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81.
2种改良土壤渗滤系统对降雨径流中氮的去除 总被引:1,自引:0,他引:1
为研究改良土壤渗滤系统对降雨径流中不同形态氮(NH+4-N,NO-3-N,NO-2-N,TN)的去除效果及径流中氮负荷对氮去除率的影响,实验分别以聚氨酯泡沫和人工草皮为改良材料,以降雨径流中的氮为处理对象进行室内模拟研究。结果表明,聚氨酯泡沫土壤渗滤系统及草皮土壤渗滤系统对TN,NH+4-N均具有较好的净化效果,并表现出良好的耐冲击负荷能力。TN平均去除率分别为72.65%和71.07%,NH+4-N平均去除率分别为98.10%和99.09%。2种渗滤系统对NO-3-N去除效果均较差,表现为-420.07%和-171.66%的负去除率。聚氨酯泡沫土壤渗滤系统对NO-2-N的平均去除率为87.29%,高于草皮土壤渗滤系统53.77%的平均去除率。总体上,聚氨酯泡沫土壤渗滤系统对径流中氮的去除效果优于草皮土壤渗滤系统,具有较好的应用前景。 相似文献
82.
Ming Dou Qiting Zuo Jinping Zhang Congying Li Guiqiu Li 《Environmental monitoring and assessment》2013,185(9):7501-7516
With rapid economic development, the Pearl River Delta (PRD) of China has experienced a series of serious heavy metal pollution events. Considering complex hydrodynamic and pollutants transport process, one-dimensional hydrodynamic model and heavy metal transport model were developed for tidal river network of the PRD. Then, several pollution emergency scenarios were designed by combining with the upper inflow, water quality and the lower tide level boundary conditions. Using this set of models, the temporal and spatial change process of cadmium (Cd) concentration was simulated. The influence of change in hydrodynamic conditions on Cd transport in tidal river network was assessed, and its transport laws were summarized. The result showed the following: Flow changes in the tidal river network were influenced remarkably by tidal backwater action, which further influenced the transport process of heavy metals; Cd concentrations in most sections while encountering high tide were far greater than those while encountering middle or low tides; and increased inflows from upper reaches could intensify water pollution in the West River (while encountering high tide) or the North River (while encountering middle or low tides). 相似文献
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85.
Bio-SR工艺去除硫化氢气体的研究 总被引:1,自引:1,他引:0
采用Bio-SR工艺,利用铁盐吸收与氧化亚铁硫杆菌的联合作用对H2S进行脱除实验。通过改进微生物的培养条件,减少了83.9%的沉淀量,一定程度上解决了挂膜后生物填料塔易堵塞的问题,保证了填料塔的连续运行。在实验选取工况下,硫化氢脱除率可达到98.4%以上,当吸收液中Fe3+浓度为5.5~6 g/L、H2S进气浓度为1 g/m3、通气量为0.08~0.12 m3/h时效果最佳,反应器可持续高效地运行。此外,对进气浓度、通气量与硫化氢去除率之间的相关性进行了进一步研究,其结果有利于反应器及运行参数的优化设计。 相似文献
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A trimetal oxide was developed as a fluoride adsorbent by coprecipitation of Fe(II), Al(III) and Ce(IV) salt solutions with a molar ratio of 1:4:1 under alkaline condition. The material retained amorphous structure and maintained relatively stable fluoride adsorption performance at calcination temperatures lower than 600 degrees C. The optimum pH range for fluoride adsorption was 6.0-6.5 and the adsorbent also showed high defluoridation ability around pH 5.5-7.0, which is preferable for actual application. A high fluoride adsorption capacity of 178 mg g(-1) was acquired under an equilibrium fluoride concentration of 84.5 mg l(-1), adsorbent dose of 150 mg l(-1) and pH 7.0. The adsorption isotherm could be better described by the two-site Langmuir model than the one-site model, suggesting the existence of two types of active sites on the adsorbent surface. Coexistence of high concentrations of phosphate or arsenate only led to partial inhibition of fluoride adsorption, which further suggests the existence of heterogeneous adsorption sites. Sulfate and chloride did not affect fluoride adsorption, and nitrate influenced it only when the concentration of NO(3)(-)-N exceeded 50 mg l(-1). A high desorption efficiency of 97% was achieved by treating fluoride loaded Fe-Al-Ce oxide with NaOH solution at pH 12.2. A column experiment using the adsorbent fabricated into 1mm pellets was performed at an initial fluoride concentration of 5.5 mg l(-1), space velocity of 5h(-1) and pH of 5.8, and 2240 bed volumes were treated with the effluent fluoride under 1.0 mg l(-1). 相似文献
88.
A trace analytical method of benzene, toluene, ethylbenzene and xylenes (BTEX) in water has been developed by using headspace solid-phase microextraction (HS-SPME) coupled to cryo-trap gas chromatography-mass spectrometry (GC-MS). The chromatographic peak shape for BTEX was improved by using cryo-trap equipment. The HS-SPME experimental procedures to extract BTEX from water were optimized with a 75 microm carboxen/polydimethylsiloxane (CAR/PDMS)-coated fiber at a sodium chloride concentration of 267 g l(-1), extraction for 15 min at 25 degrees C and desorption at 290 degrees C for 2 min. Good linearity was verified in a range of 0.0001-50 microg l(-1) for each analyte (r(2)=0.996-0.999). The limits of detection (LODs) of BTEX in water reached at sub-ng l(-1) levels. LODs of benzene, toluene, ethylbenzene, m/p-xylene and o-xylene were 0.04, 0.02, 0.05, 0.01 and 0.02 ng l(-1), respectively. The proposed analytical method was successfully used for the quantification of trace BTEX in ground water. The results indicate that HS-SPME coupled to cryo-trap GC-MS is an effective tool for analysis of BTEX in water samples at the sub-ng l(-1) level. 相似文献
89.
通过分析现阶段我国建筑行业农民工的常见职业性伤害事故以及职业安全健康现状,从教育、技术、监管3个方面提出了引导农民工学会利用法律、通过合法渠道维护自身权益;改善农民工的就业环境,加强个体防护,讲究文明礼貌,遵守职业行为准则,培养科学、文明、健康的生活方式等具体措施,为农村富余劳动力转移提供更多的就业机会,增加农民收入促进城乡经济协调发展,保障建筑行业农民工的职业安全健康提供科学依据。 相似文献
90.
阐述了碱性工业废水脱硫的机理以及p H值、液气比、进气SO2浓度等对脱硫效率的影响。利用碱性工业废水对燃煤锅炉烟气脱硫,其脱硫效率平均可达70%~80%。 相似文献