循环水养殖旋转式生物流化床生物过滤功能   总被引：2，自引：0，他引：2  

柳瑶  宋协法  雷霁霖  彭磊  黄志涛  刘宝良 《农业工程学报》2015,31(3):249-254

生物过滤是循环水养殖水处理的关键,生物过滤功能启动以及操作条件直接影响到生物过滤的效果。该文以实验室规模旋转式生物流化床为研究对象,采用自然挂膜法研究海水和淡水生物过滤功能的启动;设置了3个膨胀率50%、75%、100%和4个C/N0、0.5、1.0、2.0,研究其对旋转式生物流化床处理养殖污水效率的影响。结果表明:1)以氨氮和亚硝态氮浓度降低并稳定为判断标准,淡水和海水系统旋转式生物流化床生物过滤功能启动完成分别需要47和60 d;2)污水处理效率随膨胀率增大而提高,该研究膨胀率为100%时处理效率最高,总氨氮转换率高达881 g/(m3·d);3)C/N增大,抑制生物膜的硝化功能,污水处理效果变差,C/N大于2.0时污水处理效果显著变差。该研究可为旋转式生物流化床在应用过程中生物过滤功能的启动和日常操作管理提供技术指导。  相似文献   

江蓠筏式人工育苗杂藻清除技术的研究     

李修良  李美真  刘秋明 《中国水产科学》1997,4(4):73-77

根据生态调查和筏式育苗效果的比较，采取了调低海水比重，每十天浸泡苗帘一次的方法清除杂藻。海水比重调节幅度在１．０２１－１．０１６之间，逐步降低海水比重浸泡苗帘，清除杂藻和各种动物幼虫，使江蓠育苗取得了成功。  相似文献   

虹鳟海水驯养试验报告   总被引：2，自引：0，他引：2  

赵现振  杜敦杰 《齐鲁渔业》1994,11(3):8-12

对４批１８８１尾不同规格的虹鳟进行由淡水过渡到海水的驯养试验。过渡时间５－７天，最小体长３．５ｃｍ，过渡成活率９９．５％。在海水中饲养６４天，增重率为８０％。利用对虾育苗池进行的自然水温海水越冬试验，存活率８７％。１９８５年底专家鉴定认为，本研究成果处于国内同类研究先水平。  相似文献   

生菜海水灌溉适宜浓度的筛选     

杨小锋  李劲松  杨沐  任红  黄植 《北方园艺》2011,(18):1-5

以“中丰”、“南疏”、“细叶苦苣Ⅰ”、“碎叶苦苣”生菜品种为试材,采用无土栽培方式研究了不同海水浓度对生菜生长和品质的影响.结果表明:随着海水浓度的增加,生菜的地上鲜质量、地下鲜质量、叶面积、地上千质量、地下干质量及硝酸盐含量均呈现下降趋势;而叶绿素a、叶绿素b及叶绿素含量随着海水浓度升高,基本呈现先增加后降低趋势;适宜海水浓度有利于改善生菜的可溶性蛋白、可溶性糖及维生素C含量等内在品质.综合考虑生菜产量、叶绿素b、叶绿素、硝酸盐、可溶性蛋白、可溶性糖、维生素C含量等指标,生菜海水灌溉最适宜浓度为14.5％.  相似文献   

利用海水作管道试压介质的技术要求     

高发光  鲍宇  仇斌 《油气储运》2007,26(12):57-60

针对淡水稀缺区不能满足管道水试压需求且施工成本高的问题,提出了在沿海地区合理利用海水作试压介质的必要性。结合利比亚西部管道的应用实践,指出海水作为管道试压介质必须通过相应设备及材料改善水质。介绍了海水处理原理、程序、要求及应注意的问题。  相似文献   

Can smolting be assessed by food intake in steelhead trout,Oncorhynchus mykiss (Walbaum)?     

Juhani Pirhonen  Carl B Schreck  & Paul W Reno 《Aquaculture Research》2003,34(15):1459-1463

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Free polyamine concentrations in coastal seawater during phytoplankton bloom   总被引：1，自引：0，他引：1  

Naoyoshi Nishibori  Akihiko Yuasa  Motosuke Sakai  Shinsuke Fujihara  Sachio Nishio 《Fisheries Science》2001,67(1):79-83

SUMMARY: Polyamines are widely distributed in nature and known to have many roles in living organisms. We investigated the concentrations of polyamines together with inorganic nutrients during a summer bloom period in the Seto Inland Sea of Japan. Putrescine and spermidine were the major polyamines in the coastal seawater. The concentrations at 1 m depth varied widely during the sampling period and ranged from 2.0 to 32.6 nM and 1.0 to 14.1 nM. Spermine concentrations were much lower than putrescine and spermidine. In addition, other polyamines (diaminopropane, cadaverine, norspermidine, homospermidine, norspermine) were also detected. Putrescine and spermidine seemed to be significant compounds in dissolved organic nitrogen in coastal seawater.  相似文献   

Feed intake,growth and osmoregulation in Arctic charr,Salvelinus alpinus (L.), transferred from freshwater to saltwater at 8°C during summer and winter     

Arne M. Arnesen  Even H. Jørgensen  Malcolm Jobling 《Fish physiology and biochemistry》1993,12(4):281-292

The purpose of the current study was to examine seasonal changes in seawater tolerance and growth performance of anadromous Arctic charr (Salvelinus alpinus L.) held at the same temperature (8°C) during winter and summer. Charr (20–27 cm), previously reared in freshwater under natural photoperiod, were transferred either directly (DT) from freshwater to seawater (35 ppt), from freshwater to brackish water (20 ppt), or were gradually adapted (GT) to seawater over a period of 10 days. Control fish were held in freshwater. Feed intake and osmoregulatory ability were then monitored on three occasions during the following 59 days. Two experiments were carried out, one during winter (December–January) and the other during summer (June–July). In both experiments fish mortality was low. Plasma osmolalities recorded in fish transferred to seawater were within normal ranges, but osmolalities on day 10, were significantly lower in summer (313 mOsm/kg (DT), 328 mOsm/kg (GT)) than in winter (323 mOsm/kg (DT), 352 mOsm/kg (GT)). In winter, feed intake and growth rates were high in fish kept in fresh and brackish water, but charr transferred directly to seawater ate little and lost weight. Fish that were gradually adapted to seawater occupied an intermediate position. During summer the observed differences in feed intake were small and all fish had relatively high growth rates. These results suggest that Arctic charr display seasonal changes in feed intake and growth performance that parallel seasonal changes in hypoosmoregulatory capacity. The ability to survive and hypoosmoregulate in full strength seawater does not, however, seem to be a particularly good indicator of successful seawater adaptation with respect to the ability to display high rates of feed intake and growth. During winter, a gradual transfer to seawater appeared to lead to improved feeding and growth compared to direct transfer.  相似文献   

A radioimmunoassay for N-terminal peptide of chum salmon proopiocortin     

Akiyoshi Takahashi  Hiroshi Kawauchi  Tetsuya Hirano 《Fish physiology and biochemistry》1987,3(2):53-61

A highly specific radioimmunoassay was developed for N-terminal peptide of salmonid proopiocortin using a guinea pig antiserum to the chum salmon peptide (sNPP 1). Since sNPP I has no tyrosine residue nor free N-terminal amino group, a mixture of minor components of sNPP 1, which have extensions of H-Val-LysGly- and H-Lys-Gly- at the N-terminus, were iodinated by the lactoperoxidase method after incorporation of 3-(phydroxyphenyl)-propionate to the terminal amino groups. Plasma and pituitary extracts of several salmonid species showed parallel displacement to the standard hormone. Samples from carp, goldfish, tilapia, and eel, as well as the plasma of hypophysectomized rainbow trout, showed no crossreactivity. Proopiocortin-related hormones isolated from the chum salmon pituitary, including melanotropins, endorphins, corticotropin-like intermediate lobe peptides, and gonadotropin and prolactin showed negligible cross-reactivity. NPP contents in the pars intermedia of rainbow trout and chum salmon were 10 to 15 times greater than those in the pars distalis. Plasma levels of NPP in the mature chum salmon caught in the bay were about 50ng/ml. Plasma NPP levels in the mature chum salmon of both sexes decreased after transfer from seawater to fresh water. Plasma cortisol showed a concomitant change with NPP, thus supporting previous findings that NPP modulates corticotropin action on the trout interrenal.  相似文献   

Cortisol stimulates intestinal fluid uptake in Atlantic salmon (Salmo salar) in the post-smolt stage     

Sean C. Cornell  David M. Portesi  Philip A. Veillette  Kristina Sundell  Jennifer L. Specker 《Fish physiology and biochemistry》1994,13(3):183-190

The fluid uptake rate of the posterior intestine of salmonids increases during the parr-smolt transformation. Intestinal fluid uptake in post-smolt Atlantic salmon was investigated after treatment with cortisol and growth hormone (GH), alone or together. Two replicate experiments were conducted in August 1991 and August 1992. Cortisol was emulsified in vegetable shortening and vegetable oil (1:1) and implanted into the peritoneal cavity. GH was administered as intraperitoneal injections in a saline vehicle on days 0 and 2. On days 5 and 6, plasma cortisol levels, gill Na⁺,K⁺-ATPase activity, andin vitro measurements of fluid transport rate (J_v) across the posterior intestine were measured. Implants of cortisol elevated the plasma cortisol levels within a physiological range, and resulted in elevated gill Na⁺,K⁺-ATPase activity, as expected. The fluid uptake rate across the posterior intestine was roughly doubled by cortisol treatment. GH treatment did not affect intestinal fluid transport, gill Na⁺,K⁺-ATPase activity, or plasma cortisol concentrations. The seawater-adapting increase in the rate of fluid uptake by the posterior intestine of smolting salmon is probably stimulated by elevated plasma cortisol concentrations.  相似文献