Division of Geosciences and Environmental Engineering, Luleå University of Technology, SE-971 87, Luleå, Sweden.
Department of Environment and Minerals Resources, Greenland Institute of Nature Resources, 3900, Nuuk, Greenland.
Environ Sci Pollut Res Int. 2019 Oct;26(30):31284-31300. doi: 10.1007/s11356-019-06180-0. Epub 2019 Aug 30.
The geotechnical, chemical, and mineralogical properties of green liquor dregs (GLDs) generated as byproducts from five paper mills were investigated to assess their buffering and heavy metal immobilization capacities and their roles as water and oxygen barriers. One type of GLD was further studied to test the effects of the retrieval process and the storage, drying, and hydration of GLD. The high water retention capacity of the GLDs is valuable for limiting O diffusion. Laboratory results showed that the GLDs had hydraulic conductivities of 3.7 × 10-4.6 × 10 m/s and varied regularly in plasticity. The chemical and mineralogical compositions of the GLDs varied greatly, reflecting the raw material used to produce paper and the process used to retrieve GLDs. Although they had high total heavy metal contents, none of the leached elements from the GLDs (L/S 10 cm/kg) exceeded the European Union's limits for landfills of non-hazardous waste. The GLDs exhibited high buffering capacities. In a supplementary test, the buffering capacities varied (0.0041-0.0114 M H/g GLD) over 72 d after acid was added to the GLD. Changing the filtration process did not greatly affect the GLDs' properties but mainly affected the hydraulic conductivity, total heavy metal contents and sulfur content. Analyzing the storage of GLDs is necessary in the mining industry because remediation measures require large amounts of material over short periods. The buffering capacity of the dried GLD decreased slightly. The effect of dewatering caused by the mixing of 2% Na-lignosulfate with GLD (w/w) was low.
研究了来自五家造纸厂的副产品绿液渣 (GLD) 的岩土、化学和矿物特性，以评估其缓冲和重金属固定能力以及作为水和氧气屏障的作用。进一步研究了一种 GLD，以测试回收过程以及 GLD 的储存、干燥和水合作用的影响。GLD 的高持水能力对于限制 O 扩散很有价值。实验室结果表明，GLD 的水力传导率为 3.7×10-4.6×10 m/s，且具有规则的塑性变化。GLD 的化学成分和矿物成分差异很大，反映了用于生产纸张的原料和回收 GLD 的工艺。尽管它们的总重金属含量很高，但从 GLD 中浸出的元素（L/S 10 cm/kg）均未超过欧盟对非危险废物填埋场的限制。GLD 表现出很高的缓冲能力。在补充测试中，向 GLD 中添加酸后 72 天内，缓冲能力变化（0.0041-0.0114 M H/g GLD）。改变过滤过程不会对 GLD 的性质产生很大影响，但主要影响水力传导率、总重金属含量和硫含量。在采矿业中分析 GLD 的储存是必要的，因为修复措施需要在短时间内使用大量材料。干燥 GLD 的缓冲能力略有下降。将 2% Na-木质素磺酸盐与 GLD（w/w）混合引起的脱水效果较低。
