接种物对厌氧同步脱硫反硝化特性的影响实验研究

分别以厌氧污泥、脱氮硫杆菌菌悬液和厌氧污泥并添加脱氮硫杆菌菌悬液为接种物,以硫化物和硝酸盐为进水基质,考察不同接种物条件下,各反应器的硫化物氧化特性、反硝化特性、生化反应机理及微生物特性。结果表明,在无菌条件下,硫化物不能被硝酸盐化学氧化。接种脱氮硫杆菌菌悬液的2#反应器的硫氧化速率为1.98 g S/(m3.h),停留24 h硫化物的去除率高达97%,脱硫能力最强,该接种条件下以硝酸盐氧化硫化物为主反应,优势菌为杆菌,进水的NO3--N/S应控制在0.4以下,可以实现高效生物脱硫。接种厌氧污泥的1#和3#反应器的脱氮效果比2#反应器好,停留时间为24 h时,硝酸盐的平均去除率为96%。单独接种厌氧污泥的1#反应器的硫氧化速率为1.78 g S/(m3.h),其优势菌为球菌,该接种条件下以硝酸盐氧化硫化物和硝酸盐氧化单质硫为主反应,进水的NO3--N/S应控制在0.8左右。以厌氧污泥联合脱氮硫杆菌为接种物时,硫氧化速率为1.71 g S/(m3.h),反应器以硝酸盐氧化硫化物、硝酸盐氧化单质硫以及异养反硝化为主反应,驯化后优势菌为球形、卵圆形和短杆状,应控制进水NO3--N/S为1.2,可以实现同步脱硫反硝化,该工艺既可以用于含硫废水的处理,也可以用于C/N低的硝酸盐废水的处理。     

气升式反应器中微生物烟气脱硫研究

基于微生物酸性铁溶液烟气脱硫特性,实验构建了一套内循环气升式反应器.在反应器中,利用处于对数生长期的氧化亚铁硫杆菌(Thiobacillus ferrooxidans)酸性铁溶液进行了模拟烟道气SO2脱除实验研究.为寻求高脱硫率,实验研究了铁离子浓度、入口氧含量、细菌数和pH值的变化对脱硫率的影响.考察了反应液中Fe(Ⅱ)离子浓度的变化规律.实验表明,含T.f菌酸性铁溶液的脱硫效果较高;Fe离子浓度在7.67 g/L左右时脱硫率最佳;入口气中氧含量、反应液中细菌数和pH值越高,反应液的脱硫率也就越高.反应液中的Fe(Ⅱ)离子浓度是一先扬后抑的变化过程.     

序批式气升环流反应器处理硝基苯废水

采用序批式气升环流反应器(SAR)处理硝基苯废水,研究了硝基苯浓度和COD/N对处理过程的影响,分析了缺氧段COD和硝基苯降解动力学。结果表明,硝基苯在缺氧段被还原为苯胺,而苯胺在好氧段得到快速降解。硝基苯与基质(葡萄糖-COD)最佳质量比为1∶35~1∶25,该条件下反应器对硝基苯和COD去除率分别可达99%~100%和92%~94%。由于受传质限制,进水需要维持106 mg/L的氨氮(葡萄糖-COD/N比值为100∶10)以满足缺氧段微生物对氨氮的营养需要。缺氧段COD的降解符合二级动力学,反应速率常数k2为2.7×10-4L·mg/h;硝基苯的降解符合一级动力学,反应速率常数k1为0.14 h-1。研究表明,序批式气升环流反应器可作为一种简单而有效的反应器用于处理硝基苯废水。     

固定床吸附柱处理含Mn2+酸性矿山废水

为了探究同步去除酸性矿山废水(AMD)中酸度及重金属离子的新型多功能矿物环保材料,确定最佳运行方式,在固定床操作条件下,对比研究复合颗粒吸附柱、锰砂柱、复合颗粒-锰砂混合填充柱对AMD中酸度、Mn2+的去除效果,确定小型连续流反应器的最佳吸附剂;在确定最佳吸附剂的基础上,对比研究升流淹没式、降流淹没式、降流非淹没式吸附柱对AMD中酸度、Mn2+的去除效果,确定小型连续流反应器的最佳运行方式;并结合SEM、XRD等微观分析揭示复合颗粒动态吸附去除重金属离子的规律及机理。实验结果表明:3种吸附材料对Mn2+的吸附容量关系为:PG柱(28.871 mg·g-1)>PG-MS柱(16.935 mg·g-1)>MS柱(2.194 mg·g-1);3种运行方式对Mn2+的吸附容量关系为:降流非淹没式(28.817 mg·g-1)>升流淹没式(26.532 mg·g-1)>降流淹没式(23.479 mg·g-1)。因此,固定床吸附柱处理含Mn2+酸性矿山废水动态实验的最佳吸附材料为膨润土-钢渣复合颗粒,复合颗粒的最佳运行方式为降流非淹没式。PG在去除Mn2+的过程中不仅存在吸附、化学沉淀等作用,还存在聚沉作用,即具有吸附-聚沉协同作用,并且Mn2+在复合颗粒表面的赋存状态主要以Mn-Si-O相结合的矿物相以及CaMn7O12沉淀物存在。     

气升回流一体化中试反应器的污泥减量化

为了减少分散型污水处理设施中剩余污泥的产量以及解决其维护频率高和运行设备复杂等问题,开发了一种集去除有机物、脱氮及污泥减量于一体的气升回流一体化反应器。该反应器由缺氧区、好氧区、沉淀区及气升区组成。中试反应器规模为10.31 m~3,以实际生活污水为处理对象,研究其污泥减量机理。结果表明,当进水容积负荷在0.14~1.39 kg COD·(m~3·d)~(-1)之间时,系统对COD、NH_4~+-N、TN及SS的平均去除率分别为88.6%、93%、66.9%和93%,其污泥表观产率系数Yobs为0.139 g TSS·(g COD)~(-1),表明该工艺具有良好的污泥减量化效果。根据稳态—ASM3号模型及氨氮的物料衡算分析可得:通过细胞裂解—隐性生长作用去除的污泥量占反应器污泥减少总量的77.6%,而原生动物和后生动物捕食的污泥量约占系统污泥减少总量的22.4%。该系统污泥自消解速率为0.44 kg TSS·d~(-1)。     

16SrDNA克隆文库分析含硫污水生物反应器中生物群落

利用生物脱硫技术处理炼油厂含硫污水,硫化物选择性地氧化成单质硫。在进水硫化物605.3 mg·L-1的条件下,硫化物去除率90.7%,单质硫生成率达到80.8%。提取反应器中的DNA样本,构建16S rDNA克隆文库对反应器中的生物群落进行分析。对51个阳性克隆子(长度约为1 400 bp)进行测序,测序结果在NCBI数据库利用Blast比对并构建系统发育树。测序结果表明,生物脱硫反应器细菌种群可分为10个类群,数量最多的是γ-变形菌(γ-Proteobacteria)占76.6%,其余类群共占23.4%。γ-Proteobacteria类群中数量最多的是具有脱硫功能的Halothiobacillus sp.(66.7%)、Thiovirga sp.(25.6%)以及Pseudomonas sp.(7.7%)。系统发育树分析结果表明,生物脱硫系统中形成了以化能自养型脱硫菌为主的微生物群落结构,异养菌数量较少。     

基于硫酸盐还原菌的气提内循环反应器处理酸性矿山废水

针对硫酸盐还原菌(SRB)处理酸性矿山废水(AMD)易受酸、重金属、代谢产物硫离子等多重毒性抑制的问题,采用气提内循环反应器对AMD进行处理,研究了反应器内涉硫组分的演变、产碱效率、微生物群落结构、重金属的去除效果。结果表明:气体内循环反应器可有效解除多重毒性抑制,体系中硫酸盐去除率由36.5%提升至91.24%;且其产碱效率提升了3倍,明显优于传统反应器,脱硫弧菌属的相对丰度也由48%提升至73%;硫化氢与重金属反应得到金属硫化物纯度可达98.12%,出水中Cu~(2+)和Zn~(2+)浓度分别为0和2 mg·L~(-1),可达到《污水综合排放标准》二级标准。以上结果可为SRB生物技术处理AMD的高效控制提供参考。     

柠檬酸强化钢渣湿法烧结烟气脱硫及机理

在鼓泡反应器中考察了添加柠檬酸强化钢渣湿法烧结烟气脱硫的影响因素,包括钢渣粒度,吸收浆液浓度、进口二氧化硫浓度、停留时间,pH值,柠檬酸与钢渣的浸泡时间等,结果表明,柠檬酸浓度为2.0 mmol/L、钢渣浓度为4%、二氧化硫进口浓度为1 500 mg/m3、烟气停留时间为7 s、钢渣强化时间为2 h、钢渣粒度>200目,脱硫率达到90%以上。经4 mmol/L的柠檬酸强化后的钢渣浆液脱硫率比单纯钢渣浆液提高18.41%,达到90.99%的脱硫率,且有效反应时间延长50%,达到60 min以上。柠檬酸的加入,一方面促进了钢渣碱性组分溶解,另一方面在吸收液中形成柠檬酸和柠檬酸盐缓冲体系,增加了气液界面SO2浓度,提高了SO2的气液传质速率。     

硫自养反硝化去除地下水中硝酸盐氮的研究

研究实际地下水硫自养反硝化动力学过程,考察季节因素(温度)对动力学的影响,实验结果表明,地下水升流式硫自养滤柱反硝化动力学符合1/2级动力学模型,其反应速率常数受温度的影响很大,用阿仑尼乌斯方程计算硫自养反硝化活化能为80.38 kJ/mol。硫自养反硝化产生的硫酸根与反硝化掉的硝酸根离子呈线性相关。在地下水不经任何预处理的条件下,硫自养反硝化仍能有效地脱除地下水中的硝酸盐,反应器出水的pH值仍维持在中性范围。     

序批式活性污泥法工艺处理含盐废水动力学模型研究

为了实现含盐废水序批式活性污泥法(SBR)工艺的启动,采用逐步提高废水中NaCl浓度负荷的方法对活性污泥进行驯化,并建立有机物(COD)与NH4+-N的降解动力学模型。结果表明,经过280d的驯化和稳定运行,SBR系统可以有效降解含盐废水,COD去除率高于74%,NH4+-N平均去除率高于90%,实现了SBR工艺处理含盐废水的启动和稳定运行。含盐废水有机物(COD)降解动力学参数r0(无盐条件下的COD去除速率)为129.87mg/(L.h),KY(盐抑制常数)为7700.01mg/L;含盐废水硝化反应动力学参数Ks(饱和常数)为186.52mg/L,vmax(NH4+-N的最大比降解速率)为0.0034h-1。     

AnMBR对高浓度餐厨废水的处理效能

餐厨废水是一类高油、高盐、高氮等较为复杂的废水,在传统厌氧处理中面临污泥漂浮流失、有机负荷低及COD去除效果差等问题。通过构建中试规模厌氧膜生物反应器(anaerobic membrane reactor, AnMBR)处理餐厨废水,考察了3个运行阶段(污泥驯化阶段、容积负荷(volume loading rate, VLR)提升阶段和污泥停留时间(sludge retention time, SRT)缩短阶段)的厌氧消化性能、稳定性能、污泥性质和膜性能变化。结果表明,在污泥驯化阶段,低负荷(1.5 kg·(m³·d)⁻¹)污泥驯化方式能够实现AnMBR的快速启动,甲烷产率由227 mL·g⁻¹ (以COD计)迅速提升至267 mL·g⁻¹,COD去除率达到99%。在VLR提升阶段,当负荷由3.0 kg·(m³·d)⁻¹逐渐增加至12.0 kg·(m³·d)⁻¹时,甲烷产率由283 mL·g⁻¹升高并稳定至335 mL·g⁻¹左右,COD去除率达到98.5%。然而此阶段污泥浓度由13.39 g·L⁻¹迅速升高至45.59 g·L⁻¹,从而导致膜污染加剧,平均膜通量下降速率由0.53 L·(m²·h·d)⁻¹增至0.78 L·(m²·h·d)⁻¹。在SRT缩短阶段(由100 d缩短至40 d),尽管排泥量由0.4 L·d⁻¹增加至1 L·d⁻¹,甲烷产率并没有受到明显影响,仍稳定在335 mL·g⁻¹左右,COD去除率达到98.9%。此外,缩短SRT增大了排泥量,反应器内污泥浓度由45.59 g·L⁻¹逐渐降低至45.27 g·L⁻¹,缓解了膜污染,膜通量下降速率减缓到0.42 L·(m²·h·d)⁻¹。在整个运行阶段,AnMBR对毒性物质氨氮具有良好的耐受能力,尽管体系内氨氮质量浓度高达2 600 mg·L⁻¹,VFA/ALK始终低于0.04,表明AnMBR不仅对外界环境变化有着较好的缓冲能力,而且对消化体系的内源性抑制因素也有着良好的耐受能力。综上,AnMBR在处理餐厨废水时表现了良好的处理性能和稳定性能。     

Electro-Fenton decolourisation of dyes in an airlift continuous reactor using iron alginate beads

In this study, electro-Fenton dye degradation was performed in an airlift continuous reactor configuration by harnessing the catalytic activity of Fe alginate gel beads. Electro-Fenton experiments were carried out in an airlift reactor with a working volume of 1.5 L, air flow of 1.5 L/min and 115 g of Fe alginate gel beads. An electric field was applied by two graphite bars connected to a direct current power supply with a constant potential drop. In this study, Lissamine Green B and Reactive Black 5 were selected as model dyes. Fe alginate gel beads can be used as an effective heterogeneous catalyst for the degradation of organic dyes in the electro-Fenton process, as they are more efficient than the conventional electrochemical techniques. At optimal working conditions (3 V and pH 2), the continuous process was performed. For both dyes, the degree of decolourisation increases when the residence time augments. Taking into account hydrodynamic and kinetic behaviour, a model to describe the reactor profile was obtained, and the standard deviation between experimental and theoretical data was lower than 6 %. The results indicate the suitability of the electro-Fenton technique to oxidise polluted effluents in the presence of Fe alginate gel beads. Moreover, the operation is possible in a continuous airlift reactor, due to the entrapment of iron in the alginate matrix.     

AnMBR处理高盐榨菜废水的运行效能及膜污染特性

为了解决高盐榨菜废水的处理问题,对厌氧膜生物反应器(anaerobic membrane reactor, AnMBR)处理高盐榨菜废水的3个运行阶段(盐度提升阶段、负荷提升阶段和排泥运行阶段)的消化性能和膜污染特性进行了研究。结果表明,当盐度由初始的12.9 g·L⁻¹逐渐升高到33.5 g·L⁻¹左右、且负荷维持在0.5~1.0 kg·(m³·d)⁻¹(以COD计)时,COD去除率及沼气产率随盐度的提升先下降后升高,最后分别稳定在75%和300 mL·g⁻¹(以COD计)以上,低负荷耐盐性驯化方式能够实现AnMBR的快速启动;当负荷逐渐增加约至7.6 kg·(m³·d)⁻¹时,COD去除率达到80%左右,沼气产率稳定在330~380 mL·g⁻¹,VFA/ALK始终低于0.15,这表明AnMBR对高盐榨菜废水具有良好的处理效果和较强的运行稳定性;在排泥运行阶段,AnMBR的COD去除率和沼气产率均有明显上升,分别达到83%和400 mL·g⁻¹左右,这表明排泥可以提高消化性能。此外,排泥有利于减缓膜污染。SEM-EDX表征结果表明,膜面污染物中存在大量的有机物和无机盐类晶体物质,工程应用中建议采用NaClO清洗+酸清洗的组合清洗方式。以上研究结果可以为高盐榨菜废水处理工业化应用提供参考。     

Performance evaluation of sequencing batch reactor for beverage industrial wastewater treatment

Attempts were made in this study to examine the effectiveness of sequencing batch reactor (SBR) for the treatment of beverage industrial wastewater. The SBR was operated at three different organic loading rates (OLRs): 2, 1.7 and 1.1 kg COD/m3 d. Results of continuous long-term operation showed that by decreasing OLR from 2 to 1.7 kg COD/m3 day, the removal efficiency was increased from 95.5 to 99.3% for COD, from 95.3 to 98.1% for BOD and from 87 to 97.7% for TSS. While further decreasing of the OLR to 1.1 kg COD/m3 day, there is no significant adverse effect on organics removal. Also, residual total nitrogen (TN) concentration decreased by decreasing the OLR. However, increasing the OLRs exerted a slightly negative effect on the removal of total phosphorous. On the other hand, the experimental data indicated that the substrate utilization kinetic followed Monod's kinetics model approximately. The maximum specific substrate utilization rate (micro(max), half velocity coefficient (Ks), growth yield coefficient (Y) and decay coefficient (Kd) were 2.94 d(-1), 15.22 mg/L, 0.2384 g VSS/g COD and 0.2019 h(-1), respectively.     

Sulfur speciation: Methodology and application to sulfide oxidation studies at the sediment-water interface

A single column ion chromatographic method for the determination of sulfide, sulfite, sulfate and thiosulfate was developed. It uses an anion exchange column (Waters, IC-Pak A) and a borate-gluconate buffer at pH 8.5 that contains EDTA and ascorbic acid to prevent sulfite oxidation. This eluent has relatively low background values for both conductivity and ultraviolet absorption, which allows determination of the above sulfur anions with high sensitivity. The mean percent recovery of the investigated anions in synthetic mixtures were 98.6, 100.0, 99.6 and 100.2 % for sulfide, sulfite, thiosulfate and sulfate, respectively. The method was applied to study sulfide ion oxidation at the water-sediment interface using six aquifer samples collected within the continental United States. Results indicated that sulfide ion disappearance follows a pseudo first-order profile and that the rate of disappearance correlates with the total organic carbon and clay content of the sediment.     

基于异养-硫自养反硝化耦合技术的陶粒-硫磺混合生物填料对城市污水处理厂尾水的深度脱氮

针对城市污水处理厂脱氮能力的不足,设计了2种不同体积比的陶粒-硫磺混合生物填料反应器(陶粒与硫磺的体积比分别为2∶1和5∶1),并用其对城市污水处理厂尾水进行了深度处理。结果表明,陶粒与硫磺体积比为2∶1的混合生物填料反应器(R2,高硫耦合组)在C/N为4,HRT为4 h的条件下处理模拟废水时脱氮效率最高,TN平均去除率和平均出水质量浓度分别为(92.62±1.36)%和(2.39±0.22) mg∙L^-1。相比于R1(异养对照组),R2在保证脱氮效率的同时,碳源投加量更少;此外,R2在最佳条件下促进了体系内反硝化微生物群落Thauera(陶厄氏菌属)和Thiobacillus(硫杆菌属)的生长,二者的相对丰度之和为39.13%。     

Treatment of carbofuran-bearing synthetic wastewater using UASB process

In the present study, fate of carbofuran in anaerobic environments and the adverse effects of carbofuran on conventional anaerobic systems were evaluated. Carbofuran degradation studies were carried out in batch reactors with varying carbofuran concentrations of 0 to 270.73 mg/L corresponding to a sludge-loading rate (SLR) of 2.12 x 10(-6) to 3.83 x 10(-3) g of carbofuran/g of volatile suspended solids (VSS)/d. Carbofuran concentration was reduced to undetectable levels at the end of 8 and 13 days in the batch reactors operated with a SLR of 2.12 x 10(-6) and 3.33 x 10(-5) g of carbofuran/g of VSS/d, respectively. Performances of two anaerobic reactors i.e. upflow anaerobic sludge blanket (UASB) and modified UASB (with tube settlers) were evaluated in the presence and absence of carbofuran using synthetic wastewater. In the absence of carbofuran, the soluble chemical oxygen demand (COD) removal efficiency in the conventional UASB reactor at 8 h and 6 h hydraulic retention time (HRT) was nearly 88% and 76%, respectively, whereas in modified UASB reactor it was increased to 90% at 8 h HRT and 78% at 6 h HRT. When 28 mg/L (SLR of 1.19 x 10(-2) g of carbofuran/g of VSS/d) of carbofuran was introduced in the reactors, the COD removal efficiency was reduced to 41% and 44% in conventional and modified UASB reactors respectively. However, the reactor could maintain around 80% COD removal efficiency at a carbofuran concentration of 7.84 mg/L (SLR of 3.64 x 10(-3) g of carbofuran/g of VSS/d). The reactor efficiency was also measured in terms of specific acetoclastic methanogenic activity (SMA). The toxic effect of carbofuran was reversible to a certain extent. Carbofuran removal efficiency in the conventional UASB reactor at carbofuran concentrations of 7, 13 and 28 mg/L were 40 +/- 3%, 27 +/- 3%, and 11 +/- 3%, respectively. In modified UASB reactor, carbofuran removal efficiency was almost uniform at 7 and 13 mg/L but it was reduced nearly by 56% at 28 mg/L. The major metabolite of carbofuran i.e. 3-keto carbofuran was found in all the reactors.