微波消解法快速测定废水中的总磷

采用微波对废水中的总磷进行消解,考察了消解时间、功率等不同实验条件对标样微波消解的影响,得出本实验消解的最佳条件,即过硫酸钾溶液用量为 0.5 mL,压力为10 MPa,消解时间为 2 min：并将该法与总磷测定的常规方法进行了比较,结果表明,过硫酸钾-微波消解法操作简单,效率高,对工作环境污染小.最后对微波消解法的精密度和准确度进行验证,实验结果表明其具有良好的精密度和准确度.     

稻田磷素流失及其环境效应分析

根据稻田磷素流失和环境效应的研究成果,对稻田磷素运移规律和环境效应进行了分析和总结.对磷素在稻田土壤和径流中的迁移方式和规律,稻田磷素流失的机理和影响因素、稻田磷素流失的环境效应以及相应的研究方法和控制措施进行了初步探讨,并结合国内外的实际提出稻田磷素研究领域的研究重点.     

Bioavailability of particle‐associated nutrients as affected by internal regeneration processes in the Nyanza Gulf region of Lake Victoria

Land‐use changes have been implicated a lot in the eutrophication of many lakes while forgetting the role of internal loading as influenced by the hydrological regimes of a given lake. The phosphorus loading of Nyanza Gulf is influenced both by internal and external loading with the internal loading playing a greater role in its eutrophication. The shear on the Apatite Phosphorus (AP) rich residual rock in the western end of the gulf through strong currents across the Rusinga Channel erodes the rock into non‐apatite inorganic phosphorus (NAIP) which is readily available for primary productivity. The current suspends the phosphorus rich apatite sediment together with the reserved phosphorus within sediments to the water column. The NAIP concentration on the western end of the gulf is exceptionally high, >1500 mg kg^?1, and together with the hydrological forcing; is believed to be the driving force of Nyanza Gulf eutrophication. External loading through rivers and municipal discharges exacerbates the problem. The external loading mainly influences the inner gulf on the eastern shore while the internal loading affects mainly the western end of the gulf. Nyanza Gulf eutrophication can be managed by adopting the following measures: (i) the Mbita Causeway needs to be opened and a bridge erected in its place in order to reduce the strong current through the Rusinga Channel and the residence time within the gulf, by increasing the flushing rates; (ii) the farming communities within the basin need to be sensitized on the controlled use of fertilizers; (iii) the municipal wastes should be treated to tertiary level before discharge into the lake; and (iv) reduce erosion within the basin through re/afforestation.     

Evidence for internal phosphorus loading,hypoxia and effects on phytoplankton in partially polymictic Lake Simcoe,Ontario

Hypoxia and cyanobacterial blooms were extensive in Lake Simcoe during the 1980s and are still a problem to a lesser degree despite extensive nutrient load reduction from the catchment basin. The continuing signs of productivity indicate a potential internal phosphorus (P) source. Internal P load, as a redox-dependent release from bottom sediments, is hard to determine in a large, relatively shallow and partially unstratified lake such as Lake Simcoe. Of the lake's three major basins, only Kempenfelt Bay stratifies long enough to develop hypoxia in the stagnant summer hypolimnion. The following indications of sediment P release are available from historic data: 1) hypolimnetic hypoxia still occurs in Kempenfelt Bay although the hypoxic factor (number of days that an area equal to the bay's surface area is overlain by water of ≤ 2 mg/L dissolved oxygen, DO) has decreased substantially and significantly from 15.8 d/yr (1980–1994) to 4.0 d/yr (1995–2011); 2) hypoxic factors for other lake sections and at different DO levels also indicate widespread hypoxia; 3) concentrations of redox dependent metals, Fe and Mn, increase with depth; and 4) euphotic zone P and chlorophyll concentrations increase and water clarity decreases during fall turnover. Cyanobacterial blooms appear to occur in response to internal load as supported by occasional cyanobacteria counts. These indicators provide evidence that internal loading is likely occurring and affecting the water quality in Lake Simcoe. We expect that further monitoring, specific for internal load, will corroborate these results.     

紫色土丘陵区典型生态-水文单元径流与氮磷输移特征

通过对紫色土丘陵区典型农业-集镇-林地复合型小流域3次降雨-径流全过程的连续监测,测定了径流过程中泥沙含量和不同形态氮磷浓度,以期认识典型农村生态-水文单元降雨径流过程中氮磷迁移规律。结果表明：降雨-径流过程中悬浮泥沙的流失主要集中在径流前期,其峰值出现在雨强最大时;集镇径流污染的影响主要表现在径流前期,是径流前期铵态氮偏高的主因;降雨-径流过程中,颗粒态氮与可溶态氮比（PN/DN）、颗粒态磷与可溶态磷比（PP/DP）的峰值均出现在雨强较大时：其中 PN/DN 多小于1,而 PP/DP 范围为1.1~30.2,说明氮素流失主要通过可溶态的方式,而磷的迁移以颗粒态磷为主。因此在紫色丘陵区建议利用湿地植物与沉砂池等综合措施控制土壤侵蚀和非点源污染以保护当地生态环境安全。     

附着生物膜的泥沙颗粒对磷的吸附特性研究

附着在泥沙表面的生物膜具有很强的吸附特性,对水环境中营养盐等物质的迁移转化具有重要的作用.本文对去除生物膜的泥沙和表面附着生物膜的泥沙分别进行了吸附营养盐磷的实验研究,对比了去除生物膜与附着生物膜的泥沙颗粒对磷的吸附能力,研究了附着生物膜的泥沙颗粒吸附磷的动力学及热力学特征.研究结果表明,去除生物膜的泥沙对磷的吸附性微小,而附着生物膜的泥沙颗粒对磷的吸附能力很强,在相同条件下附着生物膜的泥沙颗粒的吸附量比纯净泥沙吸附量高出1个数量级;同时附着生物膜的泥沙颗粒吸附磷的动力学特性符合准二级动力学模型,等温吸附特性符合Langmuir等温式,吸附速率和平衡吸附量随泥沙粒径减小而增大.     

Nitrogen and phosphorus changes and optimal drainage time of flooded paddy field based on environmental factors

While many controlled irrigation and drainage techniques have been adopted in China, the environmental effects of these techniques require further investigation. This study was conducted to examine the changes of nitrogen and phosphorus of a flooded paddy water system after fertilizer application and at each growth stage so as to obtain the optimal drainage time at each growth stage. Four treatments with different water level management methods at each growth stage were conducted under the condition of ten-day continuous flooding. Results show that the ammonia nitrogen (NH⁺₄-N ) concentration reached the peak value once the fertilizer was applied, and then decreased to a relatively low level seven to ten days later, and that the nitrate nitrogen (NO^-₃-N) concentration gradually rose to its peak value, which appeared later in subsurface water than in surface water. Continuous flooding could effectively reduce the concentrations of NH⁺₄-N, NO^-₃-N , and total phosphorus (TP) in surface water. However, the paddy water disturbance, in the process of soil surface adsorption and nitrification, caused NH⁺₄-N to be released and increased the concentrations of NH⁺₄-N and NO^-₃-N in surface water. A multi-objective controlled drainage model based on environmental factors was established in order to obtain the optimal drainage time at each growth stage and better guide the drainage practices of farmers. The optimal times for surface drainage are the fourth, sixth, fifth, and sixth days after flooding at the tillering, jointing-booting, heading-flowering, and milking stages, respectively.     

A/O工艺实现城市污水半亚硝化与生物除磷

城市污水半亚硝化是实现其厌氧氨氧化的基础和关键步骤,但相关研究甚少,为此,利用A/O反应器处理实际城市污水,研究实现半亚硝化的可行性及其对生物除磷的影响.结果表明:A/O反应器可实现稳定的亚硝酸盐积累,积累率约为85%;通过调整水力停留时间可控制A/O反应器出水NO2--N/NH4+-N在1.0左右,满足厌氧氨氧化对进水水质的要求;温度和溶解氧质量浓度的波动会导致亚硝酸盐积累的破坏.实现半亚硝化的稳定后,A/O反应器除磷稳定性变差,可能与出水游离亚硝酸质量浓度(FNA)增加有关.     

不同AMF菌剂对白三叶草坪的扶壮作用

为探讨不同丛枝菌根真菌(Arbuscular Mycorrhizal Fungi,AMF)在白三叶草坪扶壮中的作用,选用摩西球囊霉、根内球囊霉两种广适菌种,分别研究单菌、混菌对白三叶草的促进作用．结果表明:单独施加摩西球囊霉对植物的侵染率最高,达53.84％;白三叶草对混菌的依赖性最强,并且植物地上器官依赖性高于地下;AMF可明显提高白三叶草坪的扶壮率,混菌效果优于单菌,株高、地上及地下生物量的扶壮率可分别增加40.7％、76.6％、35.7％;AMF可有效增强白三叶草对根际土壤中营养物质的吸收能力,水解性氮、有效磷利用率提高51.6％、48％．水解性氮是影响AMF促进白三叶生长的主要限制因子,施加菌剂时,无需补充磷肥,但可补充少量氮肥．     

磷矿反浮选捕收剂的评价方法

磷矿反浮选捕收剂大多数是由天然脂肪酸制成的,种类繁多,性能各异.从市场快速、准确地选择磷矿反浮选捕收剂,对浮选实践和浮选研究十分重要.浮选捕收剂的评价有助于掌握捕收剂的浮选性能,了解其在浮选过程中的作用.浮选法是浮选捕收剂的传统评价方法,程序复杂,耗时耗力.提出了一种新的浮选研究方法:燃烧-吸附量评价法,通过燃烧无机的矿石样品来测定其表面吸附的有机捕收剂量,评价磷矿反浮选捕收剂的性能.通过对油酸、硬脂酸和软脂酸这些结构明确且浮选工作者熟悉的脂肪酸的浮选性能和在白云石上的吸附量,建立了一个评价模型,验证燃烧-吸附量评价法的可行性.