木素磺酸钙与硝酸联合处理河涌底泥的试验研究

Treatment of River Sediments with Calcium Lignosulfonate and Nitric Acid

用不同浓度的木素磺酸钙和硝酸为提取剂,采用单一、复合、顺序提取的方法处理受重金属污染的河涌底泥,比较不同方法的处理效果。结果显示,木素磺酸钙单一处理底泥,重金属的去除率较低,而用硝酸单一处理则较高。在硝酸浓度为0.1 mol/L时,Cr,Cu,Ni,Zn的去除率分别为15.9%,60.8%,73.4%,75.8%。用木素磺酸钙和硝酸复合处理底泥,重金属去除率与硝酸单一处理时相近。顺序处理中,先用木素磺酸钙后用硝酸提取,木素磺酸钙对后一步硝酸提取重金属有阻碍作用,两步总去除率比硝酸单一处理低;若先用硝酸后用木素磺酸钙提取,硝酸对后一步木素磺酸钙提取重金属有促进作用,Cr,Cu,Ni,Zn的两步总去除率分别可达到29.8%,83.1%,98.5%,100%。

Single, compound, order extractions with nitric acid and calcium lignosulfonate at various concentrations were adopted for the treatment of heavy metals contaminated sediments, and the effects of different treatment were compared. The results showed that the removal efficiency of heavy metals was low in single treatment with calcium lignosulfonate, but higher in single treatment with nitric acid. The removals of Cr, Cu, Ni and Zn were 15.90%, 60.8%, 73.4% and 75.8% respectively at 0.1 mol/L nitric acid. The removal of heavy metals in compound extraction with nitric acid and calcium lignosulfonate was similar for that in single extraction with nitric acid. For order extraction, extraction with calcium lignosulfonate followed by nitric acid was ineffective for removal of heavy metals, and the effect of calcium lignosulfonate on the extraction of heavy metals with nitric acid was inhibition. The total removals of heavy metals were lower than that in single extraction with nitric acid. Extraction with nitric acid followed by calcium lignosulfonate was effective, and the effect of nitric acid on the extraction with calcium lignosulfonate was promotion. The total removals of Cr, Cu, Ni and Zn in two steps amounted to 29.8%, 83.1%, 98.5% and 100%.