陶粒形态对超轻淤泥陶粒混凝土强度影响

固化处理城市河道沟渠淤泥,高温烧制陶粒建材是我国城市建设的重要途径,既有助于城市生态环境改造和治理,又可为基础设施修建提供优质环保建筑材料。本文开展了苏州某商品淤泥陶粒基本性能及其浇筑混凝土强度的试验研究。研究表明:淤泥陶粒具有质轻、级配良好、空隙率高、吸水率高等优点;淤泥陶粒混凝土由于陶粒强度和上浮问题,抗压强度低于普通混凝土,下降幅度随淤泥陶粒替代率的增加而增加;较高替代率下,不规则淤泥陶粒混凝土均匀性和强度优于球形淤泥陶粒混凝土。     

连续在线滤袋式淤泥脱水技术

以太湖淤泥为研究对象,研究了絮凝剂和滤袋性质对淤泥脱水性能的影响,并进行了滤袋脱水中试研究。结果表明,淤泥的含水率为90％时,在PAM和PAC最佳添加量55mg／L和1000mg／L条件下,淤泥比阻从8．7×10^7S2／g降低到2．0×10^7S2／g,Zeta电位从-28．77mV变成-4．68mV,滤袋平均过滤速度提高了137．9％,脱水性能显著提升。不同含水率下的实验得出了淤泥的最佳絮凝剂添加曲线;特殊材料滤袋相比于普通材料滤袋,滤袋的脱水综合能力大幅度提升,平均过滤速度达到0．479m^3／（m^2·h）,淤泥回收率为98．7％,泥饼含水率为71．6％;中试实验表明,淤泥经过4h过滤后,淤泥的含水率降到较低的65％,最终回收率可达到98．6％,滤液中污染物浓度满足国家排放标准。与传统技术相比,本技术具有脱水周期短、成本低、操作简单、安全性强等优点。     

南京河西淤泥质粉质粘土卸荷回弹变形研究

通过大量室内固结回弹试验,研究了南京河西地区淤泥质粉质粘土的卸荷回弹变形规律.固结-回弹-再压缩曲线表明该地区淤泥质粉质粘土的弹性变形要比其塑性变形量小得多,卸荷再压缩后,土体的压缩性也明显降低;通过分析卸荷比和回弹率、回弹应变以及回弹模量的关系曲线,确定了该地区淤泥质粉质粘土的临界卸荷比和极限卸荷比指标,从而可以确定...     

Control strategy of shortcut nitrification

Shortcut nitrification for ammonium-rich wastewater is energy-saving and cost-effective procedure that has become one of the hotspots in the field of biological denitrogenation. An orthogonal experiment was performed to study the combined effects of operational parameters on the performance of internal-loop airlift bioreactor for shortcut nitrification. The optimum operational parameters for the shortcut nitrification were fotmd as temperature 35 ℃, pH 8.0, dissolved oxygen concentration 1.0 mg/L, ammonium concentration 4 mmol/L and HRT 16 h, which have different influence on the performance of shortcut nitrification reactor. The pH, temperature and dissolved oxygen concentration have significant bearing on the process. The results showed that the shortcut nitrification reactor could be successfully started up within 42 d, and the reactor performance is steady with minimum NO2-/NOx- of 85.2%, maximum 93.4% and average value of 91.4% in effluent. Based on the analysis of experimental data, a new control strategy named “priority ＋ combination” for shortcut nitrification was suggested. Through this strategy, the startup and operation of shortcut nitrification for ammonium-rich sludge digester liquids were optimized. The control strategy works well to keep the reactor operation in steady state and in achieving high-efficiency for shortcut nitrification.     

河湖淤泥制备陶粒轻集料的研究进展

近年来,河湖疏浚底泥的处理处置及资源化问题一直是人们研究的热点,利用河湖淤泥生产新型建筑材料是其中的主要方向之一。系统研究了河湖淤泥的化学组成和物理特性,分析了利用河湖淤泥制备陶粒轻集料的可行性。综述了利用河湖淤泥制备陶粒的国内外研究进展情况,对河湖淤泥陶粒制备的工艺流程进行了分析,重点研究了原材料组成和焙烧制度对淤泥陶粒性能的影响。结果发现,Fe_2O_3、Ca O、原料质量比K、焙烧温度及焙烧时间等对陶粒性能影响显著。最后结合应用现状对淤泥陶粒的应用前景作了总结和展望,以期为河湖淤泥的资源化研究工作提供借鉴。     

Adsorption removal of phosphate from aqueous solution by active red mud

Red mud is the waste of alumina industry and has high TiO_2 and Fe_2O_3 content which are active components for the adsorption of anion pollutants.In this study,the uptake of phosphate by red mud activated by heat treatment and acid-heat treatment was investigated. The factors influencing the adsorption were also investigated.The result showed that the red mud sample treated using acid-heat method at 80℃with 0.25 mol/L HC1 for 2 h achieved the highest phosphate removal.For the heat-activated red mud,the sample heated at 700℃for 2 h preformed better than the other heat treatment.Phosphate removal by the activated red mud was significantly pH dependent,and pH 7 was the optimal pH for phosphate removal.The adsorption fits Langmuir isotherm model well and the maximum adsorption capacities of the acid-heat activated red mud and the heat activated samples were 202.9 mgP/g and 155.2 mgP/g,respectively.     

重复污染下铬在淤泥中的行为表征

在实验室条件下，对铬在重复污染时的吸附解吸特征作了初步研究。结果表明：随吸附次数增加，其吸附量有减少趋势，但淤泥中总的吸附量增加，在浓度〉１０μｇ．ｍｌ＾－１时，经三次吸附，体系ｐＨ有所下降，导致吸附量急增。淤泥中的吸附铬极不易解吸；而高吸附量的淤泥在二次解吸时有解吸现象发生，但数量极小。     

Determination of hemoglobin adduct of a musk xylene metabolite in trout as biomarker of exposure by gas chromatography mass spectrometry

Introduction Nitromusksarewidelyusedassyntheticfragranceingredientsinformulationofsoaps,laundrydetergents,lotions,andbody careproducts,andsoon.Thecommercial anddomesticuseanddischargeofthesecompoundsfrommunicipalsewagesystemshaveledtotheirubiquitousoccurr…     

有机高分子絮凝剂在江苏内河淤泥中的降解研究

研究了有机高分子絮凝剂在江苏内河脱水淤泥中降解情况.以江苏2地区无锡古运河、吴江横草路内河泥样为代表,经过有机高分子絮凝剂聚二甲基二烯丙基氯化铵-丙烯酰胺PDA(Poly-Dimethyldiallylammonium chloride-Acrylamide)絮凝脱水后,以显微拍照、浊度和透过率为指标,考察淤泥样微量有机高分子絮凝剂的降解情况.在20 d时,古运河絮凝泥样1%质量分数的悬浮液透过率由77.8%减少为36.9%,浊度由32.8 NTU增加为117.4 NTU;横草路絮凝泥由90.9%减少为52.1%,浊度由15.45 NTU增加为94.2 NTU,两个地区的降解泥样浊度和透过率与各自原泥样的相应值都随降解时间的递增而趋向一致.同时采用显微拍照的方法观察淤泥的降解情况,20 d常温降解后絮凝淤泥重新以小颗粒状分散排布.实验结果表明:常温下存放20 d时,淤泥样中微量PDA已基本降解为小分子,降解后淤泥的物理状态和原泥趋近.     

兰州市排污沟淤泥的有机质特征及来源分析

文章对兰州市西部工业区、生活区、医院等功能区的排污沟上、中、下段淤泥中饱和烃组成与分布特征进行了分析,初步认识了饱和烃的来源和组成特征。分析表明,排污沟淤泥中分布多种类型的饱和烃化合物,主要包括正构烷烃、无环类异戊二烯烷烃、萜类化合物、甾烷等。正构烷烃组成特征均为双峰态后峰型,主峰碳数为C15-C18和C25-C31。样品中检测出27种萜类化合物,其中五环萜类较三环萜类化合物占优势。甾烷化合物主要包括规则甾烷、重排甾烷、孕甾烷,以规则甾烷为主。有机质生物标志物参数表明,排污沟淤泥中有机质具有成熟和不成熟的特征,主要为现生植物、矿物油和化石燃料对烃类化合物的贡献,并且在不同区段由于外源有机物的加入而表现不同,有机质为多源混合来源。人类活动较集中的中段受矿物油和化石燃料燃烧污染程度明显比上游和下游严重。