铅锌矿区重金属污染土壤修复植物及其制浆造纸性能研究

Study on the Plants for Remediation of Heavy Metal Polluted Soil in Lead-Zinc Mine and Its Applicaton in Pulp and Paper Making

中文关键词:  铅锌矿区  重金属  植物修复技术  硫酸盐法蒸煮  制浆造纸

Key Words:lead-zinc mine  heavy metal  phytoremediation technology  kraft cooking  pulp and paper making

中文摘要:

      介绍了某废弃铅锌矿区土壤重金属污染情况，筛选出矿区内几种对重金属污染土壤修复性能好的优势植物，并以优势植物为原料进行蒸煮实验，研究其制浆造纸性能和安全性。结果表明，实验矿区土壤Pb、Zn、Cd含量均超过国家土壤环境二级标准；筛选的6种主要优势植物中，桑树、五节芒、蜈蚣草对重金属的富集能力强，可作为重金属污染土壤修复的主要优势植物；当蒸煮用碱量（以Na₂O计）和硫化度均为20%时，蜈蚣草蒸煮粗浆得率仅31.1%，卡伯值和无机物含量较高，分别为19.4和9.55%；而用五节芒和桑树蒸煮粗浆得率较高，分别为48.4%和45.1%，卡伯值较低，分别为7.8和13.8；用蜈蚣草浆抄造纸张的耐破度、撕裂度、抗张强度均非常低，而用五节芒浆和桑树浆抄造纸张的强度性能较好。并且五节芒浆和桑树浆成纸的重金属含量接近我国国家标准对食品包装用原纸的理化指标要求。

Abstract:

      This paper researched the heavy metal pollution situation in an abandoned lead-zinc mine, moreover, the dominant plants with excellent remediation effect of heavy metal polluted soil in the mine were selected. Furthermore, the cooking process with the selected dominant plants as the raw material was conducted, the pulpability and the physical properties and safety performances of formed paper were evaluated. The results showed that the content of Pb, Zn and Cd in the lead-zinc mine exceeded China’s national environmental soil secondary standard. Six main plants were selected in the mine, among them, the enrichment behaviors of mulberry, miscanthus floridulus and pteris vittata were stronger, and could be used as the main plants for the remediation of heavy metal polluted soils. When alkali charge and sulphidity were 20%, the pulp yield of pteris vittata was only 31.1%, Kappa number and inorganic substance amount were 19.4 and 9.55%, respectively, which were relatively high. Comparatively, the higher pulp yield of miscanthus floridulus and mulberry were 48.4% and 45.1%, respectively. Kappa number was 7.8 and 13.8, respectively. The bursting strength, tear strength and tensile strength of the formed paper with pteris vittata pulp were very low, but strength performances of formed papers with miscanthus floridulus and mulberry pulps were better. Finally, the heavy metal contents of formed papers with miscanthus floridulus and mulberry pulps were close to the physical and chemical index requirements of Chinas national standards for food wrapping paper.