摘要
柠檬酸/酒石酸可使方解石产生矿物溶蚀及生物矿化等现象,研究它们之间的反应规律对富含有机酸环境中方解石矿物的稳定性评估及相应的地球化学效应研究具有重要意义。通过批量平衡法,研究开放系统条件下方解石与柠檬酸/酒石酸之间的反应规律及对应的溶液化学变化。结果表明:①初始浓度为20 mg·L-1条件下,初始pH值由7.7升至9.7,柠檬酸与酒石酸的反应去除量均显著下降,这是由于方解石表面的静电效应及溶液中HCO_(3)^(-)与CO_(3)^(2-)的竞争效应不断增强,对两种酸的表面吸附反应起抑制作用。②初始pH值为7.7及8.3条件下,初始浓度为20 mg·L-1的两种酸与方解石反应7 h后便达到平衡,pH值和Ca浓度较空白值变化不大,辅证了反应的主导机制为表面吸附。③在0~900 mg·L-1浓度范围内,柠檬酸和酒石酸在初始pH值为8.3条件下,其反应去除量均能用Langmuir吸附模型很好地拟合,辅证了以上的反应去除机制均为表面吸附;初始pH值为7.7条件下,柠檬酸的反应去除量可用Langmuir吸附模型拟合,反应的主导机制仍为表面吸附,而酒石酸的反应去除量呈现持续陡增现象,Langmuir与Freundlich吸附模型均难以拟合,这是由于酒石酸的反应主导机制是沉淀反应。④初始pH值为8.3,在0~900 mg·L-1浓度范围内,在5℃、20℃、35℃温度条件下,两种酸的反应去除结果均可用Langmuir吸附模型拟合,反应的主导机制仍为表面吸附。与酒石酸相比,随着温度的升高,柠檬酸吸附量的增幅更大;同时,3种温度条件下柠檬酸带来的pH值和Ca浓度增幅均比酒石酸带来的更大。
Citric acid/tartaric acid can cause mineral dissolution and biomineralization of calcite,so the study on reaction pattern between them is of great significance for the assessment of the stability of calcite minerals and the study on the corresponding geochemical effects in organic acid-rich environments.The reaction between calcite and citric acid/tartaric acid and the corresponding solution chemistry change were studied by batch equilibrium method under open system conditions.The results show that①at the initial concentration of 20 mg·L-1,the reaction removal of citric acid and tartaric acid decreases significantly when the initial pH value increases from 7.7 to 9.7;this is attributed to the electrostatic effect on the surface of calcite and the increasing competition between HCO_(3)^(-) and CO_(3)^(2-) in the solution,which inhibit the surface adsorption reaction of the two acids on calcite.②At the initial pH of 7.7 and 8.3,the reaction of the two acids with an initial concentration of 20 mg·L-1 and calcite reaches equilibrium after 7 h;compared with the blank values,the pH and Ca concentration have little change,which prove that the dominant mechanism of the reaction is surface adsorption.③In the concentration range of 0-900 mg·L-1,the reaction removal results of citric acid and tartaric acid at the initial pH of 8.3 could be well fitted by the Langmuir adsorption model,which proves that both of the above removal mechanisms are surface adsorption;at the initial pH of 7.7,the reaction removal results of citric acid still could be fitted by the Langmuir adsorption model,and the removal mechanism is still surface adsorption;while the removal of tartaric acid shows a continuous steep increase,which cannot be fitted by the Langmuir or Freundlich adsorption model,and this is due to the fact that the dominant mechanism of tartaric acid removal by reaction is precipitation reaction.④At an initial pH of 8.3,a concentration range of 0-900 mg·L-1 and the temperatures of 5℃,20℃,and 35℃,the removal result
作者
李振炫
桂尉竣
苏畅
向育斌
孙晓雯
吴超越
黄利东
David DECROOCQ
LI Zhen-xuan;GUI Wei-jun;SU Chang;XIANG Yu-bin;SUN Xiao-wen;WU Chao-yue;HUANG Li-dong;David DECROOCQ(Jiangsu Collaborative Innovation Center of Atmospheric Environment and Equipment Technology/Jiangsu Key Laboratory of Atmospheric Environment Monitoring and Pollution Control,Nanjing University of Information Science&Technology,Nanjing 210044,Jiangsu,China;Joint International Research Laboratory of Climate and Environment Change(ILCEC),Nanjing University of Information Science&Technology,Nanjing 210044,Jiangsu,China;School of Chemistry and Materials Science,Nanjing University of Information Science&Technology,Nanjing 210044,Jiangsu,China;Nanjing Institute of Environmental Sciences,Ministry of Ecology and Environment,Nanjing 210042,Jiangsu,China;School of Applied Meteorology,Nanjing University of Information Science&Technology,Nanjing 210044,Jiangsu,China;Département des Sciences de la Terre,Universitéde Lille,Lille 59650,Nord,France)
出处
《地球科学与环境学报》
CAS
北大核心
2023年第6期1398-1413,共16页
Journal of Earth Sciences and Environment
基金
国家自然科学基金项目(41303096,41201515)
教育部留学回国科研启动基金项目(S131304001)
江苏省自然科学基金项目(BK20210655)。
关键词
方解石
柠檬酸
酒石酸
吸附
溶解
络合
沉淀
溶液化学
calcite
citric acid
tartaric acid
adsorption
dissolution
complex
precipitation
solution chemistry
