电解凝絮法处理高盐度有机废水的实验研究

应用电解凝絮法处理紫胶合成树脂生产过程中排放出的高盐度有机废水实验结果表明,该方法能够有效地去除废水中的有机污染物,提高透明度,COD_Cr去除率达94%,BOD₅去除率达90%以上,并且设备简单、耐冲击性好、操作方便、不需要投加化学药剂,易实现现代化管理。      

Responses of microbial interactions to elevated salinity in activated sludge microbial community

● Salinity led to the elevation of NAR over 99.72%. ● Elevated salinity resulted in a small, complex, and more competitive network. ● Various AOB or denitrifiers responded differently to elevated salinity. ● Putative keystone taxa were dynamic and less abundant among various networks. Biological treatment processes are critical for sewage purification, wherein microbial interactions are tightly associated with treatment performance. Previous studies have focused on assessing how environmental factors (such as salinity) affect the diversity and composition of the microbial community but ignore the connections among microorganisms. Here, we described the microbial interactions in response to elevated salinity in an activated sludge system by performing an association network analysis. It was found that higher salinity resulted in low microbial diversity, and small, complex, more competitive overall networks, leading to poor performance of the treatment process. Subnetworks of major phyla (Proteobacteria, Bacteroidetes, and Chloroflexi) and functional bacteria (such as AOB, NOB and denitrifiers) differed substantially under elevated salinity process. Compared with subnetworks of Nitrosomonadaceae, Nitrosomonas (AOB) made a greater contribution to nitrification under higher salinity (especially 3%) in the activated sludge system. Denitrifiers established more proportion of cooperative relationships with other bacteria to resist 3% salinity stress. Furthermore, identified keystone species playing crucial roles in maintaining process stability were dynamics and less abundant under salinity disturbance. Knowledge gleaned from this study deepened our understanding of microbial interaction in response to elevated salinity in activated sludge systems.     

盐度对军曹鱼稚鱼血液生理生化及鳃Na~+-K~+ ATPase活性的影响

军曹鱼稚鱼[体重(6.52±0.71)g]在适应不同盐度(5、10、20、30和37)14 d后盐度5和10处理组特定生长率(SGR)显著低于其它组(P﹤0.05),且该两组血红蛋白、血细胞比容和红细胞数也显著低于盐度30和37组, 而血清皮质醇和乳酸含量则明显高于盐度30和37组.此外,低盐度组中稚鱼血糖有升高趋势,门冬氨酸氨基转移酶(AST)含量随盐度降低而升高,但碱性磷酸酯酶(ALP)变化则相反.血清渗透压、Na+ 和Cl-离子浓度与盐度呈正相关,而K+浓度呈负相关.鳃NKA活性在盐度20组中最低,在盐度10组中最高.研究显示军曹鱼稚鱼有较强的盐度适应能力,适度降低盐度并不影响其生长,但在过低盐度中仍呈应激反应,且盐度变化还可影响多项血液生理生化指标.     

Evaluation of the Temporal Transferability of a Model Describing Dissolved Solids in Streams of the Upper Colorado River Basin1

Kenney, Terry A. and Susan G. Buto, 2012. Evaluation of the Temporal Transferability of a Model Describing Dissolved Solids in Streams of the Upper Colorado River Basin. Journal of the American Water Resources Association (JAWRA) 48(5): 1041‐1053. DOI: 10.1111/j.1752‐1688.2012.00667.x Abstract: The application of a nonlinear least‐squares regression model describing the sources and transport of dissolved solids in streams of the Upper Colorado River Basin, and that was calibrated using data from water year 1991, was evaluated for use in predicting annual dissolved‐solids loads for the years 1974 through 1998. Simulations for each water year were run using annual climate data. To evaluate how well the model captures the observed annual variability across the basin, differences in predicted annual dissolved‐solids loads for each simulated year and 1991 were compared with differences in monitored annual loads. The temporal trend of the differences between predicted annual loads for the simulated years and the load for 1991 generally followed the trend of the monitored loads. The model appears to underpredict the largest annual loads and overpredict some of the smaller annual loads. An underprediction bias for wetter years was evident in the residuals as was an overprediction bias, to a lesser degree, for drier years. A regression analysis on the residuals suggests that the underprediction bias is associated with precipitation differences from 1991 and with previously defined downward trends in dissolved‐solids concentrations in the basin. In general, given the representative climatic conditions, the model adequately performs throughout the period examined. However, the model is most transferable to years with climatic conditions similar to 1991.     

沉积物与盐度对罗红霉素生物有效性的影响

在河口环境,沉积物与盐度对抗生素的生物有效性有重要影响。使用超高效液相色谱-串联质谱(UPLC-MS/MS)分析单一和复合控制系统(水、水-沉积物、水-斑马鱼、水-沉积物-斑马鱼)中的各相态中的罗红霉素,以期量化各相态中罗红霉素的迁移、分布。随着暴露时间延长,水体中罗红霉素浓度不断减少,沉积物和斑马鱼体内罗红霉素不断蓄积。沉积物的存在会减少罗红霉素在斑马鱼中的生物有效性。在高盐度环境下,沉积物拥有更大的吸附效率,符合盐析效应,导致罗红霉素的生物有效性及斑马鱼富集能力下降。水-沉积物-斑马鱼系统达平衡时,沉积物为罗红霉素的主要富集场所,可积累42.0%的罗红霉素。同时,斑马鱼可吸收和富集0.16%的罗红霉素。上述研究为研究抗生素环境行为和毒理提供了参考。     

高盐度有机废水对生物处理系统的影响研究进展

高盐度有机废水是一种难处理的废水,如皂素废水、石油开采废水以及海水直接利用后排放出的废水,主要是因为高含盐量对微生物的生长有很强的抑制作用,严重抑制了生物法在高盐度废水处理中的应用。讨论了国内外对含高盐有机废水生化处理技术的研究进展以及盐对生物处理系统的影响,并全面分析了高盐度有机废水生物处理的可行性。     

A dynamic hydrological Monte Carlo simulation model to inform decision-making at Lake Toolibin,Western Australia

Lake Toolibin, an ephemeral lake in the agricultural zone of Western Australia, is under threat from secondary salinity due to land clearance throughout the catchment. The lake is extensively covered with native vegetation and is a Ramsar listed wetland, being one of the few remaining significant migratory bird habitats in the region. Currently, inflow with salinity greater than 1000 mg/L TDS is diverted from the lake in an effort to protect sensitive lakebed vegetation. However, this conservative threshold compromises the frequency and extent of lake inundation, which is essential for bird breeding. It is speculated that relaxing the threshold to 5000 mg/L may pose negligible additional risk to the condition of lakebed vegetation. To characterise the magnitude of improvement in the provision of bird breeding habitat that might be generated by relaxing the threshold, a dynamic water and salt balance model of the lake was developed and implemented using Monte Carlo simulation. Results from best estimate model inputs indicate that relaxation of the threshold increases the likelihood of satisfying habitat requirements by a factor of 9.7. A second-order Monte Carlo analysis incorporating incertitude generated plausible bounds of [2.6, 37.5] around the best estimate for the relative likelihood of satisfying habitat requirements. Parameter-specific sensitivity analyses suggest the availability of habitat is most sensitive to pan evaporation, lower than expected inflow volume, and higher than expected inflow salt concentration. The characterisation of uncertainty associated with environmental variation and incertitude allows managers to make informed risk-weighted decisions.     

The effect of saline water disposal: implications for monitoring programs and management

In an effort to combat rising groundwater tables andexpanding saline lakes, saline water has been disposedof into the aquatic environment, despite there beinglittle information as to the environmental effects.Monitoring of the effect of saline lake water disposalon aquatic macroinvertebrates and water quality wasconducted in the Barwon River, south west Victoria,Australia, in association with toxicity tests. Thedisposal of saline lake water was associated withchanges in macroinvertebrate community structure.Contrary to expectations, increases in electricalconductivity (a measure of salinity) was not the onlywater quality parameter associated with saline waterdisposal. An experiment was conducted where thetoxicity of saline lake water was compared to that ofa prepared solution of the same electricalconductivity. Toxicity was greater in the saline lakewater than the prepared solution. The results suggestthat saline water disposal is impacting onmacroinvertebrate fauna but electrical conductivity isnot the only factor responsible. These results haveconsequences for both management of aquatic resourcesand for monitoring programs which are discussed.     

盐分对一株硫氧化细菌氧化能力的影响

通过液体选择培养基、平板划线的方法从脱硫污泥中分离筛选出一株硫氧化细菌,并对其进行初步鉴定和生长特性的分析.结果表明,该细菌为化能自养型细菌,短杆状,大小为0.5～0.8 μm×1.2～3.0 μm,革兰氏染色显阴性.以5％的接种量接种于富集培养基,S2-初始浓度为100 mg/L时,SOB在60 h内基本将还原态硫氧化完全,pH最低降到2左右.当溶液中有SO42-量积累和电导率升高后,对SOB氧化S2O32-过程有明显的抑制作用.该菌株对盐分的耐受值为7 650 μS/cm(以电导率计).     

有机无机氮配施对不同程度盐渍土硝化和反硝化作用的影响

以内蒙古河套灌区轻度盐渍土S₁（EC=0.62 dS·m^-1）及中度盐渍土S₂（EC=1.17 dS·m^-1）为对象,研究硝化和反硝化进程对盐渍化程度和有机无机氮配施比例的响应及其影响因素.本试验设置了6个处理,包括不施氮（CK）、单施无机氮（U₁）以及用有机氮（U₃O₁、U₁O₁、U₁O₃和O₁）替代25%、50%、75%和100%的无机氮.结果表明,盐度升高会降低土壤硝化势而提高土壤反硝化能力,同一处理S₁土壤硝化潜势较S₂土壤高出28.81%~69.67%,而反硝化能力降低17.16%~88.91%.盐度升高会降低AOB丰度及硝化贡献率,但会增加AOA丰度和硝化贡献率;盐度增加会提高土壤nirK和nirS型菌丰度,同时会增加N₂O/（N₂O+N₂）产物比,但会抑制nosZ丰度.S₁土壤,以U₁O₁处理硝化势和反硝化能力最大,较单施化肥增幅分别达到18.59%和15.87%;S₂土壤,各施肥处理之间土壤硝化势差异不显著,反硝化能力以O₁处理最大,较单施化肥提高88.26%.S₁和S₂盐渍土分别以U₁O₁及O₁处理获得较高的AOB基因丰度及硝化贡献率,且增大了nirS和nosZ基因丰度,并显著降低N₂O/（N₂O+N₂）产物比.综上,相比单施无机氮,轻度盐渍土以有机无机氮各半配施,中度盐渍土以单施有机氮更加利于土壤硝化反硝化过程进行.