Treatment Of Train Laundry Wastewater By Aerobic Biological Process

Linear Alkylbenzene Sulphonate (LAS), the key pollutant of the train laundry wastewater is classified as the second kind of contaminant of environmental standard. It inhabits the degradation of other poisonous substance, and affects the survival of animals and aquatic life. Besides, it forms into colloidal particle with the oil stain and dust particle in use. At present, train laundry wastewater is mainly treated by means of physical-chemical processes, but these methods are generally considered to have some problems, which are the unstable treatment results, the higher cost, and the complicated process. It is imperative that one suitable process should be found to treat this kind of wastewater.This paper made use of aerobic biological treatment including Lab-scale Sequencing Batch Reactor (SBR), pilot scale Biological Contact Oxidation-Membrane Biological Reactor (BCO-MBR) and Membrane Biological Reactor (MBR) to treat the railway laundry wastewater, also put the Alcaligenes sp. Strain into the SBR and MBR test equipment. Preliminary research on the selection of process parameter, the observation of the treatment results, the results contrast between the conventional process and addictive microorganism process, the magnification design of SBR and MBR, the contrast of SBR and MBR from technology and economic cost, as well as the membrane fouling were carried out. The above research provides some reference for the design and operation of the treatment for the railway laundry wastewater.An Alcaligenes sp. Strain was able to degrade LAS up to 120mg/L after it was purified and acclimated. The culture medium composition was determined as the beef extract-peptone culture, the incubation time was 48h after comparing its growth and degradable performance between the beef extract-peptone culture and LAS proliferated culture. The degradation of LAS in the train laundry wastewater by inoculating this strain was observed, at same time, the suitable amount of inoculums was identified as 2 % (v/v).By kinetic parameter experiment, effect experiment of dissolved oxygen concentration, as well as the orthogonal experiment including aeration time and dissolved oxygen and temperature, the suitable aeration time is 4~5h, dissolved oxygen 2.0 ~ 3.0mg/L, and temperature 20~30℃. The zero-order and...