开放系统下铅锌对地质碳汇的影响研究

Influence of lead and zinc on geological carbon sink under oxygen-rich conditions

自工业革命以来,资源需求量不断增加,矿产资源被过度开采引起一系列地质环境问题,针对采矿学者研究主要集中在地质环境灾害、矿山的修复技术方法和采矿暴露出的重金属对人类身体健康造成的危害等方面,鲜有学者研究采矿中重金属元素与地质碳汇的关系,随着双碳目标成为国家战略,重金属与地质碳汇机理研究对双碳战略目标有重要的科学意义。本文通过研究不同岩样在不同浓度铅、锌溶液中的溶解特征来探究开放系统条件下铅锌对地质碳汇的影响,研究发现:(1)随着实验时长的增加,所有组别的pH值呈下降趋势,电导率呈上升趋势。(2)0.5 mg/L的铅溶液可能会抑制岩石的溶解,HCO_(3)^(-)的浓度在第10天时突然变大随后又逐渐减小,而当加入灵川县铅锌矿场的铅锌矿粉末后溶液中HCO_(3)^(-)浓度倍增。0.1 mg/L铅溶液中加入铅锌矿粉末后,其水溶液中的HCO_(3)^(-)浓度明显少于未加入铅锌矿粉末的对照组。故认为铅可能作为抑制剂影响岩样在溶液中的溶解。(3)在1和5 mg/L锌溶液中加入铅锌矿粉末,无论其浓度高低,灰岩、角岩和灰岩+角岩3个实验组别HCO_(3)^(-)浓度将明显高于未加入铅锌矿粉末的对照组,故认为锌可能起催化作用。(4)通过对干燥后的岩样进行非原位SEM图像扫描发现,无论低浓度还是高浓度铅溶液,其溶蚀坑较无铅溶液明显增多,溶蚀台阶也明显呈无规则状,但在高浓度的铅溶液中更加突出,并且伴随着置换反应的发生,由低浓度到高浓度的铅溶液中可以观察到一些孔隙的发展和裂缝的形成。

Since the Industrial Revolution,the increasing demand for resources has led to the overexploitation of mineral resources,resulting in a series of geological and environmental problems.Research in mining has primarily focused on geological and environmental hazards,mine restoration technologies,and the health hazards posed by heavy metals exposure.However,few scholars have studied the relationship between heavy metals and geological carbon sinks.With the“dual-carbon”goal becoming a national strategy,research on the mechanisms of heavy metals and geological carbon sinks has significant scientific importance.This study investigates the influence of lead and zinc on geological carbon sinks under open system conditions by examining the dissolution characteristics of different rock samples in various concentrations of lead and zinc solutions.The findings are as follows:(1)With increasing experimental time,the pH value of all groups showed a decreasing trend,while the conductivity showed an increasing trend.(2)A 0.5 mg/L lead solution may inhibit rock dissolution,as the HCO_(3)^(-) concentration initially increased significantly on the 10th day before gradually decreasing.When lead-zinc ore powder from the Lingchuan County lead-zinc mine was added,the HCO_(3)^(-) concentration in the solution doubled.Data showed that the HCO_(3)^(-) concentration in the 0.1 mg/L lead solution with added lead-zinc ore powder was significantly lower than in the control group without the ore powder.This suggests that Pb 2+may act as an inhibitor,affecting the dissolution of rock samples in the solution.(3)In the 1 mg/L and 5 mg/L zinc solutions with added lead-zinc ore powder,the HCO_(3)^(-) concentrations in the limestone,hornfels,and limestone+hornfels groups were significantly higher than in the control groups without the ore powder,indicating that zinc may act as a catalyst.(4)Scanning non-in situ SEM images of the dried rock samples revealed that both low and high concentrations of lead solutions increased the number of dissolution pits compared to the lead-free solution.The dissolution steps were also more irregular in high-concentration lead solutions,accompanied by replacement reactions.From low to high concentrations of lead solutions,the development of porosity and the formation of cracks were observed.