Graduate Institute of Environmental Engineering, National Taiwan University, 71 Chou-Shan Rd., Taipei 106, Taiwan.
Bioresour Technol. 2011 Sep;102(17):7802-6. doi: 10.1016/j.biortech.2011.06.036. Epub 2011 Jun 15.
Boron is an essential nutrient for animals and plants, but it can be harmful in excessive levels. In this study, three types of crushed shells (oyster, hard clam and freshwater clam) were pretreated and then reused as mineralizers to remove and recover the boron from concentrated wastewater by using the microwave hydrothermal method. Chemical and physical properties of raw and pretreated crushed shells were determined and compared using SEM, XRD, BET and WD-XRF. Effects of pretreatment method (heated or pyrolysis), particle sizes, initial boron concentrations, reaction times and shells dosages on boron recovery were investigated. The oyster shells pretreated by heat performed better than heated hard clam and freshwater clam shells, and the boron recovery efficiency reached around 95% within 10 min of reaction time. The experimental results indicate that the pretreated oyster shell is an effective mineralizer for removal and recovery of boron from concentrated wastewater.
硼是动植物必需的营养元素,但在高浓度下可能有害。在这项研究中,三种粉碎贝壳(牡蛎、硬壳蛤和淡水蛤)经过预处理后,再通过微波水热法,被重新用作矿化剂,从浓缩废水中去除和回收硼。使用 SEM、XRD、BET 和 WD-XRF 对原始和预处理粉碎贝壳的化学和物理性质进行了测定和比较。考察了预处理方法(加热或热解)、颗粒大小、初始硼浓度、反应时间和贝壳用量对硼回收的影响。经过加热预处理的牡蛎壳比经过加热预处理的硬壳蛤和淡水蛤壳表现更好,在 10 分钟的反应时间内,硼的回收率达到了 95%左右。实验结果表明,预处理过的牡蛎壳是一种从浓缩废水中去除和回收硼的有效矿化剂。