共查询到20条相似文献，搜索用时 78 毫秒
1.
为探讨聚丙烯塑料发泡材料(EPP)、悬浮球填料和海绵填料对集装箱循环水养殖废水中细菌吸附性能的差异,以及3种填料挂膜启动和挂膜成熟后对氨氮(NH_4~+-N)、亚硝酸盐氮(NO_2~--N)和硝酸盐氮(NO_3~--N)的净水效果,以集装箱循环水养殖废水为研究对象,采用自然挂膜的方式进行了为期3个月的试验,并对相关指标进行测定。结果显示:EPP填料对养殖废水中细菌的吸附能力最好,另外两种填料对细菌的吸附能力次之并且差异不显著(P0.05);3种填料自然挂膜成熟的时间分别为21 d、26 d和30 d;各填料挂膜成熟后处理高浓度NH_4~+-N养殖废水时,NH_4~+-N浓度与NO_2~--N浓度之间的关系可以用多项式y=ax~2+bx+c进行拟合,NH_4~+-N浓度与NO_3~--N浓度之间的关系可以用对数式y=aln(x)+b进行拟合。研究表明:EPP填料、悬浮球填料和海绵填料均可作为生物填料用于集装箱循环水养殖系统。 相似文献
2.
为研究不同养殖模式对南美白对虾(Litopenaeus vannamei)生长性能及肠道菌群的影响，在设施大棚中构建了中试规模的南美白对虾循环水养殖模式(RAS)和生物絮团养殖模式(BS)2种模式，每种模式为3个平行，每个平行投放南美白对虾苗10万尾，初始放养殖密度为500尾/m3。每隔1 d测定养殖水体的水质指标，待100 d饲养结束后，测定南美白对虾生长指标和肠道菌群。结果显示：RAS和BS组养殖水体中的总氨氮(TAN)、亚硝酸盐氮(NO-2-N)、硝酸盐氮(NO-3-N)、温度、pH和溶氧(DO)等指标无显著差异(P>0.05),但BS组有近20 d的NO-2-N积累，进而影响南美白对虾的生长。BS组的特定生长率、存活率和最终养殖密度显著低于RAS组(P<0.05),饲料系数和肥满度无显著差异(P>0.05)。两种养殖模式下对虾肠道菌群在门水平无显著差异，属水平显著差异(P<0.05),RAS养殖模式中的... 相似文献
3.
半滑舌鳎成鱼开放流水与循环水养殖模式下生长及肌肉营养成分差异研究 总被引：1，自引：1，他引：0
为半滑舌鳎的集约化养成提供基础数据,设定开放流水和循环水两种养殖模式,以处于快速生长期的大规格鱼种(0.640 ±0.063) kg为研究对象,检测半滑舌鳎的生长及肉质相关指标,实验共进行7个月,结果显示:①半滑舌鳎在两种养殖模式下的成活率分别为79.89％和90.38％,月增重率分别是0.154 7和0.1109 kg,肥满度分别是0.920和0.838,生长激素分泌量分别是2.812和2.706 μg/L.循环水养殖模式组在成活率、增重率、肥满度和生长激素分泌量上分别高于开放流水养殖模式组13.13％、39.5％、9.8％和3.92％.②两种养殖模式,开放流水养殖模式组在粗蛋白、氨基酸、PUFA上更占优势,但在粗脂肪、MUFA上循环水养殖模式明显占优势,分别高于开放流水养殖模式组41.732％和16.912％.实验表明,循环水养殖模式优越的水质环境更适合半滑舌鳎的育肥.本实验说明,半滑舌鳎在循环水养殖模式下具有很好的适应性,其生长处于较好的状态,营养品质上也能够得到保证.同时,也说明循环水养殖模式可以极大地发掘半滑舌鳎的养殖潜力,是一种适合半滑舌鳎集约化养殖的具有优势的养殖模式. 相似文献
4.
5.
1 什么是“海水健康养殖”? 海水健康养殖是指根据海水养殖对象(鱼、虾蟹、贝、藻等)正常活动、生长、繁殖所需的生理、生态要求,选择科学的养殖模式,将健康的海水养殖对象通过系统的规范管理技术,使其在人为控制生态环境下健康快速生长。 2 海水健康养殖的主要内容有哪些? 主要内容有: (1)人为控制生态环境条件,保持与海水养殖对象正常所需最适范围相同; (2)养殖模式(包括各种防疫手段)能使养殖对象的生长(活动)、生理机能均正常,能利用自身抵抗力(免疫力)抵御病原入侵及环境变迁; (3)投喂适当的能完全满足其营养需求的安全性好、无公害饲… 相似文献
6.
在对虾人工养殖过程中，养殖水化学环境和水体生态结构的优劣是决定养殖成功与否的关键。长期以来，水产科技工作者一直致力于调节和优化养殖水体生态结构的研究，如利用化学物质抑制有害藻类的繁殖和生长，以高等水生植物抑制藻类生长(Saayda，T．T．，l974；Moss，B．，1980)，起到了生态修饰的效果。但用生物法调节水化学环境和水体生态结构比化学法有更大的优越性。 相似文献
7.
利用自制的硝化细菌菌剂促进移动床生物膜反应器(Moving bed biofilm reactor,MBBR)的挂膜启动,分析不同载体氨氮负荷、碳氮比条件下反应器运行状况,并进一步进行了实验室模拟循环水养殖草金鱼实验。结果显示,利用自制硝化菌剂能够完成整个移动床反应器的启动过程,在接种15 d后使循环出水氨氮稳定在1 mg/L以下。单位体积载体氨氮负荷实验表明,MBBR能够在100 mg TAN/(L填料·d)条件下,使出水满足一般水产养殖水质要求(氨氮0.5 mg/L,亚硝氮0.1 mg/L)。进水碳氮比在1以内时MBBR能够稳定高效运行。在实验室模拟循环水养殖过程中,经菌剂强化的MBBR能维持循环出水氨氮低于0.5 mg/L,亚硝氮低于0.05 mg/L。 相似文献
8.
健康养殖就是根据养殖对象正常生长、活动和繁殖所需要的生理、生态要求，采用科学的养殖模式和规范的管理技术，使其在人为控制的生态环境下健康快速生长的养殖模式。健康养殖要以有效防治为主，在养殖过程中消灭病原、改善养殖环境的各项理化因子，消除发病因素，使养殖水产品在无污染的环境下生长。健康养殖必须符合国家食品安全标准，使养殖的产品保证做到安全、健康。病害防治，是这个系统中的重要环节，所以在水产品的健康养殖中，做好鱼病防治工作就显得十分重要。 相似文献
9.
鳜鱼，又称桂花鱼，隶属于鲈形目，鱼旨科，喜栖静水或缓流水域中，尤水草繁茂处，白天少动，多夜间在水草丛中觅食，黄昏和拂晓是其摄食高峰，暗视觉灵敏，靠偷袭捕捉活饵而生长，鳜鱼苗出膜即以其它种鱼苗为食，一生拒食死饵，因此自然条件下苗种成活率低，生产过程中，苗种培育及其饵料成了其养殖生产迅速发展的两大制约因素。东江水库位于湘南山区的资兴市境内，水面２４万亩，蓄水量８１．２亿立方米，号称“湘南洞庭”，它同时亦是一个富饶的鱼仓，水库中放养的四大家鱼生长迅速，野杂鱼类、凶猛鱼类繁盛，尤其盛产鳜鱼，其鳜鱼远销韶… 相似文献
10.
11.
A sustainable aquaculture production involves alternatives, as recirculating aquaculture systems (RAS), in order to increase the water supply efficiency. This paper aims: a) to propose a method for dimensioning a RAS filled and additionally supplied with water from a rainwater harvesting systems (RHS) and; b) to evaluate the efficiency of the system based on the supply of rainwater from the RHS, the quality of water in the RAS, and the development of aquatic organisms. A pilot aquaculture farm for rainbow trout (Oncorhynchus mykiss) production was designed and dimensioned. On one hand, the RAS with a configuration based on a treatment tower provided acceptable values of pH, TAN, and alkalinity. The temperature was slightly above the recommended temperature but did not negatively impact trout development. On the other hand, the water use efficiency reached 178 L/kg of fish, instead of 210,000 L/kg in an open flow system for trout rearing. The RHS fulfilled the additional required water on the test period of the pilot farm and is expected to supply at least 92% on average during the useful life. Regarding the aquatic organisms’ development, the system allowed both a better Length/ weight ratio and a lesser mortality rate compared to previous studies of RAS. In contrast to other studies in the literature, the mathematical models for dimensioning the system were calculated as a function of the final biomass expected in the tank instead of the quantity of supplied feed. Therefore, this method confirmed the applicability of this alternative criterion for designing biofilters and aquaculture systems. 相似文献
12.
An optimal flow domain in culture tanks is vital for fish growth and welfare. This paper presents empirical data on rotational velocity and water quality in circular and octagonal tanks at two large commercial smolt production sites, with an approximate production rate of 1000 and 1300 ton smolt/yr, respectively. When fish were present, fish density in the two circular tanks under study at Site 1 were 35 and 48 kg/m3, and that in four octagonal tanks at Site 2 were 54, 74, 58 and 64 kg/m3, respectively. The objective of the study was twofold. First, the effect of biomass on the velocity distribution was examined, which was accomplished by repeating the measurements in empty tanks under same flow conditions. Second, the effect of operating conditions on the water quality was studied by collecting and analysing the water samples at the tank’s inlet and outlet. All tanks exhibited a relatively uniform water velocity field in the vertical water column at each radial location sampled. When fish were present, maximum (40 cm/s) and minimum (25–26 cm/s) water rotational velocities were quite similar in all tanks sampled, and close to optimum swimming speeds, recommended for Atlantic salmon-smolt, i.e., 1–1.5 body lengths per second. The fish were found to decrease water velocity by 25% compared to the tank operated without fish. Flow pattern was largely affected by the presence of fish, compared to the empty tanks. Inference reveals that the fish swimming in the tanks is a major source of turbulence, and nonlinearity. Facility operators and culture tank designers were able to optimize flow inlet conditions to achieve appropriate tank rotational velocities despite a wide range of culture tank sizes, HRT’s, and outlet structure locations. In addition, the dissolved oxygen profile was also collected along the diametrical plane through the octagonal tank’s centre, which exhibits a close correlation between the velocity and oxygen measurements. All tanks were operated under rather intensive conditions with an oxygen demand across the tank (inlet minus outlet) of 7.4–10.4 mg/L. Estimates of the oxygen respiration rate in the tank appears to double as the TSS concentration measured in the tank increases from 3.0 mg/L (0.3 kg O2/kg feed) up to 10–12 mg/L (0.7 kg O2/kg feed). Improving suspended solids control in such systems may thus dramatically reduce the oxygen consumption and CO2 production. 相似文献
13.
Emmanuelle Roque d&#x;orbcastel Jean-Paul Blancheton Alain Belaud 《Aquacultural Engineering》2009,40(3):135-143
The objective was to compare water quality and fish growth and mortality in a pilot scale recirculating system (RS) and a control tank in flow through system (FTS). The RS was designed after the Danish Model Trout Farm and operated with a make up water renewal rate of 9 m3 kg-1 of fish produced. RS water quality did not decrease significantly with water flow rate decrease in the RS. During the experiment, the RS water treatment system presented solids removal efficiency of 59.6 ± 27.7% d−1, ammonia oxidation of 45 ± 32 g m−3 d−1, oxygenation yield of 392 ± 132 g of O2 kWh−1 and CO2 degassing of 23.3 ± 11.9% pass−1. In the RS, nitrite concentration was 0.15 ± 0.07 mg l−1, close to the toxicity threshold; a N2 supersaturation phenomenon was measured, probably due to the air injection depth. The biofilter and sedimentation area management has to be improved to avoid organic matter decomposition and release of dissolved elements. Even if no N2 over-saturation apparent effect on fish performance and aspect were detected, the airlift depth has to be modified in the case of industrial development of the RS. Some improvements of the water treatment system, especially on the airlift and sedimentation area, are suggested.Concerning fish growth, no significant differences were observed between the RS and the FTS. No pathologies were detected and cumulative mortality rates (0.1%) were similar to the farm's usual data. There were no significant effects of water flow rate decrease in the RS on fish performance and energy savings were recorded to be 0.7 kWh kg−1 of fish produced between RS1 and RS2. The global energy cost of the RS was 3.56 kWh kg−1 of fish produced (0.107 € kg−1 of fish produced). Even if the energy consumption of the water treatment system can be improved, the results confirm that recirculating system can be used for industrial trout on growing, without fish performance deterioration. 相似文献
14.
通过对工厂化循环水养殖进水流速的智能调控,可降低饵料残留,避免水质恶化。为此,本研究采用数值模拟方法探究了进水流速对工厂化循环水养殖池流场特性的影响,并基于该研究设计出一套确定进水流速调控的实验方法。首先,通过对比Standard k-ε、RNG k-ε和Realizable k-ε 3种湍流模型及多种壁面函数的仿真效果,确定RNG k-ε模型和标准壁面函数作为仿真配置。同时,针对多相流模型,对欧拉多相流模型和DPM离散相模型进行对比,为提高计算准确性选用DPM离散相模型,并基于上述模型进行网格无关性验证、制定网格划分方案。其次,以大菱鲆(Scophthalmus maximus)养殖为例,模拟不同进水流速下养殖池流场、排污和水温调节的效果。最后,针对仿真结果提出进水流速调控方案。结果显示,日常采用1.0 m/s的进水流速,可有效提高适宜流速区面积并控制水处理成本;投饵前,采用0.2 m/s的进水流速可以解决循环水养殖中存在的饵料浪费问题;进食结束后,采用1.2 m/s的进水流速可快速排出残饵避免水质恶化;水温异常时,采用15 ℃的水、以1.2 m/s的进水流速注水230 s,可使20 ℃的水下降到正常水平,精准化控制水温。采用本研究提出的方法,可针对不同养殖生物和养殖环境设计进水流速智能调控策略,可用于解决循环水养殖过程中饵料浪费、水质变差和水温异常等问题。 相似文献
15.
斑节对虾封闭式育苗技术研究 总被引：2，自引：0，他引：2
斑节对虾封闭式育苗的主要技术措施：育苗池中密布气石５．５个／ｍ２;抽取大潮期海水经砂滤后入池,育苗过程中不添水换水;调节苗池光照强度约０．６～１μＥ／ｍ－２·Ｓ－１;投喂优质饵料６次／ｄ,混投优质中肋骨条藻和亚心形扁藻,掌握适当的投饵量;每天定时投放１０×１０－６的光合细菌等。试验结果,平均单位水体出苗量为５．７万尾／ｍ３,成活率５６．３％。 相似文献
16.
Pedro M. Domingues Philip E. Turk Jose P. Andrade Phillip G. Lee 《Aquaculture International》1998,6(5):387-402
Studies were conducted to determine the potential for large scale culture of the mysid shrimp Mysidopsis almyra. Reproduction was consistent, as newly hatched mysids were always present in the culture trays. At the end of 45 day preliminary trials, the populations in the culture trays had increased 323.3% and 256.6%. A larger pilot-scale system connected to a biological filtration tank was constructed and operated for 17 weeks. Two rectangular trays (125 cm × 50 cm × 8 cm deep) were placed one above the other; water volume in each tray was 20 l. The room was kept dark. Temperatures were maintained at 26(2) °C and salinities at 20(2). A total of 1,000 adult mysids were placed in the culture tray and the hatchlings were collected and moved into a hatchling tray. Water circulation was static except for twice-daily water exchanges; newly hatched Artemia nauplii (24 h incubation) were fed to the mysids immediately after each water exchange. Feeding presented no technical problem to the pilot-scale culture of mysids in static water systems but the cost of Artemia did represent the largest expense. Mean (SD) mysid production throughout the 17 weeks of the trial was 133(69) hatchlings d–1 with highest production [244(30) hatchlings d–1] occurring between weeks 11 and 13. Mean survival in the hatchling tray after the 14 day growth periods was 41.4%. Reproduction occurred at ammonia-nitrogen and nitrite-nitrogen concentrations as high as 1.5 mg l–1 and 0.250 mg l–1 respectively, and at pH values as low as 7.6. When pH decreased to 7.38, reproduction halted abruptly and mortality increased sharply. © Rapid Science Ltd. 1998 相似文献
17.
We studied the effect of rearing densities of Pacific white shrimp, Litopenaeus vannamei in three densities with three replicate treatments [T1: 0.4 million post-larvae (PL) ha−1, T2: 0.5 million PL ha−1, T3: 0.6 million PL ha−1] and water cutback approach on rearing environment, water use efficiency, water footprint and production performance. Conditional water exchange was carried out based on water quality parameters. Water quality suitability index was very good (7.5–9.0) up to 13th, 10th and 5th week of culture in T1, T2 and T3, respectively; which was attributed to rearing density, smaller-sized shrimp and low early feed input. Optimum rearing density of 50 PL m-2 (T2) led to total water use of 3.25 × 104 m3. It was seeming as a way to improve shrimp productivity (10.58 t ha−1 120 d−1), consumptive water use index (1.72 m3 kg-1 biomass), total water footprint (1229 m3 t−1 biomass) and net consumptive water productivity (USD 1.28 m-3). L. vannamei culture with low to moderate water exchange as in T2, helped uphold water quality suitable for the shrimp growth, improved water use efficiency (0.58 kg biomass m-3 water), minimized sediment load (45.3 m3 t-1 biomass), effluent outputs (0.63 × 104 m3), pumping cost (USD 30.1 t−1 biomass produced), and ratio of output value to the cost of cultivation (1.97). The findings and advancement in knowledge would offer the basis to augment shrimp rearing efforts and the water management approaches will help in preventing the production of waste and effluent while increasing water use efficiency and production performance. 相似文献
18.
观测研究了七带石斑鱼(Epinephelus septemfasciatus)幼鱼和云纹石斑鱼(Epinephelus moara)幼鱼在封闭式循环养殖系统中的生长特性,用SPSS 17.0软件中的Curve Estimation对相关数据进行模型分析与参数估计。结果表明,经过122 d的养殖,七带石斑鱼幼鱼平均体质量由(114.836±25.343)g增加到(213.861±38.604)g,相对增长率为0.707%,全长(TL)与养殖时间(t)的函数关系式为TL=-0.006t3+1.622t+13.954,体质量(W)与体长(BL)的关系式为W=0.436BL2.055;云纹石斑鱼幼鱼平均体质量由(79.620±13.007)g增加到(238.086±46.307)g,相对增长率为1.631%,全长(TL)与养殖时间(t)的函数关系式为TL=-0.013t2+2.008t+11.540,体质量(W)与体长(BL)的关系式为W=0.018BL3.083。两种幼鱼丰满度生长差异不显著(P0.05),都保持在2.2-3.4之间。 相似文献
19.
Twenty outdoor holding tanks (10 m–3 each), were filled with ground water and grouped into five feeding schemes: live zooplankton cultured outside the fish growing tank (LFS); direct nursery pond fertilization schedule in static (MS) as well as in exchanged water (EMS); intermediate conditions between the LFS and MS (IS); and supplementary food system using mixture (1:1) of finely ground mustard oilcake and boiled rice (SFS). Two hundred common carp (Cyprinus carpio) fry were introduced into each of the twenty outdoor tanks maintained at ambient temperature outside the laboratory. After 90 days of rearing, the fish were harvested and analysed for various growth parameters and food conversion efficiency. The average weight of carp attained in the LFS was significantly higher than that in the other four feeding schemes. The frequency distribution of final body weight of common carp showed the preponderance of large and small fish in the LFS and MS, respectively. Likewise, plankton intake by the carp fry was highest in the LFS. The rate of survival was much higher in the LFS as compared with the rest of the treatments. The water quality remained far better in the former than the latter. © Rapid Science Ltd. 1998 相似文献
20.
水温 饵料 投饵率对河蟹生长和饵料转化率的影响 总被引：3，自引：0，他引：3
在实验室条件下研究了水温、饵料和投饵率对河蟹生长的影响。结果表明,在10～26℃水温范围内,河蟹对不同饵料的摄饵率和特定生长率均与水温呈正相关关系;相比之下,用配饵投喂,河蟹对温度的变化较为敏感,但配饵的饲养效果明显次于螺蛳。随着水温的升高,当螺蛳的投饵率由半饱增至全饱时,河蟹的湿重生长率增长不明显,而体蛋白量则增加了13%～28%。在适温范围内,适当降低投饵率可提高饵料转化率和蛋白质利用率,可是蟹体蛋白量的增加则明显下降。 相似文献