玉米芯强化生物反应器对罗非鱼循环养殖废水脱氮效果研究

研究了以玉米芯同时作为反硝化碳源和生物膜载体的人工强化生物反应器对罗非鱼(Oreochromis spp.)循环养殖废水的脱氮效果,并对新型反应器脱氮微生物多样性进行了分析。结果表明,实验室条件下,人工强化挂膜方式可明显缩短装置的启动时间,新型脱氮装置具有良好的脱氮效果,氨氮可从(8.00±2.22)mg·L~(-1)降至3.50 mg·L~(-1),硝酸盐可从(31.50±1.57)mg·L~(-1)降至0.5 mg·L~(-1),较好地实现了高溶氧养殖废水的同步硝化反硝化作用,总氮去除率达85%以上。微生物群落结构分析表明,人工富集培养的硝化菌和反硝化菌均较为成功,随着装置运行时间的延长,玉米芯表面生物膜菌群也随之发生变化,参与脱氮的硝化细菌菌属主要由亚硝酸螺菌属(Nitrosospira)、亚硝酸单胞菌属(Nitrosomonas)、亚硝酸球菌属(Nitrosococcus)3个属组成;丰度最大的反硝化菌属为产碱菌属(Alcaligenes)、副球菌属(Paracoccus)、假单胞菌属(Pseudomonas)和脱氮硫杆菌(Thiobacillus denitrificans)。     

移动床生物膜反应器处理低浓度氨氮养殖废水试验

采用移动床生物膜反应器(MBBR)处理低浓度氨氮养殖废水,在不同水力停留时间(HRT)和不同曝气条件下,分析MBBR处理人工模拟的低浓度氨氮(2 mg/L左右)养殖废水的进出水氨氮、亚硝酸盐氮和硝酸盐氮的浓度变化,探讨HRT和曝气量对MBBR处理低浓度氨氮养殖废水的影响,并以实际鲟鱼养殖废水(氨氮浓度0.5～1.5 mg/L)和其他研究成果进行验证和比较.结果显示:MBBR的最优HRT为6～8 min,最优曝气量为180 L/h,相应的氨氮去除率为70％ ～ 75％,氨氮去除负荷为560～700 g/(m3.d),填料生物膜厚度为26～38 μm;膜表层结构多样,物种丰富,膜生长良好.该反应器对处理低浓度氨氮养殖废水具有的高效能力.     

封闭循环水产养殖系统中三种生物滤池除氨氮效果的比较

分析了封闭循环水产养殖系统中生物滤池所采用的软性滤料、弹性滤料、半软性滤料3种生物滤料的特点,对填装这3种滤料的生物滤池处理养殖污水中氨氮的能力进行了比较和分析。实验结果表明,(1)在同样的水力停留时间下,加入同体积滤料的3个生物滤池对氨氮的去除能力不同,3个生物滤池的氨氮去除率均随着进水氨氮质量浓度的增加而降低;(2)在不同的水力停留时间条件下,每个生物滤池对氨氮的去除能力不同,水力停留时间为80 min时的氨氮去除率最高。在该系统中综合考虑水力停留时间及滤料的不同,弹性滤料滤池在水力停留时间为80 min时去除氨氮的效果最好,平均去除率达到53.2%。     

泰国海水养殖废水生物净化与循环利用技术

1泰国海水养殖简况泰国目前约有35000个水产养殖场,从业人员50多万,养殖品年产量近33万t。主要养殖品种有斑节对虾、南美白对虾、泥蚶、紫贻贝、牡蛎、鲈鱼等,其中虾类占绝对优势。泰国的海水虾类养殖已成为国民经济的支柱产业之一,目前其产量占世界总产量的近1/3,年销售额约20     

动物生物反应器的应用现状

简要介绍了国外制作转基因动物的常用方法,如显微注射法、逆转录病毒介导法、配子介导法、干细胞法和核移植法等方法和原理及应用上的优劣。并综述了动物生物反应器的分类及其在生产中应用的范围和效果,概括了目前国外在动物转基因生物反应器上取得的成果,为我国动物生物反应器的研究提供技术依据。     

微藻生物反应器的研究进展

微藻在转化太阳能和生产各种代谢产物方面有着无可比拟的优越性。因其独特的营养和药用价值等,微藻被广泛应用于食品、医药、饲料、甚至能源等诸多领域。生物反应器是微藻大量培养的一场革命,它使微藻高效、大规模化生产成为可能。概述了微藻生物反应器的研究历史、现状,对我国在微藻生物反应器研究方面取得的进展以及微藻生物反应器应用前景进行了综述。     

水生生物协同净化罗非鱼废水试验

利用微生物絮凝物——蚤状浸——浮萍、空心莱对罗非鱼废水进行净化处理，探讨水生生物协同净化罗非鱼废水的过程及它们之间的相互关系。     

生物强化移动床生物膜反应器处理水产养殖循环水初步研究

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。     

应用生物脱氮新技术处理循环养殖废水的研究

由于氨氮的传统去除在工艺运行上有多方面的局限性,寻求低价可靠的生物完全脱氮工艺,成为循环水养殖系统中亟待突破的关键技术,近年来迅速发展的一些生物脱氮新技术为解决这一难题提供了新的思路。综述了循环养殖废水脱氮研究现状及生物脱氮新技术,指出了将脱氮新技术应用于养殖废水处理具有的多方面的优点及存在的一些有待于研究解决的问题。     

转基因动物乳腺生物反应器研究概况

转基因动物乳腺生物反应器经历了近20年的研究,取得了巨大的进展。本文主要介绍了乳腺生物反应器的概念、原理、建立、鉴定、特点以及乳腺生物反应器特别是在生产基因工程药物上的应用,并对我国的研究状况做了一个概述。     

欧洲循环水养殖系统研究进展

欧洲循环水养殖系统技术随着欧盟和欧洲各国环保法规的加强而不断创新和发展。本文对欧洲正在使用生命周期法对循环水养殖进行环境影响评估的状况,以及欧洲应用独特的循环水养殖系统技术增加了养殖的品种进行了介绍和分析。并着重介绍了欧洲循环水养殖系统新技术的应用及其发展状况,特别阐述了脱硝反应技术、淤泥浓缩技术和臭氧技术等新技术在循环水养殖系统的应用情况。在此基础上,指出了循环水养殖可能面临的新挑战。     

不同水力停留时间条件下PCL为碳源去除水产养殖水体硝酸盐的效率及微生物群落分析

构建以丝瓜络为碳源的固相反硝化系统,探究不同水力停留时间 (HRT)和进水硝酸盐浓度 (INC)下该系统的反硝化性能,为丝瓜络作为水产养殖尾水反硝化碳源的工艺优化提供理论依据。以丝瓜络 ( LS)为一维反硝化反应器 (denitrification reactor, DR)外加碳源,在流场环境下,测定不同HRT (16、20、24和28 h)和INC (50、75、100和125 mg/L)下反硝化系统对硝酸盐氮 (NO₃⁻-N)、亚硝酸盐氮 (NO₂⁻-N)、氨氮 (NH₄⁺-N)、总氮 (TN)、总磷 (TP)和化学需氧量(CODcr)的去除效果。并采用高通量测序技术对丝瓜络反硝化反应器 (LS-DR)在运行初期和末期时的细菌群落结构进行分析。当INC为50 mg/L,HRT为24 h时,LS-DR对NO₃⁻-N和TN均有较好的去除效果,去除率分别为98.97%±0.52%和97.84%±0.94%,此时出水NO₂⁻-N浓度也达到较低水平 (小于0.5 mg/L);在HRT为24 h的基础上,当INC增加至75、100和125 mg/L时,其NO₃⁻-N去除率和NO₃⁻-N去除速率 (NRR)均随INC的增加而显著增加,出水COD则随INC的增加而降低,但均未实现完全反硝化,然而,LS-DR在整个实验期间均能完全去除NH₄⁺-N;扫描电镜结果显示,丝瓜络表面结构有利于微生物附着生长;高通量测序结果显示,LS-DR的优势菌门包括变形菌门 、拟杆菌门 、弯曲杆菌门 、厚壁菌门 和疣微菌门;被鉴定的优势菌属中热单胞菌属 (1.46%)、陶厄氏菌属 (0.55%)、固氮螺菌属 (3.32%)、Simplicispira (1.01%)、假黄色单胞菌属 (0.39%)、草螺菌属 (3.02%)和Uliginosibacterium (0.9%)主要参与反硝化的进行,Cytophaga xylanolytica (1.61%)和Cloacibacterium (2.69%)主要参与了丝瓜络的降解,黄杆菌属 (1.17%)和Diaphorobacter (0.64%)既能进行反硝化,也能降解丝瓜络。LS-DR的最佳HRT为24 h,最适宜的INC为50 mg/L。本研究为丝瓜络固相反硝化工艺的优化提供了理论基础,为开发新型缓释碳源在养殖尾水处理中的应用提供参考。

     

Microscreen effects on water quality in replicated recirculating aquaculture systems

This study investigated the effects of three microscreen mesh sizes (100, 60 and 20 μm) on water quality and rainbow trout (Oncorhynchus mykiss) performance compared to a control group without microscreens, in triplicated recirculating aquaculture systems (RAS). Operational conditions were kept constant during a 6-week period where the microscreens were manually rinsed three times a day. The effects of microscreen cleaning frequency and nitrification performance were subsequently assessed.Compared to the control group, microscreens removed particles, reduced particulate organic matter, and increased β-values. Particulate parameters reached steady-state in all treatment groups having microscreens at the end of the trial. The time to reach equilibrium seemingly increased with increasing mesh size but the three treatment groups (100, 60 and 20 μm) did not significantly differ at the end of the trial. Increased backwashing frequency over a 24-h period had no further significant effects on the parameters measured. The results demonstrated the role and importance of a microscreen, and showed that mesh size, within the range tested, is less important at long operations under constant conditions.Fish performed similarly in all treatments. Preliminary screening of trout gills did not reveal any pathological changes related to microscreen filtration and the resulting water quality. Biofilter performance was also unaffected, with 0′-order nitrification rates (k_0a) being equivalent for all twelve systems (0.148 ± 0.022 g N m⁻² d⁻¹).Mechanisms for RAS equilibrium establishment, within and between systems with different mesh sizes, are discussed.     

微生物固定化载体筛选及其水质处理效果研究

为得到吸附能力强、水质处理效果良好的微生物固定化载体,本实验沸石、火山石、陶环、核桃壳、牡蛎壳五种不同载体对蜡样芽孢杆菌(Bacillus cereus,NY5株)的负载性能,以及在以养殖废水作为空白对照,游离NY5作为阳性对照的条件下,不同载体固定NY5对养殖的处理效果,并利用主成分分析法对水质处理效果进行综合评价。结果显示:沸石和牡蛎壳对NY5的负载性能较好,载菌量分别达1.25×10~9、9.0×10~8CFU/g;在养殖废水处理方面,火山石NY5组第7天、牡蛎壳NY5组第21天时NH_4~+-N浓度与空白对照相比分别降低53.4%、56.6%;火山石NY5组第7天时NO_3~--N浓度与空白对照相比降低87.9%;第28天时火山石NY5组、牡蛎壳NY5组NO_2~--N浓度与空白对照相比分别降低90.1%、80.2%;第14天时火山石NY5组TN浓度与空白对照相比降低51.6%。从主成分分析的结果也可以看出,火山石NY5组和牡蛎壳NY5组对养殖废水综合处理效果较好。     

循环水养殖系统生物挂膜的消氨效果及影响因素分析

针对工厂化循环水养殖系统,利用海水中的自然净化微生物挂膜,挂膜成功后,形成了很好的硝化作用,进行不同水温、进水氨氮浓度和水力停留时间(HRT)影响因素实验。结果表明,相同的进水氨氮浓度,随着水温的升高,不同水温之间氨氮浓度变化差异显著(P0.05)。在28℃水温时,经过生物膜120 h的净化处理,进水氨氮浓度降低到最低;随着进水氨氮浓度和HRT的增大,氨氮去除率及特殊去除率也不断的增大,但在同一进水氨氮浓度下,氨氮特殊去除率随着水力停留时间的延长反而降低。     

Peracetic acid degradation and effects on nitrification in recirculating aquaculture systems

Peracetic acid (PAA) is a powerful disinfectant with a wide spectrum of antimicrobial activity. PAA and hydrogen peroxide (HP) degrade easily to oxygen and water and have potential to replace formalin in aquaculture applications to control fish pathogens, for example the ectoparasite, Ichthyophthirius multifiliis.We studied water phase PAA and HP decay in three aquaculture situations, i) batch experiments with two types of system waters, ii) PAA decay at different fish densities, and iii) degradation of PAA in submerged biofilters of recirculating aquaculture systems (RAS). Furthermore, effect of PAA on the nitrification activity and the composition of the nitrifying population were investigated.PAA and HP decay showed first order kinetics. High dosage PAA/HP in water with low COD inhibited HP removal, which was not observed in water having a higher COD content. PAA decay was significantly related to fish stocking density, with half life constants for PAA of 4.6 and 1.7 h at 12 and 63 kg m^− 3, respectively.PAA application to RAS biofilter showed rapid exponentially decay with half life constants of less than 1 h, three to five times faster than the water phase decay rates.Biofilter surface specific PAA removal rates ranged from 4.6 to 13.9 mg PAA m^− 2 h^− 1 and was positively correlated to the nominal dosage. Low PAA additions (1.0 mg L^− 1) caused only minor impaired nitrification, in contrast to PAA application of 2.0 and 3.0 mg L^− 1, where nitrite levels were significantly increased over a prolonged period, albeit without fish mortality. The dominant ammonium oxidizer was Nitrosomonas oligotropha and the dominant nitrite oxidizer was Nitrospira. Based on the present findings and other recent results from field and in vitro studies, application perspectives of PAA are discussed.     

Economic feasibility of recirculating aquaculture systems in pangasius farming

This study aims to analyze the economic feasibility of recirculating aquaculture systems (RAS) in pangasius farming in Vietnam. The study uses a capital budgeting approach and accounts for uncertainty in key parameters. Stochastic simulation is used to simulate the economic performance of medium and large farms operating with a traditional system or RAS. Data are obtained through structured surveys and a workshop in the Mekong River Delta. Results show that for large farms, net present value increases from an average of 589,000 USD/ha to 916,000 USD/ha after implementing RAS. Overall, the probability that RAS is a profitable investment is found to be 99% for both farm sizes. With RAS, the crucial parameters determining profitability are price, yield, costs of fingerling, feed, and initial investment. Findings on the robustness of the economic performance of RAS are useful to support public and private decision making towards increasing the sustainability of pangasius production.     

Membrane performance and fouling behavior of membrane bioreactors installed in marine recirculating aquaculture systems

Accumulation of fine suspended solids and colloids in a recirculating aquaculture system (RAS) can be avoided by integrating a membrane filtration unit into the system, where the inclusion of a membrane bioreactor (MBR) may be an alternative. The main purpose of the study was to identify how the feeding regime affected membrane performance and fouling phenomena caused by dissolved and submicron colloidal particles in the system, and how the membrane impacted general water quality and particle characterization. To be able to evaluate membrane performance and fouling behavior, transmembrane pressure (TMP) was monitored and assessed in relation to changes in rearing conditions and different water quality parameters observed. From this study the positive influence on the chosen water quality parameters was apparent, where an improved water quality was observed when including a membrane filtration in RAS. Selected water quality parameters and TMP changed during the experimental period in response to the feeding regime, where algae paste, decaying rotifers and dry feed seemed to contribute the most to membrane fouling. Analysis of the concentration of submicron particles and particle size distribution (PSD) (particles < 1 μm) showed both a higher concentration and a more spread distribution in the rotifer/algae paste and dry feed period compared to the Artemia period, which might explain the observed increase in fouling. This study also showed that adapted procedures for concentrate removal are important to prevent hydrolysis of retained particles in the concentrate and leakage of nutrients and organic matter back to the system.     

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。