Effectiveness of Activated Carbon and Biochar in Reducing the Availability of Polychlorinated Dibenzo-p-dioxins/Dibenzofurans in Soils
Effectiveness of Activated Carbon and Biochar in Reducing the Availability of Polychlorinated Dibenzo-p-dioxins/Dibenzofurans in Soils
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DOI：
10.1021/es2029697
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发表时间：
2012-01-17
影响因子：
11.4
通讯作者：
Ghosh, Upal
中科院分区：
文献类型：
--
作者：
Chai, Yunzhou;Currie, Rebecca J.;Ghosh, Upal
研究了5种活性炭和2种生物炭作为改性剂，降低两种土壤中老化的多氯二苯并对二恶英/二苯并呋喃（PCDD/Fs）的有效性。通过聚甲醛（POM）被动吸收和蚯蚓（E. fetida）生物吸收测量，所有吸附剂（ACs和生物炭）均显著降低了PCDD/Fs的可用性。7种吸附剂在土壤总有机碳的0.2倍（0.2倍）水平上进行了修正，使POM中总PCDD/Fs的被动吸收（物理化学有效性）降低了40%至92%（或毒性当量降低了48%至99%）。粒径越细、大孔越大的吸附剂的还原效率越高。再生AC粉末状和椰子AC粉末状被证明是最有效的，两种生物炭也表现得相当好，尤其是粉末状。随着POM与土壤浆体接触时间从24 d增加到120 d， POM对PCDD/F的被动吸收量增加了约4 ~ 5倍，而ac降低其理化有效性的效果保持不变。在0.2X和0.5X两种剂量水平下，POM被动吸收对再生AC的还原效率与蚯蚓生物吸收（生物利用度）测量的效率相当。未改良土壤的生物群落-土壤积累因子（BSAF）值在4 - cdd /F为0.1 ~ 8 - cdd /F为0.02之间。在两种剂量水平下，除两个hexa-CDD/Fs外，再生AC将bsaf降至0.03以下。蚯蚓对椰子活性炭和玉米秸秆生物炭的还原效率通常低于POM，这可能是由于这些吸附剂的粒径较大，蚯蚓无法吸收。
Five activated carbons (ACs) and two biochars were tested as amendments to reduce the availability of aged polychlorinated dibenzo-p-dioxin/dibenzofurans (PCDD/Fs) in two soils. All sorbents (ACs and biochars) tested substantially reduced the availability of PCDD/Fs measured by polyoxymethylene (POM) passive uptake and earthworm (E. fetida) biouptake. Seven sorbents amended amended at a level of 0.2 X soil total organic carbon (0.2X) reduced the passive uptake (physicochemical availability) of total PCDD/Fs in POM by 40% to 92% (or toxic equivalent by 48% to 99%). Sorbents with finer particle sizes or more macropores showed higher reduction efficiencies. The powdered regenerated AC and powdered coconut AC demonstrated to be the most effective and the two biochars also performed reasonably well especially in the powdered form. The passive uptake of PCDD/F in POM increased approximately 4 to 5 fold as the contact time between POM and soil slurry increased from 24 to 120 d while the efficacy of ACs in reducing the physicochemical availability remained unchanged. The reduction efficiencies measured by POM passive uptake for the regenerated AC were comparable to those measured by earthworm biouptake (bioavailability) at both dose levels of 0.2X and 0.5X. The biota-soil accumulation factor (BSAF) values for unamended soil ranged from 0.1 for tetra-CDD/F to 0.02 for octa-CDD/F. At both dose levels, the regenerated AC reduced the BSAFs to below 0.03 with the exception of two hexa-CDD/Fs. The reduction efficiencies measured by earthworm for coconut AC and corn stover biochar were generally less than those measured by POM probably due to larger particle sizes of these sorbents that could not be ingested by the worms.