厌氧升流式污泥层反应器内污泥颗粒化对固液分离效果的影响

厌氧升流式污泥层反应器在较高的COD容积负荷和水力负荷下稳定运行的关键是要有良好的固液分离,而固液分离的必要条件是污泥的沉降速度大于混合液在三相分离器的沉降区的最小断面上的向上流速。通过小型装置的试验表明,污泥的沉降速度与污泥的性状和浓度有关,使反应器内的污泥颗粒化能改善污泥沉降性、提高固液分离效果,使反应器能在相当高的COD容积负荷(20—30kgCOD/m~3·d)和水力负荷(0.8m~3/m~2·h)下稳定运行。本文叙述了厌氧升流式污泥层反应器内的污泥颗粒化过程,并简要地讨论了培养颗粒污泥的基本条件。     

嘉定城区河流水质现状评价及污染防治对策

通过对嘉定中心城区河流的水质现状调查和评价，提出了引清排污、加强市政措施等污染防治对策。     

论深入广泛推行清洁生产

在全面分析了国内推行清洁生产现状的基础上，根据中国的工业和资源特点，阐述了推行清洁生产的必要必,现时，从技术和管理两方面指出了中国推行清洁生产的巨大潜力，最后，有针对性地提出了深入广泛推行清洁生产的4条措施：（1）加快完善清洁生产政策，（2）深入实施清洁生产审计，（3）加强清洁生产技术的理论研究，（4）积极在中小企业中广泛推广清洁生产。     

碳酸钙和海泡石组配对水稻中Pb和Cd迁移转运的影响

为研究组配改良剂LS(碳酸钙+海泡石)对农田土壤重金属Pb和Cd的固化效果以及水稻各部位吸收累积Pb和Cd的影响,在湘南2个矿区(矿区A和矿区B)附近污染稻田中施用了不同添加量的LS (0、2、4和8 g/kg),并进行了水稻种植的田间实验。结果表明,(1)施用2~8 g/kg的LS能使矿区A和矿区B土壤pH值分别增加1.11~1.95和1.61~2.31个单位,能使矿区A和矿区B土壤中Pb和Cd的TCLP提取态含量分别降低18.6%~62.7%、15.7%~37.1%和38.6%~66.7%、0~76.6%。(2)LS能不同程度地降低水稻各部位重金属含量。矿区A糙米中Pb和Cd含量降低9.4%~35.6%、56.1%~66.8%;矿区B糙米中Pb含量降低14.4%~36.6%,而Cd含量变化不明显。(3)LS对水稻中Pb和Cd在各部位之间的转运系数均有不同程度的影响,其中Pb和Cd从茎叶到谷壳的转运系数最大,说明水稻茎叶对重金属的转运能力最强。(4)LS添加量为8 g/kg时,Pb和Cd从谷壳到糙米的转运系数最小,且糙米中Pb和Cd含量最低。     

Promoting effect of vanadium on catalytic activity of Pt/Ce–Zr–O diesel oxidation catalysts

A series of Pt–V/Ce–Zr–O diesel oxidation catalysts was prepared using the impregnation method. The catalytic activity and sulfur resistance of Pt–V/Ce–Zr–O were investigated in the presence of simulated diesel exhaust. The effect of vanadium on the structure and redox properties of the catalysts was also investigated using the Brunauer–Emmett–Teller method,X-ray diffraction, H2temperature-programmed reduction, CO temperature-programmed desorption, X-ray photoelectron spectroscopy, and Energy Dispersive Spectroscopy. Results showed that the Pt particles were well dispersed on the Ce–Zr–O carrier through the vanadium isolation effect, which significantly improved the oxidation activity toward CO and hydrocarbons. An electron-withdrawing phenomenon occurred from V to Pt, resulting in an increase in the metallic nature of platinum, which was beneficial to hydrocarbon molecular activation.     

Flotability and flotation separation of polymer materials modulated by wetting agents

The surface free energy, surface tension and contact angles were performed to investigate the properties of wetting agents. Adsorption of wetting agents changes wetting behavior of polymer resins. Flotability of polymer materials modulated by wetting agents was studied, and wetting agents change significantly flotability of polymer materials. The flotability decreases with increasing the concentration of wetting agents, and the wetting ability is lignin sulfonate (LS) > tannic acid (TA) > methylcellulose (MC) > triton X-100 (TX-100) (from strong to weak). There is significant difference in the flotability between polymer resins and plastics due to the presence of additives in the plastics. Flotation separation of two-component and multicomponent plastics was conducted based on the flotability modulated by wetting agents. The two-component mixtures can be efficiently separated using proper wetting agent through simple flotation flowsheet. The multicomponent plastic mixtures can be separated efficiently through multi-stage flotation using TA and LS as wetting agents, and the purity of separated component was above 94%, and the recovery was more than 93%.     

林可霉素生产废水的厌氧生物处理工艺

采用单相中温升流式厌氧污泥床(UASB)反应器厌氧生物工艺处理含有有毒难降解有机物的林可霉素生产废水.当进水COD 8000～14000 mg/L,HRT约10h时,COD容积负荷可达20～35kg/(m³·d),COD去除率为50%～55%.适时调整并维持较高的表面水力负荷[0.2～0.4 m³/(m²·h)]、较高的进水有机基质浓度(COD为2000～3000mg/L)和污泥COD负荷[0.2～0.5 kg/(kg·d)],并适当延长启动驯化时间可培养出沉降性好、污泥活性较高的颗粒污泥.废水厌氧生物降解动力学符合Monod方程,动力学常数V_max=1.3 d^-1,K_s=8133mg/L.废水中不可生物降解物质占总COD的比例约为30%,这是废水COD去除率偏低的重要因素.     

麦草畏除草剂厌氧降解可生化性测定

苯环由¹⁴C标记合成的麦草畏除草剂,厌氧降解反应至第7天,转化率达64%,有¹⁴C标记的CO₂产生;第16天,转化率达91%,出现一种主要的中间代谢产物,有CH₄产生;第27天,转化率达95%,仍然只有一种主要的中间代谢产物.麦草畏苯环的断裂量仅占总量的2.96%,转化成CO₂的为0.74%,转化成CH₄的为0.11%.在降解27d中,主要中间代谢产物是3,6-二氯水杨酸,占麦草畏总量的92.04%.3,6-二氯水杨酸的苯环没有被打开,可生化性极低,仍然继续污染环境研究结果为控制麦草畏对人体健康危害,进行生物修复工程,提供了重要的参考依据.     

环氧化合物分子结构与致变活性的关系

由化学物质毒性效应登录(RTECS)1998年光盘系统检索获得86种环氧化合物对鼠沙门氏菌致变活性数据.应用主成分分析法从11种分子描述符中选择出5种对致变活性有明显影响的描述符:碳原子数,苯环数,氢原子数,烷基数和氧原子数.通过样本学习集训练并优化神经网络结构,建模分类预报:对于86个样本,低和高2类活性,正确分类率达到92%.结果表明:3～4个骈接苯环的环氧化物的特殊结构具有很强的致变活性.     

西昆仑山区土壤垂直带谱

西昆仑山区位于青藏高原西北隅,高山深谷,原面广阔,地形复杂,气候多样,致使本区土壤垂直带谱类型众多,概分为极干旱、干旱、半干旱和高寒干旱、高寒半干旱5个类型。其中干旱和半干旱型土壤垂直带谱中广布着草原和草甸草原,是塔里木盆地南缘重要的天然牧场。特别是半干旱型中还有云杉林分布,是昆仑山系唯一森林分布区。 本区土壤垂直带谱在边缘山脉与内部山脉之间,低海拔山地与耸立在5000m左右高原面上的高海拔山地之间有明显的差别。