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11.
Distribution and spectral characteristics of chromophoric dissolved organic matter in a coastal bay in northern China 总被引:1,自引:0,他引:1
Guiju Li Jing Liu Yulan M Ruihua Zhao Suzheng Hu Yijie Li Hao Wei Huixiang Xie 《环境科学学报(英文版)》2014,26(8):1585-1596
The absorption spectra of chromophoric dissolved organic matter(CDOM),along with general physical,chemical and biological variables,were determined in the Bohai Bay,China,in the springs of 2011 and 2012. The absorption coefficient of CDOM at 350 nm(a350) in surface water ranged from 1.00 to 1.83 m-1(mean: 1.35 m-1) in May 2011 and from 0.78 to 1.92 m-1(mean:1.19 m-1) in April 2012. Little surface-bottom difference was observed due to strong vertical mixing. The a350 was weakly anti-correlated to salinity but positively correlated to chlorophyll a(Chl-a) concentration. A shoulder over 260–290 nm,suggestive of biogenic molecules,superimposed the overall pattern of exponentially decreasing CDOM absorption with wavelength. The wavelength distribution of the absorption spectral slope manifested a pronounced peak at ca. 300 nm characteristic of algal-derived CDOM. All a250/a365 ratios exceeded 6,corresponding to CDOM molecular weights(Mw) of less than 1 kDa. Spectroscopically,CDOM in the Bohai Bay differed substantively from that in the Haihe River,the bay's dominant source of land runoff; photobleaching of the riverine CDOM enlarged the difference.Results point to marine biological production being the principal source of CDOM in the Bohai Bay during the sampling seasons. Relatively low runoff,fast dilution,and selective photodegradation are postulated to be among the overarching elements responsible for the lack of terrigenous CDOM signature in the bay water. 相似文献
12.
耐酸厌氧消化污泥处理餐厨垃圾 总被引:1,自引:0,他引:1
采用耐酸驯化的厌氧消化污泥处理餐厨垃圾,在酸性条件下(pH=4.5),对实验装置容积负荷从1.0kgVS/(m3·d)分9次逐级增加到5.0kgVS/(m3·d)的过程进行了跟踪监测,并较深入地研究了驯化污泥代谢活性和处理效果。实验结果表明,pH4.5的耐酸厌氧消化污泥,最佳投加负荷约为4.5kgVS/(m3·d),此负荷下容积产气率,CH4含量平均值均达最大,分别为1.68m3/(m3·d),75.0%。耐酸厌氧消化装置持续增料运行46d,产甲烷菌仍能保持较高的活性,其COD去除率范围为40.4%-75.0%,仍能保持pH7.2时处理效果的65.0%-91.8%,表明在低pH、低碱度下实现稳定的产甲烷过程是可行的。 相似文献
13.
采用耐酸驯化的厌氧消化污泥处理餐厨垃圾,在酸性条件下(pH=4.5),对实验装置容积负荷从1.0 kg VS/(m3·d)分9次逐级增加到5.0 kg VS/(m3·d)的过程进行了跟踪监测,并较深入地研究了驯化污泥代谢活性和处理效果。实验结果表明,pH 4.5的耐酸厌氧消化污泥,最佳投加负荷约为4.5 kg VS/(m3·d),此负荷下容积产气率,CH4含量平均值均达最大,分别为1.68 m3/(m3·d),75.0%。耐酸厌氧消化装置持续增料运行46 d,产甲烷菌仍能保持较高的活性,其COD去除率范围为40.4%~75.0%,仍能保持pH 7.2时处理效果的65.0%~91.8%,表明在低pH、低碱度下实现稳定的产甲烷过程是可行的。 相似文献
14.
海洋环境地球化学——Ⅳ.胶州湾娄山河口海域铬迁移转化规律研究 总被引:1,自引:0,他引:1
本文对排放入胶州湾中铬的主要污染源——娄山河河口海域及上游工业废水中铬的迁移形态特征及其转化;废水及河口海域海水中六价铬向三价铬的转变及其速率以及河口海域海水中三价铬向底质的迁移及其影响因素等地球化学过程进行了现场调查和室内模拟实验。实验结果进一步证实了胶州湾娄山河口及沿岸海域中铬的可能的迁移机制为Cr_水~(VI)→Cr_水~(Ⅲ)→Cr_水~(悬)→Cr_(底质~(酸溶)→Cr_(底质)~总,并为这一过程作了定量估算,提出了胶州湾娄山河口海域铬的迁移模式图。 相似文献
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