Research On Anaerobic Hydrolysis-acidification Of Sludge As A Carbon Source

Recycling technologies of Sewage sludge have become the hot topic for water treatment workers now because of the sharp decrease and the pollution in natural resources. Moreover, the shortage of carbon sources in wastewater treatment plant is always ubiquitous, and the short-chain fatty acid produced in the process of Sludge hypoxic hydrolysis acidification can offer extra carbon sources for nitrogen and phosphorus removal bacteria. This subject adopt the technology of hypoxic hydrolysis acidification to tackle with the residual sewage sludge in wastewater treatment plant, and to inspect the category of VFAs produced in the process by changing the parameters and reaction conditions. Besides, by using the VFAs released before as carbon resource, it also discusses the effects on technology of nitrogen and phosphorus removal which taken by different carbon sources and operating conditions.Conducting experiments by using acetic acid and propionic acid separately, and comparing with the experiment which regarded the wastewater as a carbon source, the results show: the Anaerobic phosphate concentration of #1 acetic acid system and #2 propionic acid system in general are higher than #3 wastewater SBR systems’; the #3 system is the best one in TP water treatment effect, high concentrations of anaerobic phosphate during the period of reaction makes #1 acetic acid’s SBR reactor and #2 propionic acid’s SBR reactor fluctuate in Tp concentration of effulent. And the fluctuations during the later period were caused by the decrease of Phosphate concentration and the instability of Polyphosphate ability in reactor.Separately inspecting the effects on Low oxygen hydrolysis acidification taken by aeration rate、SRT and sludge concentration, the results show that:1) Low oxygen hydrolysis acidification is obviously better than aerobic aeration on accumulating the SCOD and VFAs, so the lower on aeration rate,the better for hydrolysis acidification. 2) During the 4d to 8d of SRT, the concentration of VFAs increased sharply; during the 8d to 12 d to 16 d, the concentration of VFAs increased slower than before. When sludge remains too long, Acetic acid of methanogenic bacteria metabolize by using acetic acid as the matrix, and consuming the carbon resource(VFAs) of sludge hypoxic hydrolysis acidification. 3) With the increase of sludge concentration, The degree of hydrolysis acidification of sludge also grows. But if residual sludge concentration is too high,it is also not good for Low oxygen acid hydrolysis yields. The Acid yield curves of different sludge have the same tendency which increased at first till to the top of the yield, then decreased, and it showed the best reaction time is about 15 d.By inspecting the effect on biological nitrogen and phosphorus removal which taken by the product of Sludge hypoxic hydrolysis acidification which regarded as carbon resource. The result shows that: the less we take acidizing fluid into SBR system, the slower the Interpretation of the phosphorus reaction rate goes and the sooner the process of Phosphorus absorption finishes; when on the condition of TN=30mg/L(working condition 1) and TN=40mg/L(working condition 2) of water inflow, the removal rate and the denitrification ability of NH4+—N are stable; the experiment shows that the TN and the removal rate of ammonia nitrogen reach the top when there are 80 of sludge for 1 of flow of acidizing fluid.