Park J H, Ok Y S, Kim S H, Cho J S, Heo J S, Delaune R D, Seo D C
Divison of Applied Life Science (BK21 Program), Institute of Agriculture and Life Science, Gyeongsang National University, Jinju, 660-701, Republic of Korea.
Korea Biochar Research Center, Department of Biological Environment, Kangwon National University, Chuncheon, 200-701, Republic of Korea.
Environ Geochem Health. 2015 Dec;37(6):969-83. doi: 10.1007/s10653-015-9709-9. Epub 2015 Jun 4.
The phosphorus (P) adsorption characteristic of sesame straw biochar prepared with different activation agents and pyrolysis temperatures was evaluated. Between 0.109 and 0.300 mg L(-1) in the form of inorganic phosphate was released from raw sesame straw biochar in the first 1 h. The release of phosphate was significantly enhanced from 62.6 to 168.2 mg g(-1) as the pyrolysis temperature increased. Therefore, sesame straw biochar cannot be used as an adsorbent for P removal without change in the physicochemical characteristics. To increase the P adsorption of biochar in aqueous solution, various activation agents and pyrolysis temperatures were applied. The amount of P adsorbed from aqueous solution by biochar activated using different activation agents appeared in the order ZnCl2 (9.675 mg g(-1)) > MgO (8.669 mg g(-1)) ⋙ 0.1N-HCl > 0.1N-H2SO4 > K2SO4 ≥ KOH ≥ 0.1N-H3PO4, showing ZnCl2 to be the optimum activation agent. Higher P was adsorbed by the biochar activated using ZnCl2 under different pyrolysis temperatures in the order 600 °C > 500 °C > 400 °C > 300 °C. Finally, the amount of adsorbed P by activated biochar at different ratios of biochar to ZnCl2 appeared in the order 1:3 ≒ 1:1 > 3:1. As a result, the optimum ratio of biochar to ZnCl2 and pyrolysis temperature were found to be 1:1 and 600 °C for P adsorption, respectively. The maximum P adsorption capacity by activated biochar using ZnCl2 (15,460 mg kg(-1)) was higher than that of typical biochar, as determined by the Langmuir adsorption isotherm. Therefore, the ZnCl2 activation of sesame straw biochar was suitable for the preparation of activated biochar for P adsorption.
评估了用不同活化剂和热解温度制备的芝麻秸秆生物炭对磷（P）的吸附特性。在最初1小时内，未处理的芝麻秸秆生物炭以无机磷酸盐形式释放出0.109至0.300mg L(-1)的磷。随着热解温度升高，磷的释放量从62.6mg g(-1)显著增加至168.2mg g(-1)。因此，未经物理化学特性改变的芝麻秸秆生物炭不能用作去除磷的吸附剂。为了提高生物炭在水溶液中的磷吸附量，采用了各种活化剂和热解温度。用不同活化剂活化的生物炭从水溶液中吸附的磷量顺序为：ZnCl2（9.675mg g(-1)）>MgO（8.669mg g(-1)）>>0.1N - HCl>0.1N - H2SO4>K2SO4≥KOH≥0.1N - H3PO4，表明ZnCl2是最佳活化剂。在不同热解温度下，用ZnCl2活化的生物炭吸附的磷量顺序为600℃>500℃>400℃>300℃。最后，不同生物炭与ZnCl2比例下活化生物炭吸附的磷量顺序为1:3≈1:1>3:1。结果发现，对于磷吸附，生物炭与ZnCl2的最佳比例和热解温度分别为1:1和600℃。根据朗缪尔吸附等温线测定，用ZnCl2活化的生物炭的最大磷吸附容量（15460mg kg(-1)）高于典型生物炭。因此，ZnCl2活化芝麻秸秆生物炭适合制备用于磷吸附的活化生物炭。
