活性炭对水中2,4-二氯酚的吸附研究

以活性炭作为去除水中2,4 二氯酚的吸附剂,考察了振荡时间、水样pH值对吸附效果的影响,采用Langmuir和Freundlich模式对吸附等温线作了线性拟合,结果表明2,4 二氯酚在活性炭上的吸附可用Langmuir和Freundlich较好地描述,吸附呈单分子层形式且易于进行,活性炭对2,4 二氯酚吸附性能良好,吸附剂易于再生。     

解偶联剂对活性污泥产率的影响及机理研究

以2,4-二硝基酚(dNP)为解偶联剂,采用序批式实验分析研究了投加解偶联剂dNP对活性污泥法处理效果和污泥产率的影响,并阐述了这种影响产生的机理。实验表明,当污泥浓度ρ(MLVSS)为1800mg/L,ρ(CODCr)为1700mg/L,dNP投加量为5mg/L时污泥产率降低达19%,处理效果仅降低1%,实验同时表明dNP经济有效的投加量为1~5mg/L。     

驯化污泥对厌氧生物降解2,4-二氯酚的影响

以2,4-二氯酚(2,4-DCP)为目标污染物,考察葡萄糖共基质条件下厌氧污泥驯化过程中目标物的生物降解以及驯化污泥对2,4-DCP降解效果的影响.结果表明:厌氧污泥具有降解2,4-DCP的潜力,连续驯化2个月其对污染物的降解能力逐步增强.2,4,6-TCP(2,4,5-三氯酚)与2,4-DCP长期共存可加快厌氧污泥对...     

含2,4-二氯酚活性炭的微波再生研究

对吸附2,4-二氯酚(DCP)后的颗粒活性炭(GAC)进行了微波再生研究,考察了微波功率、微波辐照时间和GAC用量对DCP解吸和GAC损耗的影响。结果表明,DCP解吸率随着微波功率、辐照时间以及GAC用量的增加而提高,但相应的GAC损耗量亦随之增加。微波功率420 W,辐照时间3 min,饱和吸附DCP的GAC 5 g,DCP解吸率达95.5%,而GAC损耗量仅为9.1%。通过测定多次再生后GAC的碘值,表明2次吸附-再生循环后GAC碘值超过了新鲜GAC的碘值,5次循环后GAC碘值下降不明显。     

超声波协同铁粉降解水中2,4-二氯酚的研究

采用超声波/铁粉协同降解水中2,4-二氯酚。考察了初始浓度、超声功率、铁粉投加量以及pH对降解效率的影响,并初步探讨了超声波/铁粉协同降解2,4-二氯酚的动力学规律。结果表明,超声波与铁粉对2,4-二氯酚的降解具有明显的协同效应。降解效率随超声功率和铁粉投加量的增大而增大,随初始浓度的增大而减小。pH对2,4-二氯酚的降解有显著影响,在pH为4时,降解效率最高。超声波/铁对2,4-二氯酚的协同降解符合一级反应动力学规律,降解速率常数为1.52×10-2min-1,与铁粉单独作用和超声单独作用相比,分别提高了约5倍和13倍。     

活性炭对水中2，4-二氯酚的吸附研究

以活性炭作为去除水中2，4-二氯酚的吸附剂，考察了振荡时间、水样pH值对吸附效果的影响，采用Langmuir和Fmundlich模式对吸附等温线作了线性拟合，结果表明2，4-二氯酚在活性炭上的吸附可用Langmuir和Freundlich较好地描述，吸附呈单分子层形式且易于进行，活性炭对2，4-二氯酚吸附性能良好，吸附剂易于再生。     

UV-H2O2系统对水中2,4-二氯酚氧化降解研究

研究了用UV-H2O2体系对水中2,4-二氯酚氧化降解。结果表明,UV-H2O2体系中H2O2的投加量主要由UV光强度和有机物初始浓度来确定,酸性和中性条件下有利于UV-H2O2体系对2,4-二氯酚的降解;最佳反应温度在20～25℃;UV-H2O2光氧化技术适用于低浊度水的深度处理,降解效果以浊度6 NTU为分界点。在Fenton试验中,向质量浓度为20mg/L的2,4-二氯酚溶液加入2.0mg/L的Fe2+,同时把H2O2的投加量减为0.204mg/L,pH值3.0左右,此时UV-H2O2-Fenton体系对2,4-二氯酚的氧化效率大大提高,比单纯Fenton体系的降解率提高1倍,达到95.6%。用UV-Fenton体系去除有机污染物在效果和经济上均具有明显的优越性。     

有机膨润土负载纳米铁去除2,4-二氯酚

用具有良好吸附能力的有机膨润土作载体,通过FeSO4与NaBH4反应制得有机膨润土负载的纳米铁(nanoscale zero-valent iron supported onorganobentonite,NZVI/CTMAB-Bent).用X射线衍射、Brunauer-Emmett-Teller法对NZVI/CTMAB-Bent进行了结构表征,并将NZVI/CTMAB-Bent作催化剂用于2,4-二氯酚的去除.考察了NZVI/CTMAB-Bent与2,4-二氯酚反应过程中,介质pH值、不同起始浓度的2,4-二氯酚对其去除率的影响,并与相同铁含量的纳米铁(nanoscale zero-valent iron,NZW)进行了比较.结果表明:在相同实验条件下,2,4-二氯酚与NZVI/CTMAB-Bent反应120 min后去除率达90.6%,不仅远高于相同铁含量NZVI对2,4-二氯酚去除率(23.2%),而且也明显优于相同铁含量的NZVI和含土量相同的有机膨润土对2,4-二氯酚去除率的加和(39.0%).     

二氧化钛光催化降解2,4-二氯酚的研究

实验采用溶胶-凝胶法制备了一种新型的TiO_2催化剂,选择"优先控制污染物"2,4-二氯酚为目标污染物,紫外光为光源组成的光催化降解体系。采用紫外分光光度仪,分析了TiO_2光催化降解2,4-二氯酚,并对降解产物进行了分析。所制备的催化剂性能稳定,具有良好的光催化效果。     

2,4-二氯过氧化苯甲酰合成新工艺研究

研究了以对甲苯磺酰氯为原料合成2,4-二氯过氧化苯甲酰的新工艺,该工艺对原工艺进行了重大改革,其材料成本仅为原工艺的1/10。     

生物预酸化处理明胶废水对活性污泥减量化的作用

明胶废水具有高钙、高COD等特点而难于处理。通过对明胶废水进行生物预酸化处理,研究了活性污泥法处理明胶废水过程中COD去除率、MLSS、MLVSS以及无机灰分的变化。结果表明,经过生物预酸化处理后,明胶废水的p H由11.8降至7.4左右,COD由1 058 mg/L降至671 mg/L。后续活性污泥法处理过程中,与未进行生物预酸化处理相比,MLSS、MLVSS呈明显下降趋势,最终COD去除率达到90%;同时由于反应器维持在较低的p H下运行,避免了曝气生成CaCO_3沉淀,污泥无机灰分减少。生物预酸化处理对污泥减量化有明显贡献。     

Addition of activated carbon to batch activated sludge reactors in the treatment of landfill leachate and domestic wastewater

Leachate from a municipal landfill was combined with domestic wastewater and was treated in batch activated sludge systems. The effectiveness and applicability of the addition of Powdered Activated Carbon (PAC) to activated sludge reactors was investigated. Isotherm tests were carried out with PAC in order to estimate the extent of adsorption of organic matter onto PAC. Then, in activated sludge reactors COD (Chemical Oxygen Demand) removal and nitrification were studied both in the absence and presence of PAC for comparison purposes. In both cases, Oxygen Uptake Rates (OUR) were measured with respect to time in order to investigate substrate removal and change in microbial activity. Addition of PAC to activated sludge increased COD removal by removing mainly the non‐biodegradable fraction in leachate. The COD decreases in batch reactors were best expressed by a first‐order kinetic model that incorporated this non‐biodegradable leachate fraction. With added PAC, nitrification was also enhanced. But in all of the batch runs a significant accumulation of NO₂ ‐N took place, indicating that the second step of nitrification was still inhibited. © 2001 Society of Chemical Industry     

超声功率对超声破解污泥的影响

超声破解是促进污泥厌氧消化的一项新技术,超声功率直接影响污泥破解的效率和能耗。本文通过探头式和槽式超声波反应器不同功率组合成单功率模式、双功率模式和三功率模式破解污泥的试验,得出低功率长时间利于污泥超声破解,但速率较低,低功率组合可提高破解速率。综合分析比较,得出三功率模式中,低功率组合更利于污泥超声破解。     

好氧颗粒污泥处理啤酒废水的研究

以葡萄糖模拟废水培养出的好氧颗粒污泥为接种体,通过啤酒废水驯化,考察该污泥处理啤酒废水的可行性。实验结果表明,葡萄糖好氧颗粒污泥经驯化后能够迅速适应这种以糖类有机污染物为主的啤酒废水,驯化前后的污泥形态、生物活性差别不明显,相应的比耗氧速率分别为41.90和39.54g[O2]/(kg[MLSS].h)。驯化后的MLSS的质量浓度为8.23g/L左右,反应器的有机负荷稳定在4.3g[COD]/(L.d),而出水COD的质量浓度保持在45mg/L以下。因此,采用好氧颗粒污泥处理易生化的中低浓度工业废水有良好的应用前景。     

The use of 3,3′,4′,5‐tetrachlorosalicylanilide as a chemical uncoupler to reduce activated sludge yield

To determine whether chemical additions can be used to reduce sludge production in biological wastewater treatment, 3,3′,4′,5‐tetrachlorosalicylanilide (TCS) was added to activated sludge cultures as a metabolic uncoupler. Batch tests confirmed that TCS is an effective chemical uncoupler in reducing the sludge yield at concentrations greater than 1.0 mg dm^?3; a TCS concentration of 1.0 mg dm^?3 reduced sludge yield by approximately 50%. Substrate removal capability and effluent nitrogen concentration were not affected adversely by the presence of TCS when dosed every other day in a range of 2.0–3.6 mg dm^?3 during the 40‐day operation of activated sludge batch cultures. Such sludge growth reduction was associated with the enhancement of microbial activities in terms of the specific oxygen uptake rate and dehydrogenase activity. Sludge settleability of the treated and control samples was qualitatively comparable and not significantly different. Filamentous bacteria continued to grow in sludge flocs only in the control reactor at the end of the 40‐day trial. These results suggest that TCS treatment of activated sludge systems may reduce excess sludge yield. Copyright © 2003 Society of Chemical Industry     

臭氧氧化对活性污泥特性的影响

研究了对活性污泥采用臭氧处理,以考察污泥的减量效果及其对污泥特性的影响。结果表明:在臭氧投加量0.01～0.15gO3/gVSS范围内,污泥浓度显著下降、SCOD浓度迅速升高,活性污泥总悬浮固体(TSS)最大可以减少39.6%,SCOD浓度可提高60.6倍,污泥的SCOD产率为0.6739gSCOD/gVSS,同时发现,破解后的污泥活性和体积指数SVI下降;试验确定最佳臭氧投加量在0.03gO3/gVSS左右。试验结果对今后污泥减量技术的推广应用提供了理论基础。     

Effect of sludge retention time in sludge holding tank on excess sludge production in the oxic‐settling‐anoxic (OSA) activated sludge process

The activated sludge process is a core technology in wastewater treatment plants. Excess sludge produced in the process must be treated and disposed of properly and may account for up to 60% of total plant operating cost. Therefore, it is necessary to develop new biological concepts to minimize excess sludge production. The oxic‐settling‐anoxic process (OSA process), a modified activated sludge process, may produce less excess sludge than the conventional activated sludge process. The effect of sludge retention time in the sludge holding tank of the OSA process on excess sludge yield has been studied. Four pilot‐scale activated sludge systems were employed, one of which was a conventional activated sludge process, and was used as the control system. The other three were OSA systems operated with different sludge retention times (5.5 h, 7.6 h, and 11.5 h) in the sludge holding tank. All systems were operated with synthetic wastewater for 7 months. Results showed that the three OSA processes with 5.5 h, 7.6 h, and 11.5 h sludge retention time reduced the excess sludge by 33%, 23% and 14%, respectively. Compared to the control process, chemical oxygen demand (COD) removal efficiency and effluent NH₃–N concentration were not significantly influenced, but total nitrogen (TN) removal efficiency decreased by 0–9%. Total phosphorus (TP) removal efficiency of OSA processes with 7.6 h and 11.5 h sludge retention time increased by 19%. Sludge settleability was excellent in the three OSA processes. No distinct shift in the diversity of the predominant species was found in microbial populations. We conclude that the OSA system could reduce excess sludge production. Results suggest 6–7 h sludge retention time would be optimal. Copyright © 2007 Society of Chemical Industry     

Characteristics of phenol degradation by immobilized activated sludge

The effects of various factors involved in phenol degradation through an immobilized activated sludge with a photo-crosslinked resin were investigated. The immobilized activated sludge showed a higher relative activity of phenol degradation across a broader range of pH than free activated sludge. A higher rate of phenol degradation was observed when the bead size was smaller. The phenol degradation in the free activated sludge was inhibited at the 3000 mg/L of phenol, while that in the immobilized activated sludge was maintained at the same concentration for 28 h without any inhibition. The degradation rates of phenol were not directly proportional to the increasing amount of immobilized bead dosage, but the phenol degradation was completed in a shorter time than that for the free activated sludge. For the repeated reaction of immobilized activated sludge, the relative activity is increased up to eight times after seven repeated initial cycles. Continued treatment of immobilized activated sludge showed more than 95% of phenol removal efficiency under a loading rate of 5.59 kg-phenol/(m³ d), which is twice as large as the loading rate for the free activated sludge.     

活性污泥系统比耗氧速率在线检测与变化规律

为了研究活性污泥微生物代谢活性和基质降解效率,建立了一种在线测量SBR工艺比耗氧速率(SOUR)的方法,并考察了活性污泥系统SOUR在有机物降解与氨氧化过程中的变化规律。结果表明:无论在恒定DO还是在恒定曝气量条件下,SOUR曲线上均先后出现了溶解性COD降解、氨氮氧化和内源呼吸3个阶段。由于异养菌竞争溶解氧相对于硝化细菌占据优势,导致先去除COD后氨氧化。当恒定DO为1.0mg·mL-1时,异养菌降解COD的SOUR为0.36mgO2.(gMLSS)-1.h-1;氨氧化过程中,硝化细菌的SOUR为0.18mgO2.(gMLSS)-1.h-1,当氨氧化结束时,SOUR骤降,该现象表明氨氮到NO2-阶段的氧化结束,此时系统应停止曝气,防止NO2-进一步氧化为NO3-,因此通过SOUR的指示作用可以实现短程硝化启动与维持。