| The paper recommends a technological way treating alkaline straw-pulping mill black liquor:acidification-anaerobic-aerobic and do experiment to test it .During the experiment the capacity of ABR (anaerobic battle reactor)was mainly studied.In the paper the pollution situation of alkaline straw-pulping mill industry in China was introduced. Based on the present treatment technology and the requirement of mill companies,the treatment technology was proposed:vitriol acidification -pH control and liquid dilution - ABR anaerobic treatment - SBR aerobic treatment.The result of acidification is:in 60 10% vitriol was used to decrease pH to 4,the exenterate of CODCr is 57.1%,SS is 80.6% and BOD5 25%.After the biological system can normally run ,in the anaerobic reactor granule sludge presented.When the wastewater with CODcr 6000mg/L was put into the anaerobic reactor ,the treatment temperature is between 25 C and 38,keep HRT separately 12h,18h and 24h,corresponding Nv change from 6.5 kgCOD/m3d to 12.84kgCOD/m3d,the exenterate of CODcr is steadily over 48%,the anaerobic process was separated in two stages. The influence of temperature,pH,Na+,SO42- on anaerobic process were discussed and corresponding practical measures were advanced.Aerobic treatment ran well. The exenterate CODcr and BOD5 kept steadily over 70% and 81%.The experimental results showed that the acidificated black liquor mixed with 10 tunes middle liquor,HRT was kept in 24h in anaerobic process,in aerobic process was aired 8h,the discharge can be drained with the standards. Based on the experimental results and technics,the preliminary technical and economical evaluation was analyzed. The treatment station should be invested 11.85Million yuan when the mill factory discharge black liquor500m3/d,every day the cost for pro m3 black liquor is 10.4yuan. If the lignin will be reclaimed,the cost can be compensated and profit can be obtained. |
PDF Full Text Request