Sludge Acclimation Of Microbiological Treatment Of Hypersaline Refractory Waste Water

This research was aimed at microbiological treatment of phenyl acetic acid manufacturing waste water. This waster water was characterized by hypersalinity, high concentration of refractory organic pollutants. Low BOD/COD. The result showed that salt-tolerant sludge could be achieved by taking salt as selection pressure. When the influent COD was 3429mg1L with the concentration of sodium chloride 45000mg/L, the volumetric loading could reached to 1 .55kgCOD/m3 d with the effluent COD 11 5mg/L. The acclimation course of salt-tolerant sludge was divided into two phases: the lag phase and the sludge growth phase. In the lag phage the bacteria population increased from lO9ceIl/gVSS to lO11cell/gVSS. The predominant species in the matured salt-tolerant sludge is salt-tolerant bacteria strain Al (Arthrobacter sp.) and strain P3(Pseudomonas sp.). in the sludge growth phage, the sludge concentration increased from 3.1 g/L to 6.Og/L. Salt-tolerant sludge operated under high salinity was not sensitive to salinity change while the sludge operated under low salinity was sensitive to salinity change. The osmoregulation mechanism of strain Al (Art hroba cter sp.) was studied,it was found that Al accumulated K~, free amino acid and QAC as its osmoprotecant.The intracellular level of K~, free amino acid and QAC increased by 3 times;2 times;6.7 times respectively when the level of sodium chrolide in MM increased from 0.1 M to 1 .OM. It was also found that K~ could stimulate the synthesis of free amino acid and QAC. The positive effect of K~ to the salt-tolerant sludge operated under high salinity was due to its role as osmoprotectant and stimulator to the synthesis of other osmoprotectant. Contact Oxidation Method was employed to treat hypersaline refractory industrial wastewater in field scale. The result show that the volumetric loading could reach to 1.2kg COD/rn3 d while the effluent COD is 96.3mg/L with the COD removal efficiencies 96.7%.