利用高硅铁尾矿制备氧化铁及二氧化硅微粉

采用酸浸法处理高硅铁尾矿,制备工业原料Fe2O3和SiO2微粉.最佳工艺条件为:反应温度100℃,反应时间90 min,铁尾矿中位粒径6.19 μm,盐酸体积分数60％.在上述最佳条件下,制备的SiO2产率(所得产品中SiO2的质量占原铁尾矿中SiO2质量的比例,下同)达98.2％,品质达到YB/T 115-2004《...     

催化氧化法处理难生化炼油污水研究

以三级生化处理后的炼油污水为研究对象,考察了催化氧化过程的氧化作用和混凝作用,结果表明,催化氧化法去除有机物主要通过将大分子有机物氧化分解为小分子有机物,从而提高污水的可生化性;催化氧化对有机物氧化具有选择性,对苯甲酸和苯胺等芳香类化合物去除效果好,去除率分别达到92.2%和84.8%;对草酸和乙酸等小分子有机酸去除效...     

石油化工企业灭火中的环境保护

从消防的角度对消防水的产生与特点进行探讨,阐述消防污水的产生与特点、灭火中应注意的问题以及消防污水紧急处置的措施,对石化企业的防火设计及消防监管提出了一些建议,阐明在消防灭火过程中,应树立强烈的环保意识,避免因火灾引发的突发环境事件造成政治、经济和社会方面的重大影响。     

利用废硅藻土制备白炭黑

以废弃硅藻土为原料,采用硫酸酸浸除杂、氢氧化钠合成硅酸钠、硫酸酸化,再经清洗、干燥等步骤,制得白炭黑。考察了不同因素对制备效果的影响。实验结果表明,酸浸最佳工艺条件为：硫酸质量分数17％,酸浸温度40℃,液固比（硫酸溶液与废弃硅藻土的质量比）3．0：1;碱处理最佳工艺条件为：碱加入量（氢氧化钠与酸浸后硅藻土的质量比）0．4,碱处理时间60min。在此条件下制备出的白炭黑的总产率可达46．7％,产品质量符合HGT3061—1999《橡胶配合剂沉淀水合二氧化硅技术条件》中的D类标准,可实现废弃硅藻土的资源化利用。     

高铁酸钾降解苯胺废水的机制研究

研究了高铁酸钾投加量、初始pH及苯胺初始浓度对苯胺降解效果的影响.结果表明.苯胺废水的COD去除事随高铁酸钾投加量和苯胺初始浓度的增大而升高,而初始pH对COD去除率影响不明显.对高铁酸钾降解苯胺废水后的产物进行了气相色谱/质谱(GCIMS)分析.在此基础上详细探讨了高铁酸钾降解苯胺的机制.     

The effect of excess Zn on mineral nutrition and antioxidative response in rapeseed seedlings

Zinc (Zn) is a necessary element for plants, but excess Zn can be detrimental. To investigate Zn toxicity, rapeseed (Brassica napus) seedlings were treated with 0.07–1.12 mM Zn for 7 d. Inhibition of plant growth along with root damage, chlorosis and decreased chlorophyll (a and b) content in newly expanded leaves (the second and third leaves formed following cotyledons) were found under Zn stress. The Zn content increased in plants under external Zn stress, while concentrations of phosphorus, copper, iron, manganese and magnesium reduced significantly, especially in roots. Meanwhile, increased lipid peroxidation was detected biochemically and histochemically. Compared with controls, NADH oxidase and peroxidase (POD) activity increased in leaves and roots of plants under high Zn, but superoxide dismutase (SOD), catalase and ascorbate peroxidase activities decreased. The changes in glutathione S-transferase activity and in ascorbic acid, dehydroascorbate, non-protein thiols and glutathione contents were also measured under Zn stress. Isoforms of SOD and POD were separated using non-denaturing polyacrylamide gel electrophoresis and their activities were analyzed. Our results suggested that excess Zn exerts its toxicity partially through disturbing nutrient balance and inducing oxidative stress in plants. These data will be helpful for better understanding of toxicity of Zn and the adaptive mechanism in Zn non-hyperaccumulator plants.     

接种物对厌氧同步脱硫反硝化特性的影响实验研究

分别以厌氧污泥、脱氮硫杆菌菌悬液和厌氧污泥并添加脱氮硫杆菌菌悬液为接种物,以硫化物和硝酸盐为进水基质,考察不同接种物条件下,各反应器的硫化物氧化特性、反硝化特性、生化反应机理及微生物特性。结果表明,在无菌条件下,硫化物不能被硝酸盐化学氧化。接种脱氮硫杆菌菌悬液的2#反应器的硫氧化速率为1.98 g S/(m3.h),停留24 h硫化物的去除率高达97%,脱硫能力最强,该接种条件下以硝酸盐氧化硫化物为主反应,优势菌为杆菌,进水的NO3--N/S应控制在0.4以下,可以实现高效生物脱硫。接种厌氧污泥的1#和3#反应器的脱氮效果比2#反应器好,停留时间为24 h时,硝酸盐的平均去除率为96%。单独接种厌氧污泥的1#反应器的硫氧化速率为1.78 g S/(m3.h),其优势菌为球菌,该接种条件下以硝酸盐氧化硫化物和硝酸盐氧化单质硫为主反应,进水的NO3--N/S应控制在0.8左右。以厌氧污泥联合脱氮硫杆菌为接种物时,硫氧化速率为1.71 g S/(m3.h),反应器以硝酸盐氧化硫化物、硝酸盐氧化单质硫以及异养反硝化为主反应,驯化后优势菌为球形、卵圆形和短杆状,应控制进水NO3--N/S为1.2,可以实现同步脱硫反硝化,该工艺既可以用于含硫废水的处理,也可以用于C/N低的硝酸盐废水的处理。     

Removal of silver nanoparticles in simulated wastewater treatment processes and its impact on COD and NH(4) reduction

The increasing utilization of silver nanoparticles in industrial and consumer products has raised concern to wastewater treatment utilities due to its antimicrobial activity. In this work, the removal of citrate stabilized silver nanoparticles (Ag-NPs) during the wastewater treatment processes and its impact on treatment performance were examined. During simulated primary clarification, over 90% of the Ag-NPs remained in the wastewater, indicating that the majority of silver nanoparticles in sewage would enter the subsequent treatment units. During sequencing batch reactor processes, silver nanoparticles were effectively removed in each cycle throughout the 15-d experimental duration. Continuous input of silver nanoparticles into the wastewater did not significantly alter chemical oxygen demand (COD) removal. NH(4) removal was reduced at the beginning of the SBR experiment but quickly recovered at the later stage of the experiment. This study demonstrated that in the near future it is unlikely that citrate-stabilized Ag-NPs released into sewage will cause significant adversary effects on the COD and NH(4) removal of activated sludge processes in municipal wastewater treatment plants.     

Biodegradation of nicosulfuron by the bacterium Serratia marcescens N80

By enrichment culturing of the sludge collected from the industrial wastewater treatment pond, we isolated a highly efficient nicosulfuron degrading bacterium Serratia marcescens N80. In liquid medium, Serratia marcescens N80 grows using nicosulfuron as the sole nitrogen source, and the optimal temperature, pH values, and inoculation for degradation are 30-35°C, 6.0-7.0, and 3.0% (v/v), respectively. With the initial concentration of 10 mg L?1, the degradation rate is 93.6% in 96 hours; as the initial concentrations are higher than 10 mg L?1, the biodegradation rates decrease as the nicosulfuron concentrations increase; when the concentration is 400 mg L?1, the degradation rate is only 53.1%. Degradation follows the pesticide degradation kinetic equation at concentrations between 5 mg L?1 and 50 mg L?1. Identification of the metabolites by the liquid chromatography/mass spectrometry (LC/MS) indicates that the degradation of nicosulfuron is achieved by breaking the sulfonylurea bridge. The strain N80 also degraded some other sulfonylurea herbicides, including ethametsulfuron, tribenuron-methyl, metsulfuron-methyl, chlorimuron-ethyl,and rimsulfuron.     

几种倒伞型表面曝气机的充氧性能

对安徽某科技公司产自行研究的几种倒伞型表面曝气器的充氧性能进行模拟比较研究,利用合肥某氧化沟装置在清水条件下对各叶轮的氧总转移系数KLa、理论充氧能力qc、理论动力效率E及水体流速v进行了测试,对比分析了叶片安装角度、片数及叶片设计对充氧能力的影响。结果表明,叶片导流辐板斜角设计对充氧效率影响最大,是叶轮性能提升最关键因素。