Sacko Oumar, Engle Nancy L, Tschaplinski Timothy J, Kumar Sandeep, Lee James Weifu
Department of Chemistry and Biochemistry, Old Dominion University, Norfolk, VA, 23529, USA.
Oak Ridge National Laboratory, PO Box 2008, Oak Ridge, TN, 37831, USA.
Bioresour Bioprocess. 2022 Jan 6;9(1):2. doi: 10.1186/s40643-021-00491-2.
Biochar ozonization was previously shown to dramatically increase its cation exchange capacity, thus improving its nutrient retention capacity. The potential soil application of ozonized biochar warrants the need for a toxicity study that investigates its effects on microorganisms.
In the study presented here, we found that the filtrates collected from ozonized pine 400 biochar and ozonized rogue biochar did not have any inhibitory effects on the soil environmental bacteria Pseudomonas putida, even at high dissolved organic carbon (DOC) concentrations of 300 ppm. However, the growth of Synechococcus elongatus PCC 7942 was inhibited by the ozonized biochar filtrates at DOC concentrations greater than 75 ppm. Further tests showed the presence of some potential inhibitory compounds (terephthalic acid and p-toluic acid) in the filtrate of non-ozonized pine 400 biochar; these compounds were greatly reduced upon wet-ozonization of the biochar material. Nutrient detection tests also showed that dry-ozonization of rogue biochar enhanced the availability of nitrate and phosphate in its filtrate, a property that may be desirable for soil application.
Ozonized biochar substances can support soil environmental bacterium Pseudomonas putida growth, since ozonization detoxifies the potential inhibitory aromatic molecules.
先前研究表明生物炭臭氧化可显著提高其阳离子交换能力，从而增强其养分保留能力。臭氧化生物炭在土壤中的潜在应用使得有必要开展一项毒性研究，以调查其对微生物的影响。
在本研究中，我们发现，即使在溶解有机碳（DOC）浓度高达300 ppm时，从臭氧化松木400生物炭和臭氧化罗格生物炭收集的滤液对土壤环境细菌恶臭假单胞菌也没有任何抑制作用。然而，当DOC浓度大于75 ppm时，臭氧化生物炭滤液会抑制聚球藻PCC 7942的生长。进一步测试表明，未臭氧化的松木400生物炭滤液中存在一些潜在的抑制性化合物（对苯二甲酸和对甲苯酸）；生物炭材料经湿臭氧化后，这些化合物的含量大幅降低。养分检测试验还表明，罗格生物炭的干臭氧化提高了其滤液中硝酸盐和磷酸盐的有效性，这一特性可能有利于土壤应用。
臭氧化生物炭物质可支持土壤环境细菌恶臭假单胞菌的生长，因为臭氧化可使潜在的抑制性芳香分子解毒。
