值和水中的盐度似乎是决定沉积物中重金属迁移率的重要因素，而当对沉积物施加诸如洪水或疏浚等任何氧化过程时，沉积物中潜在的金属释放是一个令人担忧的问题。
