| 顾鑫锋,潘慧,张连毅,丁竹红.镧改性生物炭在砂柱中单独运移及与Cr （Ⅵ）共运移[J].农业环境科学学报,2023,42(2):352-361. |
| 镧改性生物炭在砂柱中单独运移及与Cr （Ⅵ）共运移 |
| Transport of single La-modified biochar in a sand column and its co-transport with Cr(Ⅵ) |
| 投稿时间：2022-06-08 |
| DOI：10.11654/jaes.2022-0579 |
| 中文关键词: 镧改性生物炭 Cr (Ⅵ) 石英砂介质 共迁移 滞留 土壤 地下水 |
| 英文关键词: La-modified biochar Cr (Ⅵ) quartz sand media co-transport retention soil groundwater |
| 基金项目:国家重点研发计划项目（2018YFC1800600）；国家自然科学基金项目（21677075） |
|
| 摘要点击次数: 885 |
| 全文下载次数: 663 |
| 中文摘要: |
| 为探究稀土金属改性生物炭在土壤-地下水中的运移行为，本研究选择常见稀土元素镧制备改性生物炭，并经球磨后制成镧改性生物炭细颗粒（La-BC），采用柱实验分别从流速、pH、离子强度和腐植酸浓度4个方面来研究La-BC单独运移和与Cr（Ⅵ）共运移时其在饱和均质石英砂介质中的运移和滞留规律。研究表明：流速从1.0 mL·min-1增至1.5 mL·min-1时，单独运移实验出流液中La-BC的质量回收率由58.0%增至73.4%，共运移实验出流液中La-BC的质量回收率为78.7%~80.1%。pH从5升至7时，La-BC单独运移及共运移时的穿透曲线的相对浓度（Ct/C0）峰值分别从0.66增至0.93和从0.80增至0.85。离子强度增至5 mmol·L-1时，La-BC单独运移时的Ct/C0峰值降低至0.05，与Cr（Ⅵ）共运移时La-BC的穿透峰值为0.81~0.75。腐植酸浓度由0增至10 mg·L-1时，La-BC单独运移及与Cr（Ⅵ）共运移时出水中La-BC质量回收率分别减少了约13个和3个百分点。相较于La-BC单独运移，共运移中Cr（Ⅵ）的存在除了在中性实验条件下抑制La-BC运移能力外，其余实验条件下皆促进了La-BC在饱和介质中的运移。因此，较低的流速、较低的pH环境、一定的离子强度及腐植酸浓度有助于改性生物炭的滞留稳定。 |
| 英文摘要: |
| In order to investigate the transport of rare earth metal-modified biochar in soil-groundwater, lanthanum, a common rare earth element, was used to prepare modified biochar in this study. The lanthanum-modified biochar was then ball-milled to obtain fine biochar particles(La-BC). The transport and retention of La-BC alone(single-transport), and together with Cr(Ⅵ) (co-transport), in a saturated quartz sand column were studied at different conditions of flow rate, pH, ionic strength, and humic acid concentration. The results showed that the mass recovery of La-BC in the effluent increased from 58.0% to 73.4% in single-transport and ranged from 78.7% to 80.1% in cotransport when flow rate was increased from 1.0 mL · min-1 to 1.5 mL · min-1. The peak relative concentration(Ct/C0) values of La-BC breakthrough curves in single-transport and co-transport increased from 0.66 to 0.93 and from 0.80 to 0.85 when pH increased from 5 to 7. The peak Ct/C0 values of La-BC breakthrough curves were reduced to 0.05 in single-transport when ionic strength increased to 5 mmol·L-1, and to 0.81-0.75 in co-transport. The mass recovery in the effluent was reduced by about 13 percentage points and about 3 percentage points in single-transport and co-transport when humic acid concentration increased from 0 to 10 mg·L-1. Compared with single-transport, the existence of Cr(Ⅵ) in co-transport inhibited transport of La-BC under neutral conditions in a saturated medium and promoted its transport under other experimental conditions. Therefore, appropriately low flow rate, low pH, a certain ionic strength, and humic acid concentration contribute to the retention and stabilization of the modified biochar. |
| HTML
查看全文
查看/发表评论 下载PDF阅读器 |
