生物淋滤法提高制革污泥脱水性能的研究

Studies on the enhancement of dehydration property of tannery sludge by bioleaching technique.

通过1000L的搅拌釜式(STR)生物淋滤反应器,在去除制革污泥中重金属铬的同时,研究了生物淋滤技术对处于不同反应阶段污泥的比阻值、ζ电位值、自然沉降性、离心脱水率、离心液中悬浮固体(SS)浓度等指标的影响,并采用电镜扫描仪观测污泥颗粒结构的变化,评价原始污泥和生物淋滤污泥的脱水性能差异.结果表明,生物淋滤处理后,其比阻值从195×1012m/kg下降到5.4×1012m/kg;ζ电位从-25.8mV上升到+2.6mV,污泥由疏松的絮状变成紧实的块状;12h的自然沉降率达到61%;2000r/min时离心脱水率达到83%,离心后上清液中SS下降到946mg/L,固体回收率达到97.3%.制革污泥经过生物淋滤处理后,脱水性能得到了明显的提高.

At the same time of removing the heavy metal chromium in the tannery sludge through a 1000L stirred tank bioleaching reactor, the influence of bioleaching technique on the indexes such as specific resistance value, ζ potential, natural subside property, centrifugal dehydration rate and centrifugal suspended solid （SS） concentration in centrifugal liquor at different reaction stages was studied; and the change of sludge particulate structure was observed adopting electronic scanning instrument; and the dehydration property difference of original sludge and bioleaching sludge was evaluated. After bioleaching treatment, the specific resistance value declined to 5.4×10^12m/kg from 195×10^12m/kg; potential increased to ＋2.6mV from -25.8mV; and the sludge changed from dispersed cotton form to tight lump form; the natural sedimentation rate of 12h reached 61%; at 2000r/min, the centrifugal dehydration rate reached 83%; after centrifuge SS in the upper clean water decreased to 946mg/L, the solid reclaim rate reached 97.3%. The dehydration property of tannery sludge enhanced obviously after bioleaching treatment.