酵母提取物对大型蚤急性毒性实验的影响

为了缩短大型蚤急性毒性实验的周期,并且验证毒性实验的灵敏度和稳定性,对投加酵母提取物饲养的大型蚤的生长周期、2次产卵时间间隔、产卵数量、以及幼蚤灵敏度和稳定性进行研究,并将其应用于已知毒性物质和环境样品的毒性检测.结果表明,酵母提取物的适宜投加量为18.00～22.00 mg/L.在该浓度下饲养的大型蚤可保持较好的怀卵量,生长至成熟期和2次怀卵的时间间隔较短,幼蚤的灵敏度较好,毒性测试结果稳定.采用此方法测定的4种重金属和4种有机物的大型蚤急性毒性的24 h-EC50和48 h-LC50与已发表的实验结果比较相近,证明该方法准确、可靠.将该方法应用于城市生活污水急性毒性的测定发现,投加酵母提取物饲养的大型蚤所产幼蚤可以明显区分生活污水原水和处理后最终出水.因此,采用投加适量酵母提取物饲养大型蚤的方法可以缩短实验周期,为测定环境样品生物毒性提供方便.     

丙烯腈废水及几种处理工艺出水的毒性

分别利用小麦、发光菌毒性测试技术研究了模拟丙烯腈废水以及几种处理工艺出水对小麦芽伸长、根伸长、发芽率和发光菌发光度的毒性效应差异。结果表明,丙烯腈对小麦芽伸长的毒性影响最大;各类物质对小麦根伸长和发芽率并未造成毒性影响;其他物质对发光菌发光度的毒性最大。模拟废水对小麦芽伸长、根伸长、发芽率和发光菌发光度的毒性效应分别为:部分相加、部分相加、协同和拮抗作用。几种处理工艺出水对上述指标的毒性影响顺序依次是:模拟废水加成出水活性炭吸附出水Fenton法出水;Fenton法出水模拟废水加成出水活性炭吸附出水;Fenton法出水活性炭吸附出水模拟废水加成出水;活性炭吸附出水加成出水Fenton法出水模拟废水。比较几种处理工艺出水的毒性发现,几乎每种废水的毒性都有所降低,这说明几种处理工艺能有效降低模拟废水的毒性,具有深刻的实际指导意义。     

应用自动识别和定量系统评价两种污水再生工艺对微量有机污染物的去除效果

采用气质联用分析,并结合自动识别与定量系统(AIQS-DB)考察2种再生水厂采用的深度处理工艺对微量有机污染物的去除效果。结果表明,以污水为原水的膜生物反应器(MBR)+臭氧氧化+生物活性炭滤池(BAC)工艺用于再生水生产,MBR工艺对有机污染物的去除起主要作用;城市污水厂二级出水为原水的混凝沉降+浸没式超滤(SMF)/连续微滤(CMF)+部分反渗透(RO)+臭氧氧化工艺用于再生水生产,其SMF和CMF工艺段的膜截留作用均可有效消减有机污染物含量,SMF的效果优于CMF;2种工艺中采用的臭氧技术都能进一步加强部分物质的去除效果。气质联用结合AIQS-DB可用于再生水中污染物的筛查和不同污水再生工艺对微污染物消减效果的评价。     

大型蚤标志酶用于城市二级出水毒性的评价

大型蚤是一种国际公认的标准实验生物,广泛应用于污水、地表水等水质毒性检测。毒性水平较低的城市二级出水,对大型蚤往往无急性毒性效应,而具有慢性毒性效应,但慢性毒性检测周期过长,因此探索一种更灵敏的指标,实现快速检测,对于控制二级出水的水质风险具有重要意义。本研究考察了大型蚤在短期暴露于城市二级出水条件下,其体内乙酰胆碱酯酶、超氧化物歧化酶、过氧化氢酶、ATP酶、羧酸酯酶和碱性磷酸酯酶的酶活变化特征,从中筛选出对二级出水毒性响应灵敏的标志酶指标。实验结果表明,碱性磷酸酯酶、过氧化氢酶对二级出水毒性响应相对较灵敏,具有成为标志酶的潜力,研究结果为城市二级出水生物毒性评价方法优化提供新的思路。     

温度对臭氧氧化再生水的影响

以再生水厂进水、混凝沉淀出水和微滤出水作为实验对象,对比研究了温度对臭氧氧化效果的影响。结果表明,对于3种不同水质的再生水而言,臭氧对色度、UV_(254)和UV_(410)的去除存在最佳温度。在臭氧投加量为5 mg·L~(-1)及停留时间为20 min的条件下,原水水质越好,臭氧氧化处理的最佳温度越低,并且臭氧灭菌效果越好。24℃以下时臭氧再生水的灭菌率均为100%。随水温升高,臭氧灭菌效果稍有减弱,但都高于98%。     

不同水力负荷下塘-湿地组合处理系统对再生水磷的净化效果

通过研究天津市空港经济区塘湿地组合处理系统对区内污水处理厂MBR出水（再生水）的净化过程，探讨再生水总磷（TP）及活性磷（SRP）的净化效果。研究表明：MBR出水SRP含量较高，SRP/TP高达84%。在3个水力负荷100、150及200 m³/d下，系统对磷均保持良好的处理效果，TP浓度由1.64 mg/L降至0.36 mg/L，SRP浓度由1.30 mg/L降至0.28 mg/L。同时，系统SRP/TP由进水的84%降至出水的54.5%，SRP去除效果显著。再生水中SRP含量较高的问题通过塘湿地组合处理系统得到了良好的解决，从而有效降低再生水回用景观水体所带来的藻华风险。     

纳滤生产再生水示范工程运行效果分析

纳滤(NF)作为一种深度处理工艺,在再生水生产领域具有广阔应用前景,但目前其在生活污水深度处理方面的工程应用不多。为此,对北京市某再生水厂的NF示范工程进行了跟踪研究,评价了NF工艺对各水质指标的去除效果及稳定性。结果表明:该示范工程的NF工艺可以有效地去除化学需氧量(COD)、总磷(TP)、重金属等指标,使出水的这些指标达到《地表水环境质量标准》中Ⅲ类水的相关标准;但对TN的截留能力较差,截留率不足15%,为出水达标的限制因子;NF工艺对大部分微量有机污染物的截留率在70%以上,但对于双酚A和卡马西平截留率较低,分别只有64.1%和53.4%,截留率与目标物分子质量大小及带电情况有关。细菌发光实验结果表明,NF工艺可以保障出水达到无毒状态。     

好氧颗粒污泥法处理石化废水

实验以吉林石化污水处理厂初沉池出水为原水在SBR中培养好氧颗粒污泥。实验初期,依次以比例为40%、60%的含石化废水的培养液进行培养,于第15天SBR中出现颗粒污泥,此后直接采用石化废水培养,同时逐步缩短沉降时间,第27天起反应器出水稳定,COD去除率达到89%,TN、NH3-N和TP去除率分别达到56%、86%和90%。采用此方法培养的颗粒污泥平均粒径约为1.3 mm,外表棕黄色,颗粒表面粗糙,在扫描电子显微镜(SEM)下观察到好氧颗粒污泥主要由杆状菌和丝状菌组成,颗粒内部存在若干孔隙。研究结果表明,在SBR中通过逐步增加石化废水进水比例,缩短沉降时间可以快速培养出好氧颗粒污泥,好氧颗粒污泥处理石化废水效果良好。     

不同再生水处理工艺出水水质回用途径适应性分析

为分析典型再生水处理工艺出水的回用途径适应性,采用标准指数法评价了4座不同处理工艺的再生水厂出水质量,为再生水处理工艺选择和安全回用提供参考。结果表明,4种再生水处理工艺出水用于市政杂用水时基本是安全的;除反渗透(RO)工艺外,其他工艺出水回用于景观环境用水时都存在氮磷指标超标问题;膜处理工艺的出水可以满足工业用水标准,但是常规絮凝过滤工艺出水用作工业用水应注意氮磷等指标的进一步处理;各种再生水处理工艺出水质量均不能满足地下水回灌用水标准,主要是氨氮和环境激素DBP超标问题,用作地下水回灌用水时存在一定的环境风险。     

不同工艺再生水补给对景观湖水质变化的影响

再生水回用于景观水体过程中,为了比较不同再生水工艺对景观水体富营养化的影响,以"二级出水+BAF+O3+GFH"和"二级出水+O3"作为再生水处理工艺,以岸滤(bank filtration,BF)作为水质维持工艺,进行再生水景观水体水质保障技术研究。结果表明,"二级出水+O3"出水流量较大,水力流动快,每天运行24 h,平均出水流量25.5 m3/d,氮磷含量偏高;"二级出水+BAF+O3+GFH"出水的氮磷指标控制在较低水平,GFH出水流量8～14 m3/d,水力流动较缓,湖中出现蓝藻。2套系统中BF对NH4+-N的去除率分别为30.5%和20.8%。"二级出水+O3+BF"系统中人工湖进水TN平均浓度24.309 mg/L,TP平均浓度0.583 mg/L,N/P=41,适宜水网藻生长,对湖中N(主要是NH4+-N)、P有较强的去除能力;"二级出水+BAF+O3+GFH+BF"系统中人工湖进水TP<0.05 mg/L,适宜蓝藻生长。     

Bioindicators for toxicity assesment of effluents from a wastewater treatment plant

The discharge of effluents and toxic compounds into aquatic systems represents a growing environmental problem involving an impact on water ecology and potential effect on human health. Most municipal wastewaters are complex mixtures; their complexity led as to carry out a hazard assessment using chemical analyses and biological tests.This study investigates biochemical alteratiobns in two sentinel organisms, the Anodonta cygnea mussel and the Xenopus laevis frog exposed for different lengths of time to various concentrartion of wastewater of the S. Antonino Ticino treatment plant. The results point out the long-life of toxic compounds.     

污泥堆肥施用于草坪草栽培:Zn和Cu的分布特征简

为了探索污泥堆肥中重金属在土壤-植物系统中的积累与转移特性，通过温室盆栽实验，分析了污泥堆肥对草坪草高羊茅、黑麦草和白三叶生物量积累的情况，研究了污泥堆肥中Zn和Cu在植物和土壤中的分布特征。结果表明，污泥堆肥施用可以有效促进3种草坪草的积累生物量，在0~6 kg/m²的污泥堆肥施用量范围内，草坪草的生物量积累随着施用量的增加而提高。土壤中Zn和Cu的含量随污泥堆肥施加量的增加而增大，85%以上的Zn和Cu残留在土壤中。污泥堆肥中的Zn和Cu均可以被植物吸收，随着污泥堆肥施用量的增加，草坪草对Zn和Cu的吸收量增大，但当污泥堆肥施用量超过一定阈值时，草坪草吸收Zn和Cu不再增加，甚至减少；对于不同的草坪草，这一阈值有所不同。植物对Zn和Cu的吸收量只占土壤中Zn和Cu减少量的5%左右。根据生物富集系数（BCF）的计算结果推测，污泥堆肥的施用对土壤环境的影响大于对植物体内累积Zn和Cu的影响。     

The arbuscular mycorrhizal fungus Glomus mosseae can enhance arsenic tolerance in Medicago truncatula by increasing plant phosphorus status and restricting arsenate uptake

A pot experiment examined the biomass and As uptake of Medicago truncatula colonized by the arbuscular mycorrhizal (AM) fungus Glomus mosseae in low-P soil experimentally contaminated with different levels of arsenate. The biomass of G. mosseae external mycelium was unaffected by the highest addition level of As studied (200 mg kg⁻¹) but shoot and root biomass declined in both mycorrhizal and non-mycorrhizal plants, indicating that the AM fungus was more tolerant than M. truncatula to arsenate. Mycorrhizal inoculation increased shoot and root dry weights by enhancing host plant P nutrition and lowering shoot and root As concentrations compared with uninoculated plants. The AM fungus may have been highly tolerant to As and conferred enhanced tolerance to arsenate on the host plant by enhancing P nutrition and restricting root As uptake.     

Marine macroalgal community structure, metal content and reproductive function near an acid mine drainage outflow

Marine macroalgal communities were examined near the outflow of acid mine drainage (AMD) from the Britannia Mine, British Columbia, Canada. No marine algae were present within 100 m of the mouth of Britannia Creek, which carries the AMD into the marine environment. At greater distances (300-700 m) from this Creek, mean summer cover of filamentous green algae, mostly Enteromorpha intestinalis, was >60%, which was significantly higher than at nearby reference stations. At still greater distances (600-1000 m) from Britannia Creek, Fucus gardneri dominated algal communities that were similar to those at reference stations. No consistent differences were detected in mean plant length, mean per cent cover or mean oocyte production between F. gardneri near Britannia Creek and those at reference stations. Cu body burden in F. gardneri near Britannia Creek was five to 17 times higher than in reference plants.     

不同水温下鲴鱼对铜绿微囊藻的控制作用及对水质的影响

在室内受控模拟条件下开展实验,研究了在19、23、27、31、35℃5个水温梯度下鲴鱼对铜绿微囊藻和水质的影响。研究结果表明,在不同水温下,鲴鱼对铜绿微囊藻具有较强的控制作用,实验结束时铜绿微囊藻密度减少至初始密度的18%~30%,摄食率和消化率分别为6.83×104~8.32×104cells/(g·d)、93%~98%;叶绿素a的去除率为68%~88%;实验组TP、TN去除率分别为22%~25%、20%~38%,对照组的分别为80%~94%、28%~40%。对照组NH+4-N浓度变化很小(0.071~0.073 mg/L),而实验组氨氮浓度显著增大(2.222~3.645 mg/L),分别为初始值的31、34、42、51和46倍。     

耐寒人工湿地植物石龙芮和酸模联用研究

为了提高人工湿地在寒冷季节的运行效率，对2种非夏季植物作为湿地植物处理生活污水的可行性进行了研究。结果表明,在本实验条件下2种植物对N、P元素都具有很好的去除效果，对COD的去除也达到45%～50%。通过单一植物系统和复合植物系统的处理效果比较，发现石龙芮酸模复合植物系统对污水中的P元素和COD的去除率更高。研究表明，石龙芮和酸模作为人工湿地植物具有可行性，与常规植物互补使用能在一定程度上延长人工湿地的运行时间。     

Historical alteration in the nitrogen concentration and N natural abundance of mosses in Germany: Indication for regionally varying changes in atmospheric nitrogen deposition within the last 140 years

Historical alterations of nitrogen deposition in the western part of Germany were investigated by comparing nitrogen concentrations and ¹⁵N natural abundance of historical and recent samples of the two pleurocarpous mosses Pleurozium schreberi and Scleropodium purum. Pooling of the data revealed only slight tissue N increases over the past 140 years which were significant nevertheless. At closer examination on the single site level historical increases of N concentrations were found particularly for some sites in regions where agricultural activities were considerably intensified during the second half of the 20th century. The comparison of δ¹⁵N values showed a strong depletion of ¹⁵N natural abundance in areas currently heavily influenced by livestock management. This indicates an increased impact of NH_y compounds. However, the almost unchanged δ¹⁵N values in some low mountain range areas with only moderate intensification of agriculture point to a more or less constant ratio of NH_y/NO_x input over time. Significant correlations of both tissue N concentrations and ¹⁵N natural abundance between the two species justify the assumption that they use the same nitrogen source, probably atmospheric deposition.     

Phytoremediation potential of the novel atrazine tolerant Lolium multiflorum and studies on the mechanisms involved

Atrazine impact on human health and the environment have been extensively studied. Phytoremediation emerged as a low cost, environmental friendly biotechnological solution for atrazine pollution in soil and water. In vitro atrazine tolerance assays were performed and Lolium multiflorum was found as a novel tolerant species, able to germinate and grow in the presence of 1 mg kg⁻¹ of the herbicide. L. multiflorum presented 20% higher atrazine removal capacity than the natural attenuation, with high initial degradation rate in microcosms. The mechanisms involved in atrazine tolerance such as mutation in psbA gene, enzymatic detoxification via P₄₅₀ or chemical hydrolysis through benzoxazinones were evaluated. It was demonstrated that atrazine tolerance is conferred by enhanced enzymatic detoxification via P₄₅₀. Due to its atrazine degradation capacity in soil and its agronomical properties, L. multiflorum is a candidate for designing phytoremediation strategies for atrazine contaminated agricultural soils, especially those involving run-off avoiding.     

地表水中隐孢子虫和贾第鞭毛虫微球的混凝去除

以向地表水中投加的隐孢子虫微球和贾第鞭毛虫微球为对象,研究通过对给水混凝工艺对其的去除效果进行比较,着重考察了不同混凝剂种类、投加量及水样pH值对去除效果的影响.结果表明,混凝工艺可较为有效地去除地表水中的两虫微球,去除率最高可达4 lg.相比常规的金属盐类混凝剂,高分子的PAC、PAFC混凝剂对两虫微球的混凝去除率更...