Abstract —— Excess biomass produced during the biological
treatment of wastewaters requires costly disposal. Excess sludge treatment and
disposal currently represents a rising challenge for wastewater treatment plants
due to economic, environmental and regulation factors. As environmental and
legislative constraints increase, thus limiting disposal options, there is considerable
impetus for reducing the amount of biomass produced. This paper reviews current
strategies for reducing sludge production based on these mechanisms: uncoupling
metabolism, lysiscryptic growth, predation on bacteria, thermal treatment, activated
sludge ozonation process, anoxic-settling-anaerobic (OSA),and so on.. Suitable
engineering of the physical conditions and strategic process operation may result
in environments in which biomass production may be reduced. But employing any
strategy for reducing sludge production may have an impact on microbial community
 in  biological wastewater treatment processes and reduced biomass
production may result in an increased nitrogen concentration in the effluent.

Key word: sludge reduction, waste water treatment, activated  sludge tereatment.

1 前言

目前世界上80％以上的污水处理厂应用的是活性污泥法处理污水，它最大的弊端就是处理污水的同时产生惊人的大量剩余污泥。污泥中的固体有的是截留下来的悬浮物质,有的是由生物处理系统排出的生物污泥,有的则是因投加药剂而形成的化学泥，污水处理厂产生的污泥量约为处理水体积的0.15 % —1 %左右 。污泥的处理和处置,就是要通过适当的技术措施,使污泥得到再利用或以某种不损害环境的形式重新返回到自然环境中。这些污泥一般富含有机物、病菌等,若不加处理随意堆放,将对周围环境产生新的污染。

对这些污泥处理方法主要有：农用、填海、焚烧、埋地。但这些方法都无一例外地存在弊端。如污泥中重金属的含量通常超过农用污泥重金属最高限量的规定。此外,污泥中还含有病原体、寄生虫卵等, 如农业利用不当,将对人类的健康造成严重的危害。填埋处置容易对地下水造成污染,同时大量占用土地。焚烧处置虽可使污泥体积大幅减小,且可灭菌,但焚烧设备的投资和运行费用都比较大。投放远洋虽可在短期内避免海岸线及近海受到污染,但其长期危害可能非常严重,因此,已被界上大多数国家所禁用。