养殖用水重复利用过程中的C/N

环境基质中的C/N会影响水体中细菌菌体组成的C/N、细菌群落组成和细菌氮素代谢途径,进而会影响养殖水体的自养硝化、异养反硝化和氨氮同化过程的效率,影响养殖水体的重复利用率。文章对养殖水体中主要功能菌对基质中C/N的响应、养殖水体中C/N对硝化作用、反硝化作用和无机氮同化的影响及相应调控策略进行了分析和总结,可为提高水产养殖用水的氮素控制效率和养殖用水的重复利用率提供参考。     

自养硝化过程去除循环水养殖系统水体中氨氮的研究进展

氨氮是养殖水体主要的控制指标,自养硝化过程将水体中的氨氮经亚硝酸盐转化成硝酸盐,是水体中氨氮最常见的一种转化途径,也是循环水养殖系统中常用的氨氮控制方式。根据国内外关于循环水养殖水体中自养硝化过程的研究报道,结合养殖水体特征,分析了利用固定膜式自养硝化过程控制养殖水体氨氮的优势和劣势、水产养殖过程中影响自养硝化效率的因素以及在实际使用过程中的注意事项,对自养硝化过程的建立进行重点介绍,为实际应用提供参考。     

循环水养殖系统生物反应器脱氮技术

硝酸盐是氨态氮等有害物质经过硝化反应后形成的产物,硝酸盐氮对养殖对象的毒性相对较低,但高浓度硝酸盐氮也会影响养殖对象的生长。本文介绍了影响生物反应器脱氮的主要因素,重点介绍了生物反应器脱氮方法,包括异养反硝化、自养反硝化、厌氧氨氧化等三种常见的脱氮方法。     

硝化细菌富集方法的研究

在集约化养殖水体中有机物和“三氮”的浓度往往明显增加 ,随着有机物的增加 ,异氧微生物得以大量繁殖 ,而自养微生物如硝化细菌由于其自身的特点 :自养性、好氧性、生长速度慢、依附性和产酸性 ,在水体中的数量受到相对抑制。据调查研究表明 ,在人工控温养鳖池水体中硝化细菌的数量仅为 1 3(ＭＰＮ) /ｍｌ[1] ,如此低的硝化细菌的存在直接影响到硝化效果和生物脱氮的效率 ,容易导致ＮＨ4+ -Ｎ浓度升高。一般情况下 ,废水中硝化细菌的浓度与硝化速率成正比。因此 ,提高硝化细菌的浓度对降解养殖水体中氨氮具有十分重要的意义。目前 ,国外已…     

养殖水体中微生物全程自养脱氮初步研究

利用3种微生物对养殖水体的不同脱氮特性,研究了微生物对养殖水体的全自养脱氮.结果表明,水温25～30 ℃、pH 7.0～7.3及最大DO 3.5 mg/L时,光合细菌、枯草芽孢杆菌以1:1的接种水平,养殖水体中氨氮、亚硝酸盐氮的去除率分别为85.4%、89.5%,可以很好地实现对养殖水体的全自养脱氮.     

凡纳滨对虾养殖系统中异养和自养型生物絮团的微生物特性及其与养殖水环境的关系

生物絮团的群落结构特征与其营养类型密切相关, 并与系统水质相互影响。本研究应用高通量测序技术研究了凡纳滨对虾(Litopenaeus vannamei)养殖系统中异养、自养型生物絮团的微生物群落结构特征, 讨论了絮团微生物与养殖水环境的相互作用。群落结构分析表明, 异养、自养型生物絮团的优势门类均为变形菌门(Proteobacteria, 相对丰度占比 24.2%~70.45%)、拟杆菌门(Bacteroldota, 相对丰度占比 8.45%~28.09%); 属水平上, 对构建生物絮团骨架起重要作用的亮发菌属(Leucothrix)相对丰度在两种生物絮团间无显著差异(P＞0.05); 此外, 注释为硝化螺旋菌门(Nitrospirota)的 OTU 仅存在于自养絮团。功能基因预测分析表明, 自养型生物絮团 amoA、amoB 等硝化基因的丰度(0.17%, 0.20%)明显高于异养型生物絮团(0.10%, 0.09%)。絮团微生物组成的变化改变了水体氮循环路径, 造成氨氮、亚硝酸盐、硝酸盐浓度的不同, 并受到水质差异的反作用。生物絮团的营养类型对对虾特定生长率无显著性影响。结论认为: 与异养型生物絮团相比, 自养型生物絮团硝化细菌和硝化基因的丰度、多样性明显升高, 微生物组成与功能更加合理, 能有效控制养殖水质, 维持养殖系统的平衡与良性发展。     

黄河三角洲对虾生物絮团高效健康养殖技术

1对虾生物絮团高效健康养殖技术概述 1．1生物絮团养殖技术提出背景 对虾生物絮团养殖技术最早由以色列养殖专家Avnimelec在1999年提出,并于2005年在印度尼西亚试验成功,主要通过操控水体营养结构,向水体中添加有机碳物质,调节水体中的C／N比,促进水体中异养细菌的繁殖,利用微生物同化无机氮,将水体中的氨氮等养殖代谢产物转化成细菌自身成分,并且通过细菌絮凝成颗粒物质被养殖动物所摄食,起到维持水环境稳定、实现零换水、提高养殖成活率、降低饲料系数和防治病害等作用的一项技术,它被认为是解决水产养殖产业发展所面临的环境制约和饲料成本的有效替代技术。     

菌藻联合调控氨氮新技术

随着淡水养殖集约化规模的扩大,水体氨氮的控制成为水质控制的关键。本文由水体的氮循环过程阐述r养殖水体氨氮积累的成因及危害,简单介绍了利用生物控制水体氨氮方法,并提出了菌藻联合调控新技术。1水体的氮素循环构成氮循环的主要环节是：生物体内有机氮的合成、氨化作用、硝化作用、反硝化作用和固氮作用。自然水体中的氮来自水生动植物尸体及排泄物的积累及腐败,含氮有机化合物通过营腐生细菌分解成氨氮、硫化氧等小分子无机物,然后由各种自养型微生物主要为硝化细菌的作用,转化为亚硝酸盐和硝酸盐,这3种氮素一方面被藻类和水生植物吸收,另一方面硝酸盐在缺氧条件下被反硝化细菌通过脱氮作用将硝态氮转化为氮气逸出水体,大气中的氮被固氮菌利用重新回到水体。     

鱼类循环水养殖中的水质参数自动控制

鱼类循环水养殖是一种工业化的养殖方式,其主要特征是养殖水体的循环利用,这一过程要对养殖水体进行处理,对水质参数进行监测与控制,要涉及物理、化学、生物及控制理论等许多学科的理论与技术。本文列出了循环水养殖水体中影响鱼类生长的各种因子并总结了前人的研究成果,进而提出了一些水质参数的控制方式。其中着重分析了溶解氧、pH值和氨氮的监测与控制方式,为进一步实验研究奠定基础。     

生物膜法SBR（BSBR）在循环养殖水处理中影响因素分析

膜法SBR（sequence batch reactor）是将SBR法与接触氧化法相结合的一种新型生物膜法处理工艺。此研究以总氨氮（TAN）及总氮（TN）的去除反应速度作为考察指标，分析生物膜法SBR（biofilm sequence batch reactor，BSBR）处理水产循环养殖系统水体中影响TAN及TN去除效果的主要因素。其中，pH和碱度对硝化反应有很大的影响，pH控制在6．3以上时TAN处理效果较好。溶解氧（DO）对反硝化反应也有较大的影响，同时考虑到水生生物的生长需求，在此试验系统中进入反应器的水体DO最好能控制在4．5～6．5mg·L^-1。水温保持在20％左右，可以保证有一个较好的脱氮效果。     

Nitrification kinetics of biofilm as affected by water quality factors

Various types of fixed film biofilters have been used in recirculating aquaculture systems under different water quality and operating conditions. The effectiveness of the nitrification process can be evaluated by nitrification kinetics. Nitrification in the bacterial film of the biofilter involves physical, chemical and biological processes that are governed by a variety of parameters such as substrate and dissolved oxygen concentrations, organic matters, temperature, pH, alkalinity, salinity and turbulence level. The impacts of these parameters upon nitrification kinetics make predicting the performance of a biofilter for a given application an engineering challenge. Knowing the performance of a biofilter is critical for both designers and managers. This paper summarizes the current knowledge on nitrification kinetics as affected by the aforementioned factors based on literature and the results from the authors’ laboratories. These factors were ranked according to their significance of impact on biofilter nitrification performance. The information presented can be used as a reference for the design and operation of biofilters in recirculating aquaculture systems.     

Likely Effects of the Increasing Alkalinity of Inland Waters on Aquaculture

The rising atmospheric carbon dioxide (CO₂) concentration is increasing the solubility of limestone, calcium silicate, and feldspars, resulting in greater total alkalinity concentration in inland waters. This phenomenon will result in inland waters having slightly greater alkalinity concentration (and buffering capacity), higher pH when at equilibrium with atmospheric CO₂, and more available carbon for photosynthesis. However, the changes in water quality will be small. Fluctuations in CO₂ concentration resulting from CO₂ use in photosynthesis by aquatic plants and release of CO₂ by respiration, acidity resulting from nitrification of ammonia nitrogen from feeding waste and fertilizer, and application of liming materials to ponds will continue to be the dominant factors affecting pH and alkalinity in waters of inland aquaculture systems.     

Effect of particulate organic carbon on heterotrophic bacterial populations and nitrification efficiency in biological filters

Competition between heterotrophic and nitrifying bacteria is of major practical importance in aquaculture biofilter design and operation. This competition must be understood to minimize the negative impact of heterotrophic bacteria on an aquaculture system. On the other hand, the heterotrophic population is suspected of having a positive effect against pathogenic bacteria. Little information is available on the bacterial communities present within aquaculture systems, except for nitrifying bacteria, but a combination of traditional aquacultural engineering research methods and novel microbiological techniques offers new opportunities for the study of these communities.

The heterotrophic bacterial population activity and the nitrification efficiency of a submerged biological filter were studied for an influent TAN concentration of 2 mg/l and varying C/N ratios. The TAN removal rate was found to be 30% lower at a C/N ratio of 0.5 than at a C/N ratio of 0. For higher C/N ratios the reduction in nitrification efficiency was 50% while the attached bacterial abundance was doubled. Moreover, results confirm that abundance of sheared and attached bacteria are correlated. It is not known to what extent biofilter configuration might influence the relationship between heterotrophic and nitrifying bacteria, and further work will be carried out with moving bed and fluidized filters. A better understanding of the role of the heterotrophic bacteria in RAS will help to optimize any positive “biocontrol” effect and to minimize the microbial degradation of rearing water and the reduction of nitrification rates.     

Waste management in recirculating aquaculture system through bacteria dissimilation and plant assimilation

Wastewater management and disposal in aquaculture is becoming increasingly important due to stringent water regulations regarding waste discharges into natural water systems. Recirculation aquaculture is one of the technologies designed to reduce waste discharge through the nitrification process. However, nitrification results in nitrate accumulation which is normally reduced by dilution through water exchange. Water exchange is only possible with sufficient water. Although nitrification is a conventional process, it has limitations because the autotrophic bacteria require long start-up and multiplication periods. The nitrifiers require high levels of oxygen with relatively higher aeration costs. Moreover, the bacteria are sensitive to rapid changes in pH, temperature, and flow rate. Denitrification can be a solution to the limitations of nitrification since denitrifiers are most abundant in the natural environment and have higher growth rates than nitrifiers. In addition, the process reduces energy costs since there is no need for aeration, water consumption is also reduced drastically since water exchange is minimized. Organic loading can be reduced when fish waste is utilized as a carbon source. An alternative process to manage aquaculture wastes is through anaerobic ammonium oxidation (anammox), where ammonia and nitrite are converted into nitrogen gas. Anammox can efficiently reduce ammonia and nitrites from culture water, but it has not received wide application in aquaculture. Aquaculture wastewater contains nutrients which are essential for plant growth. The plants maintain good water quality by absorbing the dissolved nutrients. Denitrification, anammox, and nutrient uptake by plants are feasible strategies to reduce wastes from aquaculture effluents.     

Does acidification lead to impairments on oxidative status and survival of orange clownfish Amphiprion percula juveniles?

Fish Physiology and Biochemistry - The nitrification process in recirculating aquaculture systems can reduce water pH. Fish can also be exposed to water acidification during transport, an important...     

盐碱和pH对鱼类生长和发育的影响

＂以渔改碱＂是开发利用我国约6.9×108km2低洼盐碱水域的有效途径。水体中的盐度过高会显著影响鱼类的渗透压调节、能量收支、生长发育、组织功能以及血浆电解质浓度等;碱度过高会引起＂碱病＂和多种异常生理、生化而迅速死亡。盐碱和pH对鱼类理化的影响还有协同作用,盐碱过高时对鱼产生联合毒性作用,pH值升高时同样也会加剧这种作用。本文综述了盐碱和pH对鱼类的理化影响、毒性作用等,探讨了鱼类在盐碱水中的生长机制,以期为盐碱水域的开发利用提供基础资料。     

Comparative analysis of nitrogen and phosphorus budgets in a bioflocs aquaculture system and recirculation aquaculture system during over-wintering of tilapia (GIFT,Oreochromis niloticus)

Nitrogen (N) and phosphorus (P) budgets in a bioflocs technology (BFT) aquaculture system and a recirculation aquaculture system (RAS) during over-wintering of tilapia (GIFT Oreochromis niloticus)for 64 d were compared in the current study. Fish feed was the major input of N in both systems, specifically, 94±0 % and 82±4 % for the RAS and BFT aquaculture system, respectively. The rate of N recovery in the BFT aquaculture systems was estimated to be 48±5 % of input N, which was significantly different from that of the RAS (37±4 %). There was no significant difference between the RASs and BFT aquaculture systems in terms of P recovery rate. The regular backwashing of the drum filter and biological filter in RAS accounted for 41 ± 2 % of input N and 39 ± 2 % of input P. Approximately 54 % of unassimilated nitrogen N was removed by nitrification in the BFT aquaculture systems. The results from the present study suggest that nitrification may be the dominant pathway for ammonia removal in a BFT aquaculture system rather than by heterotrophic bacterial assimilation.     

牡蛎壳作为生物絮凝养殖系统缓释碱度源的效果

为优化生物絮凝系统碱度调控策略,实验研究了在生物絮凝—罗非鱼养殖系统中牡蛎壳补充碱度的可行性。在系统启动阶段评估了不同牡蛎壳添加量0 g/L(对照组,A组)、0.36 g/L(B组)和0.72 g/L(C组)补充碱度的可行性。结果显示,C组碱度、pH和钙离子水平显著高于A组,但B与C组组间的水质差异不显著,牡蛎壳补充碱度效果明显。在生物絮凝系统启动阶段的基础上,对比研究了两种形态的牡蛎壳[(壳粉,E组)、(壳,F组)]为生物絮凝在罗非鱼养殖系统中补充碱度的效果。各组的水质指标、鱼体酶活免疫性能以及细菌群落组成均无显著差异,牡蛎壳及壳粉对罗非鱼生长没有明显的负面影响,可以被应用到生物絮凝养殖系统中,但补充碱度效果不明显。牡蛎壳补充碱度与形态无关。研究表明,在目前实验条件下,牡蛎壳在生物絮凝养殖系统中不能完全替代碳酸氢钠,还需进一步优化相关工艺。     

Efficiency of biofloc technology in suspended growth reactors treating aquacultural solid under intermittent aeration

Aquacultural solid waste from a recirculation aquaculture system was used as a substrate to produce heterotrophic bacteria in suspended growth reactors. The efficiency of nitrogen recycling under intermittent aeration (IA, 0.5-h aeration/0.5-h non aeration) and continuous aeration (CA) strategy was investigated. The nitrogen dynamics, biochemical composition of biofloc and efficiency of nitrification/denitrification/ammonium assimilation of biofloc were determined. No significant differences were observed in the nitrogen recycling rate, crude protein and polysaccharides contents of biofloc between the IA and CA reactors. The energy used for intermittent aeration was almost one half of that for continuous aeration. IA strategy (0.5-h aeration/0.5-h non aeration) appears to be more effective to produce biofloc in aquaculture solid waste in reactors than CA strategy.     

硝化型和光合自养型生物絮团对泥鳅生长、肠道菌群和水体微生物群落结构的影响

为了解硝化型和光合自养型生物絮团对于泥鳅(Misgurnus anguillicaudatus)的养殖效果, 设置清水组(CW 组)、硝化组(BFT 组)和光合自养组(ABFT 组)生物絮团养殖泥鳅 45 d, 比较泥鳅的生长和消化酶活性、两类絮团的营养组成情况, 以及养殖水体和泥鳅肠道微生物的群落结构。结果显示, BFT 组和 ABFT 组的饲料转化率、特定生长率和末均重没有显著性差异(P＞0.05)。与 CW 组相比, 两实验组的饲料转化率显著降低; BFT 组的终末密度与 CW 组相比没有显著性差异(P＞0.05)。与 CW 组相比, BFT 组和 ABFT 组生物絮团可以提供(36.69±1.17)%和 (40.20±1.05)%的粗蛋白; 与 BFT 组相比, ABFT 组的生物絮团粗脂肪含量显著提高(P＜0.05), 并且促进脂肪酸由饱和向不饱和转化。ABFT 的泥鳅胰蛋白酶和脂肪酶的活性显著高于另外两组(P＜0.05)。微生物群落分析表明, 添加藻类对成熟生物絮团 Alpha 多样性指数、群落门水平和属水平没有显著影响。泥鳅摄食生物絮团会导致肠道菌群 sobs 指数显著降低。BFT 组肠道的优势菌群为变形菌门(Proteobacteria)、放线菌门(Actinobacteriota)和绿弯菌门 (Chloroflexi); ABFT 组为变形菌门和蓝藻门(Cyanobacteria)。属水平上, ABFT 组检测到高水平的气单胞菌属 (Aeromonas)。本研究表明, 硝化型和光合自养型生物絮团养殖均适合作为泥鳅绿色健康养殖的新模式。