la Cecilia Daniele, Maggi Federico
Laboratory for Environmental Engineering, School of Civil Engineering, The University of Sydney, Bld. J05, Sydney 2006, NSW, Australia.
J Contam Hydrol. 2017 Aug;203:104-121. doi: 10.1016/j.jconhyd.2017.05.004. Epub 2017 Jun 1.
A comprehensive biodegradation reaction network of atrazine (ATZ) and its 18 byproducts was coupled to the nitrogen cycle and integrated in a computational solver to assess the in-situ biodegradation effectiveness and leaching along a 5m deep soil cultivated with wheat in West Wyalong, New South Wales, Australia. Biodegradation removed 97.7% of 2kg/ha ATZ yearly applications in the root zone, but removal substantially decreased at increasing depths; dechlorination removed 79% of ATZ in aerobic conditions and 18% in anaerobic conditions, whereas deethylation and oxidation removed only 0.11% and 0.15% of ATZ, respectively. The residual Cl mass fraction in ATZ and 4 byproducts was 2.4% of the applied mass. ATZ half-life ranged from 150 to 247days in the soil surface. ATZ reached 5m soil depth within 200years and its concentration increased from 1×10 to 4×10mg/kg over time. The correlation between ATZ specific biomass degradation affinity Φ and half-life t, although relatively uncertain for both hydrolyzing and oxidizing bacteria, suggested that microorganisms with high Φ led to low ATZ t. Greater ATZ applications were balanced by small nonlinear increments of ATZ biodegraded fraction within the root zone and therefore less ATZ leached into the shallow aquifer.
将阿特拉津（ATZ）及其18种副产物的综合生物降解反应网络与氮循环相耦合，并集成到一个计算求解器中，以评估澳大利亚新南威尔士州韦亚隆西部一块种植小麦的5米深土壤中的原位生物降解效果和淋溶情况。生物降解去除了根区每年2千克/公顷阿特拉津施用量的97.7%，但随着深度增加，去除率大幅下降；脱氯在好氧条件下去除了79%的阿特拉津，在厌氧条件下去除了18%，而脱乙基和氧化分别仅去除了0.11%和0.15%的阿特拉津。阿特拉津及其4种副产物中的残留氯质量分数为施用量的2.4%。阿特拉津在土壤表层的半衰期为150至247天。阿特拉津在200年内到达5米的土壤深度，其浓度随时间从1×10增加到4×10毫克/千克。尽管对于水解细菌和氧化细菌而言，阿特拉津比生物质降解亲和力Φ与半衰期t之间的相关性相对不确定，但表明具有高Φ的微生物导致阿特拉津的t较低。在根区内，更大的阿特拉津施用量通过阿特拉津生物降解部分的小非线性增量得到平衡，因此较少的阿特拉津淋溶到浅层含水层中。
