堆肥制作中微生物侵染秸秆的环境扫描电镜(ESEM)观察

为了探索堆肥制作中木质纤维素类物质的生物降解过程,在堆肥进程中取不同分解阶段的秸秆样品,利用环境扫描电镜(ESEM)观察微生物的分布情况,并从机械作用的角度探讨了微生物在秸秆分解过程中的作用。结果表明,堆肥制作前新鲜秸秆表面未发现微生物分布,堆肥制作前期微生物开始附着在秸秆表面,随着堆肥进程,秸秆表面微生物密度有所增加,秸秆分解时产生的裂缝中发现也有微生物分布。堆肥制作中,参与秸秆分解的微生物以群落形式分布,从个体形态来看,这些微生物主要由球菌和丝状菌组成,但不同形态微生物个体大小差异较大。分析认为大型丝状菌通过秸秆分解产生的裂缝侵入秸秆内部时所产生的机械作用可促进秸秆的崩解。     

Influence of zeta potential on the flocculation of cyanobacteria cells using chitosan modified soil

Using chitosan modified soil to flocculate and sediment algal cells has been considered as a promising strategy to combat cyanobacteria blooms in natural waters. However, the flocculation efficiency often varies with algal cells with different zeta potential (ZP) attributed to different growth phases or water conditions. This article investigated the relationship between ZP of Microcystis aeruginosa and its influence to the flocculation efficiency using chitosan modified soil. Results suggested that the optimal removal efficiency was obtained when the ZP was between -20.7 and -6.7 mV with a removal efficiency of more than 80% in 30 min and large floc size of >350 μm. When the algal cells were more negatively charged than -20.7 mV, the effect of chitosan modified soil was depressed (<60%) due to the insufficient charge density of chitosan to neutralize and destabilize the algal suspension. When the algal cells were less negative than -6.7 mV or even positively charged, a small floc size (<120 μm) was formed, which may be difficult to sink under natural water conditions. Therefore, manipulation of ZP provided a viable tool to improve the flocculation efficiency of chitosan modified soil and an important guidance for practical engineering of cyanobacteria bloom control.     

Cyanobacterial bloom dynamics in Lake Taihu

<正>Lake Taihu is the third largest freshwater lake in China and serves as an important drinking water source for the local populace;however,decades of excessive nutrient loading fueled by anthropogenic activities have resulted in hypertrophic conditions,promoting the annual formation of nuisance phytoplankton blooms(Chen et al.,2003;Duan et al.,2009)     

堆肥-生物强化对重度石油污染土壤的修复作用

为解决微生物强化修复油污土壤过程中降解菌在低温环境下活性较低的问题,利用有机堆肥作为固体培养基对降解菌进行扩大培养,将获得的降解菌-堆肥制剂施入油污土壤中进行修复研究.利用重量法和GC-MS分析土壤中石油烃含量变化,利用Illumina Mi Seq对土壤微生物群落结构进行分析.结果表明,利用堆肥作为固体基质可对降解菌进行扩大培养.低温环境下利用堆肥-降解菌制剂对油污土壤修复30 d,土壤中石油烃、烷烃、多环芳烃去除率分别为27.0%、19.6%、10.0%;自然放置的土壤中3种烃去除率分别为4.5%、9.5%、2.3%.加入降解菌-堆肥制剂进行修复的土壤香农指数和Ace指数分别由4.42和1718.5增加为5.30和2170.5;土壤中变形菌门(Proteobacteria)和放线菌门(Actinobacteria)所占丰度由53.4%和25.9%分别降低至48.9%和14.1%,拟杆菌门(Bacteroidetes)所占丰度由5.0%增加至24.5%.属水平上,不动细菌属(Acinetobacter)和假单胞菌属(Pseudomonas)所占丰度由0.02%和3.4%分别提高至15.2%和4.6%.研究结果表明,在低温条件下向石油污染土壤中施入降解菌-堆肥制剂可提高土壤中的石油烃去除率,并使土壤微生物群落结构发生明显变化.     

石灰石沟-堆肥湿地系统处理酸性矿山废水的研究

为探讨石灰石沟-潜流堆肥湿地系统处理酸性矿山废水(AMD)的效果及影响因素,进行了6个月模拟试验,测定出水水质和植物生长等相关的影响因素.结果表明,石灰石沟可有效提高AMD的pH值,降低其酸度与重金属含量,但随着石灰石沟中氢氧化物的积累,后期处理性能下降;堆肥湿地可显著降低AMD的酸度与重金属,出水酸度随时间持续降低,出水的Cd、Pb在检测限以下,Zn、Cu平均浓度分别为1.8mg/L, 2.6μg/L,均达到农业灌溉水标准,而无前置堆肥的普通湿地后期Cd、Zn、Cu偏高;东南景天在湿地系统也能正常富积Cd/Zn;狭叶香蒲使堆肥湿地的产碱过程受到抑制,出水酸度升高,但其对堆肥湿地的重金属去除没有产生显著影响.     

生活垃圾堆肥恶臭气体的生物滴滤净化性能研究

城市生活垃圾生物处理过程中会产生并散发大量的恶臭物质. 以纤维表面活性炭(ACOF)生物滴滤器(BTF)为载体,以进气风量及循环液流量为调控参数,对城市生活垃圾生化预处理过程中散发的恶臭气体进行现场试验. 结果表明:高气力负荷时,生物滴滤器对恶臭气体具有较好的净化效果.在空塔气速为1 274 m/h,液气比为1 L/m3左右时,总挥发性有机物(TVOCs)的去除率可保持在70%以上,而臭气浓度的去除率也大于70%,设备压降为2 150 Pa左右,总挥发性有机物(以异丁烯计)的消除能力可达130 g/(m3·h). BTF运行过程中压降保持相对稳定,循环液中ρ(COD_Cr)和ρ(NH₃-N)未出现明显的累积现象,说明BTF对于污染物有良好的降解能力.      

猪粪堆肥与化肥配施对水稻产量和氮效率的影响

采用大田试验方法研究猪粪堆肥与化肥配施对水稻产量和氮效率的影响.结果表明:在本试验条件下,猪眄粪堆肥与化肥配施能显著提高水稻籽粒产量,增加水稻每穗实粒数.尤其是1 500 kg·hm-2猪粪堆肥 化肥配施处理,稻谷产量达8 595 kg·hm-2,比未施氮处理和化肥处理分别增产57.8%和13.6%,差异达显著水平.猪粪堆肥与化肥配施处理水稻氮素养分效率均高于化肥处理.猪粪堆肥与化肥配施的氮肥回收率为35.3%～38.6%,而化肥处理仅为27.6%.     

Modelling cyanobacteria in shallow coastal seas

There is an increasing need to describe cyanobacteria bloom dynamics using ecosystem models. We consider two fundamentally different ways how cyanobacteria are currently implemented: a simple approach without explicit consideration of the life cycle which assumes that cyanobacteria grow due to nitrogen fixation alone and an advanced approach that computes the succession of four different stages of the cyanobacteria life cycle based on internal quotas of energy and nitrogen. To qualitatively and quantitatively intercompare these different approaches and with observations, we use the Baltic Sea ecosystem model ERGOM coupled to the one-dimensional water column model GOTM. Four experiments are carried out: three, using the simple approach with either (a) a prescribed constant minimum production, (b) no minimum value or (c) a prescribed constant minimum concentration, and one with (d) the full predictive life cycle. The model data of 35 years (1970-2005) are analyzed for the timing of the bloom, the interannual variability, the annual mean nitrogen fixation rates and the effect of cyanobacteria on eukaryotic phytoplankton. The results show significant differences. In the climatological seasonal mean, only the advanced approach which resolves the life cycle produces a realistic bloom onset and duration. The interannual variability of blooms is unrealistically small in the experiments with a prescribed minimum value. Annual mean nitrogen fixation rates diverge by up to 30% between the four model solutions. Finally, the representation of the cyanobacteria also influences the seasonal cycle of eukaryotic phytoplankton, i.e., flagellates. This study demonstrates that the way how cyanobacteria are implemented in coupled biological-physical models strongly determines the fluxes into the system and between the individual compartments.     

园林绿地施用污泥堆肥对环境影响研究

园林绿地施用污泥(来源于天津纪庄子污水处理厂)堆肥的试验表明:径流和渗滤水中硝酸盐的增加是最主要的污染问题,但污泥堆肥用量控制在50t/hm2以内,不会对地面水和地下水产生不良影响?该厂污泥中的重金属和有机污染物亦不会对径流和渗滤水产生明显不良影响?      

利用MALDI-TOF MS技术简便、快速检测水华蓝藻的方法研究

以水华蓝藻为研究对象,用基质辅助激光解吸电离飞行时间质谱(MALDI-TOF MS)技术对其进行测定分析并获得了蛋白质指纹图谱。对铜绿微囊藻标准株(NIES-843)样品通过3种前处理方法得到的质谱图进行对比,确定了质谱分析的样品前处理方法,建立了利用MALDI-TOF MS技术简便、快速检测水华蓝藻的方法。对在水华中出现的4种不同蓝藻进行MALDI-TOF MS分析,结果表明各种蓝藻具有其特征性波谱,可据此对水华蓝藻进行区分和鉴定。该方法快速、简便、精确、可程序化,具有广泛的应用前景。