基质浓度对ABR厌氧氨氧化反硝化脱氮除碳效能影响及动力学特征

采用厌氧折流板反应器(ABR)为研究对象,以一定COD、NH+4-N和NO-2-N比例增加进水基质浓度,以明确基质负荷提高对ABR厌氧氨氧化和反硝化协同体系脱氮除碳的影响,并通过基质去除模型获得反应器对基质的耐受程度.研究表明,ABR反应器能够实现厌氧氨氧化反硝化耦合脱氮除碳,当进水基质COD、NO-2-N和NH+4-N浓度从220、168和60 mg·L~(-1)提高至420、270和110 mg·L~(-1)时,反应器脱氮效能下降,COD、NO-2-N、NH+4-N和TN去除率分别为97%、94%、30%和78%,厌氧氨氧化对TN去除的贡献率从43.08%骤降至16.49%,反硝化脱氮贡献率从53.81%增至82.07%.动力学模型拟合发现,Stover-Kincannon模型(R2=0.937,TN;R2=0.975,COD)较一级基质去除模型(R2=0.314,TN;R2=0.016,COD)更适合评价反应器对基质的承受力;Stover-Kincannon模型表明,反应器对TN和COD的最大基质利用率分别为1.43 g·L-1·d-1和3.33 g·L-1·d-1,饱和常数(KB)分别为1.2和3.79,研究认为ABR协同脱氮除碳体系理论上还有继续提升基质负荷的潜力.     

An innovative approach to minimize excess sludge production in sewage treatment using integrated bioreactors

The present investigation deals with an application of integrated sequential oxic and anoxic bioreactor(SOABR) and fluidized immobilized cell carbon oxidation(FICCO) reactor for the treatment of domestic wastewater with minimum sludge generation. The performance of integrated SOABR-FICCO system was evaluated on treating the domestic wastewater at hydraulic retention time(HRT) of 3 hr and 6 hr for 120 days at organic loading rate(OLR)of 191 ± 31 mg/(L·hr). The influent wastewater was characterized by chemical oxygen demand(COD) 573 ± 93 mg/L; biochemical oxygen demand(BOD5) 197 ± 35 mg/L and total suspended solids(TSS) 450 ± 136 mg/L. The integrated SOABR-FICCO reactors have established a significant removal of COD by 94% ± 1%, BOD5 by 95% ± 0.6% and TSS by 95% ± 4% with treated domestic wastewater characteristics COD 33 ± 5 mg/L; BOD59 ± 0.8 mg/L and TSS 17 ± 9 mg/L under continuous mode of operation for 120 days. The mass of dry sludge generated from SOABR-FICCO system was 22.9 g/m~3. The sludge volume index of sludge formed in the SOABR reactor was 32 mL/g and in FICCO reactor it was 46 mL/g. The sludge formed in SOABR and FICCO reactor was characterized by TGA, DSC and SEM analysis. Overall, the results demonstrated that the integrated SOABR-FICCO reactors substantially removed the pollution parameters from domestic wastewater with minimum sludge production.     

Effects of tourmaline on nitrogen removal performance and biofilm structures in the sequencing batch biofilm reactor

The effects of tourmaline on nitrogen removal performance and biofilm structures were comparatively investigated in two identical laboratory-scale sequencing batch biofilm reactors(SBBRs)(denoted SBBR1 and SBBR2) at different nitrogen loading rates(NLRs) varying from(0.24 ± 0.01) to(1.26 ± 0.02) g N/(L·day). SBBR1 was operated in parallel with SBBR2, but SBBR1 was filled with polyurethane foam loaded tourmaline(TPU) carriers and another(SBBR2) filled with polyurethane foam(PU) carriers. Results obtained from this study showed that the excellent and stable performance of SBBR1 was obtained. Ammonia nitrogen removal and total nitrogen removal were higher in SBBR1 than that in SBBR2 with increase of NLR. At an NLR of(0.24 ± 0.01) g N/(L·day), the majority of the spherical and elliptical bacteria were surrounded by the extracellular polymeric substance(EPS) and bacillus or filamentous bacteria in two SBBRs biofilms. When NLR increased to(1.26 ± 0.02) g N/(L·day), the clusters were more obvious in the SBBR1 biofilm than that in the SBBR2 biofilm. Bacteria in SBBR1 were inclined to synthesis more EPS, and the formed EPS could protect the bacteria from free ammonia(FA) under extreme condition NLR(1.26 ± 0.02) g N/(L·day). The results of polymerase chain reaction-denaturing gradient gel electrophoresis analysis showed that the microbial community similarity in SBBR2 decreased more obviously than that in SBBR1 with the increase of NLR, which the microbial community in SBBR1 was relatively stable.     

Selection of cost-effective magnesium sources for fluidized struvite crystallization

Struvite crystallization has been considered a promising approach to recover phosphorus from wastewater. However, its practical application is limited, probably because of the high cost of magnesium(Mg). In this study, a comprehensive economic analysis was conducted using five Mg sources(MgCl_2, MgSO_4, MgO, Mg(OH)_2, and bittern) during the operation of a pilot-scale fluidized bed reactor(FBR), using swine wastewater as the case matrix. First, the economic operating conditions were investigated, and subsequently, the performance and the costs of the five Mg sources were compared. The results indicated that the FBR could be operated most economically at pH of 8.5 and Mg to phosphorus(Mg/P) molar ratio of 1.5. Under these conditions, no significant differences in phosphorus removal and product quality could be found between the five Mg sources. Selecting the most economical Mg source was thus highly dependent on the prices of the reagents and Mg sources. Low-solubility Mg sources were preferable when NaOH was priced higher, while high-solubility Mg sources proved more economical when HNO_3 was expensive. The bittern was the most economical choice only when the distances for total inorganic orthophosphate removal and struvite recovery were shorter than 40 and 270 km, respectively. The current study provides an overview of the economic selection of an Mg source, which can help reduce the cost of struvite crystallization.     

含能材料反应釜温度模型仿真辨识

目的验证一种基于遗忘因子最小二乘法(FFRLS)的含能材料反应釜温度预测模型辨识方法的正确性和有效性。方法首先利用基于机理建模方法对系统模型进行分段处理,并得到其具体结构,然后结合历史数据,利用FFRLS对系统模型参数进行辨识,最后得到含能材料反应釜温度仿真模型。结果在Matlab仿真平台上对该方法的正确性和有效性进行验证,模型参数慢时变状态下该方法辨识参数的模型参数均方根误差(RMSE)皆小于10%,模型参数突变状态下,参数RMSE最小为5.89%,最大为18.69%。结论该方法能准确、有效地对含能材料反应釜温度模型进行辨识。     

厌氧浮动生物膜反应器处理高浓度有机废水

本文探讨了厌氧浮动生物膜反应器、处理高浓度有机废水的研究。试验结果表明，在温度２０℃￣２８℃，容积负荷为５．３８￣２０．６２ｋｇＣＯＤ／ｍ＾３·ｄ，水力停留时间２３．４ｈ，ＣＯＤ去除率在９０％以上，反应器内污泥持留量高，抗冲击负荷能力强。微生物既有附着生长系统，也有大量悬浮颗粒污泥，生物膜中与颗粒污泥中的生物相有明显差异。     

高浓度褐藻酸钠生产废水处理工程设计

利用以EGSB反应器为主体的生物法与混凝工艺相结合处理高浓度褐藻酸钠生产废水，处理水质可达到国家污水综合排放二级标准。工程实践表明该工艺具有投资与占地面积少，运行效果稳定，可回收能源等优点。     

折流式水解反应器处理印染废水温影响研究

在水温为5℃、9．7℃、14．9℃、19．7℃、23．5℃和31．1℃6种温度的条件下，应用折流式水解反应器对印染废水进行水解试验研究。结果表明，提高水温可增大COD、色度及UVA254的去除效率，相应的ORP值变小，pH值升高，水解程度加深。水温5℃时，水解效果较差；水温在10—23．5℃内，水解效果相对较好，31．1℃水解效果最好，研究结果能为工程应用提供一定的参考。     

流动床生物膜反应器在污水处理中的应用研究现状

给出了流动床生物膜反应器的定义、分类及其特点 ,并对各种流动床生物膜反应器的优缺点及近年来在污水处理中的应用状况进行了总结 ,根据实际应用效果 ,提出了各类反应器的适用处理对象     

鼓泡塔中有机酸强化粗颗粒石灰石新型烟气脱硫

对传统石灰石湿法烟气脱硫进行了改进,提出了一种新型烟气脱硫方法,即在鼓泡塔中添加有机酸,采用大颗粒石灰石(210 μm)代替传统的细颗粒石灰石(5～20 μm)进行脱硫.实验在鼓泡搅拌吸收反应器中对比研究了新老两种脱硫工艺.结果表明,当210 μm石灰石浆液中醋酸摩尔浓度达10～30 mmol/L,其脱硫率和石灰石利用率分别为95%和93.5%,均达到甚至优于传统石灰石脱硫结果.实验研究了影响脱硫率的各种因素:添加醋酸浓度、入口SO2浓度、石灰石浆液浓度、气体停留时间以及温度等,并提出添加醋酸促进SO2吸收的机理.运用该新型烟气脱硫方法,可降低电厂的基础投资和运行费用,大大加强系统的稳定性和抗击烟气中SO2波动的能力.