A Biosurfactant-Enhanced Soil Flushing for the Removal of Phenanthrene and Diesel in Sand

In order to examine the potential of biosurfactants in soil remediation, and to investigate the effects of several operating conditions, such as flow rate, biosurfactant concentration and surfactant type, biosurfactant-enhanced soil flushing was conducted. In the biosurfactant-enhanced soil flushing process, the removal efficiency increased as the flow rate decreased. Rhamnolipid showed no effect on the removal efficiency of phenanthrene and diesel from sand in the concentration range 0.3-0.5%. However, rhamnolipid showed higher efficiencies for the removal of phenanthrene and diesel from sand than Tween 80. Based on total recovery, following an equivalent pore volume flush, it was more difficult to remove diesel than phenanthrene. In order to obtain the specific removal efficiency, more pore volumes of surfactant solution may be required in field applications. Under optimum conditions, the biosurfactant removed as much as 70% of the phenanthrene and 60% of the diesel in the sand. These results indicate that the use of biosurfactants in the flushing process is favorable, not only with respect to the environment, but also on removal efficiencies.     

不同收获时期和控氮条件对水培小白菜硝酸盐含量的影响

在水培中采用收获前降低营养液浓度、完全停止供氮以及在不同时期采收等方法来研究小白菜硝酸盐含量的控制方式及其效果,结果表明:适时采收和收获前适当控氮可以降低小白菜的硝酸盐含量。在小白菜生长第26d左右硝酸盐含量最低,此后l~2d产量增长较快,此时采收品质较好;小白菜硝酸盐含量呈明显的日变化,并且与硝酸还原酶活性呈正相关,在下午16:00时左右采收硝酸盐含量最低,仅为894mg.kg-1;完全断氮7d后,小白菜硝酸盐含量显著降低,但产量也受到明显的影响。而采用低浓度营养液控氮4d左右采收既可控制硝酸盐含量又不会使产量过低。     

南京市郊主要蔬菜硝酸盐污染现状评价

以ＷＨＯ／ＦＡＯ规定的日允许摄入量换算得到的标准评价了南京市郊主要蔬菜品种的ＮＯ－３污染状况。结果表明，双闸镇蔬菜基地的大白菜和青菜样品属重污染，菠菜属轻污染，萝卜污染程度居中，因而有必要采取有效的污染防治措施     

双波长标准加入法同时测定水中硝酸盐和亚硝酸盐

本文应用双波长标准加入法同时测定了硝酸盐和亚硝酸盐，在研究硝酸盐和亚硝酸盐紫外光谱的基础上，精确选择亚硝酸盐等吸收点波长２０２．５ｎｍ，２１６．５ｎｍ为测定波长。亚硝酸盐含量回归方程经推导得Ｃ＝－３．８４１＋１５６．６Ａ，相关系Ｒ＝１．０００。将该法用于合成样品及实际水样分析，所得结果较满意。     

含砷废水净化剂的制备及其应用研究

本文描述了用黄铁矿和还原铁粉或其代用品为原料制备含砷废水净化剂－硫化亚铁的新方法，获得了制备的最佳条件，探讨了其在含砷废水处理中的应用条件和影响因素，结果表明，该净化剂的生产及其处理含砷废水的工艺简单，经济高效，具有良好的开发应用前景。     

厌氧条件总磷还原为磷化氢种泥筛选及功能菌株鉴定

厌氧除磷是一种高效、节能、低耗的方法。获取经济、方便、高效的种泥是实现该方法的前提,种泥中产生磷化氢功能菌株的组成及特性是提高处理效能和开发新工艺的基础,目前此研究未见有关报道。本研究依据厌氧除磷理论,利用厌氧培养反应瓶、筛选培养基和微生物筛选、分离、鉴定的方法。以A2/O厌氧池、污泥浓缩池污泥、养殖场新鲜猪粪、鸡粪、牛粪及鸭粪为研究种泥,通过跟踪厌氧培养过程培养液中总磷的去除率和吸收液中磷化氢的生成量筛选出最佳种泥,并对最佳种泥的菌株进行筛选、分离和鉴定。结果表明,6种泥中鸡粪的厌氧除磷能力最强,鸭粪能力最弱,浓缩池中的污泥和猪粪次之,牛粪及厌氧池污泥有一定的作用。本试验条件下鸡粪是厌氧除磷的最佳种泥。经过3个周期的厌氧培养,6种泥培养液总磷的去除率和吸收液中磷化氢的含量随培养时间增长都有不同程度增加。鸡粪的最佳培养时间为5d。鸡粪培养液经21d培养后分离到1株芽孢杆菌属、1株假单胞菌属及2株肠杆菌科,明确了2株肠杆菌科中1株为埃希氏菌属另1株为柠檬酸杆菌属。     

水分和氮素供应对菠菜硝酸盐累积和钾素吸收的影响

研究了水分和氮素供应对露地秋菠菜的硝酸盐累积和钾、氮吸收的影响。结果表明：与传统的水氮管理措施相比，采用水分平衡法和氮素专家系统进行的水氮供应并没有造成作物减产，但对钾、氮元素的吸收却有明显的影响，同氮素吸收相比，作物对钾素的吸收数量更高；并且作物对钾、氮的吸收比例随氮素供应水平的增加而降低，试验还动态监测了菠菜最新展开叶的叶柄汁液中的硝酸盐和K^ 浓度在一天内的变化情况。结果表明，不同水氮处理的菠菜叶柄汁液的硝酸盐浓度在白天均没有发生显著变化；叶柄汁液中的K^ 浓度和NO3^-／K^ 的浓度比在白天受氮素供应水平的影响很大，供氮量高，K^ 浓度和NO3^-／K^ 浓度比的变化也大，但受灌水量影响不大。图3表2参17。     

一种新的好氧反硝化菌筛选方法的建立及新菌株的发现

利用间歇曝气富集,氰化钾(KCN)选择培养基筛选好氧反硝化的细菌,通过形态学特征、生理生化反应及16SrDNA同源性比较对筛得菌株进行鉴定,并对其好氧反硝化相关基因napA进行扩增并测序比较.筛选到一株可以柠檬酸钠为碳源,硝酸钾为氮源,进行好氧反硝化的细菌.在溶解氧(DO)为(9.0±0.5)mg/L的培养基中,该菌株5 d内将硝态氮由282.0 mg L-1降解至149.2 mg L-1,其硝态氮去除率为46.47 ng mg-1min-1,同时亚硝态氮仅有少量的积累.经鉴定,初步判定它为假单胞菌属,命名为Pseudomonas sp.Y2-1-1.从其基因组中扩增出与好氧反硝化相关的周质硝酸盐还原酶(NAR)的亚基napA基因,并与已报道的napA基因进行Blast比较,发现具有较大差别.利用间歇曝气富集,氰化钾(KCN)选择培养基筛选好氧反硝化的细菌是非常有效的.初步认为Pseudomonas sp.Y2-1-1是一株新的好氧反硝化菌.图6表3参12     

Treatment of azo dye Orange II in a sequential anaerobic and aerobic-sequencing batch ractor system

We studied the biodegradation of Orange II in a sequential anaerobic and aerobic-sequencing batch reactor system. Granular activated carbon was used either packed into a column or added directly into the anaerobic reactor to investigate the treatment performance between the two operation conditions. We found that the circulation of mixed liquor between the anaerobic reactor and the carbon-packed column enhanced the chemical oxygen demand from 28 to 52% and Orange II removal efficiencies from 88 to 96%, under simultaneous adsorption and biodegradation process. The morphology of microbes was observed under an electron-scanning microscope.     

The influence of sorption material preparation on the removal of metal ions from the aqueous solution

ABSTRACT

Very important in adsorption processes is the preparation of material sorbents and from this reason, the impact of washing agent of raw sorbent was analysed. The adsorption capacity was studied in relation to the function of the equilibrium time, the amount of biosorbent and the initial metal(II) ions concentration. In this research for the sake of comparison, the sorptive properties of out-of-date coffee were compared to coffee washed with different agents (mineral acids and water). The scanning electron microscopy and Fourier transform infrared spectroscopy were used to characterise the biosorbents and to identify the functional groups that participated in metal(II) ions bonding. The obtained results clearly indicate that the out-of-date coffee are effective biosorbent for cadmium(II) and nickel(II) ions from aqueous solution. However, for metal(II) ions removal efficiency could influence sorbent preparation and nickel(II) ions were best adsorbed on coffee washed with water, but cadmium(II) ions on raw biosorbent (out-of-date coffee). The best results of sorption were achieved after the contact time of 30 and 60?min, respectively for cadmium(II) and nickel(II) ions.