2株氨氮去除菌的分离鉴定及去除率影响因素分析

为了获得养殖池塘中高效去除氨氮的菌株,本研究采用富集培养分离的方法从虾贝混养池中筛选得到2株氨氮去除能力较高的菌株,编号分别为9A-7和9A-19。分子生物学及生理生化鉴定结果一致表明,菌株9A-7为非典型弧菌（Vibrio atypicus）,菌株9A-19为魔鬼弧菌（Vibrio diabolicus）。不同生长时期与氨氮去除率的关系结果显示,氨氮去除与菌株的生长是同步的。条件优化结果表明,培养液盐度、pH和培养温度对2菌株去除氨的效率均存在显著影响,其中盐度对2菌株氨氮去除率的影响相似,低pH和高温对菌株9A-7的去除率影响较小,而高pH对菌株9A-19去除率影响较小。当氨氮浓度为50mg/L,温度为25℃、盐度为30‰、pH为7.5时,培养至24h菌株9A-7和菌株9A-19除氨率分别高达74.67％和90.67％。这些结果为2株筛选菌的实际应用提供了依据。     

高铁酸钾对微囊藻毒素的去除效果探讨

研究高铁酸钾对微囊藻毒素（MC—LR）的去除效果,探讨不同反应影响因素（反应时间、K2FeO4质量浓度、温度和pH）对去除率的影响。结果表明,K2FeO4能够有效地去除水中的MC—LR。K2FeO4对MC—LR的去除率与K2FeO4。投加质量浓度、反应时间成正相关,其中K2FeO4质量浓度对去除效果的影响较为明显;反应温度对去除率的影响不显著;pH对去除率也有重要影响,当pH分别为2和10时去除率分别为94．51％和87．96％。正交试验的结果也进一步证明了不同反应影响因素对去除效果的影响显著程度。     

不同pH和滤料对硝化细菌消氨效果的影响

为了解在不同pH和滤料条件下硝化细菌对氨氮(NH_4~+-N)和亚硝酸盐氮(NO_2~--N)的去除效果,通过试验,探讨了5.0~10.0等6个pH梯度以及陶环、珊瑚石、生物刷和生物球等4种滤料的消氨效果。在pH 8.0~9.0时,至试验第7天氨氮去除率分别达99.86%、98.95%,明显高于pH 6.0、7.0和10.0组(去除率分别为66.18%、71.43%和70.51%)。在pH 7.0~9.0时,亚硝酸盐氮浓度的增加小于氨氮浓度的下降,特别是在pH 9.0时两者浓度变化差异明显。生物刷、陶环、珊瑚石和生物球分别在试验的第3、4、6、7天,氨氮去除率达100%。陶环组和珊瑚石组,NO_2~--N质量浓度在达到最高值(9.60 mg/L和10.00 mg/L),之后开始逐步下降。生物刷组和生物球组在达到最高值(9.55 mg/L和11.00 mg/L)之后基本维持不变。结果表明:硝化细菌适宜碱性的环境条件(pH 8.0~9.0),水体pH 9.0最有利于硝化细菌对NH_4~+-N和NO_2~--N的去除。不同滤料对硝化细菌去除NH_4~+-N和NO_2~--N有不同的影响。陶环对硝化细菌去除NH_4~+-N和NO_2~--N都有良好效果,生物刷只对去除NH_4~+-N有良好效果,珊瑚石只对去除NO_2~--N有良好效果。多种滤料配合使用有利于产生优势互补的效果。     

养殖水电化学同步脱氮响应面优化与验证

本研究先通过单因子实验分析了电流密度、极板面积比、极板间距和初始pH对总氨氮(TAN)和硝态氮(NO3–-N)去除率的影响。采用Design-Expert软件中Box-Behnken的中心组合原则设计四因素三水平响应面实验,考察不同影响因子对脱氮效率的影响,并建立响应面模型优化反应条件,最后对优化的反应条件进行验证。结果显示,电流密度、极板面积比、极板间距和初始pH的变化对TAN去除影响不大,在所选反应条件下,TAN去除率均高于80%,但反应条件的改变显著影响硝酸盐(NO3?)的去除,NO3?去除率在29.8%~80.9%范围内变化。响应面模型的回归系数R2为0.9340,校正系数R2为0.8681,说明该模型具有较好的准确性。NO3?去除最优反应条件：电流密度为25.6 mA/cm2,阴阳极板面积比为1.6∶1,极板间距为2.5 cm,初始pH为6.6,对该反应条件下的脱氮效果展开实验验证发现,TAN去除率为87.3%,NO3?去除率为81.5%。研究表明,电化学处理可实现对TAN和NO3–-N的同步去除,同时,响应面模型的运用有助于优化电化学法在养殖水处理中的脱氮效率。     

米尔伊丽莎白菌拮抗菌X2的筛选鉴定及其特性分析

本实验旨在筛选对米尔伊丽莎白菌(Elizabethkingia miricola)有抑制作用的拮抗菌，并对其生长特性及其去除氨氮和亚硝酸盐的作用进行分析。实验采用平板对峙法从“稻蛙”养殖稻田土壤中分离到1株对米尔伊丽莎白菌有较强抑制作用的菌株X2。采用形态学特征观察和16s rDNA测序对X2进行鉴定，随后对X2在不同pH、盐度、温度等条件下的生长曲线进行了测定，以评估其环境适应性，并将X2接种于氨氮和亚硝酸盐培养基中，测定去除率以评估其去除氨氮和亚硝酸盐的能力。结合形态学特征及菌株16s rDNA序列分析，X2鉴定为侧孢短芽孢杆菌(Brevibacillus laterosporus)。结果显示：X2在pH 5～9、盐度5‰～50‰、温度20～40℃之间均能生长，最适pH、盐度、温度分别为7、5‰和35℃。这表明X2对环境的适应性较强，具有较强的耐酸碱性、耐盐性，适温性广等特性。X2在去除氨氮、亚硝酸盐方面也表现出了很强的能力，在X2接种浓度为5.0×10⁷ CFU/mL时氨氮的去除率最高，达到74.95%;接种浓度为5.0×10⁵ CFU...     

蜂窝煤渣对氨氮吸附特性探讨

通过对蜂窝煤渣用量、pH值、吸附时间、氨氮浓度、离心时间对氨氮吸附特性的影响试验,探讨了利用蜂窝煤渣吸附法去除废水中氨态氮的可行性。结果表明:蜂窝煤渣用量2.00 g,pH值4～6,吸附时间90 min,氨氮的初始浓度5.0 mg/L,离心时间10 min条件下,对氨氮的去除率比较高。将燃烧后废弃物作为吸附材料,可以减少环境污染,在一定程度上达到了去除氨氮的效果,具有良好的发展前景。     

养殖水体中二氧化碳去除技术试验研究

高密度循环水养殖水体中的二氧化碳积累是影响水处理效果和养殖效果的重要因素。研究通过对其影响因子的有效变控和再行检测＂水样＂中的游离CO2浓度等参数,获得对于CO2去除效果具有量化意义的试验结果。试验表明：CO2一次去除率最高接近80%,pH值显著升高,CO2浓度与pH值呈负相关对应关系。适当增加填料层厚度和密度、设计较大出水位置高度、选用优质填料及恰当气水体积比,都能起到提高CO2去除效果的作用。影响CO2去除率的主要因素有：起始CO2浓度、循环水流量、气水体积比、填料品种、CO2去除装置的结构型式、输入空气的流速等。养殖水体中的高浓度二氧化碳,可以通过特别设计的CO2去除装置加以高效去除。     

浅海养殖环境复合生态净化菌群的筛选及其净化功能

本研究由浅海网箱区富营养沉积物经多步富集和筛选获得高效复合生态净化菌群,对浅海养殖区的有机物、氨氮和亚硝酸氮有明显去除效果.研究了不同条件对复合菌液去除养殖水体中氨氮、亚硝酸氮和有机物能力的影响,并确定了最佳净化条件.结果表明,复合菌添加量、葡萄糖添加量,处理时间、温度、pH和盐度对复合菌的去除效果均有影响,实验条件确定为复合菌的添加量为3%、处理时间为4 d、温度为30±2 ℃、pH值为8.1±0.2、葡萄糖添加量为2 g/L和盐度为(30±10) g/L 时,去除效果达到最佳,此时氨氮、亚硝酸氮和溶解有机物的去除率可分别达到79.1%、85.2%和88.7%.     

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%。     

5种因子对赤红球菌HDRR2Y去除氨氮和亚硝酸盐效应的影响

赤红球菌(Rhodococcus ruber)是常见的污水、废水处理微生物,为探究环境因子对赤红球菌HDRR2Y去除氨氮(的养殖水体中,通过国标法检测氨氮和亚硝酸盐浓度的变化,检验菌株培养液去除氨氮及亚硝酸盐的效果。按照温度、转速、盐度、接种菌量、底物浓度(氨氮和亚硝酸盐) 5个因素进行Plackett-Burman实验设计,探讨这些因子对赤红球菌去除氨氮和亚硝酸盐效应的影响。结果显示,发酵过程中,菌株HDRR2Y浓度在36 h内从初始的5×104 CFU·mL^-1增至4.08×109CFU·mL^-1。添加菌株培养液后,养殖水体氨氮质量浓度从初始的15 mg·L^-1降至5.56 mg·L^-1,去除率为62.96%;亚硝酸盐质量浓度从15 mg·L^-1降至6.95 mg·L^-1,去除率为59.37%。5种因子中,温度和氨氮浓度对菌株HDRR2Y去除氨氮影响最显著(P<0.05),影响权重程度依次为：温度>氨氮浓度>转速>菌量>盐...     

Nitrogen removal characteristics of <Emphasis Type="Italic">Pseudomonas stutzeri</Emphasis> F11 and its application in grass carp culture

This study was designed to investigate the denitrification characteristics of Pseudomonas stutzeri F11 under different environmental conditions and to evaluate the effect of these characteristics on nitrogen removal and the water microbiome in an experimental grass carp aquaculture system. The results showed that the optimal growth conditions of strain F11 were (1) ammonia-nitrogen (N), nitrite-N, or nitrate-N as sole N source; (2) initial ammonia-N concentration of 10–30 mg N/l; (3), initial nitrite-N concentration of 200 mg N/l; (4) sodium citrate as carbon source; (5) rotation (r) speed of 200 r/min; a C:N ratio of between 2 and 10; (6) culture at 32–37 °C. The addition of P. stutzeri F11 to the experimental grass carp aquaculture system reduced the levels of ammonia-N, nitrite-N, and total N in the water over an extended range, but had no effect on nitrate-N level. Results of the 454 pyrosequencing analysis indicated that the structure of the microbial community in the aquaculture water changed significantly after the addition of P. stutzeri F11 preparations. The addition of P. stutzeri F11 to the aquaculture system also altered the microbiome metabolism in the water, especially the bacteria involved in nitrogen metabolism. These results suggest that the addition of P. stutzeri F11 to an experimental grass carp aquaculture system decrease nitrogen levels and alter the microbial community structure of the water; as such, this bacterial strain could be a potential candidate for the regulation of water quality in aquaculture systems.     

Alkalinity and Hardness: Critical but Elusive Concepts in Aquaculture

Total alkalinity and total hardness are familiar variables in aquatic animal production. Aquaculturists—both scientists and practitioners alike—have some understanding of the two variables and of methods for adjusting their concentrations. The chemistry and the biological effects of alkalinity and hardness, however, are more complex than generally realized or depicted in the aquaculture literature. Moreover, the discussions of alkalinity and hardness—alkalinity in particular—found in water chemistry texts are presented in a rigorous manner and without explanation of how the two variables relate to aquaculture. This review provides a thorough but less rigorous discussion of alkalinity and hardness specifically oriented toward aquaculture. Alkalinity and hardness are defined, their sources identified, and analytical methods explained. This is followed by a discussion of the roles of the two variables in aquaculture, including their relationships with carbon dioxide, pH, atmospheric pollution, ammonia, and other inorganic nitrogen compounds, phytoplankton communities, trace metals, animal physiology, and clay turbidity. Liming and other practices to manage alkalinity and hardness are explained. Changes in alkalinity and hardness concentrations that occur over time in aquaculture systems are discussed. Emphasis is placed on interactions among alkalinity, hardness, water quality, and aquacultural production.     

福瑞鲤对氨氮胁迫的生理响应

以福瑞鲤(Cyprinus carpio)为材料,研究不同浓度氨氮(0、10、20和30 mg/L)处理对幼鱼鳃组织中抗氧化系统和Na~+/K~+-ATP酶活力的影响。结果显示,氨氮胁迫6 h诱导H_2O_2含量、总抗氧化能力(T-AOC)和超氧化物歧化酶(SOD)活性迅速显著升高,并在胁迫24 h时达到最高水平。胁迫96 h后,各处理组H2O2含量、SOD活性和总抗氧化能力均低于对照组水平,MDA含量显著增加。氨氮胁迫后,Na~+/K~+-ATP酶基因转录水平和蛋白活性呈先降低后升高又降低的变化趋势,参与胁迫过程中渗透压的调控。研究结果表明,低浓度氨氮胁迫后,福瑞鲤鳃组织通过调节细胞抗氧化能力,提高Na~+/K~+-ATP酶活性,有效改善鱼体的抗氨氮胁迫能力,但是高浓度氨氮胁迫对鳃组织造成氧化损伤。     

脱二氧化碳装置对循环水养殖系统pH的影响

为了调节循环水系统中养殖水体的pH,根据气体交换原理,设计一种脱二氧化碳(CO_2)装置。采用该装置去除养殖水体中的CO_2,并对由于CO_2含量累积造成的pH下降进行调节,使养殖鱼类处在一个适宜的pH环境中。试验时水温控制在(25±0.5)℃,每1 h取水样测1次pH,每4 h测1次碱度。水样取自养鱼桶内的水,检测前先对水样用40μm孔径针头过滤器进行过滤处理,实验周期24 h。结果显示,循环水系统加装脱二氧化碳装置能有效去除CO_2,使水体稳定在一个适宜的pH范围(7.39~7.42);CO_2质量浓度呈降低趋势,24 h后由开始的13.16 mg/L降低到7~8 mg/L,降低近50%,而不加装脱二氧化碳装置的循环水系统CO_2质量浓度持续上升,24 h后增加到37 mg/L左右,pH持续降低,最终降低到6.72~6.81。研究表明,脱二氧化碳装置能够有效去除水体中的CO_2,使水体pH维持在一个适宜鱼类生长的范围。     

pH、氨氮胁迫对中国对虾HSP90基因表达的影响

研究了pH、氨氮胁迫对中国对虾Fenneropenaeus chinensis血细胞、肝胰腺、鳃和肌肉组织HSP90基因时空表达的影响.分别将中国对虾暴露于pH7.0、9.0的水体中148h和不同氨氮浓度的水体中96h,结果表明,pH（7.0,9.0）胁迫条件下中国对虾鳃、肌肉和血细胞HSP90基因表达均上调,肝胰腺HSP90基因表达对两种pH胁迫差异明显：pH7.0胁迫条件下,HSP90基因表达3h达峰值后明显降低;pH 9.0胁迫时,HSP90基因表达水平逐渐升高,整个胁迫过程中均显著高于对照组（P＜0.05）,说明中国对虾肝胰腺组织是高pH胁迫的响应器官.6mg/L氨氮浓度组鳃和肌肉组织HSP90基因表达水平24h达最高值,分别为对照组的5.46和1.55倍;各胁迫组肝胰腺和血细胞HSP90基因表达水平分别于6h和48h达到最高值,为对照组的1.33～2.08倍和2.20～5.45倍.肝胰腺组织对氨氮胁迫表现敏感,短时间内（6h）通过上调HSP90基因表达水平保护细胞;鳃组织HSP90基因表达波动范围最大,说明鳃组织需要更高表达量的HSP90保护细胞.当氨氮浓度持续48～96h维持在2～6mg/L,各组织HSP90基因表达水平显著降低.     

一株内循环流水养殖池塘光合细菌的分离鉴定及氮磷去除能力的研究

为提高内循环流水养殖池塘净化区域的净化能力,从重庆潼南区内循环流水养殖池塘的底泥中分离纯化得到一株光合细菌(命名为菌株GR01).通过形态学观察、生理生化鉴定、16S rDNA基因序列分析和扫描吸收光谱,对菌株进行分类鉴定.测定菌株GR01在不同温度、不同pH、不同盐度条件下的660 nm处的吸光度(A660),确定其...     

Influence of ammonia on growth of Penaeus monodon Fabricius post-larvae

Abstract. Tiger shrimp, Penaeus monodon Fabricius, post-larvae (32·0±3mg, 1·43±0·03 cm) were exposed to control, 0·12, 0·60, 1·20 and 2·40mg/l ammonia-N (un-ionized plus ionized ammonia as nitrogen) which is equivalent to control, 6,32,63 and 126μg/1 NH₃-N (un-ionized ammonia as nitrogen) for 8 weeks in 25 ppt, as pH of 7·85–8·18 and 26–28°C by static renewal method. Growth in weight and length of the shrimps exposed to 1·20 and 2·40 mg/l ammonia-N were significantly lower (P < 0·05) than those exposed to control. The EC₅₀ (concentration that reduced growth by 50% of that of the controls) was 1·33 mg/l ammonia-N, 70 μg/l NH₃-N for weight gain, and 2·35 mg/1 ammonia-N, 123μg/l NH₃-N for length gain of P. monodon post-larvae. The'maximum acceptable toxicant concentration'(MATC) of ammonia-N and NH₃-N for P. monodon post-larvae was 0·60mg/l and 32μg/l, respectively after 6 weeks of exposure.     

Haemolymph nitrogenous constituents and nitrogen efflux rates of juvenile shrimp, Penaeus paulensis (Perez-Farfante), exposed to ambient ammonia-N

The effects of increased levels of ambient ammonia-N (7, 20 and 50 mg L^–1) on some blood nitrogenous constituents, and on ammonia-N and urea-N efflux rates of Penaeus paulensis are reported. Haemolymph urea, protein and haemocyanin levels, and the haemocyanin:protein ratio were not significantly altered in any of the situations tested. Sudden exposure to 20 mg L^–1 caused a transient increase in haemolymph ammonia-N levels, and induced pH and uric acid-N levels to increase after 24 h of exposure. A similar transient increase in haemolymph ammonia-N levels occurred during recovery, and the original pH and uric acid-N levels were restored within 30 min. The haemolymph ammonia-N and uric acid-N levels of shrimp held in 50 mg L^–1 for 24 h were higher than those held in low ammonia-N sea water at all times (control). Increased ammonia-N effluxes were found to occur upon recovery, but urea-N effluxes were not different from those of control shrimp. The amounts of ammonia-N which accumulated in the haemolymph of shrimp at high ambient ammonia-N levels were considerably lower than those excreted during the recovery period. Such findings indicate that some of the accumulating haemolymph ammonia-N was transformed into other compounds or stored elsewhere. Possible mechanisms involved are discussed.     

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。