铬污染土壤对水泥熟料强度和铬浸出浓度的影响简

为探索水泥窑协同处置铬污染土壤（CCS）的可行性,用CCS部分替代硅质原料配制生料,于1 400℃煅烧成熟料,通过化学分析、强度测试、浸提实验及XRD/SEM分析,研究了CCS对生料易烧性、熟料强度及六价铬/总铬（Cr（VI）/∑Cr）浸出浓度的影响。结果表明,CCS能改善熟料烧成,掺量从0到15%,熟料中f-CaO含量略有下降,硬化试体的3 d、28 d、90 d强度略有提高。Cr（VI）/∑Cr浸出浓度随CCS掺量增加而增大,但随养护龄期延长而减小;当CCS掺量小于8%时,熟料3 d至90 d水化物的浸出液中,Cr（VI）浓度均低于0.05 mg/L,符合Ⅱ类地表水环境质量标准限值。铬离子浸出毒性减小是由于铬在熟料矿物和水化产物中的固溶以及水化产物对它的包裹封固作用。研究表明,水泥窑协同处置CCS是一种可行的无害化处理和资源化利用途径。     

铬污染土壤对水泥熟料强度和铬浸出浓度的影响

为探索水泥窑协同处置铬污染土壤(CCS)的可行性,用CCS部分替代硅质原料配制生料,于1 400℃煅烧成熟料,通过化学分析、强度测试、浸提实验及XRD/SEM分析,研究了CCS对生料易烧性、熟料强度及六价铬/总铬(Cr(VI)/∑Cr)浸出浓度的影响。结果表明,CCS能改善熟料烧成,掺量从0到15%,熟料中f-CaO含量略有下降,硬化试体的3 d、28d、90 d强度略有提高。Cr(VI)/∑Cr浸出浓度随CCS掺量增加而增大,但随养护龄期延长而减小;当CCS掺量小于8%时,熟料3 d至90 d水化物的浸出液中,Cr(VI)浓度均低于0.05 mg/L,符合II类地表水环境质量标准限值。铬离子浸出毒性减小是由于铬在熟料矿物和水化产物中的固溶以及水化产物对它的包裹封固作用。研究表明,水泥窑协同处置CCS是一种可行的无害化处理和资源化利用途径。     

水泥窑共处置废物过程中重金属的流向分布

为了探索水泥窑共处置危险废物过程中重金属流向分布规律,研究了不同温度条件下Cr、As、Pb在煅烧熟料、颗粒物和尾气中的残留率。在900、1 000、1 100、1 200、1 300和1 450℃温度条件下,将添加Cr、As和Pb化学试剂的生料分别进行煅烧,模拟重金属在水泥窑内不同温度带的煅烧过程。结果表明,6个温度条件下,Cr主要分布在熟料中并且呈现不规则变化;颗粒物中的Cr在1 200℃条件下分布量最大,所占比例为32.79%(w);在900℃和1450℃条件下,烟气中的Cr分布量最大,所占比例为0.24%(w)。6个温度条件下As主要分布在熟料中并且1 000~1 450℃条件下稳定在81%~83%之间;在900℃条件下,As在熟料中的残留率最大,所占比例为97%(w);在1450℃条件下,As在尾气中的分布达到最大值,所占比例为0.0023%(w)。6个温度条件下,Pb在熟料中的残留率随着温度升高而逐渐减少,挥发颗粒物中的含量呈现相反的趋势;尾气中Pb的含量随着温度的升高逐渐增加。     

城市污水厂石灰干化污泥对水泥易烧性的影响

针对城市污水处理厂污泥含水率高、体积大、泥质成分复杂且易造成二次污染的特点,采用石灰干化后利用水泥工业协同处置是其实现资源化的途径之一。实验结果表明,在煅烧温度1 400℃、保温时间60 min的条件下,掺加适量的石灰干化污泥有利于提高水泥生料的易烧性,熟料中f-Ca O含量符合国家标准;掺加质量比为12%的石灰干化污泥煅烧所得熟料与空白参比熟料的物相组成基本相同,当石灰干化污泥掺量过大时应根据泥质成分对生料配比进行相应的调整,以确保熟料达到水泥生产的质量要求。研究成果可为水泥工业协同处置城市污泥提供借鉴与技术参考。     

水泥回转窑共处置含砷污泥

通过水泥窑共处置含砷污泥的煅烧实验,探讨了不同掺加量(0%、2%、5%、10%和15%)对水泥煅烧过程易烧性的影响。采用X-射线衍射仪(XRD)对熟料样品的矿物相进行研究,并对水泥制品进行抗压和抗折测试,同时对熟料中砷的固化率进行分析。实验结果表明,掺加含砷污泥对熟料游离氧化钙含量影响显著,且能降低烧成温度。且掺加浓度的提高(2%~15%)对f-CaO含量影响不大。XRD测试表明,掺烧15%含砷污泥熟料的主要矿物相没有太大变化,其抗压和抗折实验结果与参比水泥相似,符合国家标准。砷元素的固化率为84.29%。     

煤粉发泡剂对赤泥陶粒烧胀特性的影响

分析赤泥、膨润土和煤粉的理化性质,并在此基础上烧制赤泥陶粒。考察不同发泡剂煤粉掺量下所烧制陶粒的烧胀性能。采用热性质分析、矿物分析和红外光谱等手段分析陶粒样品,研究煤粉的掺量和烧结温度对陶粒烧胀过程的影响以及赤泥陶粒的烧胀机理。结果表明:烧结温度为1 000℃时,随着煤粉掺量的增加,赤泥陶粒的显气孔率和吸水率升高,而体积密度和抗压强度降低;煤粉掺量为30%时,赤泥陶粒显气孔率45.13%,体积密度0.131 g·cm~(-3),吸水率39.0%,抗压强度14.7 MPa;掺入煤粉后赤泥陶粒生料有机组分烧失量增加,熔融温度降低,烧胀过程中还原性气氛增强;烧结温度升高能够促进易熔融矿物铁橄榄石的生成,提高陶粒的烧胀性能。     

利用石油焦脱硫灰渣制备硫铝酸盐水泥

以石油焦脱硫灰渣为主要原料,经配方设计,烧制出硫铝酸盐水泥熟料,采用DSC-TG和XRD等分析方法分别确定了熟料的烧成过程、温度及矿物组成,研究了掺加一定量无水石膏配制的硫铝酸盐水泥的物理、力学性能。结果表明,该水泥熟料的适宜烧成温度为1 300~1 320℃,熟料主要矿物为C4A3S珔和C2S。根据实际需要,水泥中无水石膏的掺量可在5%~10%范围内调节,均能获得优异的物理性能。该水泥具有较高的早期强度,后期强度增长稳定。因此,利用石油焦脱硫灰渣为主要原料制备硫铝酸盐水泥是完全可行的。     

利用烧结脱硫灰制备胶凝材料的研究

研究了烧结烟气半干法脱硫灰复掺矿渣、钢渣,辅之外加剂,制备胶凝材料的可行性。结果表明,采用改性脱硫灰（GXTLH）、钢渣、矿渣及水泥熟料再混磨制备的复合胶凝材料,具有良好的安定性等水化性能和力学性能;当GXTLH 掺入量为20%、CFII 1.5%、减水剂0.5%及水泥熟料23%时,矿渣掺量在12%～44%、钢渣掺量11%～44%之间制备的胶凝材料初凝时间、终凝时间、力学性能满足GB13592-92《钢渣矿渣水泥标准》;矿渣与钢渣比、水泥熟料及外加剂等掺量一定,GXTLH掺量超过30%时,GXTLH胶凝材料的抗压抗折强度均有所下降。     

垃圾焚烧飞灰对陶瓷砖烧成影响的研究

利用DTA-TGA分析及烧成实验2种方法确定不同配比物料制陶瓷砖的最佳烧成温度及烧成范围,并对结果进行了比较;测定了不同配比物料在各自最佳烧成温度下烧成所得制品的性能及浸出毒性。结果表明:DTA-TGA分析所得烧成温度略高于实际烧成温度;飞灰掺加量的增加有利于降低陶瓷砖的烧成温度,当掺加量为10%、20%和30%时,制品最佳烧成温度分别为1 132、1 031和985℃;各配比物料在各自最佳烧成温度下烧成的制品均达MU20强度等级,满足抗风化的要求,制品浸出毒性远低于危险废物浸出毒性鉴别标准。     

以城市污泥为掺料制备烧结砖

以城市污泥为部分原料制备烧结砖,对不同烧成温度下不同污泥掺量的烧结砖的物理、力学性能进行了详细分析。结果表明,污泥可用于制备烧结砖,当污泥掺量≤12%,烧成温度为1 100℃时,烧结砖物理力学性能均符合烧结砖标准要求。此外,实验以污泥掺量为12%的烧结砖,烧成温度为1 100℃为例,进行了重金属毒性浸出实验,以考察烧制污泥砖对重金属的固化作用,进而评定污泥制砖的安全性。结果表明,经过高温焙烧,大多数重金属浸出毒性都显著降低,且符合规范要求,不会对环境造成危害。其中,重金属固化效果最好的为Zn,最差的为Cr。     

The effect of simulated rain on folpet and mancozeb residues on grapes and on vine leaves

Artificial rainfalls were used to determine the effect of the amount of the rainfall and the time interval between pesticide application and rainfall event, on folpet and mancozeb residues on grapes and vine leaves. Forty-five mm of rain were administered to the vineyard in different amounts (45; 30+15; 15+15+15 mm). Folpet showed good rainfastness on the grapes and on the leaves. A modest decrease was observed only in the experiments that had received 45 mm of rain at one go. Mancozeb showed a lower rainfastness, since a portion of the deposit was easily washed off also by a modest rainfall. The percentage of this portion was higher in the grapes (38%) than in the leaves (20%). The data obtained in these experiments show that, in the case of folpet, it is not necessary to repeat the treatment when it rains the day after, while it is recommendable to repeat it in the case of mancozeb.     

农药在土壤上吸着/解吸及其对生物利用率影响的研究进展

正确预测有机污染物在环境中的归宿 ,在很大程度上依赖对它们的吸着 -解吸动力学行为的认识。自 2 0世纪 80年代起 ,吸着 -解吸动力学逐渐受到重视。本文介绍了国内外有关农药在土壤 /沉积物上的吸着 -解吸动力学和吸着 -解吸对土壤有机污染物的生物利用率的影响等方面的近期研究成果 ,着重从实验方法、模型、机理等方面进行了详细的综述     

Ca2+和PAM 对污泥流变性和脱水性能的影响

研究了Ca2+和聚丙烯酰胺(PAM)在污泥调理过程中对污泥流变行为和脱水性能的影响,通过对粘度、毛细吸水时间(CST)、比阻(SRF)等参数的测量,发现Ca2+单独作用时对污泥脱水性能的提高不大,而不同含量的Ca2+和PAM混合后,对污泥的流变行为和脱水性能都有不同程度的影响,发现20 mg/L的PAM连同140%DS的Ca2+对污泥共同进行调理时,体系表观粘度最低,脱水性能最好,同时经济成本也较低.研究表明,还不能肯定地得出可用体系的表观粘度作为调理剂最佳投加量的控制指标.     

Persistence of deltamethrin and cypermethrin on wheat and sweetclover

Abstract

Residues of cypermethrin and deltamethrin in wheat herbage and grain and deltamethrin in sweetclover herbage were determined. Cypermethrin was applied at 28 g/ha to wheat and the residues on the herbage declined exponentially from 3.74 ppm immediately after spraying to 0.20 ppm 27 days after spraying. No cypermethrin residues were detected in the grain. Deltamethrin was applied at 6 g/ha to wheat and the residues on the herbage declined exponentially from 0.70 ppm immediatly after spraying to 0.05 ppm 27 days after spraying. No deltamethrin residues were detected in the grain. Deltamethrin was applied to sweetclover at 3, 4, 5, 10, and 16 g/ha. Residues on the herbage declined exponentially from 0.10, 0.16, 0.22, 0.40 and 0.70 ppm immediatly after spraying to 0.02, 0.03, 0.04, 0.15 and 0.18 ppm 5 days after spraying, respectively.     

基于生物表面活性剂的柴油微乳体系构建与性能研究

以生物表面活性剂鼠李糖脂（RL）为表面活性剂,中长碳链正构醇（正丁醇、正戊醇、正己醇、正庚醇及正辛醇）为助表面活性剂,采用滴定法制备RL／柴油／正构醇／水柴油微乳体系,并考察了表面活性剂用量（Km）、助表面活性剂醇的种类及用量（δas）及离子强度对柴油微乳体系最大增溶水量（Wo）的影响,并对不同条件下获得的柴油微乳体系的运动粘度（μ）和表面张力（γ）进行了表征。通过荧光法测得RL在柴油中的临界胶束浓度CMC为7g／L。当生物表面活性剂与柴油的质量比Km为0．02,助表面活性剂选用正庚醇且醇与表面活性剂的质量比δgs为0．1,NaOH溶液质量分数为0．06％时,柴油微乳体系的肛和T较低,形。最大,性能较佳。     

Effects of selected pesticides on , and on seed germination and Verticillium wilt pathogens of alfalfa

Studies on the effects of 21 fungicides and five pyrethroid insecticides on growth of , emergence and survival of alfalfa seed and the efficacy of the chemicals in control of Verticillium wilt pathogens were conducted.     

污水厂污泥一体化竖式强化渗滤浓缩自然干化与消化研究

针对目前国内污泥处理处置存在的问题,为实现污泥浓缩消化一体化,开发了污泥一体化强化渗滤浓缩自然干化与消化新工艺反应器,并进行了城市水厂污泥处理试验.结果表明,在有机负荷为0.8 kg VSS/(m3·d)、平均水力停留时间为8.3 d、污泥停留时间为120 d的条件下,污泥有机物去除率可达到44.4%,排泥含水率达到79.1%,污泥消化与浓缩过程起到了相互促进的作用.渗滤液须抽回至污水处理厂处理.     

DO和pH值在短程硝化中的作用

在SBR反应器中对DO和pH值在短程硝化和半亚硝化过程中的作用进行试验研究，结果表明，控制低DO和适宜的pH值在短程硝化过程中起着重要的作用。本试验条件下。当DO为0．5～1．0mg／L、pH值为7．5—8．0时。在SBR反应器中很容易实现短程硝化；当DO〉0．3mg／L时，DO越低，出水NO2^-N积累率越高；当pH值〉6．8时，不会影响系统NO2^-N积累的稳定性。另外，研究结果还表明，通过控制DO和pH值可以实现半亚硝化。本试验条件下，当进水氨氮浓度为120mg／L时，控制DO为0．3—0．4mg／L可实现出水半亚硝化；当进水氨氮浓度为200mg／L时，控制DO为0．5—0．6mg／L或pH值为6．8也可以实现出水半亚硝化。     

Survival of bio-inoculants on fungicides-treated seeds of wheat,pea and chickpea and subsequent effect on chickpea yield

Survival of Mesorhizobium ciceri (SP₄) and Azotobacter chroococcum (CBD-15 and M₄) was tested on chickpea (Cicer arietinum) seeds treated with fungicides bavistin [methyl N-(1H-benzimidazol-2yl) carbamate] and thiram (tetramethyl-thiuram disulfide), whereas survival of phosphate solubilizing bacteria (PSB), Pseudomonas striata (27) and Bacillus polymyxa (H₅) was examined on two cultivars (Arkel and BV) of pea (Pisum sativum) seeds treated with thiram. Viability of Azotobacter chroococcum (W₅) was also examined on wheat (Triticum aestivum) seeds treated with bavistin, captan (cis-N-trichloromethyl thio-4 cyclohexane-1, 2-dicarboximide) and thiram under laboratory conditions using standard dilution and the plate count technique. All the tested strains of diazotrophs and PSB showed decline in their viable population on prolonged contact with fungicides. However, PSB showed variation in their viable population even with the cultivar.

BV cultivar of pea seeds showed better recovery of viable P. striata (10.75 to 10.61 log no. of viable cells with in 0-24 hrs) in the presence of thiram, whereas the Arkel cultivar of pea resulted in better recovery of viable B. polymyxa. Azotobacter chroococcum (W₅), a potential strain for wheat, showed better survival in the presence of bavistin, compared to thiram and captan. Higher viable population of Mesorhizobium ciceri (SP₄) and Azotobacter chroococcum (M₄) was recovered from chickpea seeds treated with bavistin compared to thiram. However, thiram-treated seeds resulted in a greater number of extractable Azotobacter chroococcum (CBD-15). Under field conditions, adverse effect of thiram was reflected on the performance of Mesorhizobium ciceri (SP₄) and A. chroococcum (M₄) strains, resulting in reduced root and shoot biomass and grain yield, compared to bavistin treated and culture inoculated treatment. CBD-15 showed better performance in the presence of thiram compared to bavistin.     

Effect of lead on the sorption of 2,4,6-trichlorophenol on soil and peat

The effect of lead on the sorption of 2,4,6-trichlorophenol (2,4,6-TCP) on soil and peat was investigated using a batch equilibration method. Lead markedly diminished the sorption of 2,4,6-TCP, and 2,4,6-TCP had little effect on lead sorption. Peat was a more effective adsorbent for 2,4,6-TCP than soil. The desorption hysteresis of 2,4,6-TCP verified the presence of high-energy sorption sites. Mechanisms of lead suppression effect on the 2,4,6-TCP sorption included the following: Firstly, lead accelerated the aggregation of colloids, the aggregates covered the surface in part and shrunk the pore sizes of the adsorbents, hence decreased the sorption of 2,4,6-TCP. Secondly, X-ray absorption and Fourier transform infrared spectroscopy study suggested that lead competed with 2,4,6-TCP for carboxylic, phenolic and Si-OH groups of organic matter and clay minerals. Such competition was partly responsible for the overall suppression effect of lead on the sorption of 2,4,6-TCP.