Humic acid-mediated transport of a typical soil passivation remediation product(chloropyromorphite)in saturated porous media  

作　　者：Xinying Li Mengjia Zhang Siyuan Li Wei Wei 

机构地区：[1]School of Environment,Jiangsu Engineering Lab of Water and Soil Eco-remediation,Jiangsu Province Engineering Research Center of Environmental Risk Prevention and Emergency Response Technology,Nanjing Normal University,Nanjing 210023,China [2]Jiangsu Center for Collaborative Innovation in Geographical Information Resource Development and Application,Nanjing 210023,China

出　　处：《Journal of Environmental Sciences》2024年第7期51-62,共12页环境科学学报（英文版）

基　　金：supported by the National Natural Science Foundation of China(No.41931292);the Priority Academic Program Development of Jiangsu Higher Education Institutions(No.164320H101)。

摘　　要：Conversion of labile Pb species into chloropyromorphite(CPY)using phosphorus-bearing amendments was considered to be an ideal strategy in soil passivation remediation.However,the fate and transport of CPY in the soil are poorly understood.This study aims to fill the knowledge gap by evaluating the fate and transport of CPY under environmentally relevant conditions of humic acid(HA),pH,electrolyte concentration,and species through the saturated sandy medium.Results showed that bare CPY colloids are basically immobile in sandy porous media while the co-existence of HA made the transport of CPY improved by30%-93.5%.Facilitated transport of CPY was attributed to the increased stability of CPY and the repulsive interaction between CPY particles and sands due to HA adsorption.The mobility of CPY was also increased with increasing pH from 5.0 to 9.0.When the pH was 9 with a10 mmol/L NaCl background solution,the stronger energy barrier between CPY and sand led to enhanced transport behavior.The divalent Ca^(2+)had a more dramatic effect than monovalent Na^(+)on the aggregation and sedimentation of CPY colloids due to its effectivescreening of the surface charge of CPY and bridging interaction with CPY particles.Derjaguin-LandauVerwey-Overbeek theory and attachment efficiency calculation indicated that high energy barriers were responsible for the high mobility of CPY colloids,while the retention of CPY in sands was mainly caused by secondary energy minimum and physically straining.The findings of this work can help to evaluate the fate of soil passivation remediation products in natural water and soil.

关 键 词：Chloropyromorphite DLVO theory Stability Saturated porous medium TRANSPORT 

分 类 号：X53[环境科学与工程—环境工程]