Microorganisms and physico-chemical properties of soils with different slope-protecting vegetation in Daguang Highway北大核心CSCD

In order to investigate the effect of different slope-protecting vegetation on soil restoration in the highways, we collected soils at depths of 0-10 cm, 10-20 cm, and 20-30 cm from areas planted with Amorpha fruticosa, Periploca sepium, and Paederia scandens for 6-7 years in the Daming road section of the Daguang Highway, in October 2016. The physico-chemical properties and microbial community of the soils were then analyzed. The soil microbial community was analyzed by terminal restriction fragment length polymorphism (T-RFLP). The correlation between the microbial community and the physico-chemical properties of the soils was determined by redundancy analysis (RDA). The results showed that (1) the physico-chemical properties were the best for soils with Paederia scandens; the nutrient content, water holding capacity, and porosity of the soils with the three types of slope-protecting vegetation were better in the 0-10 cm layer than in the other layers; (2) the contents of soil aggregates (diameter > 5 mm) were the highest in the 0-10 cm and 10-20 cm layers for the soil with Paederia scandens; (3) the dominant bacteria in the 0-10 cm layer and dominant fungi in the 0-10 cm, 10-20 cm, and 20-30 cm layers were higher in the soils with Pe. sepium and Pa. scandens than in the soil with A. fruticosa; and (4) results of RDA showed that the physical properties of the soils were the main factors that influenced the soil microbial community. The physical properties of the soils were sensitive to the change of soil quality. Soil quality can be improved by appropriate management measures, such as burying litter, which can subsequently improve the ecological environment of soils in sloping regions. © 2018 Science Press. All rights reserved.     

厌氧推流进水对反硝化除磷好氧颗粒污泥系统的影响

实际生活污水成分复杂,且碳氮比较低,而厌氧推流进水可以通过提供局部高底物浓度来加强好氧颗粒污泥对进水中COD的利用.实验采用间歇曝气的方式在序批式反应器（SBR）中培养好氧颗粒污泥,以实际生活污水为进水,接种污水厂污泥.R1采用厌氧快速进水,R2采用厌氧推流进水,探究不同进水模式对生活污水好氧颗粒污泥系统的影响.结果表明,快速厌氧进水条件下,R1中更早出现颗粒结构,但在运行71 d时出现颗粒破裂的现象;应用厌氧推流进水模式的R2生成的颗粒结构较R1的更为致密,颗粒表面更加光滑,且反硝化聚磷菌（DPAO）的富集效果更好.最终R1和R2反应器内DPAO占聚磷菌（PAO）的比例分别为14.17%和22.07%.结果表明,厌氧推流进水模式能够加强颗粒污泥对进水中COD的利用,有利于富集DPAO,生成结构更加致密稳定的颗粒,实现"一碳两用",获得更好的脱氮除磷效果.     

电子废物拆解区微塑料与周围土壤环境之间的关系

微塑料污染无处不在,并受到了社会各界的关注.近年来,关于微塑料在水生态系统中的报道越来越多,而关于陆地生态环境,尤其在电子废物拆解区土壤微塑料污染的研究还十分匮乏.以广东省汕头地区贵屿镇废弃的以不同拆解方式所造成的电子废物拆解样地为研究对象,从生态毒理学和微生物学角度探讨了微塑料与其周围土壤环境之间的关系.通过SEM-EDS对微塑料表面进行表征,发现其表面具有老化和降解的迹象;这可能是由于微塑料长期暴露在土壤中,以及原始的拆解方法造成其表面形态及性质发生了变化.另外,在同一微塑料样品的不同表面位置,金属元素类型存在较大差异;说明微塑料所携带的一些金属元素并非本身固有,而是从周围土壤环境中吸附的.利用ICP-OES对微塑料内载固有的7种重金属（Pb、Cd、Cr、As、Ba、Co和Ni）进行分析发现,由于微塑料主要来源于各类电子废物,其所含各重金属含量在不同样地中有所不同,且几乎均高于周围土壤,尤其Ba在微塑料中的含量比在土壤中高出10³数量级.Ba在塑料中主要以BaSO₄的形式存在,常作为填料广泛添加于各种塑料中.此外,对微塑料表面微生物进行16S rRNA测序,并采用Spearman等级相关系数分析了微塑料表面细菌群落平均丰度前50的属与土壤环境因子之间的关系.这些微生物主要来源于微塑料所处的周围环境,因此环境因子的差异会直接影响微塑料表面微生物群落.由不同拆解方式所导致的电子废物污染场地具有不同的土壤环境因素,这些因素与微塑料表面微生物的相关性也存在差异.     

超顺磁性纳米材料对镉污染稻田土壤微生物和酶的影响

以磁性纳米Fe₃O₄和羟基磷灰石等为原料,制备出超顺磁性纳米Fe₃O₄-磷酸盐功能化材料（MFH）,通过在镉污染稻田土壤中投加MFH,对土壤进行磁选修复.选择对Cd具有高、低富集两种水稻,在修复后土壤中进行盆栽试验,研究MFH磁选修复对土壤微生物和酶的影响,探究该材料应用于农田镉污染修复的可能性.结果表明,施用MFH修复镉污染土壤,对Cd污染土壤有较好的修复效果,土壤中总Cd和有效态Cd浓度有了明显降低,总镉去除率为38.9%,有效镉下降率为27.3%,并且两种水稻籽粒中Cd含量均显著降低.采用MFH磁选修复土壤镉后,在两种水稻拔节期、抽穗期和成熟期土壤微生物群落多样性、群落丰富度均有所降低;栽培Cd高富集的玉针香水稻品种的处理在拔节期和抽穗期稻田土壤优势细菌Firmicutes丰度显著增加.采用MFH磁选修复土壤镉后,在两种水稻拔节期、抽穗期和成熟期土壤脲酶活性、过氧化氢酶活性以及土壤过氧化物酶活性均得到了提高;栽种Cd高富集品种玉针香的土壤POD酶活性比栽种低富集品种湘晚籼13号的土壤POD酶活性要略高,而脲酶活性则相反.     

海底地下水排放对南黄海沿岸海水细菌群落结构的影响

在南黄海沿岸岸滩采集海水样品,将同位素地球化学与分子生物学技术相结合,探讨海底地下水排放(submarine groundwater discharge, SGD)对沿岸海水微生物群落结构的影响.结果表明,南黄海沿岸水体微生物优势类群为变形菌门、放线菌门、拟杆菌门、蓝细菌门、疣微菌门、厚壁菌门等.海水中较高浓度的镭同位素活度极有可能是由近岸海底地下水排放过程导致.沿岸海水中的²²⁴Ra活度与营养盐浓度、微生物群落的多样性及丰富度具有相对同步的变化规律.溶解氧对海水中的细菌群落结构具有显著影响(p<0.05),海底地下水排放输入的高浓度溶解无机氮、溶解硅酸盐可能是影响沿岸海水中细菌群落结构特征的主要因素之一.本研究表明,海底地下水排放对沿岸微生物群落结构的影响是不可忽视的.     

锁磷剂联合好氧反硝化菌修复富营养化水体

氮磷是造成水体富营养化的主要原因,单一治理方法常常难以同时有效去除氮磷.本文利用1株分离自富营养化水体的好氧反硝化菌株（AD-19）构建固定化菌膜,并与锁磷剂Phoslock^®联合修复富营养化水体,研究了Phoslock^®的控磷效能和反硝化菌的脱氮性能及二者联合作用时对富营养化水体的修复效果.结果表明,在投加比例为80（Phoslock^®与PO₄^3--P的质量比）的条件下,Phoslock^®对模拟富营养化水体中PO₄^3--P去除率可达95%以上,并能有效抑制底泥中磷的释放.好氧反硝化菌AD-19具有较好的异养硝化-好氧反硝化功能,在以NH₄⁺-N或NO₃^--N为唯一氮源条件下生长良好并能去除97%以上的氮,经16S rDNA鉴定该菌株属于假单胞菌属（Pseudomonas sp.）.利用湖泊模拟装置论证了Phoslock^®联合固定化菌膜修复富营养化水体的可行性,进一步地,利用该技术对武汉市某公园内富营养化池塘进行修复治理,经过16 d的处理,氮磷等水质指标从劣Ⅴ类地表水提升至Ⅲ类,并持续稳定270 d以上,证明Phoslock^®联合固定化菌膜可快速和有效地修复富营养化水体,并保持水质长期稳定.     

亚硝酸盐不同生成方式对短程硝化反硝化除磷颗粒系统的影响

为了探究亚硝酸盐生成方式对短程硝化反硝化除磷颗粒系统的影响,采用2组同规格SBR反应器分别在连续和间歇曝气方式下使亚硝酸盐连续生成和间歇生成,考察其运行过程中脱氮除磷效果、污泥物理特性和微生物群落结构.结果表明,亚硝酸盐间歇生成后随即消耗,具有更好和更稳定的脱氮除磷性能,特别在TN去除上,第72 d后TN平均去除率为92.07%.碳源利用效率（以P/COD计）集中在0.21~0.22mg·mg^-1,碳源利用充分,进一步促进反硝化除磷.颗粒粒径分布集中,大小均匀,具有规则的形状和清晰的边界.微生物群落分析表明,亚硝酸盐间歇生成的系统微生物群落丰富度和多样性更高,同时富集了更多DPAOs菌属（Dechloromonas和Pseudomonas）,与Nitrosomonas共同作用使短程硝化与反硝化除磷达到动态平衡,实现系统稳定运行.     

Screening on oil-decomposing microorganisms and application in organic waste treatment machine

As an oil-decomposable mixture of two bacteria strains ( Bacillus sp. and Pseudomonas sp. ), Y3 was isolated after 50 d domestication under the condition that oil was used as the limited carbon source. The decomposing rate by Y3 was higher than that by each separate individual strain, indicating a synergistic effect of the two bacteria. Under the conditions that T = 25-40℃, pH = 6--8, HRT (Hydraulic retention time) = 36 h and the oil concentration at 0.1%,Y3 yielded the highest decomposing rate of 95.7 %. Y3 was also applied in an organic waste treatment machine and a certain rate of activated bacteria was put into the stuffing. A series of tests including humidity, pH, temperature, C/N rate and oil percentage of the stuffing were carried out to check the efficacy of oil-decomposition. Results showed that the oil content of the stuffing with inoculums was only half of that of the control. Furthermore, the bacteria were also beneficial to maintain the stability of the machine operating. Therefore, the bacteria mixture as well as the machines in this study could be very useful for waste treatment.     

微生物菌剂处理炼油废水的工程设计

炼油废水具有污染物浓度高、水质波动大、可生化性差等特点,采用常规生物处理,难以稳定达标。采用"高效微生物+生物模块"工艺路线,应用石油降解菌剂、硝化菌剂和与之匹配的工艺,处理炼油废水,出水水质稳定达到GB8978-1996《污水综合排放标准》一级标准,对COD和NH3-N的平均去除率分别为94.2%和93.1%。该工艺具有抗冲击负荷强、运行费用省、出水水质好等优点,有较好的应用价值。     

西藏当雄拉屋矿区污染土壤微生物及其活性研究

通过现场采样及室内培养分析,研究了西藏当雄拉屋矿区污染土壤微生物区系组成、主要生理类群及其活性。结果表明：矿区土壤受重金属Cu、Zn、Pb、Cd不同程度污染,矿区污染土壤几种重金属质量分数比非矿区土壤有明显的增加。矿区土壤微生物区系组成和各生理类群发生了明显变化,土壤细菌、真菌、放线菌以及各生理类群数量均显著降低,且3大微生物以及各生理类群对矿区污染的敏感性大小分别表现为放线菌〉细菌〉真菌,硝化细菌〉氨化细菌〉纤维分解菌。矿区土壤酶活性较低,对照土壤的各种酶活性最高,而矿区土壤基础呼吸和代谢商则受到刺激明显提高,其中土壤脱氢酶的活性变化最大,作为矿区重金属污染的指标更灵敏。可见,土壤中微生物区系组成及参与物质转化的生理类群种类、数量及土壤酶活和微生物活性在一定程度上可反映该矿区污染生境的重金属污染特征及其生态功能的演变规律。