含铁装饰原纸污泥制备聚合硫酸铁及其絮凝性能研究

Preparation of Polymeric Ferric Sulfate from Paper Mill Sludge and Its Flocculation Properties

中文关键词:  造纸污泥  聚合硫酸铁  氯酸钠  絮凝

Key Words:pulp mill sludge  polymeric ferric sulfate  sodium chlorate  flocculation

中文摘要:

      以含铁装饰原纸生产废水污泥为原料，NaClO3为氧化剂，经过酸溶和氧化过程，制得了液体聚合硫酸铁（PFS）絮凝剂。研究了酸溶过程中反应温度及时间对铁溶出率的影响。以Fe2+含量表征PFS质量，考察了NaClO3用量、氧化时间和温度对PFS质量的影响。研究结果表明，酸溶过程中适宜的反应条件为反应5 h，反应温度80~90℃；NaClO3氧化制备PFS的适宜条件为：n(NaClO3)∶n(Fe2+)=0.18∶1，反应时间3 h。制得的PFS各项指标均符合GB14591—2006中规定的PFS一级标准要求，PFS对造纸废水的絮凝效果优于市售PFS和PAC，适宜用量为30~45 mg/L；对制药废水的絮凝效果与市售PFS无显著差别，适宜用量为20~30 mg/L。

Abstract:

      Liquid polymeric ferric sulfate (PFS) was prepared from paper mill sludge containing ferric using sodium chlorate as oxidant. Effects of acid extraction temperature and time on ferric extraction efficiency were investigated. The influence of sodium chlorate dosage, oxidation time and temperature on the quality of PFS in term of Fe2+ concentration was studied. Extraction was favored at reaction time 5 h and temperature 80~90℃. The quality of liquid PFS obtained under the ratio of sodium chlorate to ferric ions of 0.18, reaction time of 3 h met the requirement of the first class of the national standard. The flocculation properties of PFS was further compared with commercial PFS and polyaluminium chloride (PAC). Results showed prepared PFS was more efficient than commercial PFS and PAC for COD removal of pulp mill waste water, and the proper dosage was 30~45 mg/L; there was no significant difference between prepared PFS and commercial one for COD removal of pharmaceutical waste water, and the proper dosage of prepared PFS was 20~30 mg/L.