江苏省太湖水环境综合治理科研课题No.JSZC-G2013-191;江苏省环保厅科研课题No.2012035;国家自然科学青年基金项目No.51208231 Supported by the Program of Lake Tai Protection of Jiangsu ProvinceNo.JSZC-G2013-191,the Program of Environmental Protection Bureau of Jiangsu Province No.2012035 and the National Natural Science Foundation of ChinaNo.51208231