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811.
812.
表面活性剂在生物修复海洋油污染中的应用及发展 总被引:2,自引:0,他引:2
生物修复法是治理海洋油污染的主要途径。它通常采用投加表面活性剂,投加外源微生物以及投加氮磷营养源三种方式,其中投加表面活性剂在应用中存在较大分歧。本文从结构及其作用机理的角度重点探讨了表面活性剂尤其是生物表面活性剂在生物修复海洋油污染中的应用,指出生物表面活性剂的应用是未来主要发展方向,提出其应用方面存在的问题。 相似文献
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Takemitsu?ArakakiEmail author Hiroyuki?Fujimura Asha?Mansour?Hamdun Kouichirou?Okada Hiroaki?Kondo Tamotsu?Oomori Akira?Tanahara Hatsuo?Taira 《Journal of Oceanography》2005,61(3):561-568
The northern part of Okinawa Island suffers from red soil pollution—runoff of red soil into coastal seawater—which damages coastal ecosystems and scenery. To elucidate the impacts of red soil pollution on the oxidizing power of seawater, hydrogen peroxide (HOOH) and iron species including Fe(II) and total iron (Fe(tot), defined as the sum of Fe(II) and Fe(III)) were measured simultaneously in seawater from Taira Bay (red-soil-polluted sea) and Sesoko Island (unpolluted sea), off the northern part of Okinawa Island, Japan. We performed simultaneous measurements of HOOH and Fe(II) because the reaction between HOOH and Fe(II) forms hydroxyl radical (•OH), the most potent environmental oxidant. Gas-phase HOOH concentrations were also measured to better understand the sources of HOOH in seawater. Both HOOH and Fe(II) in seawater showed a clear diurnal variation, i.e. higher in the daytime and lower at night, while Fe(tot) concentrations were relatively constant throughout the sampling period. Fe(II) and Fe(tot) concentrations were approximately 58% and 19% higher in red-soil-polluted seawater than in unpolluted seawater. Gas-phase HOOH and seawater HOOH concentrations were comparable at both sampling sites, ranging from 1.4 to 5.4 ppbv in air and 30 to 160 nM in seawater. Since Fe(II) concentrations were higher in red-soil-polluted seawater while concentrations of HOOH were similar, •OH would form faster in red-soil-polluted seawater than in unpolluted seawater. Since the major scavenger of •OH, Br−, is expected to have similar concentrations at both sites, red-soil-polluted seawater is expected to have higher steady-state •OH concentrations. 相似文献
816.
Nutrient contributions to the Santa Barbara Channel, California, from the ephemeral Santa Clara River 总被引:2,自引:0,他引:2
Jonathan A. Warrick Libe Washburn Mark A. Brzezinski Dave A. Siegel 《Estuarine, Coastal and Shelf Science》2005,62(4):559-574
The Santa Clara River delivers nutrient rich runoff to the eastern Santa Barbara Channel during brief (1–3 day) episodic events. Using both river and oceanographic measurements, we evaluate river loading and dispersal of dissolved macronutrients (silicate, inorganic N and P) and comment on the biological implications of these nutrient contributions. Both river and ocean observations suggest that river nutrient concentrations are inversely related to river flow rates. Land use is suggested to influence these concentrations, since runoff from a subwatershed with substantial agriculture and urban areas had much higher nitrate than runoff from a wooded subwatershed. During runoff events, river nutrients were observed to conservatively mix into the buoyant, surface plume immediately seaward of the Santa Clara River mouth. Dispersal of these river nutrients extended 10s of km into the channel. Growth of phytoplankton and nutrient uptake was low during our observations (1–3 days following runoff), presumably due to the very low light levels resulting from high turbidity. However, nutrient quality of runoff (Si:N:P = 16:5:1) was found to be significantly different than upwelling inputs (13:10:1), which may influence different algal responses once sediments settle. Evaluation of total river nitrate loads suggests that most of the annual river nutrient fluxes to the ocean occur during the brief winter flooding events. Wet winters (such as El Niño) contribute nutrients at rates approximately an order-of-magnitude greater than “average” winters. Although total river nitrate delivery is considerably less than that supplied by upwelling, the timing and location of these types of events are very different, with river discharge (upwelling) occurring predominantly in the winter (summer) and in the eastern (western) channel. 相似文献
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Global change models predict effects of climate change on hydrological regimes at the continental scale in Europe. The aim of this study was to gain a better understanding of the possible effect of changing external forcing conditions on the functioning of estuarine ecosystems. In densely populated areas, anthropogenic nutrient enrichment and consequent alteration of nutrient biogeochemical cycles have already had a big impact on these ecosystems. The average yearly discharge of the upper Schelde estuary increased nearly threefold over the period 1996–2000, from 28 m3 s−1 in 1996 to 73 m3 s−1 in 2000. The continuously rising discharge conditions over the five-year period were used as a reference situation for possible future effects of climate on ecological functioning through increase of discharge. At high discharges, nutrient (NH4+, NO3−, dissolved silica and PO43−) concentrations in the tidal fresh- and brackish water showed a decrease of up to 50% while total discharged nutrient loadings increased up to 100%. Opposite effects of increasing discharge on NH4+, NO3− and dissolved silica concentrations in summer and winter, resulted in the flattening out of seasonal cycles for these nutrients. Under high discharge conditions, silica uptake by diatom communities was lowered. Dissolved silica loadings to the coastal area increased concurrently with total silica loadings upstream. Salt intrusion to the marine parts of the estuary decreased. This resulted in a downstream shift of the salinity gradient, with lower salinity observed near the mouth. As a result, TDIN, NO3− and dissolved silica concentrations doubled at the mouth of the estuary. 相似文献
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江苏王港潮滩重金属Pb、Zn和Cu的累积规律 总被引:1,自引:0,他引:1
对15年来江苏王港潮滩重金属Pb、Zn和Cu积累规律研究表明,王港潮滩WG05点位现代平均沉积速率为4.13 cm/a。王港潮间带重金属垂直方向的含量具有趋同性,从表层向下逐步降低,具有明显的表聚和亚表聚特征,王港潮滩Fe与Li的相关系数非常显著,超过了0.90,这些潮滩重金属来自岩石风化的可能性较大;Pb、Cu、Al则与铁元素呈负相关,表明王港潮滩沉积物中的重金属Pb、Cu的含量受人为因素的影响较大。归一化后,Cu、Zn的归一化值在15年内相当稳定,其中Cu的波动范围在0.4~2之间,Zn在1.5~2.6之间狭小的范围内波动;这说明王港潮滩的Cu、Zn积累主要来自于地壳风化,受物源和沉积环境等自然因素控制较大,受人类活动影响较小。而Pb归一化以后在4个柱状样中都表现出随时间的变化发生了较大的波动。Pb、Cu为该区域的主要污染因子。 相似文献