Examination On The Technics Of ABR+SBR In The Treatment Of Tannery Wastewater

The components of tannery waste water are very complex , not only the consistence and the toxicity of the pollutants is high, but also the change range of the water quality and quantity is wide. In TYCHE Leather Limited Corporation the waste water be treated by physical chemistry method and ordinarily active sludge method. But the organic dirt of the waste water cannot be totally treated up to par. The amino nitrogen 100% cannot be treated up to par. This research take the technics of ABR(Anaerobic Baffled Reactor )+SBR(Sequencing Batch Reactor) to find whether this method is fit for the treatment of tannery wastewater or not. In this method, First, the pretreated tannery wastewater is pumped into ABR to hydrolyze the organic wastes that difficult to be degraded, at the same time, most of the organic matters are removed from the wastewater by anaerobic microorganisms. Secondly, the outflow from ABR inflow SBR, eliminating the residual organic wastes, nitration and denitrification take place. The main conclusion is as follows:(1)On condition of temperature 35°C, we take two start experiments. First time as a result of the sulfide and the sulfate as well as the Ca²⁺ influence, the start is defeated; In the second start experiments, the depression factors are weakened and ABR is successfully started, using the daily outflow of the first detection tank in the tannery factory after pretreatment as inflow of SBR, the COD eliminate rate stabilizes between 64%～72%.(2) HRT the longer COD elimination rate is higher.But HRT is longer, the ABR volume which needs is bigger, from the economical angle considered the ABR processing leather waste water being suitable resident time is 22～24h, the suitable speed control in rise speed is over 0.3m/h. The SBR outflow can be used as backflow to enhance the rise speed, simultaneously the denitrification can continue in ABR.(3)To the tannery wastewater containing high sulfur, the catalyzed oxygenation process is not a very good method, the production sulfate is a neutral salt pollution, moreover bring troubles to the following anaerobic process. Suggesting to use biology desulfurize treatment or the acidification and then blows to let H₂S escapes.(4) Unifieding actual situation of the tannery wastewater of the factory, the SBR reactor best movement condition is: fill 0.5h, aeration 8h, anaerobic stirring 1h, settling 1h, drawing 0.5h, idling 1h. (5) Comparing technics of ABR+SBR with the Ordinarily Active Sludge System in the tannery wastewater treatment, the COD elimination rate is higher, can up to par of the second-rate in Integrated wastewater dischage standard GB 8978-1996, but cannot up to par of the first-rate standard; In the situation of not lack of alkalinity, the ammonia nitrogen removal rate 100% up to par, the denitrogenation experiment is successful, confirmed the feasibility of ABR+SBR technics in treating tannery wastewater.