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231.
向成功启动并稳定运行630 d后的UASB生物膜反应器系统连续添加有机物,分析其对厌氧氨氧化反应脱氮效果的影响,并进行氮素浓度负荷试验.在厌氧氨氧化反应器系统中连续投加有机COD(葡萄糖),系统运行稳定,有机COD(葡萄糖)存在对系统去除氮素能力影响不大,有机COD去除率达到92.0%,仅用23 d,在同一反应器系统中成功实现了厌氧氨氧化与反硝化协同作用脱氮.氮素浓度负荷试验阶段,进水氨氮(NH 4-N)、亚硝氮(NO-2-N)以及总氮(TN)浓度负荷分别从0.063 kg/(m3·d)和0.063 kg/(m3·d)和0.126 kg/(m3·d)提升到了0.239 kg/(m3·d)、0.315 kg/(m3·d)和0.554 kg/(m3·d),相应去除率分别为84.0%、93.0%和85.0%,厌氧氨氧化工艺的UASB生物膜反应器对氮素浓度负荷仍有很大提升空间. 相似文献
232.
以盐泥为原料,采用氯化铵浸取回收盐泥中的Mg2+,以浸取液和回收的氨反应制取氢氧化镁产品。考察了盐泥浆液固含量、浸取时间、物料比(氯化铵与盐泥中氢氧化镁的摩尔比)等工艺条件对Mg2+浸取率的影响,并以比表面积为考察指标进行正交实验,确定氢氧化镁的最佳制备条件。实验结果表明:在盐泥浆液固含量为248 g/L、浸取时间为100 min、物料比为2.3的条件下,Mg2+浸取率为75.0%;在n(MgCl2):n(NH4Cl)=0.5、氨水浓度3 mol/L、氨水滴加速率 0.8 mL/min、反应温度 90 ℃的最佳条件下,制备的氢氧化镁的比表面积为17.87 m2/g,粒径约为3 μm。该工艺简单可行,为盐泥的综合利用提供了新的思路。 相似文献
233.
A benthic in situ flume and a 1D biogeochemical sediment model to evaluate solute fluxes across the sediment–water interface have been developed.
The flume was successfully used to determine oxygen and nutrient fluxes at various locations of the Neckar River in Germany.
The experimental results were linked with vertical pore water concentration profiles and independently verified with the model.
By combining experimental and model results we assessed the influence of dissolved oxygen concentrations in the water column
and the availability of degradable organic matter on sediment oxygen demand. The results and the derived relations can be
used to parameterize the sediment module of large scale water quality models, allowing one to assess the influence of sediment–water
interactions on various aspects of river water quality. Moreover, the biogeochemical sediment model can help to improve the
general understanding of the processes governing solute concentrations and fluxes in sediments and across their interfaces. 相似文献
234.
Nitrate, ammonium and dissolved organic nitrogen (DON) concentrations were measured in the lower reaches of the River Test in Hampshire to assess the impact of two effluent point sources. An 18-month survey from July 2001 to December 2002 was carried out at locations above and below fish farm inputs and a sewage effluent outfall. The concentration of nitrate exceeded 400 M at the four sites on all sample dates. A consistent increase in ammonium concentration was measured downstream of the fish farm, but not the sewage effluent input. DON samples collected downstream of the fish farm did not show a consistent increase in concentration, compared with the upstream sampling location, whereas the sewage effluent input at Romsey was a point source of DON to the River Test with a mean increase of 15 M. Nitrate was the major component of dissolved nitrogen in this aquifer-fed chalk-bed river system, with up to 10% being DON and ammonium comprising <1%. 相似文献
235.
M. Weller P. Plessing H. Rentsch J. Lattauschke W. von Hoyningen-Huene 《Atmospheric environment (Oxford, England : 1994)》2000,34(29-30)
With the development of satellite experiments supplementary and validating ground-based measurements are gaining growing importance for the inference and evaluation of radiation-related aerosol parameters. Both kinds of measurements have been conducted and interpreted mainly under globally or locally restricted aspects for a limited time period only. Results are presented from four rural regions (coastal zone, lowlands, highlands, high mountain); they are column-related aerosol parameters, deduced from monitoring programs of spectral aerosol optical depth (AOD) as well as almucantar sky irradiance measurements. After 13 years of continuous measurements of trends and variations in aerosol optical depths, these results are based on 5 years of data collection (1994–1998). There are significant differences among the parameters of the four regions when related to the inversion method of the AOD spectra. A clear interdependence was found between all column-related parameters and the real part of the refractive index, which in turn depends on the chosen retrieval method. The differences among the four regions are characterized mainly by their different altitudes, with relative humidity being responsible for their internal variation. An increase in the relative humidity from 35 to 55–60% influences the most interesting parameters such as refractive index (real part), hemispheric backscattered fraction b, and direct radiative forcing ΔF as follows: The real part of the refractive index decreases from 1.6±0.05 to 1.42±0.04, b decreases by 8–10%, and, due to the increase in AOD, ΔF increases by about 20% in the spectral region 0.4–1.0 μm. The quantities of the parameters depend on the retrieval methods too. 相似文献
236.
王建 《中国环境管理干部学院学报》2001,(Z1)
近年来氨氮污染对宁夏水环境质量的影响日趋严重,本文通过大量的监测数据,分析了水环境中氨氮污染现状及其变化趋势,研究了氨氮污染物的来源和分布,并在此基础上提出了控制氨氮污染的对策。 相似文献
237.
238.
磷酸铵镁法处理焦化厂高浓度氨氮废水 总被引:4,自引:0,他引:4
介绍了酸铵镁(magnesiumammoniumphosphate,MAP)法处理高浓度氨氮废水的技术,研究了药剂配比、反应pH值以及药剂选择等因素对氨氮去除率的影响。试验结果表明,当在剩余氨水中投加MgCl2·6H2O和Na2HPO4·12H2O药剂,Mg2+∶NH+4∶PO3-4的摩尔比为1.4∶1∶0.9,反应pH值为8.5~9.5的条件下,原水的氨氮浓度可由2000mg/L降到15mg/L。并通过对反应沉淀物的结构成分分析,探讨了MAP作为有效缓释肥开发利用的可行性。 相似文献
239.
240.
WAHMO model was used to simulate the distribution of pollutants in Dalian Bay, China as to predict well as the growth and control of alga. The observed and predicted values of main pollutants showed a good trend at all study locations and the different between them can be ignored. Simulation results illustrated that phosphate was one of limited factors to control algal growth at the location near the sewage outfall, meanwhile, away from the sewage outfall, the synergy of ammonium nitrogen and phosphate was the limited factor. 相似文献