不同浸没模式下两种滤料对水产养殖废水处理效果研究

将生物陶环和珊瑚石两种滤料分别采用半浸没式和全浸没式实验处理养殖废水。结果显示,在2种过滤模式下,生物陶环、珊瑚石生物滤料的生物膜成熟时间分别为8 d和10 d。经过20 d的处理,4个实验组NH4＋-N, NO2--N, COD的浓度均显著低于对照组,相比于对照组NH4＋-N浓度降低51％以上, COD降低40％以上;半浸没过滤模式的实验组对NH4-N、 NO2--N的去除率均显著高于全浸没实验组;全浸没实验组对COD的去除率显著高于半浸没实验组。半浸没式过滤生物陶环实验组表面AOB数量最高,达4.68×102 cfu/g,全浸没实验组HB数量均显著高于半浸没实验组。结果表明所用4种处理方式处理养殖废水均有较好效果。     

燕尾草金鱼的选育试验

生物过滤技术是循环水养殖系统中很关键的水处理技术,选择合适的滤料在很大程度上决定着生物过滤效果的好坏和循环水养殖系统能否正常运行。本次试验对一种新型悬浮式滤料在循环水高密度养殖系统中的水处理能力进行了研究,结果表明:(1)该滤料的挂膜性能好,挂膜时间短,且生物膜状态稳定;(2)该滤料的生物过滤能力好,具有较高的氨氮去除率和氨氮负荷,最高分别为57.5%和182.9 g/(m~3·d);其亚硝酸盐去除率平均为45.4%。     

挂膜方式对流化床生物滤器启动及细菌群落结构的影响

为探讨挂膜方式对流化床生物滤器的启动时间及其对微生物群落结构的影响,了解流化床生物滤器的净水机制,并将其应用于中华鲟循环水养殖系统中,研究自然挂膜法和接种微生态制剂2种挂膜法工况下滤器的启动时间,并采用焦磷酸测序方法,分析不同时期滤器中微生物群落结构的变化。结果显示:采用接种微生态制剂挂膜法滤器启动的时间显著短于采用自然挂膜法。挂膜初期,两种挂膜方式下滤料载体表面微生物种类较少,其优势细菌都是厚壁菌门;生物膜成熟后,采用自然挂膜法的滤器中细菌群落的多样性显著高于采用接种微生态制剂培养法,并且群落结构更加稳定,筛选出的功能性细菌的比例也高于采用接种挂膜方式,如黄杆菌属和紫色非硫细菌等,表明采用自然挂膜法更利于流化床生物滤器的稳定运行。     

循环水养殖系统生物滤器负荷挂膜技术

循环水养殖系统启动运行前往往需要经过一段时间的生物膜预培养,使生物膜达到成熟稳定,从而保证系统的水质净化功能。本研究通过养殖试验,研究了生物滤器负荷挂膜的技术方法,以期实现生物膜的快速成熟和系统的快速启动。为此,构建了6组循环水系统组成的养殖车间,建成后立即投入试验生产。试验为期120 d,养殖种类为红鳍东方鲀,初始放养平均体重(632.5±2.26)g。期间,红鳍东方鲀平均增重29.91%,养殖成活率98.7%,养殖密度由(19.34±1.89)kg/m3增加到(32.17±3.40)kg/m3,投饵率由0.2%增加到0.5%–0.7%,每日换水量由50%逐渐减至10%。结果表明,在生物膜的生长期,通过对投饵量及新水补充量的有效调节,可以把养殖水体中的氨氮和亚硝氮浓度控制在安全范围以内,以保证养殖鱼类的生长。生物膜在50天左右达到完全成熟,此后便可依靠生物膜的净化作用将氨氮浓度控制在0.5?1.2 mg/L、亚硝氮浓度控制在0.2?0.5 mg/L、pH值控制在6.5–7.5、COD值低于4 mg/L、细菌总数控制在800–2100 cell/ml的安全范围内。利用生物滤器负荷挂膜技术,在合理调控水质指标的条件下,循环水养殖系统建成后可以立即投入生产,实现生物滤器挂膜与养殖生产的同步进行。     

几种环境因子对循环水养殖系统中生物膜净化效率的研究

为研究环境因子对生物膜水质净化效果,对爆炸棉为滤料的生物滤器进行了试验。采用优势菌种挂膜后,在不同水温、溶氧(DO)、盐度、p H条件下,研究生物滤器对人工加富的海水养殖废水水质的净化效果。结果显示,水温28℃时,化学需氧量(CODMn)、氨氮(NH4+-N)、亚硝酸盐氮(NO2--N)、磷酸盐(PO43--P)去除率分别为69.3%、93.7%、93.7%、19.4%;DO 6.00 mg/L时,CODMn、NH4+-N、NO2--N、PO43--P去除率分别为72.8%、91.7%、97%、15.6%;盐度25时,CODMn、NH4+-N、NO2--N、硝酸盐氮(NO3--N)、PO43--P去除率分别为57.1%、98.4%、99.9%、100%、42%;p H 7.5时,CODMn、NH4+-N去除率分别为72.8%、93.3%。研究表明,水温28℃、DO 6.00mg/L、盐度25和p H 7.5为该生物滤器最适水质净化条件,此时生物膜净化效率较高,出水水质较好。     

3种填料对集装箱循环水养殖废水处理的初步研究

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。     

导流式移动床生物膜反应器流速选择及流态分析

水力条件对反应器内生物膜的生长及流态形式起着决定性作用。实验分别用0.15,0.25,0.35 m/s的水流流速对内径为44 mm的管状生物膜反应器进行水力冲击,观察不同生物滤料的挂膜情况,并利用计算流体力学软件对导流式移动床生物膜反应器流态进行数值模拟。结果显示,在低流速的水力冲击下,生物滤料的挂膜效果最好,平均厚度约为70μm,且不同结构生物滤料的挂膜情况无明显差异;反应器的模拟曝气速度为0.6 m/s时,其内部的综合流动及挂膜效果最佳。因此可知,生物膜的生长情况与同种材质生物滤料的结构形状无关,但与滤料所处的水力情况有关,膜厚度随着水流速度的增大而减小;移动床生物膜反应器的曝气量大小及结构形状是影响其流态的重要因素。本研究可以为此类反应器的设计与高效运行提供基础数据。     

循环海水养殖系统中生物膜快速形成的模拟试验

在20L水箱中加入15L人工污水模拟工厂化循环水养殖系统的生物滤池,采用优势菌种挂膜法,对滤材种类、混合菌液添加比例及接种次数等条件进行了优化,确定了快速挂膜的最佳实验室工作条件。在21d内对试验水体中的NH+4、NO-3和NO-2进行了监测。试验结果显示,最优试验条件为使用塑料弹性滤材作为生物膜载体,每7d接种1次优势菌液,硝化细菌∶反硝化细菌∶芽孢菌∶动胶菌添加比例为2∶1∶1∶1,在此条件下,第7d开始形成生物膜,第14d生物膜基本形成,第21d形成均匀完整的生物膜。成熟的生物膜在15d内对水体NH+4的最大降解量可超过5.00mg/L,即成熟生物膜降解NH+4的速率为每日降解超过0.50mg/L。当初始NH+4为5.00~10.00mg/L,成熟生物膜对NH+4和NO-2的降解能力在15d内可达到上限。     

高效脱氮菌强化挂膜生物滤器对海水养殖尾水净化效果研究

为了提高海水养殖尾水的净化效率, 研究了利用高效脱氮菌强化挂膜后的生物滤器对静止和流动养殖尾水的净化效果。首先利用自主筛选的 3 株适应海水环境、可有效去除氨氮、亚硝酸氮及有机物的高效脱氮菌[花津滩芽孢杆菌(Bacillus hwajinpoensis)SLWX₂、嗜碱盐单胞菌(Halomonas alkaliphila)X₃ 和麦氏交替单胞菌(Alteromonas macleodii)SLNX₂]的不同组合强化挂膜, 根据成熟后的生物滤器对定量静止养殖尾水中 NH₄⁺ -N、NO₂^– -N、NO₃^– -N、 总氮(TN)及化学需氧量(CODMn)的去除效果, 选出对各无机氮去除效果最佳的菌种组合作为强化菌种再次挂膜, 分析不同浓度强化菌种挂膜对流动养殖尾水中 NH₄⁺ -N、NO₂^– -N 和 NO₃^– -N 的持续净化效果,以上实验均以自然挂膜组为对照。静止尾水处理实验结果表明, 各实验组中 NO₃^– -N 浓度先上升后下降, 对养殖尾水各项无机氮及有机物指标的去除效果均优于对照组。其中, SLWX₂+X₃+SLNX₂ 组合高浓度组对养殖尾水中的各项指标去除效果最佳, 在第 48 小时对 NH₄⁺ -N、NO₂^– -N、CODMn 和 TN 的去除率分别达到 100%、100%、80.7%和 59.5%。而自然挂膜对照组的去除率分别为 95.5%、50.52%、38.1%、13.44%, 且 NO3– -N 浓度持续上升。说明脱氮菌强化挂膜可明显提高生物滤器对养殖尾水的净化效率, 有效降低养殖尾水中氮素和有机物的浓度。后期连续流动尾水净化实验结果表明, 实验组和对照组生物滤器出水的 NH₄⁺ -N、NO₂^– -N、NO₃^– -N 浓度均低于进水的, 强化挂膜组的又均低于自然挂膜组的, 其中 106 CFU/mL 实验组对无机氮的去除效果均最佳, NH₄⁺ -N NO₂^– -N NO₃^– -N 的最大去除率分别为 31.6%、11.33%、 15.6%; 105 CFU/mL 实验组次之, 且出水氮素浓度可长期维持在较低水平。说明脱氮菌强化挂膜对各项无机氮的去除效果持续优于自然挂膜。本实验的结果为脱氮菌在海水养殖尾水净化中的应用提供了理论基础和技术支撑。     

凡纳滨对虾(Litopenaeus vannamei)循环水养殖塘挂膜式生物滤器内微生物的多样性

为了解凡纳滨对虾(Litopenaeus vannamei)养殖过程中挂膜式生物滤器内不同位置间微生物群落结构多样性的差异,采集已运行46 d的挂膜式生物滤器内挂膜上部外侧和内侧、下部内侧和外侧及收集盘5个不同位置的微生物,采用分子生物学手段,通过16S rRNA基因高通量测序法对生物滤器内微生物进行多样性分析,并对不同位置间功能性微生物进行对比.结果显示,在门水平上,5个不同位置共鉴定出10个主要类群,其中,变形菌门(Proteobacteria)所占丰度比例较大,为主要优势类群,硝化螺旋菌门(Nitrospirae)在挂膜内外两侧检出比例均较高(平均4.3％),收集盘内则较低(0.33％),存在显著性差异.共鉴定出41种优势属,其中地杆菌属(Pedobacter)为绝对优势种属,短小盒菌属(Parvularcula)为次优势属,二者丰度比例均在10％以上,硝化螺旋菌属(Nitrospira)为第三优势属,挂膜不同位置丰度比例(平均4.31％)显著高于收集盘内比例(0.28％).挂膜上氨氧化细菌(AOB)平均丰度比例为1.70％,硝化细菌(NOB)平均比例为6.99％,是系统中主要去除氨氮和亚硝酸氮的微生物.生物滤器各部位微生物物种多样性丰富,微生态系统稳定,可有效维持循环水系统的水质.生物滤器硝化作用主要在上部进行,下部净化能力较弱,收集盘内基本没有硝化能力.生产中应合理配置挂膜数量,科学设计挂膜长度以提高生物滤器的净化效率.     

Development of a Model to Simulate Nitrogen Dynamics in an Integrated Shrimp–Macroalgae Culture System with Zero Water Exchange

The effluents of traditional shrimp monoculture cause pollution and promote eutrophication and hypernutrification of the receiving coastal ecosystems. Integrated aquaculture and a recirculating aquaculture system (RAS) have been proposed as an alternative to address these problems. In this study, we developed a dynamic model to simulate the concentration of total ammonia nitrogen (TAN), nitrite, and nitrate in an integrated culture of whiteleg shrimp, Litopenaeus vannamei, and seaweed, Gracilaria vermiculophylla, in a recirculating and zero water exchange system, and the effect of nitrifying and heterotrophic bacteria was also included. The experiments demonstrated that a dynamic model can explain the concentrations of dissolved inorganic nitrogen and variations in these concentrations over time in the integrated culture. The results also suggest that nitrifying and heterotrophic bacteria play an important role in the transformation of dissolved nitrogenous compounds; therefore, these bacteria should be considered within the dynamics of nitrogen in integrated systems with low water exchange.     

半滑舌鳎的循环水养殖模式及经济效益分析

2009年3月至10月进行了半滑舌鳎(Cynoglossuss semilaevis Guanther)生产性养殖试验,期间对一套循环水养殖系统的水处理效果及半滑舌鳎养殖模式进行了深入的研究。养殖水体经系统处理后,养殖池内水温18～21℃,pH 7.0～8.0,DO≥6.6 mg/L,养殖池进水氨氮0.017～0.178 mg/L,亚硝酸氮0.012～0.064mg/L。文中详细阐述了放苗前养殖车间消毒、苗种选择与运输、生物滤池的培养、苗种投放、养殖过程中系统的日常维护、饵料投喂、光照控制、水质因子控制等内容,并对养殖半滑舌鳎8个月的经济效益进行了分析。以期为国内工厂化循环水养殖半滑舌鳎提供技术支持和经济效益分析方面的参考。     

封闭循环水系统生物滤池气水比对水质净化效能的影响

通过在全封闭循环水系统中养殖半滑舌鳎(Cynoglossus semilaevis Gunthe), 研究了不同气水比对曝气生物滤池净化效能, 以及对DO、pH值的影响。结果表明: 本试验系统在温度为(19±1)℃, 系统循环次数为15次, 养殖池DO保持在12 mg/L以上的运行条件下, 随着气水比由0.75 : 1~1.50 : 1的增加, 生物滤池氨氮的去除率由35.0%增加至52.0%, NO₂-N的去除率由8.2%增加至44.6%, 气水比对硝化反应影响显著, 但对化学需氧量COD的去除率影响并不显著, 其平均去除率为10.14%; pH值有增加的趋势, 生物滤池进水口到出水口的pH值由7.97增加至 8.08; 气水比最佳运行参数为1.25:1。同时还发现1级生物滤池进水口DO接近饱和, 1级到末级滤池间DO仅降低了10%左右, 系统pH值在7.9~8.1。本研究所获参数, 可供生物膜法处理养殖循环水的条件优化作参考。

     

Use of fluidized bed biofilter and immobilized Rhodopseudomonas palustris for ammonia removal and fish health maintenance in a recirculation aquaculture system

Intensive recirculating aquaculture relies on biofilters to sustain satisfactory water quality in the system. Fluidized bed and immobilized cell technologies were used to remove ammonia from the water and maintain fish health. A high‐rate nitrifying fluidized bed biofilter combined with valveless filter was designed for use in a recirculation aquaculture system (RAS). The suspended solids produced during fish culture could automatically be removed using a valveless filter. Natural porosity with fitting proportion, steady fluidization and expanding rate was chosen as the fluidized carrier. The technology of bacterial separation and cultivation was used. The immobilized Rhodopseudomonas palustris (R. palustris) produced through a biotechnologically embedding medium is suitable for fish and could help prevent diseases. Nitrification was promoted through the selective rearing of nitrobacteria in a fluidized bed biofilter. Water quality was improved using fluidized bed biofilter and immobilized R. palustris in the RAS. In addition, the proposed system was able to reduce costs. Maximum fish load was 45 ± 3 kg m^?3 in the closed recirculating water fish culture system, and water use was reduced by 80–90%. The total ammonia nitrogen removal rate of the technology was 80–95%, and nitrite N removal rate was above 80%.     

A comparison of topologies in recirculating aquaculture systems using simulation and optimization

Recirculating aquaculture systems (RAS) are often designed using simplified steady-state mass balances, which fail to account for the complex dynamics that biological water treatment systems exhibit. Because of the very slow dynamics, experimental development is also difficult. We present a new, fast and robust Modelica implementation of a material balance-based dynamic simulator for fish growth, waste production and water treatment in recirculating aquaculture systems. This simulator is used together with an optimization routine based on a genetic algorithm to evaluate the performance of three different water treatment topologies, each for two fish species (Rainbow trout and Atlantic salmon) and each in both a semi-closed (no denitrification) and a fully recirculating version (with denitrification). Each case is furthermore evaluated at both saturated and supersaturated oxygen levels in the fish tank influent. The 24 cases are compared in terms of volume required to maintain an acceptable TAN concentration in the fish tank. The results indicate that the smallest volume is obtainable by introducing several bypass flows in the treatment system of a semi-closed RAS and that the gains can be significant. We also show that recycling already treated water back upstream in the treatment process degrades performance and that if one wishes to have a fully recirculating system with minimal water exchange, then the flows of oxygen, carbon and nitrogen must be carefully considered. For several of the cases, no optimum with denitrification could be found. We thus demonstrate that the best configuration and operation strategy for water treatment varies with the conditions imposed by the fish culture, illustrating the complexity of RAS plants and the importance of simulations, but also that computer-driven optimal design has the potential to increase the treatment efficiency of biofilters which could lead to cheaper plants with better water quality.     

生物强化反应器净化循环养殖废水的研究

利用生物膜的高效截留原理,设计了生物强化反应器,在装有弹性纤维载体的反应器内接种具有硝化反硝化作用的复合菌群,经6周左右的人工挂膜后,弹性纤维载体表面出现了肉眼可见的生物膜。试验以循环养殖废水为研究对象,探讨了不同水力停留时间(HRT)和温度(WT)对生物强化反应器净化水质效果的影响。结果显示,HRT和WT对生物强化反应器净化养殖废水效果的影响显著(P<0.05)。对HRT和WT各处理水平下的COD_Mn、TN和NH ₄-N去除率进行差异显著性分析,并综合考虑反应器的运行时间、费用和操作等因素,选取HRT=18 h、WT=30 ℃作为反应器的最佳运行条件,在此条件下反应器稳定运行3周左右。试验期间,COD_Mn、TN及NH ₄-N的平均去除率分别达44.18%、51.31%及82.08%。此外,还对反应器内载体表面的生物膜进行了可培养微生物数量动态监测。强化反应器在正式运行的25 d内,其生物膜上的可培养微生物数量不断增多,氨氧化细菌数量由35.91?10⁴ CFU/mg增长到89.43?10⁴ CFU/mg,硝化细菌数量由25.75?10⁴ CFU/mg增长到61.65?10⁴ CFU/mg,反硝化细菌数量由14.23?10⁴ CFU/mg增长到100.95?10⁴ CFU/mg；氨氧化细菌和硝化细菌在与氮素循环相关的可培养细菌中占据着主导地位(59.95%～81.25%)。脱氮细菌不断地吸附于载体表面,并成功地定殖和繁殖使得生物膜不断成熟和稳定(TN和NH ⁴-N去除率分别达51.31%及82.08%)。结果表明,生物强化反应器对循环养殖废水中COD_Mn、TN和NH ₄-N的去除效果明显。     

Problems affecting nitrification in commercial RAS with fixed-bed biofilters for salmonids in Chile

The present case study focused on the problems that affect the nitrification process at three commercial recirculating aquaculture systems (RAS) for salmonids with fixed-bed biofilters operating in Chile, where the main factors were found to be management problems: (1) large variations in daily feeding, which results in unstable nitrogenous compounds (TAN, NO₂⁻, NO₃⁻) concentration; (2) variable daily water exchange, producing unstable culture conditions (variations in pH and temperature); (3) high densities of culture, which results in overall bad culture conditions (high CO₂ concentration, high amount of fine solids, high oxygen consumption). When properly managed, the RAS have proven to tolerate up to 15% of daily variation in feeding, as low as 10% of daily “new” water inlet, and densities as high as 60 kg fish/m³ without showing any nitrification problems. The results from this study demonstrates that maintaining good water quality is essential to secure an efficient growth of both the target species and the nitrifying bacteria, therefore, the production strategies should consider both the target species and the nitrification process requirements.     

循环水系统结合鱼菜、紫外处理对镜鲤生长及水质的影响

为探索绿色环保的循环水养殖模式,设计循环水鱼菜共生系统(鱼菜组)、紫外灯鱼菜共生系统(鱼菜紫外灯组)及循环水养殖系统(循环水组),比较三种不同处理方式对镜鲤(Cyprinuscarpio var.specularis)、叶用莴苣(Lactuca sativa var.ramosa)生长和养殖水质的影响。结果显示,鱼菜组、鱼菜紫外灯组处理对镜鲤的生长无显著影响,但会显著影响镜鲤形态学指标,鱼菜组镜鲤肠体比显著低于循环水组。体成分方面,鱼菜组全鱼粗蛋白、粗脂肪显著高于循环水组,鱼菜组肝脏粗蛋白显著低于循环水组。鱼菜紫外灯组的细菌总数显著低于鱼菜组。水质方面,鱼菜组、鱼菜紫外灯组可显著降低系统中氨氮、硝酸盐氮及总磷总氮含量,鱼菜紫外灯组硝酸盐氮、总磷及总氮含量显著高于鱼菜组。综上所述,循环水系统耦合水培蔬菜单元可改善系统水质,改善鱼体成分,并且结合紫外灯处理可降低水体细菌总数。     

我国水产养殖设施模式发展研究

作为世界水产养殖大国,我国的养殖设施模式要走上可持续发展的轨道,应该在为健康养殖提供进一步保障的前提下,更加注重系统在"节水、节地、节能、减排"方面的功效。养殖池塘、流水型养殖设施、循环水养殖设施和网箱养殖设施是我国集约化养殖的主要设施模式。这些设施在发挥巨大生产力的同时,在养殖水环境控制、水资源利用、生产系统效益、系统对环境的影响等方面,不同程度地存在着问题或矛盾,没能发挥出现代设施系统在健康养殖和产业可持续发展上应有的作用。本文在对以上4种主要养殖设施模式进行分析的基础上,结合养殖设施科技领域的研究成果,提出未来我国水产养殖设施模式的发展方向以及需要解决的重大科技问题,包括池塘工程化生态养殖设施、节水型养殖设施、经济型循环水养殖设施、系统化深水网箱养殖设施等4种发展模式。     

Effect of Stocking Density on Growth,Physiological Responses,and Body Composition of Juvenile Blunt Snout Bream,Megalobrama amblycephala

The impact of stocking density on growth performance, physiological indicators, and body composition of juvenile blunt snout bream in recirculating aquaculture system was investigated in this study. Juvenile blunt snout bream were raised at stocking densities of 75, 150, 225, 300, and 450 fish/m³ for 12 wk with three replicate tanks at each density. All treatment tanks were supplied with water from the same recirculating system to ensure uniformity of water quality across groups. This study has shown that higher stocking densities had a negative effect on individual growth performance. Final body mass, specific growth rate (SGR), and weight gain decreased significantly as stocking density increased. Individual body mass as well as body length were more uniform in fish stocked at densities of 75 and 150 fish/m³ than in other groups. Stocking densities of 225 and 300 fish/m³ resulted in significant increases in serum total protein, triglyceride, lactate, and cholesterol levels, whereas blood glucose concentrations decreased significantly. In addition, decreased body lipid content and increased body moisture content were observed at stocking densities of 300 and 450 fish/m³. Overall, a density of 150 fish/m³ resulted in higher SGR and more uniform size among juvenile blunt snout bream.