可用于水体污染控制的氨氮转化菌筛选及部分降解特性的实验研究

从南京禄口水产养殖基地淡水鱼塘取淤泥作为分离菌株的土源,采用选择性富集培养法,从中分离到能以硫酸铵为氮源的菌株7株,对7个菌株进行氨氮降解实验,它们氨氮转化率分别为14.8%、19.7%、53.4%、94.2%、29.1%、63.5%和41.7%,其中AN-4菌株的转化率最高且生长良好。通过AN-4菌株16S rRNA基因序列分析以及生理生化方法,鉴定此菌株为克雷伯氏菌属(Klebsiellasp.)。对菌株AN-4转化氨氮的特性及温度、pH值、氨氮初始浓度和菌株接种量对其氨氮转化率的影响研究,结果表明,菌株AN-4降解氨氮的最适条件为:温度为30℃和pH值为8.0;当氨氮初始浓度为30mg/L时,AN-4菌株在24 h内的氨氮降解率可达85%以上,且能耐受高达200 mg/L的氨氮浓度;AN-4活化菌液浓度为108cfu/mL,当接种量为3×106cfu/mL时,AN-4菌株在24 h内的氨氮降解率为87.75%。综合上述结果,符合淡水养殖水环境条件,说明AN-4菌株适合在水产养殖中应用,为将菌株AN-4应用于水产养殖环境修复提供了理论依据。     

一株高效耐冷菌的分离鉴定及降解特性研究

寒冷地区水温偏低,污水生物处理效果差,出水达标困难。从寒冷地区水土样品中,分离到数株能在2℃下生长的低温菌株,选择优势菌N进行重点研究。从脱氢酶活性机制上,考察了不同条件对N菌株降解能力的影响;对比研究了它与常温活性污泥降解能力和脱氢酶活性的差异。结果表明:N菌株属于耐冷型低温微生物,结合16S rDNA序列同源性分析及生理生化特性鉴定为黄假单胞菌;5℃曝气8 h,接种废水COD、氨氮去除率均在90%以上;低温条件下,该耐冷菌对生活污水降解率比常温活性污泥高出40%,脱氢酶具有更高的活性,在低温污水处理方面具有广阔的应用前景。     

低温喹啉降解菌的筛选及降解性能

从吉林石化污水处理厂的活性污泥中驯化、筛选获得一株降解效率高且生长速率快高效耐冷菌,命名为WS-5。该菌能以喹啉作为惟一的碳源、氮源及能源。结合菌体的形态观察、生理生化特性实验及16S rDNA 序列同源性对比分析,鉴定菌株WS-5为恶臭假单胞菌(Pseudomonas putida)。不同降解条件下的实验结果表明,菌株WS-5的最佳降解条件是投菌量为15%,pH值范围在8~10,摇床转速为100 r/min。最佳降解环境下对200 mg/L的喹啉在132 h降解率达到了85.3%。菌株WS-5对初始喹啉浓度为50、100、200和300 mg/L的初始喹啉浓度分别在36、72、192和262 h内完全降解。这将为今后在低温条件下处理含喹啉废水提供技术指导。     

一株丙烯酰胺高效降解菌的筛选及其降解性能

从污水处理厂的活性污泥中,分离、筛选出1株高效降解丙烯酰胺的菌株A18,经16S rDNA序列分析鉴定该菌株属于Delftia tsuruhatensis,它可以降解苯胺.以丙烯酰胺为惟一碳源的无机盐培养基中,以菌株细胞的增长和丙烯酰胺的降解为依据,通过实验得出A18菌株的最适生长条件:温度为30℃,pH为7.0.在最适生长条件下,当丙烯酰胺的初始浓度约为1 000 mg/L时,菌株A18对丙烯酰胺的48 h降解率达到100％.     

一株1，2-二氯苯降解菌的分离鉴定及其降解特性

采用富集驯化方法,从盐城芦苇湿地根际土壤中分离得到一株可高效降解1,2-二氯苯的菌株,命名为DL-1。该菌株可以在以1,2-二氯苯为惟一碳源的无机培养基上生长,能够耐受最高浓度为200 mg/L的1,2-二氯苯。根据形态特征观察、生理生化鉴定和16S rDNA序列同源性分析,该目标菌株被鉴定为蜡质芽孢杆菌（Bacillus cereus）。菌株DL-1对1,2-二氯苯降解性能研究表明,该菌株为一株兼性厌氧菌,其适宜降解浓度、适宜温度、适宜pH值和适宜接种量分别为120mg/L、32℃、7和10%,在适宜降解条件下降解12,-二氯苯4 d其降解率达到80.3%。本实验为利用该菌株降解12,-二氯苯污水的应用提供了理论基础。     

一株苯胺降解菌的分离及其降解特性

从某城市生活污水处理厂曝气池的活性污泥中分离出一株以苯胺为唯一碳源和氮源的高效降解菌Z1。通过16S r DNA基因序列分析,初步鉴定菌株。结果表明,菌株Z1为假单胞菌(Pseudomonas sp.)。该菌株最适生长和降解条件为p H 6.0~8.0、30℃、盐度0.1%~1.0%。在此条件下,16 h内能够将400 mg/L的苯胺降解完全,且当苯胺初始浓度为1 300 mg/L时,苯胺的最大降解速率为41.4 mg/(L·h),32 h内降解率达到98%。菌株对苯胺的最大耐受浓度为1 800mg/L。当苯胺和苯酚共存时,苯胺的降解效果随着苯酚浓度的增大而减小,当苯酚浓度达到370 mg/L时,Z1无法降解苯胺。添加氯化铵做外加氮源能解决高浓度苯酚和苯胺共降解的问题。在苯胺降解过程中大约有43%苯胺态氮转化成氨氮释放到环境中。     

对氨基苯磺酸降解菌的分离及其特性研究

从温州地区受污染的河水中分离到一株能降解对氨基苯磺酸的菌株WZR-3,该菌株能以对氨基苯磺酸为惟一碳源、能源生长。经对其形态特征、生理生化以及16S rDNA序列分析,该菌株初步鉴定为人苍白杆菌(Ochrobactrum anthropi)。该菌株利用对氨基苯磺酸生长时最适生长温度和pH值分别为30℃和7。该菌在10 g/L对氨基苯磺酸时仍能生长,最适生长浓度为300 mg/L对氨基苯磺酸。降解底物广谱性测试表明,该菌株还能降解多种芳香类化合物。     

高温好氧反硝化菌的分离鉴定及脱氮特性

从太原市某污水处理厂SBR活性污泥中分离纯化得到一株高温(50℃)好氧反硝化菌,命名为XF3。通过生理生化特性鉴定及16S rDNA序列分析,初步鉴定为波茨坦短芽孢杆菌。通过单因子实验考察碳源、C/N、pH及接种量对该菌株的生长情况与反硝化性能的影响。结果表明,菌株XF3最适碳源为琥珀酸钠,最佳C/N为12∶1,最佳pH为7,最适接种量10%(体积分数)。同时该菌株具有良好的异养硝化能力,48 h可以将73 mg/L氨氮几乎全部降解。     

一株高效硝化菌的鉴定及其特性

本研究通过测定菌株ABT01在不同初始氮浓度、pH、C/N、温度和溶氧条件下对氨氮的去除效果,获得该菌株的最佳应用条件。实验结果表明,当初始氨氮浓度低于40 mg/L时,该菌株的氨氮去除率高达85%以上。该菌株最适脱氨氮条件均为：pH 5.0-7.0、C/N=5、35℃、摇床转速150 r/min（溶解氧5.1 mg/L）,氨氮去除率最高达96.8%。同时该菌株经16S rDNA测序、细胞壁脂肪酸组成等鉴定方法,确定ABT01为枯草芽孢杆菌（Bacillus subtilis）。研究表明,枯草芽孢杆菌ABT01具有较好的氨氮去除能力,对水产养殖水质调控有潜在的应用价值。     

一株反硝化细菌的分离鉴定及其反硝化特性

从处理城镇污水的移动床生物膜反应器中分离获得一株反硝化细菌D3,并进一步研究该菌株的系统发育地位及反硝化特性。采用16S rDNA序列分析对菌株进行初步鉴定,探讨了基质浓度、起始pH和温度对菌株反硝化活性的影响。根据形态学特征、生理生化特性及16S rDNA序列测定分析,初步鉴定菌株属于寡养单胞菌属。该菌能利用硝酸钠或亚硝酸钠进行反硝化作用,最佳电子受体是硝酸盐氮,反硝化速率最大为19.86 mg/（L·h）,最适生长pH为7.36,最适生长温度为33.5℃。菌株D3在初始硝态氮浓度为140 mg/L,以乙酸钠为惟一碳源,pH为7.36,温度33.5℃的最优生长条件下,培养10 h进入对数生长期,倍增时间为9.9 h,48 h内硝酸盐还原率达95%。     

Persistence and dissipation kinetics of trifloxystrobin and tebuconazole in onion and soil

The persistence and dissipation kinetics of trifloxystrobin and tebuconazole on onion were studied after application of their combination formulation at a standard and double dose of 75 + 150 and 150 + 300 g a.i. ha^?1. The fungicides were extracted with acetone, cleaned-up using activated charcoal (trifloxystrobin) and neutral alumina (tebuconazole). Analysis was carried out by gas chromatograph (GC) and confirmed by gas chromatograph mass spectrometry (GC-MS). The recovery was above 80% and limit of quantification (LOQ) 0.05 mg kg^?1 for both fungicides. Initial residue deposits of trifloxystrobin were 0.68 and 1.01 mg kg^?1 and tebuconazole 0.673 and 1.95 mg kg^?1 from standard and double dose treatments, respectively. Dissipation of the fungicides followed first-order kinetics and the half life of degradation was 6–6.6 days. Matured onion bulb (and field soil) harvested after 30 days was free from fungicide residues. These findings suggest recommended safe pre-harvest interval (PHI) of 14 and 25 days for spring onion consumption after treatment of Nativo 75 WG at the standard and double doses, respectively. Matured onion bulbs at harvest were free from fungicide residues.     

Sorption and Desorption Behavior of Chloroanilines and Chlorophenols on Montmorillonite and Kaolinite

The bioavailability of pollutants, pesticides and/or their degradation products in soil depends on the strength of their sorption by the different soil components, particularly by the clay minerals. This study reports the sorption-desorption behavior of the environmentally hazardous industrial pollutants and certain pesticides degradation products, 3-chloroaniline, 3,4-dichloroaniline, 2,4,6-trichloroaniline, 4-chlorophenol, 2,4-dichlorophenol and 2,4,6-trichlorophenol on the reference clays kaolinite KGa-1 and Na-montmorillonite SWy-l. In batch studies, 2.0 g of clay were equilibrated with 100.0 mL solutions of each chemical at concentrations ranging from 10.0 to 200.0 mg/L. The uptake of the compounds was deduced from the results of HPLC-UV-Vis analysis. The lipophilic species were best retained by both clay materials. The most lipophilic chemical used in the study, 2,4,6-trichloroaniline, was also the most strongly retained, with sorption of up to 8 mg/g. In desorption experiments, which also relied on HPLC-UV-Vis technique, 2,4,6-trichloroaniline was the least desorbed from montmorillonite. However, on kaolinite all of the compounds under study were irreversibly retained. The experimental data have been modelled according to the Langmuir and Freundlich isotherms. A hypothesis is proposed concerning the sorption mechanism and potential applications of the findings in remediation strategies have been suggested.     

Field and laboratory studies of the fate and enantiomeric enrichment of venlafaxine and O-desmethylvenlafaxine under aerobic and anaerobic conditions

The stereoselectivity of R,S-venlafaxine and its metabolites R,S-O-desmethylvenlafaxine, N-desmethylvenlafaxine, O,N-didesmethylvenlafaxine, N,N-didesmethylvenlafaxine and tridesmethylvenlafaxine was studied in three processes: (i) anaerobic and aerobic laboratory scale tests; (ii) six wastewater treatment plants (WWTPs) operating under different conditions; and (iii) a variety of wastewater treatments including conventional activated sludge, natural attenuation along a receiving river stream and storage in operational and seasonal reservoirs. In the laboratory and field studies, the degradation of the venlafaxine yielded O-desmethylvenalfaxine as the dominant metabolite under aerobic and anaerobic conditions. Venlafaxine was almost exclusively converted to O-desmethylvenlafaxine under anaerobic conditions, but only a fraction of the drug was transformed to O-desmethylvenlafaxine under aerobic conditions. Degradation of venlafaxine involved only small stereoisomeric selectivity. In contrast, the degradation of O-desmethylvenlafaxine yielded remarkable S to R enrichment under aerobic conditions but none under anaerobic conditions. Determination of venlafaxine and its metabolites in the WWTPs agreed well with the stereoselectivity observed in the laboratory studies. Our results suggest that the levels of the drug and its metabolites and the stereoisomeric enrichment of the metabolite and its parent drug can be used for source tracking and for discrimination between domestic and nondomestic wastewater pollution. This was indeed demonstrated in the investigations carried out at the Jerusalem WWTP.     

一株铅镉抗性菌株的分离鉴定及其生物学特性

鉴定了从黑龙江扎龙湿地土壤中筛选出的一株抗铅镉的菌株,研究了其生物学特性和部分生理生化指标。利用16SrDNA序列分析鉴定其菌属,并且研究Pb2+、Cd2+、Pb2+/Cd2+、温度、pH、盐以及抗生素对菌株生长的影响。经鉴定,该菌株为阴沟肠杆菌属(Enterobacter cloacae)。该菌株对Pb2+的去除率和吸附率分别达到了70.34%和44.39%,对Cd2+的去除率和吸附率分别达到了40.54%和25.14%。该菌株最适生长温度为25℃,最适生长pH为7.0左右。此菌株对抗生素亚胺培南最敏感。随着盐、Pb2+、Cd2+、Pb2+/Cd2+混合浓度的升高,该菌株生长受到抑制。     

Synthesis and characterization of m- and p-methylbenzyl-mercapturic acids derived from m- and p-xylenes

Chemical synthesis and physical properties of two mercapturic acids suggested as urinary metabolites of m- and p-xylenes ace described. These compounds may be used for the identification and quantivative determination by high-performance liquid chromatography of the corresponding mercapturic acids in urine.     

Copper-catalyzed chlorination and condensation of acetylene and dichloroacetylene

The chlorination and condensation of acetylene at low temperatures is demonstrated using copper chlorides as chlorinated agents coated to model borosilicate surfaces. Experiments with and without both a chlorine source and borosilicate surfaces indicate the absence of gas-phase and gas-surface reactions. Chlorination and condensation occur only in the presence of the copper catalyst. C₂ through C₈ organic products were observed in the effluent; PCDD/F were only observed from extraction of the borosilicate surfaces. A global reaction model is proposed that is consistent with the observed product distributions. Similar experiments with dichloroacetylene indicate greater reactivity in the absence of the copper catalyst. Reaction is observed in the gas-phase and in the presence of borosilicate surfaces at low temperatures. The formation of hexachlorobenzene is only observed in the presence of a copper catalyst. PCDD/F were only observed from extraction of the borosilicate surfaces. A global reaction model is proposed for the formation of hexachlorobenzene from dichloroacetylene.     

Levels of PCDDs and PCDFs in products and effluent from the Swedish pulp and paper industry and chloralkali process

Within the Swedish Dioxin Survey various samples from the pulp and paper industry and the chloralkali process have been analyzed by congener specific analytical methods. In addition to the generally discussed “bleaching pattern” of the tetrachlorinated congeners, these samples also contained higher chlorinated congeners like hexa-CDDs, hepta-CDFs, octa-CDD and octa-CDF. Consequently it is recommended that samples from the pulp industry should be analyzed for all PCDDs and PCDFs (tetra- through octa-). Counted as Nordic Toxic Equivalents (NTEQ), the recycled pulp samples had the highest contamination level followed by TMP, unbleached sulfite and bleached softwood and hardwood. In addition to the bleaching process, various chemicals used in the pulping, bleaching and wastewater treatment can contribute to the contamination.     

Aerobic and anaerobic degradation of profluralin and trifluralin

Abstract

The degradation of profluralin [N‐(cyclopropylmethyl)‐α,α,α‐trifluoro‐2,6‐dinitro‐N‐propyl‐]p‐toluidine] and trifluralin (α,α,α‐trifluoro‐2,6‐dinitro‐N,N‐dipropyl‐p‐toluidine) was studied under aerobic and anaerobic soil conditions. Three soils (Goldsboro loamy sand, Cecil loamy sand, Drummer clay loam) were each treated with 1 ppmw herbicide; anaerobic conditions were maintained by flooding. Soil samples were extracted monthly and subjected to TLC analysis. No degradation was detected in sterile controls. Aerobic degradation of both herbicides was greatest in the Cecil loamy sand soil over the entire incubation period. Degradation of profluralin in Cecil soil under aerobic conditions was 86 percent after 4 months with three products detected; 83 percent of the trifluralin was degraded with two products detected. Anaerobic degradation accounted for 72 percent of the profluralin and 78 percent of the trifluralin after 4 months. Degradation of both herbicides increased with incubation time for the first 3 months and decreased slightly thereafter. Generally there was more extensive degradation (percent and in number of products formed) of profluralin than trifluralin under the conditions tested. More degradation products were detected for both herbicides under aerobic conditions than under anaerobic conditions.     

Uptake and translocation of metformin, ciprofloxacin and narasin in forage- and crop plants

Transfer of bioactive organic compounds from soil to plants might represent animal and human health risks. Sewage sludge and manure are potential sources for bioactive compounds such as human- and veterinary drugs. In the present study, uptake of the anti-diabetic compound, metformin, the antibiotic agent ciprofloxacin and the anti-coccidial narasin in carrot (Daucuscarota ssp. sativus cvs. Napoli) and barley (Hordeumvulgare) were investigated. The pharmaceuticals were selected in order to cover various chemical properties, in addition to their presence in relevant environmental matrixes. The root concentration factors (RCF) found in the present study were higher than the corresponding leaf concentration factors (LCF) for the three test pharmaceuticals. The uptake of metformin was higher compared with ciprofloxacin and narasin for all plant compartments analyzed. Metformin was studied more explicitly with regard to uptake and translocation in meadow fescue (Festucapratense), three other carrot cultivars (D.carota ssp. sativus cvs. Amager, Rothild and Nutri Red), wheat cereal (Triticumaestivum) and turnip rape seed (Brassicacampestris). Uptake of metformin in meadow fescue was comparable with uptake in the four carrot cultivars (RCF 2-10, LCF approximately 1.5), uptake in wheat cereals were comparable with barley cereals (seed concentration factors, SCF, 0.02-0.04) while the accumulation in turnip rape seeds was as high as 1.5. All three pharmaceuticals produced negative effects on growth and development of carrots when grown in soil concentration of 6-10 mg kg⁻¹ dry weight.     

新型高效氧化偶合絮凝剂COF-I的研制及其应用研究

以硫酸铝为主要原料 ,经过化学改性后 ,制得兼具氧化和絮凝为一体的新型、高效水处理药剂COF I ,并设计正交实验找出了药剂最佳组合配方 ,且对微污染水源水、城市污水及印染废水进行了强化处理试验研究。结果表明 ,最佳配方为复合比 1∶1、添加剂含量 1 2 5 %、稳定剂含量 0 3%、氧化成分含量 1 0 % ,在最佳配方和最佳工艺条件下 ,复合药剂COF I对微污染水源水、城市污水及印染废水均具有良好的处理效果