循环流速对活性污泥水解-好氧循环工艺处理活性艳蓝KN-R废水的影响

采用活性污泥水解-好氧循环工艺降解活性艳蓝KN-R废水,研究了水解、好氧反应器间循环流速对废水色度和化学需氧量(COD)去除效果的影响以及水解反应器中挥发性脂肪酸(VFA)的变化规律.研究结果表明,废水色度和COD去除率随循环流速增加呈现先增大后减小的趋势.循环流速过大,不利于COD和色度的去除.但提高循环流速,有助于减少水解反应器中VFA的积累.紫外-可见光谱分析显示,经过24 h处理后的废水,活性艳蓝KN-R的特征吸收峰降至最低,表明了活性艳蓝KN-R得到了生物降解.     

枯草芽孢杆菌提高原油采收率的物模驱油实验

针对目前常规采油开采技术的限制和原油采收率较低等问题,本研究采用单因素法对一株从油污中分离的枯草芽孢杆菌(Bacillus subtilis 32811)代谢产生物表面活性剂的发酵条件进行优化并进行微生物驱油实验。优化条件实验确定了以葡萄糖为唯一碳源,最佳的无机培养基配方(g/L):ρ(C_6H_(12)O_6)30.0,ρ(NH_4NO_3)1.0,ρ(KH_2PO_4)4.1,ρ(Na_2HPO_4·12H_2O)14.3,ρ(MgSO_4)0.096,ρ(CaCl_2)0.0008,ρ(FeSO_4)0.0011,ρ(C_(10)H_(16)N_2Na_2O_8)0.0015。发酵液表面张力从65mN/m降至25mN/m。通过微生物对原油降解的物模驱油实验,得出原油出现乳化及原油重质组分含量明显降低的结果。物模驱油实验中分别注入发酵液及先注入微生物再注入无机培养液能提高原油采收率26.1%和31.4%。说明枯草芽孢杆菌有利于提高剩余油的采收率,具有良好的应用前景。     

表面活性剂环境危害性分析

全面分析了表面活性剂存在时对土壤、水体环境的危害,研究了表面活性剂对植物、动物、人体以及微生物的影响,同时还探讨了表面活性剂的生物降解。表明全面了解表面活性剂环境安全性对推动表面活性剂工业的持续发展具有重大意义。     

受控堆肥生物降解法测定全生物降解塑料(PBS)性能

依据GB/T 19277-2003/ISO 14855:1999,对降解塑料聚丁二酸丁二醇酯(PBS)、丁二酸对苯二甲酸丁二醇共聚酯(PBST)进行堆肥化条件下生物降解能力的测定.试验结果,用此方法评价塑料生物降解性能是可行的.PBS、PBST具有良好的生物降解性.建立了高分子材料测定方法的操作系统.     

偏二甲肼污水的好氧生物降解及其动力学研究

Unsymmetrical dimethylhydrazine (UDMH) is a main liquid rocket propellant. There are plenty of toxic and stable contaminations in its wastewater. The harmful influence has been considered. Nowadays the disposal technology of wastewater containing UDMH has plenty of disadvantages, such as high energy consuming, low safety factor, numerous secondary contaminations, strong toxicity, and so on. It is necessary to find a new way for wastewater disposal. Biodegradation technology is low innocuity and cleanliness, has great degradation capacity, and can almost degrade all kinds of organic substances. In this paper the aerobic active sludge is used to treat wastewater containing UDMH which is one kind of biodegradation technology.     

混凝沉淀-ABR-接触氧化工艺处理纱线染整废水

采用混凝沉淀—ABR—接触氧化工艺处理纱线染整废水,并对工艺单元的特点和运行情况进行了分析。运行结果表明,混凝沉淀池对CODCr和色度的去除率分别为50.5%和76.9%;ABR和接触氧化池的容积负荷分别为0.73kgCODCr/(m3.d)和0.43kgCODCr/(m3.d);处理后出水CODCr<85.5mg/L,色度<40倍,系统对CODCr、BOD5、SS、色度和硫化物的平均去除率分别为89.8%、92.1%、82.8%、95.2%和99.2%。     

Biodegradation of Pine Processionary Caterpillar Silk Is Mediated by Elastase- and Subtilisin-like Proteases

Pine processionary caterpillar nests are made from raw silk. Fibroin protein is the main component of silk which, in the case of pine processionary caterpillar, has some unusual properties such as a higher resistance to chemical hydrolysis. Isolation of microorganisms naturally present in silk nests led to identification of Bacillus licheniformis and Pseudomonas aeruginosa strains that in a defined minimal medium were able to carry out extensive silk biodegradation. A LasB elastase-like protein from P. aeruginosa was shown to be involved in silk biodegradation. A recombinant form of this protein expressed in Escherichia coli and purified by affinity chromatography was able to efficiently degrade silk in an in vitro assay. However, silk biodegradation by B. licheniformis strain was mediated by a SubC subtilisin-like protease. Homologous expression of a subtilisin Carlsberg encoding gene (subC) allowed faster degradation compared to the biodegradation kinetics of a wildtype B. licheniformis strain. This work led to the identification of new enzymes involved in biodegradation of silk materials, a finding which could lead to possible applications for controlling this pest and perhaps have importance from sanitary and biotechnological points of view.     

An Overview into Polyethylene Terephthalate (PET) Hydrolases and Efforts in Tailoring Enzymes for Improved Plastic Degradation

Plastic or microplastic pollution is a global threat affecting ecosystems, with the current generation reaching as much as 400 metric tons per/year. Soil ecosystems comprising agricultural lands act as microplastics sinks, though the impact could be unexpectedly more far-reaching. This is troubling as most plastic forms, such as polyethylene terephthalate (PET), formed from polymerized terephthalic acid (TPA) and ethylene glycol (EG) monomers, are non-biodegradable environmental pollutants. The current approach to use mechanical, thermal, and chemical-based treatments to reduce PET waste remains cost-prohibitive and could potentially produce toxic secondary pollutants. Thus, better remediation methods must be developed to deal with plastic pollutants in marine and terrestrial environments. Enzymatic treatments could be a plausible avenue to overcome plastic pollutants, given the near-ambient conditions under which enzymes function without the need for chemicals. The discovery of several PET hydrolases, along with further modification of the enzymes, has considerably aided efforts to improve their ability to degrade the ester bond of PET. Hence, this review emphasizes PET-degrading microbial hydrolases and their contribution to alleviating environmental microplastics. Information on the molecular and degradation mechanisms of PET is also highlighted in this review, which might be useful in the future rational engineering of PET-hydrolyzing enzymes.     

生物可降解脂肪族聚酯在陕西土壤中的降解行为

以西安当地土壤及西安某污水处理厂的活性污泥为降解介质,对生物可降解聚酯聚乳酸(PLA)、聚丁二酸丁二醇酯(PBS)和聚己内酯(PCL)的降解性能进行了研究,并对它们的降解机理进行了初步探讨。根据偏光显微镜和扫描电镜的观察表明,降解后的聚酯膜表面均有明显被侵蚀的痕迹;在陕西当地土壤中,PCL的降解速度最快,PLA次之,PBS最慢。红外光谱表征了这三种聚合物降解前后的化学结构。     

驱油用聚丙烯酰胺降解研究进展

聚丙烯酰胺作为驱油用的聚合物得到广泛应用,但随着采出液中见到聚合物,给油井生产和污水处理带来了难题.对聚丙烯酰胺进行降解是解决这些难题的有效方法之一.本文对有关聚丙烯酰胺降解的研究成果进行了综述,从机械降解、热降解、生物降解和化学降解等方面进行阐述.