Abstract

Reactive azo dyes, if discharged in unmonitored manner to natural water bodies, can cause remarkable irreversible damage. The current study is centered on the decolorization and biodegradation of reactive blue (RB4) azo dye in an integrated sequential anaerobic-aerobic batch mode process. The biodegradation of reactive blue (RB4) was accomplished using alternatively both starch and gelatin-immobilized mixed cells. Activated sludge freshly collected from a sewage treatment plant was used as the biocatalyst. Complete decolorization of 10 mg/L RB4 under anaerobic conditions observed within 30 h by using individually mixed bacterial cells immobilized with; (1) starch cross-linked with polyvinyl alcohol (PVA-St beads), and (2) gelatin cross-linked with polyvinyl alcohol (PVA-Ge beads). The results revealed that maximum removal efficiencies of chemical oxygen demand (COD) under aerobic conditions were 89, 88, and 86%, using PVA-St beads, whereby they were 90, 85, 84% using PVA-Ge beads occurred within 70, 90 and 100 h at detected concentrations of 10, 20, and 40 mg/L, respectively. The effect of biocarrier has been proven to be negligible as the results were comparable using both bio-carriers.

摘要

活性偶氮染料如果以不受监控的方式排放到天然水体中，会造成显着的不可逆损害。目前的研究集中在活性蓝 (RB4) 偶氮染料在集成的连续厌氧-好氧间歇模式过程中的脱色和生物降解。活性蓝 (RB4) 的生物降解是交替使用淀粉和明胶固定的混合细胞完成的。从污水处理厂新鲜收集的活性污泥用作生物催化剂。10 mg/L RB4 在厌氧条件下，30 h 内观察到使用单独混合的细菌细胞固定的完全脱色；(1)用聚乙烯醇交联的淀粉(PVA-St珠)，和(2)用聚乙烯醇交联的明胶(PVA-Ge珠)。结果表明，有氧条件下化学需氧量 (COD) 的最大去除效率为 89%、88% 和 86%，使用 PVA-St 微珠，其中使用 PVA-Ge 微珠时它们分别为 90、85、84%，发生在 70、分别在 10、20 和 40 mg/L 的检测浓度下 90 和 100 小时。已证明生物载体的影响可以忽略不计，因为使用两种生物载体的结果相当。