长期不同施肥潮土对可溶性有机碳的吸附特征

发布时间：2018-11-29 11:57

【摘要】：可溶性有机碳(DOC)吸附影响土壤元素化学行为。为此,本研究采用批处理法研究了DOC在长期不同施肥处理(对照CK、氮N、氮磷NP、氮磷钾NPK、化肥+秸秆还田NPKS、化肥+有机肥NPKM)潮土上的吸附动力学和等温吸附特征。结果表明,猪粪源DOC易于分解,需要添加0.025 mmol(1 mL 25 mmol/L)Na N3抑制其分解,抑制率超过90%。DOC吸附符合准二级动力学方程(R~2≥0.99)。不同施肥处理下,吸附速率常数k及初始速率常数h与平衡吸附Qe都没有显著差异,平均值分别为0.208 kg/(g·h)、1.60 g/(kg·h)和2.77g/kg。吸附等温式可用Langmuir方程很好拟合(R~2≥0.96),吸附容量(最大吸附量)Q_(max)在不同施肥处理下也没有显著差异(平均7.05 g/kg),但在N和NP等非平衡施肥下却保持高的亲合力,半饱和吸附浓度k_d分别为50.2和57.6 mg/L,吸附亲合常数K则分别为0.02和0.017 4 L/mg;相反,在NPKM处理下,显著低的亲合性发生,k_d和K分别为72.94 mg/L和0.013 8 L/mg。研究证明粘粉粒含量控制了不同施肥处理潮土对DOC的吸附;土壤有机碳水平不影响Q_(max),而且高土壤有机碳还降低其吸附亲合性。
[Abstract]:The adsorption of soluble organic carbon (DOC) affected the chemical behavior of soil elements. For this reason, the adsorption kinetics and isothermal adsorption characteristics of DOC on the fluvo-aquic soil treated with long-term fertilization (CK, N, P, NP, N, P, K, NPK, NPKM) were studied by batch treatment. The results showed that DOC from pig manure was easy to decompose, and 0.025 mmol (1 mL 25 mmol/L) Na N3 was added to inhibit the decomposition, and the inhibition rate was higher than that of 90%.DOC adsorption in accordance with the quasi second order kinetic equation (RN 2 鈮，

本文编号：2364930