Sharma Aman D, Lai Donna
a Faculty of Science , University of Sydney , Sydney , Australia.
b Bosch Institute, School of Medical Sciences , University of Sydney , Sydney , Australia.
J Environ Sci Health B. 2019;54(1):49-53. doi: 10.1080/03601234.2018.1531658. Epub 2018 Oct 30.
Glyphosate mobility from terrestrial to aquatic environments has raised concerns about it. Utilizing soil's inherent properties along with sorption properties of aged biochar, we hypothesized that selective application of biochar would be more effective in economic terms for glyphosate sorption on contrasting soils. To test this hypothesis, batch experiments and liquid scintillation counting for C labeled glyphosate were used. The sorption behavior of glyphosate was examined in four contrasting Australian soil types (Oxisol, Vertisol, Entisol, and Inceptisol) amended with aged biochar to determine glyphosate concentrations by measuring C activity using liquid scintillation counting. Freundlich parameters were calculated for soil-soil/biochar combinations. The pattern of glyphosate sorption was Oxisol > Vertisol > Entisol > Inceptisol. Oxisol adsorbed approximately five times more glyphosate compared with Inceptisol. Oxisol soil system adsorbed maximum amount of glyphosate principally due to the presence of iron-aluminum oxides exhibiting variable charges which got increased due to the presence of aged biochar. Considering all the soil/soil-biochar systems, Inceptisol soil system showed the least adsorption of glyphosate. A significant contribution of char was observed only in the Entisol soil system and the finding is valuable as char can be applied in Entisol soil systems to control glyphosate mobility.
草甘膦从陆地环境向水生环境的迁移性引发了人们对它的担忧。利用土壤的固有特性以及老化生物炭的吸附特性，我们推测，从经济角度来看，选择性施用生物炭对草甘膦在不同土壤上的吸附会更有效。为了验证这一假设，我们采用了批次实验以及对¹⁴C标记的草甘膦进行液体闪烁计数的方法。我们研究了用老化生物炭改良的四种不同的澳大利亚土壤类型（氧化土、变性土、新成土和始成土）中草甘膦的吸附行为，通过液体闪烁计数测量¹⁴C活性来确定草甘膦浓度。计算了土壤 - 土壤/生物炭组合的弗伦德利希参数。草甘膦的吸附模式为氧化土＞变性土＞新成土＞始成土。与始成土相比，氧化土吸附的草甘膦大约多五倍。氧化土土壤系统吸附的草甘膦量最大，主要是因为存在具有可变电荷的铁铝氧化物，而老化生物炭的存在使其电荷增加。在所有土壤/土壤 - 生物炭系统中，始成土土壤系统对草甘膦的吸附最少。仅在新成土土壤系统中观察到生物炭有显著贡献，这一发现很有价值，因为生物炭可应用于新成土土壤系统以控制草甘膦的迁移性。
