School of Environmental Science and Engineering, Shanghai Jiao Tong University, Shanghai 200240, China.
School of Environmental Science and Engineering, Shanghai Jiao Tong University, Shanghai 200240, China; Shanghai Institute of Pollution Control and Ecological Security, Shanghai 200092, China.
Sci Total Environ. 2020 Sep 1;733:139244. doi: 10.1016/j.scitotenv.2020.139244. Epub 2020 May 8.
Surface runoff is one of the major pollution sources impacting the quality of the surrounding waterbody. In this study, a highly-bioreactive top-layer soil incorporated with microorganism (BO) and peanut shell (PS) biochar or dairy manure (DM) biochar was proposed for removal of 2,4-dichlorophenol (2,4-DCP) from contaminated surface runoff. Both batch test and sandbox experiment consistently revealed that PS coupled with BO amendment (PS + BO) was most effective for sorption and degradation of 2,4-DCP, compared to BO and DM alone or in combination. About 77% of 6000 μg∙L 2,4-DCP was absorbed within 36 h in the original low permeability bioreactive PS + BO soil layer (15 cm long×15 cm wide×4.5 cm deep) with the 0.33 L∙day processing capacity of surface runoff. Increasing the addition of quartz sand into the bioreactor soil layer by threefold the original bioreactor improved the processing capacity to 17.5 L∙day. However, this permeability-optimized bioreactive layer was still not large enough to remove 2,4-DCP completely. The optimized scale by the multi-process coupling model of the convection, dispersion, adsorption, and degradation was 60 cm long × 60 cm wide × 18 cm deep where the processing capacity of 280 L·dayreached and 97.3% of 2,4-DCP was removed, correspondingly the 2,4-DCP concentration could meet the standard limit. In addition, the obtained model parameters showed that the biochar or microorganism significantly decreased the dispersion coefficient D of 2,4-DCP in the bioreactive layer. The 2,4-DCP distribution coefficient K, and first-order reaction rate λ in the PS+BO system significantly greater than that in the control, BO, and PS systems. Results from this study indicated that the top-layer soil incorporated with microorganisms and biochar is a feasible and effective approach for the surface runoff treatment.
地表径流是影响周围水体水质的主要污染源之一。在这项研究中，提出了一种高度生物活性的顶层土壤，其中掺入了微生物（BO）和花生壳（PS）生物炭或奶牛粪便（DM）生物炭，用于去除受污染地表径流中的 2,4-二氯苯酚（2,4-DCP）。批处理试验和沙盒试验均表明，与 BO 和 DM 单独或组合相比，PS 与 BO 改良剂（PS+BO）结合最有利于 2,4-DCP 的吸附和降解。在原始低渗透生物活性 PS+BO 土壤层（长 15cm、宽 15cm、深 4.5cm）中，在 36 小时内，约有 77%的 6000μg·L-1 2,4-DCP 被吸收，其表面径流处理能力为 0.33L·天-1。将生物反应器土壤层中的石英砂增加到原始生物反应器的三倍，可将处理能力提高到 17.5L·天-1。然而，这种渗透性优化的生物活性层仍然不足以完全去除 2,4-DCP。通过对流、弥散、吸附和降解的多过程耦合模型优化的规模为 60cm 长×60cm 宽×18cm 深，此时处理能力达到 280L·天-1，2,4-DCP 的去除率达到 97.3%，相应地，2,4-DCP 浓度可达到标准限值。此外，获得的模型参数表明，生物炭或微生物显著降低了生物活性层中 2,4-DCP 的弥散系数 D。在 PS+BO 系统中，2,4-DCP 的分配系数 K 和一级反应速率 λ 明显大于对照、BO 和 PS 系统。研究结果表明，掺入微生物和生物炭的顶层土壤是处理地表径流的一种可行且有效的方法。
