硝化液回流比对生物生态组合工艺脱氮除臭效果的影响

通过小试规模试验研究“厌氧产沼气池-缺氧池-跌水充氧池-人工湿地”生物生态组合工艺处理实际生活污水的效能,考察硝化液回流比对脱氮除臭效果的影响规律.结果表明,当回流比从25％逐渐增加至200％时,TN平均去除率从15.0％增加至52.3％;但是当回流比继续增加至300％时,TN平均去除率下降至44.7％.在回流比为25％、50％、100％、200％和300％时,硫化氢作为污水中的主要恶臭源,其在缺氧池中的去除率分别为23.7％、30.8％、54.7％、82.6％和90.1％.同时,硫化氢去除率随缺氧池中DO和NO3-浓度的增加而升高.系统回流比为200％时,组合工艺可获得最佳的脱氮除臭效果.     

β-甘露聚糖酶基因在枯草芽孢杆菌中的克隆及表达

从Bacillus subtilis JNA 3-10中克隆出β-甘露聚糖酶基因成熟肽链编码序列manA1和含信号肽的β-甘露聚糖酶基因manA2,在B.subtilis 168中克隆表达,分别筛选获得高效分泌表达β-甘露聚糖酶的重组菌株BPM1001(pMA5-manA1/B.subtilis 168)和BPM1002(pMA5-manA2/B.subtilis 168),结果表明菌株BPM1002总酶活力是菌株BPM1001的9.65倍,是原始菌株的13.1倍.在基因manA2下游引入His序列克隆出β-甘露聚糖酶基因manA3,获得枯草芽孢杆菌168重组菌株BPM1003.采用Ni-NTA柱纯化重组菌株BPM1003分泌表达的β-甘露聚糖酶,并研究其酶学性质,该酶促反应的最适pH为6.5,最适温度为65℃,在37℃条件下保存一个月酶活力依然保留有77.8%.5 L发酵罐放大实验结果表明魔芋粉对于产β-甘露聚糖酶具有明显的诱导作用,酶活力最高可达2 748.82 U/mL.图9表3参19     

Fhhh工程菌株降解PTA废水动力学研究

研究了工程菌株Fhhh降解精对苯二甲酸(PTA)石化废水的动力学.将测得的Fhhh降解废水的6项动力学参数值、废水自然参数值、废水排放标准控制值,输入环境生物技术信息学软件(Ebis)进行计算.结果表明,来源于3种保存方法的Fhhh菌株中,所需反应器的最小体积(V_min)为1309m³,比降解率(q_A)的最高数值为0.0136h^-1,是土著菌YZ1的4倍,高于国内外同类研究的4项数值,低于同类研究的2项数值.结果表明,Fhhh工程菌株具有降解PTA废水的显著优势.     

丁二腈高效降解菌的筛选及其降解性

以丁二腈为唯一碳源和氮源,从石化腈纶废水及其处理构筑物的生物膜中,分离、筛选出2株高效降解丁二腈的菌株:J-1-3和J-13-1.经形态学观察和生理生化特征研究,两者均被鉴定为假单胞菌(Pseudomonas spp.).通过摇瓶试验得出2菌株的最适生长条件:温度为30℃,摇床转速(间接反映通气量)为250 r/min,接种量为0.1%,初始pH为6.在最适生长条件下,分别对不同初始浓度丁二腈进行降解率试验.结果表明,2菌株对丁二腈的降解能力强,尤以J-13-1更为显著.当丁二腈的初始浓度约为6000mg/L、8000mg/L和10000mg/L时,J-13-1菌株对丁二腈的降解率分别在12.5h、14h和16h时达到100%.     

烟气脱硫菌株的筛选与烟气脱硫效率的影响因素

为了寻找烟道气中SO2的微生物转化方法,为微生物脱硫技术的工业化应用提供一定的技术依据,进行了烟气脱硫菌株的筛选和影响烟气脱硫效率有关因素的实验研究,结果表明,单一菌株中,5-2-1菌株的脱硫效率最高.培养12 d后,脱硫率达67.20%,与单一菌株相比,混合菌株有更好的脱硫能力;重金属、有机物、氟化物质对菌株脱硫能力的影响结果表明,在菌液中添加Fe3 、Mn2 不仅能促进菌株生长,还能提高生物菌株的脱硫能力;通过正交实验得出,影响生物菌株脱硫能力大小的因素顺序为:Fe3 >Mn2 >联苯>SO2 浓度>Cr3 >pb2 >pH,通过F显著性检验得知,Fe3 、Mn2、联苯的作用是显著的.     

三唑磷水解酶基因的克隆及水解产物的确定

利用鸟枪法从三唑磷降解菌株mp-4(Ochrobactrum sp.)中克隆了三唑磷水解酶基因tpd,序列分析发现,该基因与甲基对硫磷水解酶基因mpd的同源性为98%,其结构基因含有996个碱基,除终止密码子外编码331个氨基酸,但该基因编码的酶比mpd编码的酶底物范围更广,不仅能水解甲基对硫磷,而且能高效水解三唑磷.利用克隆到的tpd基因编码的水解酶水解三唑磷,将水解反应产物进行液相色谱-质谱联机分析,发现该水解产物分子量为161,经理论分析确定该水解产物为1-苯基-3-羟基-1,2,4-三唑.     

污水处理厂除臭工艺及工程应用

根据国家标准对废气中H2S、NH3的最高排放浓度、臭气浓度的明确规定,结合广州市大坦沙污水处理厂除臭的工程实例,介绍了除臭系统的3种工艺:土壤法、生物滴滤法、等离子体法,分析了除臭过程中各种方法的优缺点.     

Anaerobic benzene biodegradation by a pure bacterial culture of Bacillus cereus under nitrate reducing conditions

A pure culture using benzene as sole carbon and energy sources was isolated by screening procedure from gasoline contaminated soil. The analysis of the 16S rDNA gene sequence, morphological and physiological characteristics showed that the isolated strain was a member of genus Bacillus cereus. The biodegradation performance of benzene by B. cereus was evaluated, and the results showed that benzene could be e ciently biodegraded when the initial benzene concentration was below 150 mg/L. The metabolites of anaerobic nitrate-dependent benzene oxidation by strain B. cereus were identified as phenol and benzoate. The results of substrate interaction between binary combinations for benzene, phenol and benzoate showed that the simultaneous presence of benzene stimulated the degradation of benzoate, whereas the addition of benzene inhibited the degradation of phenol. Benzene degradation by B. cereus was enhanced by the addition of phenol and benzoate, the enhanced e ects were more pronounced at higher concentration. To our knowledge, this is the first report that the isolated bacterial culture of B. cereus can e ciently degraded benzene under nitrate reducing conditions.     

Characterization of phenanthrene degradation by strain Polyporus sp. S133

Polyporus sp. S133, a fungus collected from contaminated soil, was used to degrade phenanthrene, a polycyclic aromatic hydrocarbon, in a mineral salt broth liquid culture. A maximal degradation rate (92%) was obtained when Polyporus sp. S133 was cultured for 30 days with agitation at 120 r/min, as compared to 44% degradation in non-agitated cultures. Furthermore, the degradation was a ected by the addition of surfactants. Tween 80 was the most suitable surfactant for the degradation of phenanthrene by Polyporus sp. S133. The degradation rate increased as the amount of Tween 80 added increased. The rate in agitated cultures was about 2 times that in non-agitated cultures. The mechanism of degradation was determined through the identification of metabolites; 9,10-phenanthrenequinone, 2,2’-diphenic acid, phthalic acid, and protocatechuic acid. Several enzymes (manganese peroxidase, lignin peroxidase, laccase, 1,2-dioxygenase and 2,3-dioxygenase) produced by Polyporus sp. S133 were detected during the incubation. The highest level of activity was shown by 1,2-dioxygenase (187.4 U/L) after 20 days of culture.