Rice husk treated by sodium hydroxide had a potential to be an inexpensive adsorbent for recovery of nickel from electroplating industry. NaOH-treated rice husk could be used in many forms of grain such as no ground (RHG-T), powder < 75 μm (RH75-T) and heated at 500°C (RH500-T). The maximum adsorption capacity of RHG-T, RH75-T and RH500-T were 4.27, 5.29 and 3.88 mg g{sup}(-1), respectively. Nickel adsorbed onto NaOH-treated rice husk was also completely eluted by 0.025 M H{sub}2SO{sub}4. In addition, the ratio of Ni and Na interchange and elution test indicated that the mechanism of nickel adsorption by NaOH-treated rice husk was ion exchange process. The average ratios of Ni:Na for nickel adsorption by RH75-T, RHG-T and RH500-T were 1:1.5, 1:2 and 1:1, respectively. The fractional groups of -CH{sub}2OH, silanol (-Si-O-H) and siloxane (Si-O-Si) were transformed by NaOH treatment to -CH{sub}2O-{sup left}Na{sup}+, -Si-{sup left}Na{sup}+ and [Si-O-Si]{sup}-Na{sup}+. SEM/EDX, FTIR spectrum and the nickel adsorption by NaOH-treated avaicel (AV-T) and NaOH-treated silicic acid (SA-T) indicated that RH75-T could use both -CH{sub}2O-{sup left}Na{sup}+ and -SiO-{sup left}Na{sup}+ to adsorb nickel, while RHG-T and RH500-T trended to occur by -CH{sub}2O-{sup left}Na{sup}+ and -Si-O-{sup left}Na{sup}+, respectively.
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机译：由氢氧化钠处理的稻壳具有廉价的吸附剂，用于从电镀工业中回收镍。 NaoH处理的稻壳可以以多种形式的晶粒使用，例如无接地（RHG-T），粉末<75μm（rH75-T）并在500℃（RH500-T）下加热。 RHG-T，RH75-T和RH500-T的最大吸附容量分别为4.27,5.29和3.88mg {sup}（ - 1）。吸附在NaOH处理的稻壳上的镍也完全洗过0.025 m H} 2SO {Sub} 4。此外，Ni和Na互换和洗脱试验的比例表明NaOH处理稻壳镍吸附的机理是离子交换过程。 Ni：Na的平均比率镍氢化镍和RH500-T的镍吸附，分别为1：1.5,1：2和1：1。通过NaOH处理转化-CH {sub} 2OH，硅烷醇（-Si-OH）和硅氧烷（Si-O-Si）的分数组TOCH {sub} {sup left} na {sup} +， -si- {sup left} na {sup} +和[si-o-si] {sup} -na {sup} +。 SEM / EDX，FTIR光谱和NaOH处理的AvaIcel（AV-T）和NaOH处理的硅酸（SA-T）的吸附表明，RH75-T可以使用-ch {sub} 2o-{sup离开} na {sup} +和-sio- {sup left} na {sup} +到adsorb镍，而rhg-t和rh500-t趋势将由-ch {sub} 2o-{sup left} na {sup} +发生和-si-o-{sup left} na {sup} +。
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