一株异养硝化细菌的筛选鉴定及硝化性能研究

本研究从位于杭州某化肥厂污水池中筛选出一株异养硝化细菌。根据形态学特征及16SrDNA序列分析,初步判定该菌株为恶臭假单胞菌,命名为DF-1。通过单因素试验研究DF-1的生长和脱氮特性,结果表明以柠檬酸钠为碳源、硫酸铵为氮源时,菌株DF-1在20℃、60r/min、C/N为14条件下,培养24h后氨氮去除率达到99. 8%,总氮去除率为97. 8%。整个硝化过程中没有硝态氮和亚硝态氮积累,p H由7. 0增加到8. 8。通过反硝化能力验证试验,发现菌株不能以亚硝态氮或硝态氮为唯一氮源生长。菌株DF-1具有良好的耐高氨氮特性,在初始氨氮浓度为1000mg/L的条件下培养36h后,氨氮去除率达到52. 7%。表明菌株DF-1在高氨氮废水的生物处理方面具有良好的应用前景。     

不同电子受体反硝化除磷的研究进展

与传统好氧除磷技术相比,反硝化除磷技术具有一碳两用、节约碳源、减少曝气量以及降低产泥量等优势。文章综述了以硝态氮和亚硝态氮为电子受体的反硝化除磷技术在菌群培养方式、脱氮除磷效率和微生物群落结构等方面的技术特点及相关工艺的研究进展,总结亚硝态氮浓度抑制反硝化缺氧吸磷阈值的相关研究。最后对反硝化除磷工艺的发展前景进行展望。     

好氧同时硝化-反硝化脱氮微生物的混合培养

筛选和分离得到的多株脱氮微生物 ,能在完全好氧条件下将氨氮转化为NO2 - ,随即在好氧反硝化菌的作用下还原为N2 排放 ,整个生物脱氮过程历时较短 ,30h内对 2 0 0mg/L的氨氮去除率达 99% ,而且无中间产物NO2 - 的积累 .混合脱氮微生物菌群生长的适宜 pH范围为 7～ 10 ,探索实现混合脱氮微生物菌群高密度培养的 pH :发酵前期补酸控制 pH≤ 8,发酵中后期不控制 pH值 ,可缩短菌体的生长周期 ,提高菌体的氨氮降解速率 ,细胞质量浓度达 3.9g/L ,比自然 pH条件下提高了 6 2 .5 % .     

废水脱氮系统中好氧反硝化菌的筛选与鉴定

以硝态氮为底物,DO保持5mg/L以上,对SBR中活性污泥进行强化驯化富集好氧反硝化菌,利用BTB培养基初筛,及测定液体培养中总氮变化复筛好氧反硝化菌。通过形态学特征、生理生化反应及16SrRNA同源性分析对筛得菌株进行鉴定。结果筛选到两株菌,在以琥珀酸钠为碳源,硝酸盐为氮源,DO为5～7mg/L的培养基中,4d内TIN去除率均在70%以上。经鉴定,判断两株菌均为假单胞菌,命名为PseudomonasputidaP1和Pseudomonassp.P3。     

一种脱氮复合微生物菌剂的反硝化特性

为了提高污水处理过程中反硝化脱氮的效果,作者利用实验室已筛选出的反硝化菌株N1、N9、N10制备复合脱氮微生物菌剂,研究了温度、碳氮比(C/N)、碳源类型对复合微生物菌剂的生长和脱氮特性的影响。结果表明,在30℃、C/N为10、碳源为可溶性淀粉的条件下,48 h后复合脱氮微生物菌剂对硝态氮、总氮和化学需氧量的去除率分别达92.61%、60.02%和58.48%。同时,在C/N比为2～10均有脱氮效果,表明该复合脱氮微生物菌剂在低C/N比废水的反硝化脱氮过程中具有一定的应用前景。     

一株分离自畜禽养殖废水的异养硝化细菌及其脱氮特性分析

为了从高氨氮养殖废水中发掘高效脱氮菌株资源,本研究采用富集培养的方法,从猪粪水自然曝气池污水中分离得到1株有较高脱氮效率异养硝化菌ZF1-1;经形态学分析、16S rRNA基因序列比对和系统发育树构建,鉴定其为Bacillus siamensis ZF1-1。脱氮特性研究表明,在以硫酸铵为唯一氮源的人工废水培养基中,菌株ZF1-1在接种量1%、30 ℃、180 r/min培养72 h的条件下,对氨氮的转化率为77.55%,总氮脱除率为21.00%,且不积累中间产物硝酸盐和亚硝酸盐。菌株ZF1-1转化氨氮最适碳源是甘露醇,最适碳氮比为20。相同培养条件和培养时间下,初始氨氮浓度增加,则氨氮脱除率降低;初始氨氮浓度为100 mg/L时,氨氮转化效果最好,转化率达93.46%。Fe2+、Fe3+和Mg2+能显著提高菌株ZF1-1的氨氮脱除率,分别达到98.66%、93.48%、86.47%。将菌株ZF1-1应用于高氨氮浓度（1277.41 mg/L）的猪粪废水脱氮;结果显示,菌株ZF1-1处理效果较好,使猪粪废水氨氮和总氮浓度分别降低37.50%和22.22%。因此,菌株ZF1-1在畜禽养殖高氨氮污染废水脱氮领域具有良好的应用价值。     

异养硝化-好氧反硝化菌株的分离、鉴定及其氨氮降解过程初探

该研究采用选择性培养基从汾河底泥中分离筛选异养硝化-好氧反硝化菌,通过形态观察、生理生化试验及分子生物学技术对其进行菌种鉴定,并对其氨氮（NH4+-N）降解过程进行动态监测,测定NH4+-N降解过程中关键酶的基因及酶活。结果表明,分离筛选得到一株异养硝化-好氧反硝化菌,编号为ZH-2,其被鉴定为醋酸钙不动杆菌（Acinetobacter calcoaceticus）。该菌在NH4+-N降解过程中存在NO3--N和NO2--N两种中心代谢产物,其基因组中含有3种关键酶（氨单加氧酶（Amo）、硝酸盐还原酶（Nap）和亚硝酸盐还原酶（Nir））基因,在NH4+-N降解过程,这3种关键酶的比酶活分别为45.69 mU/mg、3.54 mU/mg和6.91 mU/mg。综上,初步确定A. calcoaceticus ZH-2的NH4+-N降解过程是NH4+-N→NH2OH→NO2--N→NO3--N→NO2--N→NO→N2O→N2的经典降解途径,为该菌的进一步推广应用提供了理论依据。     

好氧反硝化菌的分离及脱氮特性研究

研究了从活性污泥中分离得到好氧反硝化细菌106及其反硝化能力,探讨了培养基碳源、CODCr/N、培养温度及pH对菌株106反硝化作用的影响。结果表明,菌株106能在好氧条件下有效去除培养基中的硝基氮,且其脱氮率达90%以上。其最适培养条件为30℃、摇床转速160r/min、初始pH7.0,分别以琥珀酸钠和硝酸钾为唯一碳源和氮源时,最适CODCr/N为26。该菌在溶解氧为6.0±1.0mg.L-1条件下,培养24h时对NO-3-N的去除率为99.17%。该反硝化细菌106可以在好氧条件下第1d内完成脱氮,具备高效的反硝化性能,且在整个反硝化过程中一直保持低水平的亚硝酸盐浓度。      

好氧反硝化芽孢杆菌JD-014的分离鉴定及脱氮性能

为了更好地实现以绿色环保的方式处理食品工业废水中的氮素污染物,从某河道水体中分离筛选出了1株具有好氧反硝化功能的芽孢杆菌JD-014。通过对该菌株在脱氮过程中气态氮(N₂)的产生、氮平衡估算以及酶活测定证实了菌株JD-014的好氧反硝化途径,并对影响其脱氮性能的环境因素进行了研究。结果表明:以50 mg/L NO₃^--N为唯一氮源时,菌株JD-014对NO₃^--N的去除速率为0.56 mg/(L·h)。在脱氮过程中,该菌株可将NO₃^--N部分转化为N₂并伴随有相关功能酶活的检出;当碳源为丁二酸钠和柠檬酸钠、碳氮比(C/N)为10~25、温度为37℃、转速为150~200 r/min、盐度为1%以下时,该菌株脱氮性能最佳。此外,菌株JD-014还具有较好的亚硝酸盐耐受性,在NO₂^--N质量浓度为10~200 mg/L时,脱氮率可保持在46.62%~99.92%。本研究表明,好氧反硝化芽孢杆菌JD-014在实际食品加工废水的氮素污染生物处理方面具有很大的应用潜力。     

好氧反硝化菌的分离及脱氮特性研究

研究了从活性污泥中分离得到好氧反硝化细菌106及其反硝化能力,探讨了培养基碳源、CODCr/N、培养温度及pH对菌株106反硝化作用的影响。结果表明,菌株106能在好氧条件下有效去除培养基中的硝基氮,且其脱氮率达90%以上。其最适培养条件为30℃、摇床转速160r/min、初始pH7.0,分别以琥珀酸钠和硝酸钾为唯一碳源和氮源时,最适CODCr/N为26。该菌在溶解氧为6.0±1.0mg.L-1条件下,培养24h时对NO-3-N的去除率为99.17%。该反硝化细菌106可以在好氧条件下第1d内完成脱氮,具备高效的反硝化性能,且在整个反硝化过程中一直保持低水平的亚硝酸盐浓度。     

好氧颗粒污泥同步硝化反硝化脱氮过程中N2O的产生

对同步脱氮过程中影响N2O产生的条件进行了研究.结果表明,由于受反硝化反应影响,COD/NH+4-N比值为2,3时产生较多的N2O,分别为15 mg/L和25 mg/L;而比值为4,5时N2O生成量较少.同样,较高的溶氧质量浓度(3,4 mg/L)减小了颗粒污泥内部的反硝化区域,反应产生较多的N2O,控制DO质量浓度在1～2 mg/L,有利于减少N2O的排放.脱氮过程中添加NO-2-N和NO-3-N,反应产生大量的N2O,最多可以达到75 mg/L. 实验发现,NO-2-N较NO-3-N更易形成N2O.     

Characteristics of ammonium removal by heterotrophic nitrification-aerobic denitrification by Alcaligenes faecalis No. 4

Alcaligenes faecalis no. 4 has heterotrophic nitrification and aerobic denitrification abilities. By taking the nitrogen balance under different culture conditions, 40-50% of removed NH4+-N was denitrified and about one-half of removed NH4+-N was converted to intracellular nitrogen. The maximum ammonium removal rate of no. 4 (28.9 mg-N/l/h) and its denitrification rate at high-strength NH4+-N of about 1200 ppm in aerated batch experiments at a C/N ratio of 10 were 5-40 times higher than those of other bacteria with the same ability. Only a few percent of the removed ammonium was converted to nitrite, and the main denitrification process was speculated to be via hydroxylamine which was produced by ammonium oxidation.     

硝酸盐在除磷脱氮中的作用

除磷过程中，厌氧段硝基氮浓度越高、聚磷菌厌氧释磷所受的影响越大；摄磷段存在硝基氮，聚磷菌可以利用其作为替代的电子受体，在不曝气的情况下吸磷。但是，由于以硝基氮为电子受体时聚磷菌对有机物（PHA）利用率较低，所以吸磷的速率和数量均不如氧为电子受体的系统，除磷效率亦较低。研究了厌氧氨氧化反应的几种可能的电子受体，发现硝酸盐、亚硝酸盐、硫酸盐可用作该生物反应的几种电子受体，而醋酸盐是该反应的抑制剂。其中，当亚硝酸盐作为电子受体时，厌氧氨氧化菌混培物转化氨的速率最快。     

反硝化深床滤池工艺在污水处理厂的应用分析

本文通过分析污水的类型和排放规律,对反硝化深床滤池的功能进行分析,并介绍了反硝化深床滤池建设中的几个设计环节,包括滤池容积计算、设计滤速与空床停留时间等.模拟建设了一个反硝化深床滤池,再分析反硝化深床滤池的脱氮因素,以期为污水处理厂的反硝化深床滤池工艺研究人员提供一些参考.     

运用序列式生物膜反应器处理味精污水工艺研究

味精污水中含有较高的氨氮离子,序列式生物膜反应器(SBBR)能够有效实现味精污水的同步硝化与反硝化反应,减少设备占有面积和节约处理时间。经过实验得出,当溶氧(DO)为3~4mg/L能够有效地满足生物膜中好氧菌的生长需要,又不会破坏生物膜内的厌氧环境,当pH值为8.0时,温度为30℃时,对味精生产中产生的污水的化学需氧量(COD)去除率高达95.34%,氨氮的去除率达到95.78%,生物需氧量(BOD5)去除率94.1%。     

Effect of Poultry Manure on the Leaching of Carbon from a Sandy Soil as a Potential Substrate for Denitrification in the Subsoil

There is evidence from laboratory incubations that denitrifying bacteria occur in the deep subsoils of UK soils and that lack of available carbon (C) generally limits their activity. Animal manures can be a source of substantial carbon input to farming systems. This experiment measured the effect of broiler litter application on the movement of C in soil solution to depths below 1 m, which might be sufficient to allow denitrification of nitrate moving from the rooting zone towards ground water aquifers. Six broiler litter rates were applied each autumn from 1992–1994 to field plots on a loamy medium sand in Nottinghamshire, UK. Total loadings over the 3 years ranged from 0 to 125 t ha^-1 broiler litter, supplying 0–32 t ha^-1 total C. Teflon and ceramic water samplers, placed at 1·0 and 1·5 m, and monolith lysimeters (0·5 m² area, 1·5 m deep) were used to measure total organic carbon (TOC) concentrations in the drainage. Ceramic samplers indicated significantly (P<0·05) larger concentrations than Teflon samplers; there were no differences between concentrations measured by Teflon samplers and the lysimeters. Water samples analysed for both dissolved and total C showed that nearly all was in a dissolved form. TOC concentrations on plots which received no manure were less than 20 mg litre^-1 at 1 m for the duration of the experiment; concentrations peaked at 65 mg litre^-1 with the largest manure loading. There was a linear relationship between C leached and C applied, with about 5% leached below 1 m by the end of the experiment. There was some evidence of movement of C to 1·5 m depth, but there were no large peaks corresponding to those at 1 m, because of either adsorption or microbial utilisation. The results provide evidence of movement of substantial C to depth in some circumstances, particularly on fields which regularly receive large dressings of organic manure. The availability of this as a substrate for denitrification needs further examination. © 1997 SCI     

Reducing gaseous losses of nitrogen from cattle slurry applied to grassland by the use of additives

Losses of nitrogen (N) through ammonia (NH₃) volatilisation and denitrification were determined following the application of cattle slurry to grassland in autumn or spring. Denitrification was examined on two contrasting soils. A system of small wind tunnels was used to measure NH₃ loss and an acetylene inhibition technique for denitrification. Between 31 and 84% of the ammonium N (NH-N) applied in slurry was lost through NH₃ volatilisation. Acidifying the slurry to pH c 5.5 prior to application reduced these losses to between 14 and 57%. On a freely drained loam soil, denitrification from unacidified slurry applied in the autumn at 80 m³ ha^?1 was continuous throughout the winter, with the maximum rate of 0.91 kg N ha^?1 day^?1 occurring a few weeks after slurry application. The total denitrification losses were equivalent to about 29% of the NH-N applied for this treatment and 41% for the acidified slurry. The nitrification inhibitor dicyandiamide reduced the amount of N lost through denitrification by 70% when applied with the slurry at 25 kg ha^?1, by 55% at 20 kg ha^?1 and by 30% at 15 kg ha^?1. The nitrification inhibitor nitrapyrin did not appreciably reduce denitrification. Denitrification losses were consistently small from slurry applied to the freely drained loam soil in spring, or to a poorly drained, silty clay in autumn or spring. Neither nitrification inhibitor was of benefit in these situations.