含锌废水处理技术的研究进展

综述了传统的物理化学法和生物法处理含锌废水的原理,系统阐述了其研究进展.微生物固定技术是一种新兴而有效的生物处理技术,尤其是硫酸盐还原菌固定化技术,将厌氧活性污泥包埋,构建稳定高效的微生物体系,以加强其抗毒性和处理效率.因此,在含锌废水处理方面具有很大的发展潜力,有望得到广泛应用.     

硫酸盐还原菌生理特性及其在废水处理中的应用

硫酸盐还原菌(SRB)是一类利用硫酸盐或者其他氧化态硫化物作为电子受体来异化有机物质的严格厌氧菌.介绍了SRB的生理特性及检测方法,在阐明SRB降解水中污染物原理的基础上,充分探讨了SRB在处理重金属废水、无机和有机废水中的应用现状及研究进展,指出SRB固定化技术是其发展的必经之路.     

硫化物生物氧化脱硫技术研究现状

介绍了近年来国内外硫化物生物氧化为单质硫的各种脱硫技术.分析总结了硫化物生物氧化为单质硫工艺的各种影响因素,包括氧硫比、溶解氧浓度、硫化物浓度、化学氧化、微生物菌种、pH值、温度等因素.提出了生物氧化脱硫技术的发展前景.该技术将脱硫和单质硫的回收和为一体,是一种安全、低成本将含硫废液变废为宝的工艺技术.     

顺序氯化对微生物、副产物和生物稳定性的综合控制

在中试规模试验中,研究了“短时游离氯后转氯胺的顺序氯化消毒工艺”对微生物、消毒副产物和生物稳定性指标的控制效果.该顺序氯化消毒工艺综合利用了游离氯消毒灭活微生物迅速彻底,氯胺消毒副产物生产量低的特点,通过氯化消毒技术的组合,安全经济地实现了消毒卫生学和消毒副产物指标的双重控制.该消毒工艺对细菌总数、异养菌平板计数、总大肠菌群指标的控制效果略好于传统游离氯消毒,对脊髓灰质炎病毒和大肠杆菌f2噬菌体的灭活效果与游离氯相同.相同原水条件下,顺序氯化消毒工艺比游离氯消毒工艺产生的三卤甲烷浓度减少35.8%～77.0%;卤乙酸减少36.6%～54.8%.消毒进水水质越差,顺序氯化消毒工艺在消毒副产物控制方面就越有优势.该工艺对生物稳定性指标的控制效果明显高于游离氯消毒.     

Magnetotactic bacteria: Characteristics and environmental applications

• Magnetotactic bacteria (MTB) synthesize magnetic nanoparticle within magnetosomes. • The morphologic and phylogenetic diversity of MTB were summarized. • Isolation and mass cultivation of MTB deserve extensive research for applications. • MTB can remove heavy metals, radionuclides, and organic pollutants from wastewater. Magnetotactic bacteria (MTB) are a group of Gram-negative prokaryotes that respond to the geomagnetic field. This unique property is attributed to the intracellular magnetosomes, which contains membrane-bound nanocrystals of magnetic iron minerals. This review summarizes the most recent advances in MTB, magnetosomes, and their potential applications especially the environmental pollutant control or remediation. The morphologic and phylogenetic diversity of MTB were first introduced, followed by a critical review of isolation and cultivation methods. Past research has devoted to optimize the factors, such as oxygen, carbon source, nitrogen source, nutrient broth, iron source, and mineral elements for the growth of MTB. Besides the applications of MTB in modern biological and medical fields, little attention was made on the environmental applications of MTB for wastewater treatment, which has been summarized in this review. For example, applications of MTB as adsorbents have resulted in a novel magnetic separation technology for removal of heavy metals or organic pollutants in wastewater. In addition, we summarized the current advance on pathogen removal and detection of endocrine disruptor which can inspire new insights toward sustainable engineering and practices. Finally, the new perspectives and possible directions for future studies are recommended, such as isolation of MTB, genetic modification of MTB for mass production and new environmental applications. The ultimate objective of this review is to promote the applications of MTB and magnetosomes in the environmental fields.     

Biological conversion pathways of sulfate reduction ammonium oxidation in anammox consortia

• The SRAO phenomena tended to occur only under certain conditions. • High amount of biomass and non-anaerobic condition is requirement for SRAO. • Anammox bacteria cannot oxidize ammonium with sulfate as electron acceptor. • AOB and AnAOB are mainly responsible for ammonium conversion. • Heterotrophic sulfate reduction mainly contributed to sulfate conversion. For over two decades, sulfate reduction with ammonium oxidation (SRAO) had been reported from laboratory experiments. SRAO was considered an autotrophic process mediated by anammox bacteria, in which ammonium as electron donor was oxidized by the electron acceptor sulfate. This process had been attributed to observed transformations of nitrogenous and sulfurous compounds in natural environments. Results obtained differed largely for the conversion mole ratios (ammonium/sulfate), and even the intermediate and final products of sulfate reduction. Thus, the hypothesis of biological conversion pathways of ammonium and sulfate in anammox consortia is implausible. In this study, continuous reactor experiments (with working volume of 3.8L) and batch tests were conducted under normal anaerobic (0.2≤DO<0.5 mg/L) / strict anaerobic (DO<0.2 mg/L) conditions with different biomass proportions to verify the SRAO phenomena and identify possible pathways behind substrate conversion. Key findings were that SRAO occurred only in cases of high amounts of inoculant biomass under normal anaerobic condition, while absent under strict anaerobic conditions for same anammox consortia. Mass balance and stoichiometry were checked based on experimental results and the thermodynamics proposed by previous studies were critically discussed. Thus anammox bacteria do not possess the ability to oxidize ammonium with sulfate as electron acceptor and the assumed SRAO could, in fact, be a combination of aerobic ammonium oxidation, anammox and heterotrophic sulfate reduction processes.     

Monitoring of a Coastal Mediterranean Area: Culturable Bacteria, Phytoplankton, Environmental Factors and their Relationships in the Southern Adriatic Sea

Culturable heterotrophic bacterial and phytoplanktonic densities were investigated at four sites in the Southern Adriatic Sea (Brindisi, S. Cataldo, Otranto and S. M. di Leuca) over an annual cycle. The main phytoplankton groups, the bacterial biodiversity, as well as the faecal contamination indicators were determined. Culturable bacterial numbers averaged 4.8 ± 0.2 log CFU ml⁻¹ whereas phytoplankton numbers averaged 2.1 ± 0.4 log cells ml⁻¹. Relationships between culturable bacteria, phytoplankton and the environmental factors were established. Bacterial and phytoplankton densities usually depended significantly on temperature, dissolved oxygen, phosphate and nitrite only in the S. Cataldo transect. In all the examined transects phytoplankton showed a bloom during the January–February period followed by a bacterial peak during the February–March period. Thus we can suppose that the phytoplankton winter bloom is responsible for the availabily of organic matter for bacterial populations in the following months in this oligotrophic ecosystem.     

PEM式臭氧消毒在地上游泳池水处理中的应用

采用臭氧法水处理系统对地上游泳池的循环水进行灭菌消毒,研究了臭氧用量、循环水流量和运行时间等因素对臭氧法灭菌效果的影响。结果表明,3组PEM臭氧发生器应用于21.2 m3的地上游泳池,在4 m3/h的循环水流量下运行12 h后,水中的细菌总数与大肠杆菌群数达到国家标准,去除率均在99%以上。与盐电解法水处理系统相比较,臭氧法水处理系统的优势在于:杀菌快速高效、出水水质的理化指标较好和运行费用低廉。     

聚合物驱采出水中聚丙烯酰胺的微生物联合降解作用研究

通过对2株细菌的培养降解实验研究聚丙烯酰胺(hydrolyzed polyacrylamide,HPAM)降解菌对水环境下聚丙烯酰胺的降解作用,讨论协同降解机理。2株降解聚丙烯酰胺的菌株假单胞菌CJ419、枯草芽孢杆菌FA16在初始30℃废水样品上培养,定期测量细菌生物量和HPAM降解率。培养30 d后CJ419和FA16对聚合物的降解率最大值分别达到30.4%和25%,而以1∶1比例的混合菌降解率最大值达到80.3%。对2株菌胞外各组分研究表明:混合菌降解HPAM的机理主要由胞外降解酶系水解聚合物侧链基团导致HPAM降解为小分子物质,同时生长过程中降解菌还会释放非蛋白还原性物质引发氧化反应共同参与HPAM降解。     

三株优势菌对多环芳烃的降解性能研究

多环芳烃具有毒性、生物蓄积性和半挥发性,并能在环境中持久存在。生物修复处理具有费用低、效果好、污染物残留量低、不产生二次污染、能够保持或改善植物生长的土壤结构等优点。实验分别在对单一菌株、两两混合菌株及三株菌混合等三种情形下,对蒽、菲、芘的降解作用进行了研究。研究结果表明：单一菌株对蒽、菲、芘有一定的降解能力,菌株混合时,对蒽、菲的降解率有所提高;三株菌种混合时,黄杆菌对放线菌、红球菌的生长过程有抑制作用;蒽、菲、芘的降解过程会不断交替进行着产酸和脱羧过程,使降解液pH值出现波动;同时在降解过程中,菌体能产生表面活性物质,这有利于蒽、菲、芘的生物降解转化。