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。     

池塘工程化循环水养殖试验

经济效益是每家生产企业追求的目标,池塘养殖业因为追求高效益,采取了高密度养殖,这样势必会造成病害传播及养殖水域的污染。现在渔业发展对养殖水体环境及排放的要求非常重视,我国在2018年制定了水产养殖水排放标准,养殖者必须遵守。近年来我中心对天津市的62家水产生产企业进行了尾水监测,监测结果显示,大部分池塘富营养化、COD超标,尤其是高密度养殖池塘。多年来水产工作者摸索了各种养殖模式,不断探索池塘养殖在追求经济效益的同时不破坏养殖水域环境的养殖模式。2016年,通过参观学习交流,摸索出了适于天津的池塘养殖模式“池塘工程化循环水养殖技术集成”。它是将一片池塘分成生态净化区、水质净化区、养殖水槽3个区域,水体在池塘中循环流动,养殖水除蒸发和渗漏需适当补水外,养殖水达到零排放,实现了经济效益和环境效益双赢,此养殖模式有很好的发展前景,还有很多值得探索和提升的空间,对池塘养殖的发展有重要意义。2017年开始进行了3个养殖企业的试点建设,2018年开始向全市推广。本文详细介绍了池塘工程化循环水养殖技术,以期为这一养殖模式的推广提供技术指导。     

封闭循环水工厂化养殖实用模式试验

本试验为工厂化养鱼实用技术模式研究中的一个试验专题 ,主要在高密度循环水养殖条件下对鱼体生长特性进行观测 ,并提出适宜的投放密度、养殖周期及养殖系统中理化因子对鱼体生长的影响。试验于 2 0 0 2年 5月至 7月。经过 60d(天 )工厂化养殖试验 ,罗非鱼产量 78.2kg/m3,淡水白鲳产量 82 .2kg/m3。产生经济效益 ,罗非鱼为 96.77元 /m3,淡水白鲳为 44.84元 /m3。1　材料和方法1 .1封闭循环水养殖系统本试验采取全封闭循环水养殖系统 ,利用曝气、沉淀、过滤、生物净化等手段迅速去除养殖对象的代谢产物和饵料残渣 ,使水体得到净化并重复使用 …     

池塘循环水养鱼技术

池塘循环水养鱼是国内首创的一种高效、节能的高产养鱼技术,一般要比常规养鱼增产30—40%。其作用是通过把池塘静水用动力设备变成微流水后,达到调节水质,改善池塘生态环境,促进鱼类生长的目的,所以是培育大规格鱼种、亲鱼,促进其性腺发育,提高饲料利用率及降低生产成本的一项新的高产养碴方式。其技术要点是:     

池塘循环水养殖试验

<正>实施封闭与半封闭养殖,减少排污量和用水量、减少疾病的交叉感染和蔓延以及化学药物的使用,保护自然生态环境,开展节水节能、高效、环保型的水产养殖生产是非常有必要的。为此,我们在无公害养殖基地示范区进行了池塘循环水养殖试验。     

封闭循环水养殖系统中池塘覆膜对水质的影响

2005—2010年,对天津市天祥水产有限公司封闭循环水养殖系统水质进行了检测。结果显示:养殖池塘是否覆膜、覆膜面积大小,均会使整个养殖系统中的总硬度(TH)、总碱度(AT)、NH3-N和PO4-P在时空上产生差异。时间上,它们年份间差异极显著(P<0.01);空间上,各采样点的AT和NH3-N差异显著(P<0.05)。覆膜使系统的TH和AT稳定性减弱,CV上升了166.5%～241.7%,这种情况在养殖中期尤为突出,但对NH3-N和PO4-P稳定性的影响并不明显。养殖系统中较大面积的覆膜(43.65%)对养殖池塘TH、AT和NH3-N稳定性的影响比非覆膜池塘的大,CV分别高出了75.9%、135.6%和21.6%;而小面积(19.2%)覆膜的养殖池塘相对非覆膜池塘稳定,CV分别降低了71.9%、41.5%和91.4%。导致它们间差异及稳定性变异的原因主要归结于覆膜影响了物质与土壤间的物质交换及其间的生物活性强度。     

池塘循环水养殖技术

2008年我们在常州市武进区前黄镇湖滨村境内的常州市水产良种引繁中心的滆湖养殖基地,进行了淡水池塘循环水养殖技术的试验,通过建立集约化养殖区、生态化养殖区、尾水汇集区、生物净化区、净水     

封闭循环水养殖哲罗鱼试验

在水温15~17℃下,将5 000尾平均体质量(10±3)g的哲罗鱼Hucho Taimen幼鱼饲养在由24个直径1 800mm×高1 000mm养殖池组成的封闭循环水系统中,以探索工厂化循环水养殖哲罗鱼的主要技术参数。经过8个月的养殖表明:养殖密度达到31.8kg/m~3,成活率96%,肥满度为1.01~1.30,鱼的平均体质量增加350g,体长增加21.3cm,鱼体生长状况良好。生物滤器两天反冲洗一次,有效提高了生物滤器的氨氮转化效率;紫外线消毒方式有效对系统进行了消毒杀菌;监测表明,系统水处理效果显著,其中NH_4~-平均浓度维持在(0.56±0.05)mg/L;NO_2~-含量为(0.15±0.05)mg/L;NO_3~-平均浓度为(41.86±2.62)mg/L;溶解氧为8.37~9.45mg/L;p H8.21~8.63。     

池塘循环水清洁养殖技术探讨

滆湖流域精养池塘平均667m^2产量达1500kg,在江苏省的池塘养殖中达到相当的技术水平,为江苏省水产品的有效供给和渔民的增收致富作出了贡献。但是,由于大量饲料、鱼药的使用,以及鱼类自身代谢物大量积累,导致了池塘水质的恶化和鱼类病害频发。同时,随着工业化、城市化的迅速推进,大量的工业废水、生活废水进入外源水环境,使得水源质量严重下降,个别地方的池塘养殖甚至到了无水可换的地步。     

池塘循环水生态养殖效果分析

用多种生物修复技术结合池塘工程改造手段,构建封闭型池塘循环水生态养殖系统。养殖水体的水质指标监测结果表明,该循环系统对TN、TP、NH4+-N及CODMn的平均去除率分别达62.89%、60.24%、56.52%、47.81%,具有很好的净化效果,能够满足养殖用水的要求,在整个养殖过程中实现了养殖尾水零排放。该循环水养殖模式符合当前太湖保护的规划要求。     

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。     

凡纳滨对虾工厂化循环水养殖试验研究

为了探索健康、高效的对虾养殖模式,利用移动床生物滤器水处理技术和藻类净化技术,构建凡纳滨对虾(Litopenaeus vannamei)工厂化循环水养殖系统,并进行养殖试验研究。结果表明:在养殖期间DO为(5.85±1.09)mg/L;pH为8.11±0.40,TAN为(0.39±0.12)mg/L,水质指标符合养殖要求;对虾生长情况良好,经过92 d的养殖,收成时养殖密度4.96 kg/m2,成活率80.9%,饲料系数1.34,取得了健康、经济、高产、高效的养殖结果。     

循环水养殖系统管式射流集污特性试验研究

工厂化养殖池内的污物聚集效果是养殖池设计建造和运行管理的重要指标,对提升养殖技术和管理水平具有重要意义。针对一种典型的工厂化鱼类养殖池,对边侧管式射流系统驱动下的流场特性和污物聚集效果进行研究,探讨了射流角度、射流流速和循环抽吸方式等因素对养殖池内水体流场特性及污物聚集分布规律的影响。利用手持式ADV流速仪在养殖池内进行布点测量,获得各点流速数值,然后利用MATLAB软件进行流场插值构图,研究养殖池的流场分布特性;污物聚集特性采用图像法进行处理分析。研究表明:管式射流驱动作用下,流速从池心向外呈"V"型变化。在射流角度固定为40°条件下,射流速度越大,池心低流速区域范围越小,污物聚集效果越好。当射流速度达到0.3 m/s时,污物基本聚集于池心;在流速固定的情况下,对污物聚集效果存在一个最佳的射流角度,约为40°。池内循环抽吸模式对流场和污物聚集效果同样有着显著的影响。研究表明,采用底部抽吸时,排污孔附近的径向流速与切向流速均高于边侧抽吸模式,且污物聚集效果明显优于边侧抽吸模式。该研究成果可用于工厂化鱼类养殖池管式射流水力驱动系统的优化设计,在不影响养殖对象生长的前提下,可尽量提高射流流速,最佳射流角度一般为40°左右,并尽量采用底部抽吸模式。     

End-of-pipe single-sludge denitrification in pilot-scale recirculating aquaculture systems

A step toward environmental sustainability of recirculat aquaculture systems (RAS) is implementation of single-sludge denitrification, a process eliminating nitrate from the aqueous environment while reducing the organic matter discharge simultaneously. Two 1700 L pilot-scale RAS systems each with a 85 L denitrification (DN) reactor treating discharged water and hydrolyzed solid waste were setup to test the kinetics of nitrate and COD removal. Nitrate removal and COD reduction efficiency was measured at two different DN-reactor sludge ages (high θ_X: 33–42 days and low θ_X: 17–23 days). Nitrate and total N (NO₃⁻ + NO₂⁻ + NH₄⁺) removal of the treated effluent water ranged from 73–99% and 60–95% during the periods, respectively, corresponding to an overall maximum RAS nitrate removal of approximately 75%. The specific nitrate removal rate increased from 17 to 23 mg NO₃⁻-N (g TVS d)⁻¹ and the maximal potential DN rate (measured at laboratory ideal conditions) increased correspondingly from 64–68 mg NO₃⁻-N (g TVS d)⁻¹ to 247–294 mg NO₃⁻-N (g TVS d)⁻¹ at high and low θ_X, respectively. Quantification of denitrifiers in the DN-reactors by qPCR showed only minor differences upon the altered sludge removal practice. The hydrolysis unit improved the biodegradability of the solid waste by increasing volatile fatty acid COD content 74–76%. COD reductions in the DN-reactors were 64–70%. In conclusion, this study showed that single-sludge denitrification was a feasible way to reduce nitrate discharge from RAS, and higher DN rates were induced at lower sludge age/increased sludge removal regime. Improved control and optimization of reactor DN-activity may be achieved by further modifying reactor design and management scheme as indicated by the variation in and between the two DN-reactors.     

A novel approach to denitrification processes in a zero-discharge recirculating system for small-scale urban aquaculture

This paper presents an innovative process to solve the nitrate build-up problem in recirculating aquaculture systems (RAS). The novel aspects of the process lie in a denitrification bioreactor system that uses solid cotton wool as the primary carbon source and a unique degassing chamber. In the latter, the water is physically stripped of dissolved gaseous O₂ (by means of a Venturi vacuum tube), and the subsequent denitrification becomes more efficient due to elimination of the problems of oxygen inhibition of denitrification and aerobic consumption of cotton wool. The cotton wool medium also serves as a physical barrier that traps organic particles, which, in turn, act as an additional carbon source for denitrification. Operation in the proposed system gives an extremely low C/N ratio of 0.82 g of cotton wool/g of nitrate N, which contributes to a significant reduction of biofilter volume. The additional advantage of using solid cotton wool as the carbon source is that it does not release organic residuals into the liquid to be recycled. Operation of the system over a long period consistently produced effluents with low nitrate levels (below 10 mg N/l), and there was only a very small need to replace system water. The overall treatment scheme, also incorporating an aerobic nitrification biofilter and a granular filtration device, produced water of excellent quality, i.e., with near-zero levels of nitrite and ammonia, a sufficiently high pH for aquaculture, and low turbidity. The proposed system thus provides a solution for sustainable small-scale, urban aquaculture operation with a very high recovery of water (over 99%) and minimal waste disposal.     

Activated sludge denitrification in marine recirculating aquaculture system effluent using external and internal carbon sources

Stringent environmental legislation in Europe, especially in the Baltic Sea area, limits the discharge of nutrients to natural water bodies, limiting the aquaculture production in the region. Therefore, cost-efficient end-of-pipe treatment technologies to reduce nitrogen (N) discharge are required for the sustainable growth of marine land-based RAS. The following study examined the potential of fed batch reactors (FBR) in treating saline RAS effluents, aiming to define optimal operational conditions and evaluate the activated sludge denitrification capacity using external (acetate, propionate and ethanol) and internal carbon sources (RAS fish organic waste (FOW) and RAS fermented fish organic waste (FFOW)). The results show that between the evaluated operation cycle times (2, 4, and 6 h), the highest nitrate/nitrite removal rate was achieved at an operation cycle time of 2 h (corresponding to a hydraulic retention time of 2.5 h) when acetate was used as a carbon source. The specific denitrification rates were 98.7 ± 3.4 mg NO₃⁻-N/(h g biomass) and 93.2 ± 13.6 mg NO_x⁻-N/(h g biomass), with a resulting volumetric denitrification capacity of 1.20 kg NO₃⁻-N/(m³ reactor d). The usage of external and internal carbon sources at an operation cycle time of 4 h demonstrated that acetate had the highest nitrate removal rate (57.6 ± 6.6 mg N/(h g biomass)), followed by propionate (37.5 ± 6.3 mg NO₃⁻-N/(h g biomass)), ethanol (25.5 ± 6.0 mg NO₃⁻-N/(h g biomass)) and internal carbon sources (7.7 ± 1.6–14.1 ± 2.2 mg NO₃⁻-N/(h g biomass)). No TAN (Total Ammonia Nitrogen) or PO₄^3- accumulation was observed in the effluent when using the external carbon sources, while 0.9 ± 0.5 mg TAN/L and 3.9 ± 1.5 mg PO₄^3--P/L was found in the effluent when using the FOW, and 8.1±0.7 mg TAN/L and 7.3 ± 0.9 mg PO₄^3--P/L when using FFOW. Average sulfide concentrations varied between 0.002 and 0.008 mg S^2-/L when using the acetate, propionate and FOW, while using ethanol resulted in the accumulation of sulfide (0.26 ± 0.17 mg S^2-/L). Altogether, it was demonstrated that FBR has a great potential for end-of-pipe denitrification in marine land-based RAS, with a reliable operation and a reduced reactor volume as compared to the other available technologies. Using acetate, the required reactor volume is less than half of what is needed for other evaluated carbon sources, due to the higher denitrification rate achieved. Additionally, combined use of both internal and external carbon sources would further reduce the operational carbon cost.     

基于易控的工业化循环水养殖系统

随着可用水资源的减少,工业化循环水养殖是现代渔业的发展趋势。为了提高工业化循环水养殖的自动化程度,以及将其与物联网更好地结合起来,设计了基于易控的工业化循环水养殖系统。系统采用封闭式循环水养殖工艺,选用微滤机、流化床、低压纯氧混合装置等国内先进的循环水养殖装备构建硬件系统,使用西门子S7-300 PLC和其它智能仪表设备等构建控制系统,通过易控软件作为人机交互平台将各要素进行整合。该系统实现了工业化循环水养殖系统的养殖过程智能控制、养殖水质精准调控和养殖控制物联网化,具备自动化程度高、运行稳定、扩展性强的优点。该系统易于推广,并为将来的福利养殖系统提供了理论依据和基础数据。     

工厂化水产养殖中的自动控制技术

本文从工厂化水产养殖自动控制系统的组成、自动控制方法、自动控制技术在水质参数检测与调控中的应用等方面,论述了有关研究的技术成果和未来发展趋势.根据水产养殖工业化和自动化发展,以及自动控制技术在水产养殖中的广阔应用前景,指出了发展水产养殖自动化检测和调控精准技术的必要性,提出发展规范化、标准化的水产养殖自动化技术,以推动...     

工厂化水产养殖中的自动控制技术

本文从工厂化水产养殖自动控制系统的组成、自动控制方法、自动控制技术在水质参数检测与调控中的应用等方面,论述了有关研究的技术成果和未来发展趋势。根据水产养殖工业化和自动化发展,以及自动控制技术在水产养殖中的广阔应用前景,指出了发展水产养殖自动化检测和调控精准技术的必要性,提出发展规范化、标准化的水产养殖自动化技术,以推动水产养殖工业化的发展。     

北极红点鲑工厂化循环水养殖试验

北极红点鲑(Salvelinus alpinus)在循环水养殖模式下,体重增长趋势呈指数增长,体长增长趋势呈线性增长,增重率在15.58%～96.76%之间,其中12月最高,8月最低;特定生长率在0.47%～2.26%之间,其中12月最高,8月最低;饲料系数在1.02～1.51之间,其中6月最高,12月最低之间;肥满度在0.92%～1.71%之间,其中10月最高,4月最低。综上所述,循环水模式养殖北极红点鲑生长较快、饲料利用率较高,在天津地区冷水资源不足的情况下发展北极红点鲑循环水养殖模式是一种可行模式。