Modelling nitrogen and phosphorus cycles and dissolved oxygen in the Zhujiang Estuary Ⅰ. Model development   总被引：1，自引：0，他引：1  

Guan Weibing  Wong Lai-Ah  Xu Dongfeng 《海洋学报(英文版)》2001,20(4):493-504

wrmcrloxHuman activities related to the population growth and developrnent of industry and rnwhci-pality have led to the incrouing hadings of various POllutants into estudries during the past fewdecades. These increasing edlutant lOadings have caused declined estuallne hedth which can bemereured by a vdriety of indices. In order to obtain solutions to environrnent problerns, re-sources manageTnnt apencies are supporting a holistic approach to envirorirnental management.An effcient strategy t…  相似文献   

再力花/菖蒲生物湿地床去除河水中氮磷的试验     

王骥  张兰英  卢少勇  甘树  金相灿 《吉林大学学报(地球科学版)》2012,(Z1):408-414

采用再力花和菖蒲构建湿地床,以考察其对污染河水的净化效果。6个月的连续试验表明:在水力负荷为0.24 m3/(m2.d)、植物种植密度大于158株/m2的条件下,2种植物存活率均大于93%,说明植物能适应低污染负荷、高种植密度的无土培养环境;再力花和菖蒲湿地床月均去除率分别为:总氮(TN),48.22%～78.53%和43.23%～72.42%;总磷(TP),77.62%～85.67%和58.07%～80.77%。再力花湿地床对TN、TP的净化效果好于菖蒲湿地床;2种植物吸收N、P含量分别占去除总量的比例:N为44.14%、37.75%,P为73.43%、62.05%。湿地床技术可有效去除来水中的TN、TP,通过植物吸收作用累积N、P含量较高,不同种类的植物构建湿地床对污染河水中N、P去除效果存在显著差异,且硝化反硝化和植物吸收是去除N的主要途径,而植物吸收是去除P的有效手段。  相似文献   

Effect of Dietary Phosphorus on the Growth and Body Components of Juvenile Synechogobius hasta     

LUO Zhi）  ）*  LI Xiaodong）  GONG Shiyuan）  XI Wenqiu）    LI Yali）） Key Lab of Agricultural Animal Genetics  Breeding  Reproduction of Chinese Ministry of Education  Fishery College  Huazhong Agricultural University  Wuhan  P. R. China ） Postdoctoral Research Base  Panjin Guanghe Fishery Co. Ltd.  Panjin  P. R. China 《中国海洋大学学报(英文版)》2009,8(1)

The effect of dietary phosphorus on the growth and body components of juvenile Synechogobius hasta was determined. Different percentages of dietary phosphorus (0.63, 0.77, 0.93, 1.06, 1.22 and 1.36) were tested by feeding the fish (body weight, 15.81 g ± 0.32 g; 20 individuals each group; 3 groups each percentage) at a surplus of 5%–10% above satiation for 35 d. Dietary phosphorus did not significantly affect the specific growth rate, feed intake, feed conversion ratio and protein efficiency rate. Nitrogen ...  相似文献   

Water, organic matter, nitrogen and phosphorus contents in sediment of a large-scale mariculture area in the Zhelin Bay of eastern Guangdong Province, China     

DONG Qiaoxiang  LIN Jun  SHANG Xu  LI Jin  HUANG Changjiang 《海洋学报(英文版)》2008,27(2):133-148

The Zhelin Bay is one of the most important bays for large-scale mariculture in Guangdong Province, China. Owing to the increasing human population and the expanding mariculture in the last two decades, the ecological environment has greatly changed with frequent harmful algal blooms. A monthly survey of water content, organic matter （TOM）, and various forms of nitrogen and phosphorous in sediment from July 2002 to July 2003 in the bay was conducted. The results showed that the water content was correlated significantly with TOM and various forms of nitrogen and phosphorus and can be used as proxy for quick and rough estimate of these factors in the future surveys. TOM was also correlated significantly with various forms of nitrogen and phosphorus, indicating that it was one of the key factors affecting the concentrations and distributions of nitrogen and phosphorus in the investigated waters. Average total Kjeldhal nitrogen （TkN） content was（ 1 113.1 ± 382.5）μg/g and average total phosphorus （TP） content was（567.2± 223.3）μg/g, and both were much higher than those of similar estuaries in China and elsewhere. Average nitrogen and phosphorus tended to be higher inside than outside the bay, higher at aquaculture than non-aquaculture areas, and higher at fish-cage culture than oyster culture areas, suggesting that large-scale mariculture inside the bay played an important role in the eutrophication of the Zhelin Bay. Various forms of nitrogen and phosphorus concentrations were higher during the warm season （July--September）, which was due to the increased decomposition and concentration of organic matter resulted from the fast growth and high mortality of the cultured species. Compared with July 2002, TkN and TP contents were much higher in July 2003, in consonance with the eutrophication of the Zhelin Bay. Because exchangeable phosphorus （Ex-P）, iron-bounded phos- phorus （Fe-P） and organic phosphorus （OP） combined accounted for 34.3% of the TP and authigenic phosphorus （Au-P  相似文献   

Modelling and mass balance assessments of nutrient retention in a seasonally-flowing estuary (Swan River Estuary,Western Australia)     

Barbara J. Robson  Paul A. Bukaveckas  David P. Hamilton 《Estuarine, Coastal and Shelf Science》2008

An integrated mass balance and modelling approach for analysis of estuarine nutrient fluxes is demonstrated in the Swan River Estuary, a microtidal system with strong hydrological dependence on seasonal river inflows. Mass balance components included estimation of gauged and ungauged inputs to the estuary and losses to the ocean (outflow and tidal exchange). Modelling components included estimation of atmospheric (N fixation, denitrification) and sediment–water column nutrient exchanges. Gross and net denitrification derived using two independent methods were significantly correlated (r² = 0.49, p < 0.01) with net rates averaging 40% of gross. Annual nitrogen (N) and phosphorus (P) loads from major tributaries were linearly correlated with annual freshwater discharge and were 3-fold higher in wet years than in dry years. Urban drains and groundwater contributed, on average, 26% of N inputs and 19% of P inputs, with higher relative contributions in years of low river discharge. Overall, ungauged inputs accounted for almost 35% of total nitrogen loads. For N, elevated loading in wet years was accompanied by large increases in outflow (7x) and tidal flushing (2x) losses and resulted in overall lower retention efficiency (31%) relative to dry years (70%). For P, tidal flushing losses were similar in wet and dry years, while outflow losses (4-fold higher) were comparable in magnitude to increases in loading. As a result, P retention within the estuary was not substantially affected by inter-annual variation in water and P loading (ca. 50% in all years). Sediment nutrient stores increased in most years (remineralisation efficiency ca. 50%), but sediment nutrient releases were significant and in some circumstances were a net source of nutrients to the water column.  相似文献   

Effect of Fly Ash on Frost-Resistance and Chloride Ions Diffusion Properties of Marine Concrete     

杨文武  钱觉时  章一颖 《中国海洋工程》2009,23(2):367-377

It is necessary to pay more attention to the durability of concrete undergoing freeze-thaw cycles and seawater attack simultaneously.Investigated are the effects of water-binder ratio,fly ash (FA) contents and air-entraining agent on resistance to frost and chloride diffusion of marine concrete blended with FA in natural seawater.The results show that fly ash does not improve the frost resistance of concrete but can improve its resistance to chloride diffusion by addition of less than 30%.The resistance to frost and chloride diffusion of FA concrete can be improved with the decrease of water-binder ratio,and FA may improve both of them simultaneously only being mixed with air-entraining agent.A ratio (named as R) of the frost-resisting durability factor to chloride diffusion coefficient can be used to evaluate the durability of marine concrete.Scanning electron microscope (SEM) analyses are consistent with the evaluations by the value of R.  相似文献   

花鸟山外海域几种形态磷在柱状沉积物中的分布及环境意义   总被引：7，自引：0，他引：7  

周怀阳  郑丽波  王怀照 《海洋学研究》2000,18(4):9-13

综合运用 SEDEX化学法、ASPILA化学法和 XRF仪器分析法 ,对在东海赤潮多发区花鸟山外海域采集的柱状沉积物进行了总磷及其不同形态磷含量的系统分析。研究表明 ,总磷及其不同形态磷在沉积柱垂向上的分布有一定的变化规律。在采样深度范围内 ,总磷 (TP)、有机磷 (OP)和铁结合态磷 (Fe - P)的含量自下而上增高 ,而吸附态磷 (Ad - P)、自生钙结合态磷 (Ca- P)与碎屑态磷 (De- P)的含量向上递减。样品柱具有较均匀的粒度及矿物、化学组成 ,基本可以排除沉积物质来源和沉积环境变化对沉积物中磷含量的影响 ,而且也不能仅仅用早期成岩作用来解释磷的上述行为。不同形态磷在柱状沉积物中的分布规律 ,在一定程度上反映了近年来陆源区环境污染加剧的趋势。  相似文献   

免烧粉煤灰滤料的制备及其性能的研究     

付晓茹  黎飞虎  方华 《南京气象学院学报》2014,6(4):363-368

为了扩大粉煤灰的应用范围,减少其对环境的污染,并且寻求一种新的水处理滤料的配方与制备方法,以粉煤灰、粘土为主要原料,以生石灰、石膏、水泥为激发剂,以H₂O₂（双氧水）、NaHCO₃为发泡剂,经搅拌、成型、自然冷却等工艺在实验室制备了免烧粉煤灰滤料.结果表明,如果以孔隙率作为主要的性能评价指标,制备免烧粉煤灰滤料的最佳质量配比为：粉煤灰46.30%,粘土13.89%,生石灰18.52%,水泥13.89%,石膏1.85%,纯H₂O₂ 5.55%,此时所制滤料的孔隙率为72.24%.  相似文献   

Study on extracting alumina from fly ash by compound additive activation method     

WANG Yongwang 《世界地质(英文版)》2014,17(3):182-188

According to the chemical and mineral composition characteristics of the fly ash, alumina can be extracted from fly ash through the calcining method by using sodium carbonate and calcium carbonate additives. The effects on leaching rate of alumina have been investigated. The results showed that the fly ash can be activated effectively and the leaching rate of alumina can be improved to more than 92% through this method. The best process parameters were the ratio of raw materials, i.e. the material weight ratio of fly ash, calcium carbonate and sodium carbonate was 1.0：1.2：0.9. The activating temperature was 850℃-900℃, activating time was 3 h. This process has a potential application prospect and improves the value of comprehensive utilization of fly ash.  相似文献   

Nitrogen and Phosphorus Budget of a Polyculture System of Sea Cucumber （Apostichopus japonicus）, Jellyfish （Rhopilema esculenta） and Shrimp （Fenneropenaeus chinensis）     

LI Junwei  DONG Shuanglin  GAO Qinfeng  ZHU Changbo 《中国海洋大学学报(英文版)》2014,13(3):503-508

The nitrogen(N) and phosphorus(P) budget and the ecological efficiency of a polyculture system of sea cucumber(Apostichopus japonicus), jellyfish(Rhopilema esculenta) and shrimp(Fenneropenaeus chinensis) were studied in a cofferdam, 120.2 ha in size. The nutrients were supplied by spring tide inflow. In total, 139600 kg N yr-1 and 9730 kg P yr-1 input to the system; while 118900 kg N yr-1 and 2840 kg P yr-1 outflowed from the system concurrently, thus the outflow was 85.7%(N) and 29.2%(P) of inflow. The production of N and P was 889.5 kg yr-1 and 49.28 kg yr-1(sea cucumber) and 204 kg yr-1 and 18.03 kg yr-1(jellyfish and shrimp), respectively. The utilization rate of N and P by polycultured animals was 7.8‰ and 6.9‰, respectively, 21.9% and 38% higher than that of monocultured sea cucumber. Our results indicated that the polyculture system was an efficient culture system of animals and a remediation system of coastal environment as well; it scavenged 14.3% and 70.8% of N and P, respectively. Such an ecological efficiency may be improved further by increasing either the stocking density or the size of sea cucumber or both.  相似文献