Fe~(3+)存在下DO冲击对好氧活性污泥处理制浆中段废水的影响

Fe3+存在下,考察了处理制浆中段废水的好氧活性污泥系统在溶解氧(DO)浓度为0.5mg/L和5.5mg/L冲击7d的处理效果和污泥特性,调整DO浓度为2.0mg/L进行7d的恢复实验,考察处理效果和污泥特性,并与不加铁的空白组对照。在DO浓度为0.5mg/L和5.5mg/L冲击下,加铁组和空白组处理效果均下降,污泥沉降性能变差,加铁组下降幅度小于空白组;恢复实验中,加铁组恢复速度相对较快。与DO浓度为0.5mg/L冲击相比,DO浓度为5.5mg/L冲击对系统的影响较小,但恢复阶段却相对较慢。     

pH值对微氧磁性活性污泥系统处理含五氯酚废水的影响

研究了pH值对微氧磁性活性污泥系统处理五氯酚(PCP)废水的影响,并以微氧活性污泥系统作为对照,考察了不同pH值下PCP和CODCr去除率、微生物活性以及污泥理化特性的变化。结果表明,与微氧活性污泥系统相比,pH值在5.0～9.0范围内,微氧磁性活性污泥系统的PCP和CODCr去除率均较高,且微氧磁性活性污泥系统和微氧活性污泥系统均在pH值为7时PCP和CODCr的去除率达到最大,分别为87.5%和70.5%、77.0%和67.0%。由于磁粉的存在,微氧磁性活性污泥系统中微生物活性和絮凝性能均得到增强,当pH值为7时,微氧磁性活性污泥系统中脱氢酶浓度和胞外多聚物中蛋白质与多糖质量比(PN/PS)分别达到248.59 mg/g和1.3,而微氧活性污泥系统中这两个指标分别为173.18 mg/g和0.76。     

不同pH值下 Fe3+对好氧活性污泥处理制浆中段废水的影响

本课题以不加Fe~(3+)的活性污泥作为对照,探讨了在Fe~(3+)存在下,pH值对好氧活性污泥处理制浆中段废水的影响。研究表明,当pH值为6.5时,对照组和添加Fe~(3+)的实验组的CODCr去除率分别达到77%和79%。当超出该pH值范围,对照组和实验组的COD_(Cr)去除效果均下降。Fe~(3+)的存在提高了处理效果,特别是pH值明显偏离正常值,pH值为8.5和9.5时尤为明显。通过对脱氢酶浓度和污泥絮凝性能的研究结果表明,当pH值在5.5~7.5的范围时,两个指标都显示了污泥良好的性能,但在其他pH值条件下,污泥活性和絮凝性能均出现下降。与对照组相比,Fe~(3+)的存在提高了污泥的活性和絮凝性能。     

纳米磁粉对处理制浆中段废水驯化微氧活性污泥的影响

本实验采用共沉淀法制备了Fe_3O_4纳米磁粉,研究Fe_3O_4纳米磁粉对处理制浆中段废水驯化微氧活性污泥的影响。结果表明,投加Fe_3O_4纳米磁粉对废水的处理效果及污泥的理化特性均优于未投加纳米磁粉的空白组;当纳米磁粉投加量为1.0 g/L时,经55天的驯化,废水CODCr去除率达到80%左右,而未投加纳米磁粉的废水CODCr去除率不到70%;驯化后污泥具有良好的理化特性,污泥浓度(MLSS)为3.86 g/L,污泥体积指数(SVI)稳定在70 m L/g左右,PN∶PS值为0.87,明显优于未投加纳米磁粉的空白组。     

悬浮填料生物膜-MBR系统处理制浆中段废水的研究

采用悬浮填料生物膜-MBR系统处理制浆中段废水,并与好氧活性污泥系统进行了对比。驯化过程中,尤其是制浆中段废水所占比例较高时,悬浮填料生物膜-MBR的处理效果和污泥理化特性均明显优于好氧活性污泥系统。驯化结束时悬浮填料生物膜-MBR系统COD_(Cr)去除率高达90.6%,悬浮液固形物浓度(MLSS)达到3876 mg/L,污泥体积指数(SVI)为60.3 m L/g,而好氧活性污泥系统COD_(Cr)去除率为82.4%,MLSS为3135 mg/L,SVI为70.3 m L/g。对出水的紫外扫描结果表明,悬浮填料生物膜-MBR系统对200~300 nm波长处特征污染物的降解效果明显优于好氧活性污泥系统。     

微磁场条件下制浆中段废水冲击对微氧活性污泥系统的影响

研究了微磁场条件下制浆中段废水冲击对处理低负荷葡萄糖废水的微氧活性污泥系统的影响。采用制浆中段废水作为毒性废水对添加磁粉和无磁粉反应器微氧活性污泥进行16天的冲击,而后采用葡萄糖废水进行12天的恢复实验。经制浆中段废水冲击之后,有磁粉反应器最终出水的COD Cr去除率仍能达到71.57%,而无磁粉反应器仅37.29%。恢复实验中有磁粉反应器保持在80%以上,而无磁粉反应器仅能达到40%左右。对制浆中段废水冲击下污泥理化指标SVI和MLSS变化情况进行考察,结果表明有磁粉反应器的两项指标均优于无磁粉反应器。经过12天的恢复实验,添加磁粉反应器污泥的理化指标均能恢复到接近初始值,而无磁粉反应器性能难以恢复到接近初始值。     

pH冲击对降解五氯酚的微氧颗粒污泥理化特性的影响

在pH=6.0和9.0的冲击下,对降解PCP微氧颗粒污泥理化特性的影响进行了研究。pH=6.0或pH=9.0冲击8d,污泥中胞外多糖(PS)和蛋白质(PN)含量减少,PN/PS减少更为明显。与正常条件下相比,pH冲击后,污泥的SVI值上升,沉降速率降低,污泥平均粒径减小。与pH=6.0相比,pH=9.0冲击下,污泥理化特性恶化更为明显。     

优势菌群强化好氧活性污泥处理制浆中段废水的研究

利用实验室构建的优势菌群(B.subtilis∶B.cereus∶V.pantothenticus=35%∶50%∶15%,质量比)强化好氧活性污泥以处理制浆中段废水。污泥驯化实验表明,投加优势菌群体系的CODCr去除率和污泥的理化特性均优于不投加优势菌群体系的。当优势菌群投加量为0.3 g/L时,废水处理效果最好,处理周期为8 h,比不投加优势菌群的体系缩短了1 h,CODCr去除率达72.9%。降解动力学实验结果表明,好氧活性污泥处理制浆中段废水符合一级降解动力学模型,优势菌群投加量为0.3 g/L的体系降解速率常数最大,为0.0487 min-1,且大于不投加优势菌群的体系。     

降解五氯酚的微氧磁性活性污泥理化特性的研究

以厌氧污泥为种泥,在微磁场、低溶解氧条件下,梯度式加入五氯酚（PCP）驯化污泥,并以不加磁粉的反应器作为对照,考察驯化过程微氧磁性活性污泥的污泥浓度（MLSS）、污泥体积指数（SVI值）及絮凝性能。在整个驯化过程中,有磁粉反应器中微氧活性污泥紧实,絮体较大,MLSS高于无磁粉反应器的,在PCP浓度低于20 mg/L时,SVI值始终保持在45~55 mL/g,沉降性能良好;而无磁粉反应器中污泥松散,SVI值较高。对污泥胞外多聚物（ECPs）总量、蛋白质与多糖比值的测定结果表明,磁粉的加入大大提高了污泥的絮凝性能。     

檀皮蒸煮黑液厌氧后的好氧(SBR)处理

研究了高浓度废水 (檀皮蒸煮黑液 )厌氧处理后的好氧 (SBR)工艺处理 ,对进水浓度、pH值、曝气时间、SVI和污泥负荷等的处理效果进行了考察。结果表明 :进水CODCr为 1 6 2 0 7mg/L ,pH值为 7 0 ,曝气时间为 2 0h ,SVT为 85mL/g ,有机负荷为 0 2 5kgCODCr/kgMLSS·d时 ,去除效果好 ,CODCr去除率可达 90 %以上 ,但对色度去除效果不理想。再进行混凝处理 ,色度的去除效果好 ,处理最终出水可达标排放。     

Fe3+对好氧活性污泥理化特性的影响

探讨了Fe³⁺对好氧活性污泥理化特性的影响。结果表明：与对照样(不加Fe³⁺)相比,整个驯化过程中,加Fe³⁺反应器内的混合液悬浮物(MLSS)质量浓度和胞外多糖与蛋白质的质量比较高,但污泥体积指数却较低;加Fe³⁺反应器内的胞外多聚物含量在驯化前期高于对照样,在驯化后期却低于对照样;加Fe³⁺可以提高污泥的沉降性能和絮凝性能。     

Formation and characterization of aerobic granules in a sequencing batch reactor treating soybean-processing wastewater

Aerobic granules were cultivated in a sequencing batch reactor (SBR) fed with soybean-processing wastewater at 25+/-1 degrees C and pH 7.0+/-0.1. The granulation process was described via measuring the increase of sludge size. The formation of granules was found to be a four-phase process, that is, acclimating, shaping, developing, and maturated. A modified Logistic model could well fit with the granule growth by diameter and could be employed to estimate the maximum diameter, lag time, and specific diameter growth rate effectively. Both normal and log-normal distributions proved to be applicable to model the diameter distribution of the granules. The granule-containing liquor was shear thinning, and their rheological characteristics could be described by using the Herschel-Buckley equation. The suspended solids concentration, pH, temperature, diameter, settling velocity, specific gravity, and sludge volume index all had an effect on the apparent viscosity of the mixed liquor of granules. The matured granules had fractal nature with a fractal dimension of 1.87+/-0.34. Moreover, 83% of matured granules were permeable with fluid collection efficiencies over 0.034. As compared to activated sludge flocs, the aerobic granules grown on the soybean-processing wastewater had better settling ability, mass transfer efficiency, and bioactivity.     

Pilot-scale waste activated sludge alkaline fermentation, fermentation liquid separation, and application of fermentation liquid to improve biological nutrient removal

The use of sludge fermentative short-chain fatty acids (SCFA) as an additional carbon source of biological nutrient removal (BNR) has drawn much attention recently as it can reuse sludge organics, reduce waste activated sludge production, and improve BNR performance. Our previous laboratory study had shown that the SCFA production was significantly enhanced by controlling sludge fermentation at pH 10 with NaOH. This paper focused on a pilot-scale study of alkaline fermentation of waste activated sludge, separation of the fermentation liquid from the alkaline fermentation system, and application of the fermentation liquid to improve municipal biological nitrogen and phosphorus removal. NaOH and Ca(OH)(2) were used respectively to adjust the alkaline fermentation pH, and their effects on sludge fermentation and fermentation liquid separation were compared. The results showed that the use of Ca(OH)(2) had almost the same effect on SCFA production improvement and sludge volatile suspended solids reduction as that of NaOH, but it exhibited better sludge dewatering, lower chemical costs, and higher fermentation liquid recovery efficiency. When the fermentation liquids, adjusted with Ca(OH)(2) and NaOH respectively, were added continuously to an anaerobic-anoxic-aerobic municipal wastewater BNR system, both the nitrogen and phosphorus removals, compared with the control, were improved to the same levels. This was attributed to the increase of not only influent COD but also denitrifying phosphorus removal capability. It seems that the use of Ca(OH)(2) to control sludge fermentation at pH 10 for efficiently producing a carbon source for BNR is feasible.     

A laboratory-scale test of anaerobic digestion and methane production after phosphorus recovery from waste activated sludge

In enhanced biological phosphorus removal (EBPR) processes, activated sludge microorganisms accumulate large quantities of polyphosphate (polyP) intracellularly. We previously discovered that nearly all of polyP could be released from waste activated sludge simply by heating it at 70 degrees C for about 1 h. We also demonstrated that this simple method was applicable to phosphorus (P) recovery from waste activated sludge in a pilot plant-scale EBPR process. In the present study, we evaluated the effect of this sludge processing (heat treatment followed by calcium phosphate precipitation) on anaerobic digestion in laboratory-scale experiments. The results suggested that the sludge processing for P recovery could improve digestive efficiency and methane productivity at both mesophilic (37 degrees C) and thermophilic (53 degrees C) temperatures. In addition, heat-treated waste sludge released far less P into the digested sludge liquor than did untreated waste sludge. It is likely that the P recovery step prior to anaerobic digestion has a potential advantage for controlling struvite (magnesium ammonium phosphate) deposit problems in sludge handling processes.     

活性污泥法处理TMP废水的研究

介绍了活性污泥法处理TMP废水的试验,研究水力停留时间(HRT)、污泥年龄(0)和污泥有机负荷(F/M)等参数对COD、BOD_5和RFA的去除率及污泥特性的影响。讨论了活性污泥处理法试验的工艺条件编制程序。     

一株假单胞菌的分离鉴定及其产絮凝剂絮凝特性的研究

目的:获得高效廉价的微生物絮凝剂。方法:利用常规筛选技术从宜州龙江河沿岸排污口污泥中分离筛选菌株,菌种鉴定是经形态观察、理化特性分析以及分子水平16S rDNA系统进化分析进行的;按照常规方法考察了絮凝剂在高岭土、活性炭及酵母悬浮液中的絮凝性能和影响絮凝性能的因素。结果:获得一株产絮凝剂的菌株L2019-2,该絮凝活性菌株鉴定为维罗纳假单胞菌(Pseudomonas veronii)。其产生的生物高分子絮凝剂在无机悬浮液和有机悬浮液中均具有絮凝活性。在高岭土悬浮液中,pH为5.0、温度为30 ℃、助凝剂为Fe3+时,絮凝剂的絮凝活性较高,絮凝率达98.30%。经化学组成分析,该絮凝剂为酸性糖蛋白。结论:L2019-2所产絮凝剂具有很好的絮凝性能,可为研究微生物絮凝剂提供良好的菌种资源,在污水处理中更具有很好的应用潜力。     

Removal of antibiotics in wastewater: Effect of hydraulic and solid retention times on the fate of tetracycline in the activated sludge process

A study was conducted to examine the influence of hydraulic retention time (HRT) and solid retention time (SRT) on the removal of tetracycline in the activated sludge processes. Two lab-scale sequencing batch reactors (SBRs) were operated to simulate the activated sludge process. One SBR was spiked with 250 microg/L tetracycline, while the other SBR was evaluated at tetracycline concentrations found in the influent of the wastewater treatment plant (WWTP) where the activated sludge was obtained. The concentrations of tetracyclines in the influent of the WWTP ranged from 0.1 to 0.6 microg/L. Three different operating conditions were applied during the study (phase 1-HRT: 24 h and SRT: 10 days; phase 2-HRT: 7.4 h and SRT: 10 days; and phase 3-HRT: 7.4 h and SRT: 3 days). The removal efficiency of tetracycline in phase 3 (78.4 +/- 7.1%) was significantly lower than that observed in phase 1 (86.4 +/- 8.7%) and phase 2 (85.1 +/- 5.4%) at the 95% confidence level. The reduction of SRT in phase 3 while maintaining a constant HRT decreased tetracycline removal efficiency. Sorption kinetics reached equilibrium within 24 h. Batch equilibrium experiments yielded an adsorption coefficient (Kads) of 8400 +/- 500 mL/g and a desorption coefficient (Kdes) of 22 600 +/- 2200 mL/g. No evidence of biodegradation for tetracycline was observed during the biodegradability test, and sorption was found to be the principal removal mechanism of tetracycline in activated sludge.     

Pilot-scale evaluation of the application of low pH-inducible polyphosphate accumulation to the biological removal of phosphate from wastewaters

To investigate the possible biotechnological application of the phenomenon of low pH-inducible phosphate uptake and polyphosphate accumulation, previously reported using pure microbial cultures and under laboratory conditions, a 2000 L activated sludge pilot plant was constructed at a municipal sewage treatment works. When operated as a single-stage reactor this removed more than 60% of influent phosphate from primary settled sewage at a pH of 6.0, as opposed to approximately 30% at the typical operational pH for the works of 7.0-7.3-yet without any deleterious effect on other treatment parameters. At these pH values the phosphorus content of the sludge was, respectively, 4.2% and 2.0%. At pH 6.0 some 33.9% of sludge microbial cells were observed to contain polyphosphate inclusions; the corresponding value at pH 7.0 was 18.7%. Such a process may serve as a prototype for the development of alternative biological and chemical options for phosphate removal from wastewaters.     

Biodegradation of p-nitrophenol by aerobic granules in a sequencing batch reactor

In this study, aerobic granules to treat wastewater containing p-nitrophenol (PNP) were successfully developed in a sequencing batch reactor (SBR) using activated sludge as inoculum. A key step was the conditioning of the activated sludge seed to enrich for biomass with improved settleability and higher PNP degradation activity by implementing progressive decreases in settling time and stepwise increases in PNP concentration. The aerobic granules were cultivated at a PNP loading rate of 0.6 kg/ m3 x day, with glucose to boost the growth of PNP-degrading biomass. The granules had a clearly defined shape and appearance, settled significantly faster than activated sludge, and were capable of nearly complete PNP removal. The granules had specific PNP degradation rates that increased with PNP concentration from 0 to 40.1 mg of PNP/L, peaked at 19.3 mg of PNP/(g of VSS) x h (VSS = volatile suspended solids), and declined with further increases in PNP concentration as substrate inhibition effects became significant. Batch incubation experiments show that the PNP-degrading granules could also degrade other phenolic compounds, such as hydroquinone, p-nitrocatechol, phenol, 2,4-dichlorophenol, and 2,6-dichlorophenol. The PNP-degrading granules contained diverse microbial morphotypes, and PNP-degrading bacteria accounted for 49% of the total culturable heterotrophic bacteria. Denaturing gradient gel electrophoresis analysis of 16S rRNA gene fragments showed a gradual temporal shift in microbial community succession as the granules developed from the activated sludge seed. Specific oxygen utilization rates at 100 mg/L PNP were found to increase with the evolution of smaller granules to large granules, suggesting that the granulation process can enhance metabolic efficiency toward biodegradation of PNP. The results in this study demonstrate that it is possible to use aerobic granules for PNP biodegradation and broadens the benefits of using the SBR to target treatment of toxic and recalcitrant organic compounds.     

带选择器的好氧活性污泥法处理制浆混合废水

介绍了采用初沉池+带选择器的好氧活性污泥池处理制浆混合废水的工艺流程和工艺参数,并对实际运行效果进行了分析。