title: Optimization of typical diffuse herbicide pollution control by soil amendment configurations under four levels of rainfall intensities.
abstract: Herbicides are a main source of agricultural diffuse pollution due to their wide application in tillage practices. The aim of this study is to optimize the control efficiency of the herbicide atrazine with the aid of modified soil amendments. The soil amendments were composed of a combination of biochar and gravel. The biochar was created from corn straw with a catalytic pyrolysis of ammonium dihydrogen phosphate. The leaching experiments under four rainfall conditions were measured for the following designs: raw soil, soil amended with gravel, biochar individually and together with gravel. The control efficiency of each design was also identified. With the designed equipment, the atrazine content in the contaminant load layer, gravel substrate layer, biochar amendment layer and soil layer was measured under four types of rainfall intensities (1.25 mm/h, 2.50 mm/h, 5.00 mm/h and 10.00 mm/h). Furthermore, the vertical distribution of atrazine in the soil sections was also monitored. The results showed that the herbicide leaching load increased under the highest rainfall intensity in all designs. The soil with the combination of gravel and biochar provided the highest control efficiency of 87.85% on atrazine when the additional proportion of biochar was 3.0%. The performance assessment under the four kinds of rainfall intensity conditions provided the guideline for the soil amendment configuration. The combination of gravel and biochar is recommended as an efficient method for controlling diffuse herbicide pollution.
authors.affiliation: School of Environment, State Key Laboratory of Water Environment Simulation, Beijing Normal University, Beijing, 100875, China. Electronic address: wei@bnu.edu.cn.
authors.forename: Wei
authors.initials: W
authors.lastname: Ouyang
authors.affiliation: School of Environment, State Key Laboratory of Water Environment Simulation, Beijing Normal University, Beijing, 100875, China.
authors.forename: Weijia
authors.initials: W
authors.lastname: Huang
authors.affiliation: School of Environment, State Key Laboratory of Water Environment Simulation, Beijing Normal University, Beijing, 100875, China.
authors.forename: Peng
authors.initials: P
authors.lastname: Wei
authors.affiliation: School of Environment, State Key Laboratory of Water Environment Simulation, Beijing Normal University, Beijing, 100875, China.
authors.forename: Fanghua
authors.initials: F
authors.lastname: Hao
authors.affiliation: Beijing Uniwater Environmental Protection Technology Co, Ltd, Beijing, China.
authors.forename: Yongyong
authors.initials: Y
authors.lastname: Yu
mesh_terms: D000383:Agriculture; D001280:Atrazine / Q000032:analysis* / Q000737:chemistry; D002606:Charcoal; D004787:Environmental Pollution / Q000517:prevention & control*; D006540:Herbicides / Q000032:analysis* / Q000737:chemistry; D011891:Rain; D012987:Soil / Q000737:chemistry*; D012989:Soil Pollutants / Q000032:analysis* / Q000737:chemistry
chemical_list: D006540:Herbicides; D012987:Soil; D012989:Soil Pollutants; C540010:biochar; D002606:Charcoal; D001280:Atrazine
keywords: Atrazine leaching; Diffuse pollution control; Intensive tillage; Rainfall intensity; Soil amendment configurations