水蒸气蒸馏-离子选择电极法测定矿冶废水中氟化物

建立了采用水蒸气蒸馏进行预处理,用离子选择电极法测定矿冶废水中的氟化物的方法.实验表明,以硫酸为蒸馏试剂,最佳蒸馏条件为,硫酸用量50 mL,蒸馏温度140 ～150℃,蒸馏时间30 min,方法检出限0.05 mg/L.将该方法用于实际样品分析,测定结果的相对标准偏差为2.0％,加标回收率为93.1％.该方法能够有效...     

电极法测定降水中的氟化物

电极法测定降水中的氟具有选择性好、灵敏度高、线性范围宽，降水中的浑浊和色度不影响测定的特点，测定范围为0.05-1900mg/L，应用文中所拟测定降水中氟化物，结果令人满意。     

固氟剂应用于砖瓦厂氟治理的初步研究

首次将固氟剂应用于砖瓦厂的氟治理试验，结果表明，在所选用的４种固氟剂中，以白泥的固氟效果最佳，经过烧制，对以红壤和青紫泥为材料制成的红砖的固氟率，在实验室模拟条件试验中分别为３８．０７％和５２．９０％，在砖瓦厂生产条件试验分别为４８．０３％和５１．３５％，白泥作为一种工业废物，应用于砖瓦厂氟治理，特别是无组织排放的控制，不仅颇具良好前景，而且为白泥的处置利用提供一条“以废治废”的新途径。     

活化赤泥除氟剂的制备及除氟性能试验研究

分别采用(NH4)2HPO4,NH4HCO3,NaHCO3等对赤泥进行活化处理,并制备成球形颗粒,同时研究了活化剂浓度、焙烧温度、焙烧时间等对赤泥除氟剂吸附性能的影响。结果表明：在活化剂质量浓度为10%左右、焙烧温度500℃,焙烧时间2 h时制备的除氟剂具有较好的除氟效果,且采用(NH4)2HPO4,NH4HCO3,NaHCO3对赤泥进行活化处理制备的除氟剂能分别使溶液中氟离子的质量浓度从19 mg/L分别降低到0.085,0.13及0.19 mg/L,相应地除氟剂的吸附容量均达0.94 mg/g以上。     

Review of fluoride removal from drinking water

Fluoride in drinking water has a profound effect on teeth and bones. Up to a small level (1–1.5 mg/L) this strengthens the enamel. Concentrations in the range of 1.5–4 mg/L result in dental fluorosis whereas with prolonged exposure at still higher fluoride concentrations (4–10 mg/L) dental fluorosis progresses to skeletal fluorosis. High fluoride concentrations in groundwater, up to more than 30 mg/L, occur widely, in many parts of the world. This review article is aimed at providing precise information on efforts made by various researchers in the field of fluoride removal for drinking water. The fluoride removal has been broadly divided in two sections dealing with membrane and adsorption techniques. Under the membrane techniques reverse osmosis, nanofiltration, dialysis and electro-dialysis have been discussed. Adsorption, which is a conventional technique, deals with adsorbents such as: alumina/aluminium based materials, clays and soils, calcium based minerals, synthetic compounds and carbon based materials. Studies on fluoride removal from aqueous solutions using various reversed zeolites, modified zeolites and ion exchange resins based on cross-linked polystyrene are reviewed. During the last few years, layered double oxides have been of interest as adsorbents for fluoride removal. Such recent developments have been briefly discussed.     

土壤中氟化物的测定因素探讨

用离子选择电极法测定土壤中氟主要的影响因素为样品的制备、消解及测定3方面内容。作者通过试验得出,在样品的消解过程使用细粒的氢氧化钠可以使分析结果比粗粒氢氧化钠更准确,并减少分析误差。     

硝酸镧改性聚丙烯酸对水中氟离子的吸附试验探讨

以丙烯酸为原料,乙二醇二甲基丙烯酸酯为交联剂制得聚丙烯酸树脂(PAA),用于制备表面粗糙、介孔丰富的镧(Ⅲ)改性聚丙烯酸复合树脂(La-PAA)。试验表明,当500 mg/L氟离子溶液pH值为5、吸附时间为300 min时,La-PAA对氟离子的去除率在90%以上。Langmuir方程能较好地拟合氟离子在La-PAA上的吸附等温线,最大吸附量为159.24 mg/g,吸附动力学过程符合准二级动力学方程。