能源物质和接种物的投量对生物沥浸改善城市污泥脱水性能的影响

选用硫粉(S0)和黄铁矿粉(Fe S2)作为复合能源物质,以生物沥浸处理城市污泥脱水。通过正交试验分析了不同能源物质和接种物配比下的污泥脱水、沉降性能。结果表明:能源物质和接种物的合理配比为S0投量2 g/L、Fe S2投量6 g/L、接种物投量20%,在该投量下进行生物沥浸试验,污泥比阻由初始的3.35×1012m/kg降至3.90×1011m/kg,降幅达88.36%,污泥沉降率由68%升至78%;沥浸过程中污泥比阻、沉降率与p H值、ORP、Fe2+、Fe3+、总Fe和SO2-4质量浓度的变化同步,表明污泥脱水和沉降性能的改善是酸化、氧化和絮凝的协同作用所致;同时,细菌总数、总大肠菌群和粪大肠菌群的灭活率均在99%以上,表明生物沥浸还可高效杀灭病原微生物。

Influence of the energy substrates and inoculum dosage on the dehydration improvement of the urban sludge via bioleaching

The paper is to make an exploration of the impact of the energy substrates and inoculum dosage on the dehydration improvement of the urban sludge through bioleaching under the conditions with no chemical agents added to.So far as is done,the dewaterability of the urban sludge has so far been well improved to meet the demands of the mechanical in-depth dehydration of the urban sludge through bioleaching three times enriched with A.ferrooxidans and A.thiooxidans in addition to inoculum as energy substrates (S0 and FeS2).For the purpose,we have chosen FeS2 and inoculums for an orthogonal test by taking the aforementioned three factors of the dosage of S0 into consideration,whereas the biggest descent rate of sludge specific resistance to filtration (SRF) and the biggest escalating rate of sludge sedimentation as the evaluation indicators.Taking into account the particular features of dewaterability and settleability of the aforementioned sludge through bioleaching under the different ratios of energy substrates and inoculum addition,we have made visual analysis and variance analysis so as to work out the optimum ratio of S0,FeS2 and the inoculum dosage of 2 g/L,6 g/L and 20％,respectively.It is just on the above mentioned basis of the optimum ratio and proportion of the urban sludge treating experience that we have further confirmed that,under the status-in-situ conditions,the optimal time length for bioleaching should be 36 hours,whereas the SRF value tends to decrease from 3.35 × 1012 m/kg to 3.90 × 1011 m/kg with the drop of 88.36％,which can help to promote the dehydration of sludge to a great extent.In so doing,the sedimentation rate of sludge can get improved at a rate from 68％ to 78％,with the suspended solids of sludge being decreased from 17 000 mg/L to 14 000 mg/L.Moreover,during the bioleaching process,SRF and the sedimentation rate of the sludge can be made synchronized with the change of pH,ORP and the intensifying concentration of Fe2+,Fe3+,so that the total ferrous and SO42-can be made to reach the peak value during a period of 36 h.In addition,there would occur the reverse change after that,which tends to show that the dewaterability and settleability of the bioleached sludge can be greatly improved due to the synergetic function of acidification,oxidation and flocculation.In addition,the elimination rate of the total bacteria,the total coliform and the fecal coliform in the sludge well bioleached can reach 99％,which indicates that it would be possible for the efficient inactivation of the pathogenic microorganisms and the sludge dewaterability to get enhanced simultaneously through bioleaching treatment.