钦州湾海水中石油烃时空变化特征及其影响因素

Spatiotemporal variations of petroleum hydrocarbon and its influencing factors in seawater of Qinzhou Bay

2009年1月至11月对广西钦州典型养殖海湾-钦州湾海域表层海水石油烃进行了4次采样调查,分析该海域石油烃污染状况,探讨石油烃的时空分布特征及其影响因素。结果表明,钦州湾表层海水石油烃的质量浓度在0.001-0.095 mg/L之间,平均值为0.022 mg/L;季节变化呈现夏季最高,秋、冬季次之,春季最低的特点,夏、冬季海水受到不同程度石油污染,春、秋季均达到国家《海水水质标准》二类标准。水平分布上总体呈现春、秋季节外湾大于内湾,夏、冬季节内湾大于外湾的特征。钦州湾水产养殖活动及陆地径流输入是影响石油烃时空变化的主要因素。春季石油烃的质量浓度与温度和溶解氧等环境因子有着较好的相关性,夏季石油烃和溶解无机磷存在显著正相关。总体上钦州湾海域目前受石油烃污染程度较轻,仍有一定接纳自净能力。

In this study, we conducted four cruises in Qinzhou Bay, a typical aquaculture area in Qinzhou, Guangxi Zhuang Autonomous Region, from January to October 2009, to determine petroleum hydrocarbon（PHC） concentrations, to analyze the PHC pollution status in the surface seawater, and to determine the spatiotemporal variations of PHC and its influencing factors. Our results show that the concentrations of PHC ranged from 0.001？ 0.095 mg/L, with an average of 0.022 mg/L, and the PHC concentrations varied seasonally as follows： summer autumnwinterspring. The seawater of Qinzhou Bay displayed different PHC pollution levels in summer and winter, and seawater quality fell within the national seawater quality standards for the first and second classes of seawater in spring and autumn. The PHC concentration in the outer bay was higher than that in the inner bay in spring and autumn, and vice versa in summer and winter. Aquaculture activities and land runoff were the main factors influencing spatiotemporal variations of PHC in the surface seawater of Qinzhou Bay. The PHC concentration corresponds well with water temperature and with dissolved oxygen in spring, and is positively correlated with dissolved inorganic phosphate in summer. Overall, while Qinzhou Bay is only moderately contaminated with PHC at present, steps could be taken to improve its self-purification ability.