Seasonal oxygen, nitrogen and phosphorus benthic cycling along an impacted Baltic Sea estuary: regulation and spatial patterns
Seasonal oxygen, nitrogen and phosphorus benthic cycling along an impacted Baltic Sea estuary: regulation and spatial patterns
复制标题
DOI：
10.1007/s10533-014-9953-6
复制
发表时间：
2014-06-01
期刊：
影响因子：
4
通讯作者：
Bruchert, V.
中科院分区：
文献类型：
--
作者：
Bonaglia, S.;Deutsch, B.;Bruchert, V.
研究了温度、富营养化和氧的有效性对沿着波罗的海河口污水处理后氮（N）循环和再生氮磷（P）化学计量的调控作用。沉积物反硝化，厌氧氨氧化，异化硝酸盐还原铵（DNRA），营养交换，氧（O-2）的吸收和渗透率进行了季节性测量。不受污水处理厂（STP）释放的营养羽的影响的沉积物表现出很强的季节性的O-2吸收率和耦合硝化反硝化，厌氧氨氧化从来没有占总二氮（N-2）生产的20%以上。氮循环在沉积物中接近STP是高度依赖于氧的可用性，这掩盖了温度相关的影响。这些沉积物从低氮损失和高铵（NH 4（+））流出缺氧条件下，在秋季，到一个主要的氮损失系统在冬季时，沉积物表面被氧化。在秋季，DNRA作为主要的硝酸盐（NO3（-））还原途径取代了反硝化作用，导致氮的再循环和富营养化的潜在蔓延。与历史记录的营养盐排放和反硝化作用的比较表明，在河口的总氮损失已紧密耦合的营养盐排放量从STP。溶解无机氮（DIN）从STP释放的变化同意以及沉积N-2去除的变化。这表明，反硝化和厌氧氨氧化有效地抵消了氮负荷在整个范围内的河口的历史和现今的人为营养物排放。整体较低的N/P比的再生营养通量施加强N限制的远洋系统，并产生高的潜在滋扰蓝藻水华。
The regulatory roles of temperature, eutrophication and oxygen availability on benthic nitrogen (N) cycling and the stoichiometry of regenerated nitrogen and phosphorus (P) were explored along a Baltic Sea estuary affected by treated sewage discharge. Rates of sediment denitrification, anammox, dissimilatory nitrate reduction to ammonium (DNRA), nutrient exchange, oxygen (O-2) uptake and penetration were measured seasonally. Sediments not affected by the nutrient plume released by the sewage treatment plant (STP) showed a strong seasonality in rates of O-2 uptake and coupled nitrification-denitrification, with anammox never accounting for more than 20 % of the total dinitrogen (N-2) production. N cycling in sediments close to the STP was highly dependent on oxygen availability, which masked temperature-related effects. These sediments switched from low N loss and high ammonium (NH4 (+)) efflux under hypoxic conditions in the fall, to a major N loss system in the winter when the sediment surface was oxidized. In the fall DNRA outcompeted denitrification as the main nitrate (NO3 (-)) reduction pathway, resulting in N recycling and potential spreading of eutrophication. A comparison with historical records of nutrient discharge and denitrification indicated that the total N loss in the estuary has been tightly coupled to the total amount of nutrient discharge from the STP. Changes in dissolved inorganic nitrogen (DIN) released from the STP agreed well with variations in sedimentary N-2 removal. This indicates that denitrification and anammox efficiently counterbalance N loading in the estuary across the range of historical and present-day anthropogenic nutrient discharge. Overall low N/P ratios of the regenerated nutrient fluxes impose strong N limitation for the pelagic system and generate a high potential for nuisance cyanobacterial blooms.