PVA降解菌的复配组合及其紫外诱变处理的研究

对已筛选出的4株PVA降解菌进行不同的组合后测定PVA降解率,发现Z5与Z8菌株混合后在1周内对PVA的去除率达到了所有组合中的最高值52.07%,比单菌株提高了约22%。采用紫外照射的方法对混合菌进行诱变并利用正交实验研究其特性,结果表明,诱变后的混合菌在1周内降解了91.46%的PVA,并且碳源浓度对酶活的影响最为显著。当pH为7,碳源、氮源含量分别为1.5 g/L、0.6 g/L,NaC l浓度为1.5 g/L时,诱变菌株处于最佳生长状态。     

聚乙烯醇生物降解菌群的结构分析及优势菌株降解特性

对堆肥中降解聚乙烯醇材料的微生物菌群结构进行了分析。结果表明:降解聚乙烯醇材料的优势菌群属于芽胞杆菌科(Bacillaceae)。从降解了3年的材料表面筛选出了1株聚乙烯醇降解菌DG01,鉴定为苏云金杆菌(Bacillus thuringiensis sp.)。分别以聚乙烯醇(poly(vinyl alcohol), PVA)浓度和二氧化碳排放量为指标,对PVA的降解动力学进行了研究。结果表明:PVA生物降解过程符合一级动力学模型,R2分别为0.984 0和0.983 5。对摇瓶培养条件进行了单因素优化实验。最佳降解温度,初始pH和酵母粉浓度分别为41℃、7和1.40 g·L~(-1)。优化后,48 h内PVA初始浓度为3 g·L~(-1)的降解率达到了45.21%,提高了2.10倍。     

Fenton法降解废弃聚乙烯醇面料的实验研究

采用Fenton法降解废弃聚乙烯醇(PVA)面料,以反应温度、初始pH、Fe~(2+)/COD质量比和H_2O_2/Fe~(2+)摩尔比为考察因素,得到最佳降解条件。结果表明,Fenton法的最佳降解条件为:反应温度60℃,pH=4,Fe~(2+)/COD质量比0.3,H_2O_2/Fe~(2+)摩尔比11。此时,降解质量浓度为50g/L的PVA面料废水,降解率超过90%,降解后黏均分子量下降了99.63%,COD去除率为61.57%,BOD/COD为0.46,吨水处理的经济成本为13 069.71元。     

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。     

聚乙烯醇在超临界水氧化中降解

以H2O2为氧化剂用间歇式超临界水氧化装置对聚乙烯醇(PVA)废水进行降解研究。通过正交实验,考察了反应温度、压力、时间及氧化剂过氧倍数对降解效果的影响,并且采用GC/MS对液相降解产物进行表征推测其可能降解途径。结果表明:PVA在SCWO体系中能完全降解,反应温度440℃、压力28 MPa、氧化剂过氧倍数4、反应40 min时,COD去除率为99.03%,出水COD=89.09 mg/L。PVA在SCWO体系中降解为烯烃、烯酮、醇和羧酸类中间产物、最终降解为小分子的饱和直链烷烃类液相产物。     

三乙胺降解菌SYA-1的分离、降解性能与动力学

从农药废水处理池的活性污泥中分离筛选得到1株高效三乙胺降解菌株SYA-1,根据菌株SYA-1的形态特征、生理生化特性和16S rRNA基因序列同源性分析,此菌株鉴定为Achromobacter sp.。菌株SYA-1能以三乙胺为惟一碳、氮源生长,并在24 h内完全降解200 mg/L的三乙胺。环境因素影响实验表明,在温度30℃,初始pH 7.0,NaCl浓度≤10 g/L条件下,菌株SYA-1生长良好且对三乙胺的降解效率最佳;金属离子对菌株生长和三乙胺降解的抑制程度表现为:Cu2+Co2+Ag+Cd2+Fe3+Pb2+。菌株SYA-1降解三乙胺的动力学过程可用Haldane模型模拟,其参数为μmax=0.123h-1;K s=82 mg/L;K i=215 mg/L。为含三乙胺废水的生物降解提供了理论依据和菌株资源。     

一株不动杆菌JBX-006对聚丙烯酰胺的降解特性研究

聚丙烯酰胺结构复杂、难降解，进入环境会造成污染。从大庆油田周边土壤中富集、驯化和分离获得1株聚丙烯酰胺降解率较高的菌株JBX-006,经形态学、生理生化和分子生物学鉴定为琼氏不动杆菌(Acinetobacter junii)。对JBX-006降解聚丙烯酰胺的影响因素开展研究，分析了不同外碳源、外氮源和金属离子对其降解聚丙烯酰胺的影响，结果表明，JBX-006在5 g/L蔗糖、10.0 g/L硝酸钾、30 mg/L Fe²⁺的基础培养液中，30℃培养5 d对300 mg/L的聚丙烯酰胺降解率达到81.65%,明显高于优化前。研究获得的高效降解聚丙烯酰胺菌株JBX-006为修复聚丙烯酰胺污染土壤提供了技术支持。     

沙雷氏苯酚降解菌固定化条件优化及降解性能研究

从首都钢铁集团焦化厂曝气池中的活性污泥中分离出一株沙雷氏菌属,利用聚乙烯醇(PVA)-卡拉胶混合载体对该菌种进行固定化,并对实际焦化废水进行降解。结果表明:(1)以PVA为包埋材料,添加卡拉胶为辅助载体后,使得固定化苯酚降解菌小球在制备过程中不易出现凝集的现象,易于操作,固定化苯酚降解菌小球颗粒综合性能有所提高。(2)最佳的固定化条件:PVA质量分数为8%,卡拉胶质量分数为0.5%,KCl为0.4mol/L,菌体化包埋比(菌液和混合载体的体积比)为1.0∶5.0,固定化时间为24h。新制备的固定化苯酚降解菌在使用前需进行活化,以提高降解性能。(3)在焦化废水的实际降解中,固定化苯酚降解菌的降解性能明显优于游离苯酚降解菌,固定化的载体对固定于其中的菌种起到了保护作用。     

固定化氨氮降解菌处理氨氮废水的试验研究

考察了海藻酸钠(SA)和聚乙烯醇(PVA)含量对固定化载体性能的影响,并筛选了最优条件制备固定化氨氮降解菌,研究其对氨氮废水的处理效果。当PVA和SA质量分数分别为8.00%、1.00%时,制成的固定化载体抗压性能最好,能够形成丰富的多孔结构。固定化氨氮降解菌在处理氨氮废水前驯化168h,可以恢复较高活性。在固定化氨氮降解菌投加量2%(质量分数)、反应温度30℃、pH 8.01、溶解氧3.0 mg/L的条件下反应60h,氨氮废水中的氨氮质量浓度从最初的3 835.29 mg/L降为82.35mg/L,去除率为97.85%。固定化氨氮降解菌在投加量低于氨氮降解菌的情况下,仍然能实现与之相近的氨氮废水处理效果,证明固定化氨氮降解菌能高效处理高浓度氨氮废水。     

低温降解六六六优势菌种的选育研究

通过实验,筛选出低温条件(≤10℃)下降解六六六的优势菌株--1号菌株,同时利用正交实验测得该菌株的最佳降解条件为:pH=5.5、接菌量2 g/L、NH4Cl 0.8 g/L、KH2PO4 0.6 g/L、MgSO4 0.2 g/L.在此条件下,经30 d驯化后的菌株对六六六的降解率由原来的54.71%提高到62.58%     

Optimization of Height of Release of Air Pollutants

A number of key projects in the Environmental Protection Agency (EPA) particulate R&;D program having applicability to industry are presented. For electrostatic precipitators (ESP) there is presented the result of work on large diameter discharge electrodes which provide a decrease in penetration of up to a factor of 4 when compared to conventional small diameter electrodes. Also discussed is the multistage ESP which provides a collection efficiency that would require a collecting plate area 4 or 5 times larger with conventional ESP technology. The E-SOX technology makes use of the multistage concept to free up space in the ESP for SO₂ removals of up to 90%. Electrostatically augmented fabric filtration provides a reduction in pressure drop of about 5 0% as compared to conventional fabric filtration. Wind tunnel modeling of windbreaks for material storage piles indicates a potential for providing engineering design data that would allow significant emission reduction caused by wind erosion     

Investigation of the characteristics of the reflectivity of clouds

This paper investigates some of the reflectivity characteristics that clouds (when modelled as solid bodies) must exhibit to be compatible with observations that the reflecting surface of a cloud (i) appears almost equally bright across its face, (ii) is brightest when the cloud is opposite to the Sun but decreases in brightness as the cloud moves to other positions and (iii) increases in brightness with increasing optical thickness of the cloud in the observer's line of sight. These observations, respectively, are shown to imply that the peak value of the bidirectional total reflectivity from a cloud surface (i) increases in inverse proportion to the cosine of the angle between the Sun and the normal to the cloud surface, as the incident angle increases, (ii) appears to be directed back in the direction of the incident radiation, and (iii) increases as optical thickness of the cloud in the observer's line of sight increases. The results could have application in many fields (e.g. modelling diffuse radiance distributions for cloudy skies).     

次氯酸钠发生器的研制

介绍了电解法生产次氯酸钠的原理 ,并在原有生产工艺的基础上进行了重新设计和对设备的重新选择、改造 ,得出了各个工艺参数的最佳值 ,生产出高品质的次氯酸钠     

实验室质量管理体系内部审核的策划

在实施ISO／IEC 17025：1999标准《检测和校准实验室能力的通用要求》过程中，通过实验室质量管理体系内部审核的实践与系统分析，识别出内部审核策划阶段的关键环节，提出审核范围确定、审核计划和抽样方案制订的质量控制要求，为有序高效地实施内部审核提供了技术方法。     

Estimation of uncertainty of sampling for analysis of pesticide residues

Abstract

A computer model was used to take random samples from primary sample populations obtained from field trials to simulate the uncertainty of sampling for residue analysis of plant commodities and soil. The results indicate about 40%, 30% and 20% relative uncertainty when random samples of size 5, 10 and 25 are taken respectively, from a single lot. Therefore the sample size should be the same for establishing and enforcing legal limits.     

扬中生态环境建设的思考与实践

结合扬中生态环境的基本情况和存在的不足，进行了具体分析，对扬中未来生态建设的发展方向提出了建议及实施措施。     

Comparison of methods for evaluation of activity of photocatalytic films

Objective

This work aims to investigate the correlation between the photocatalytic activity determined by methylene blue bleaching (DIN 52980), stearic acid degradation, and degradation of acetone in gas phase.

Method

The photocatalytic TiO₂ coatings included in this investigation ranged from thin commercially available coatings (Activ^TM and BioClean^TM) and ready to use suspensions (Nano-X PK1245) to lab-produced PVD and sol?Cgel coatings. XRD analysis of the photocatalytic coatings showed that all the coatings consisted of nanocrystalline anatase, although the thickness and porosity varied considerably.

Results

The study showed that the reproducibility of the activity measurements was good. However, more importantly, the investigation showed that there is a good correlation between the activities determined by the different methods even though the characteristics of the photocatalytic coatings and the organic probe molecules varied considerably.

Conclusion

The overall findings of this work suggest that there is a good correlation between the investigated methods. These results are promising for the future work concerning standardization of methods for determination of the activity of photocatalytic films.     

Impact of overexploitation of shellfish: northeastern coast of India

India has a very extensive coastline of about 7515 km, rich in diverse living resources. These resources continue to deteriorate with rampant harvesting or are altered for other uses such as aquaculture and fisheries. The present paper deals with degrading coastal habitats in northeastern India, and projects the intensity of the stress arising from the collection of tiger prawn seeds (Penaeus monodon) for aquacultural farms and molluskan shells for poultry feed and edible lime. Indiscriminate exploitation of these resources leads to a heavy reduction of the species concerned and other associated marine communities. The magnitude of such destruction has been quantified. The impacts of biodiversity loss and their after-effects on the ecobalance of this coastal system have become a matter of great concern to ecologists to maintain security and sustainability. The authors propose a public awareness program on themes relating to the importance of biodiversity for human livelihoods.     

实验室质量管理体系内部审核的实施

在实施ISO／IEC17025：1999标准《检测和校准实验室能力的通用要求》过程中，通过实验室质量管理体系内部审核的实践与系统分析，识别出内部审核实施阶段的关键环节，提出召开首次会议、收集审核证据、确定审核发现和召开末次会议的技术方法，对提高内部审核的质量和有效性、获得可靠的审核结论具有重要意义。