卡鲁塞尔氧化沟水力学特性的大涡模拟

本文基于大涡模拟中的Smagorinsky-Lilly模型,对Carrousel氧化沟模型进行了水力学特性模拟,并研究了沟内流速和涡量分布规律.速度与压力耦合求解使用了压力隐式算子分裂PISO(Pressure-Implicit with Splitting of Operators)算法,采用VOF(Volume of fluid)方法追踪自由液面.模拟结果表明,回流现象主要出现在上中层混合液中,逆流现象主要出现于上层混合液中;转轮与转刷的推流作用是造成水面变化剧烈的原因;距转轮与转刷较近的区域、转速较快的转轮与转刷区域及直道段转刷下游水面较高一侧中上层区域的涡量较大.根据实验验证,本次模拟结果和实验值吻合度较好,Smagorinsky-Lilly模型可以准确模拟氧化沟水力学特性.     

复合催化膜生物反应器处理一氧化氮废气研究

采用溶胶-凝胶法以聚砜(PSF)中空纤维膜为载体制备了Fe-Ti O_2/PSF复合催化膜,以此构建新型复合催化膜生物反应器(HCMBR),实现膜催化与硝化反硝化耦合烟气脱硝,进一步提高NO去除能力.采用Fe-Ti O_2/PSF复合催化膜生物反应器(HCMBR)处理一氧化氮废气,实现了180 d长时间高效稳定运行,NO去除效率可达93.2%,去除能力可达167.1g·(m~3·h)~(-1).适宜运行条件为:气体停留时间9 s、自然光光照强度670 lx,p H为6.8~7.2,n C/n N=3.7.Fe-Ti O_2/PSF复合催化膜加入,复合催化膜生物反应器去除NO的效率比膜生物反应器提高了1.4%~13%,在Fe-Ti O_2/PSF复合催化膜附着稳定的生物膜后,复合催化膜生物反应器去除NO的效率比湿式膜催化反应器提高了59.5%~66%.     

垃圾渗沥液中氨氮的电化学氧化

针对目前国内外垃圾渗沥液处理中存在的问题,采用电化学氧化与上流式厌氧污泥床（UASB）相结合,研究建立了对香港垃圾渗沥液的二步法处理工艺．本文着重探讨了电化学间接氧化去除渗沥液中氨氮的反应机制及主要影响因素,并通过实验找出了最佳的操作条件：入水初始 pH值为9.0;流速为0.01－0.10cm/s;CI加入量2000mg/L;电流密度 32.3mA/cm²．在此条件下,经过 6h电解后,UASB反应器出水中NH_－N和COD的去除率分别达到100％和87％．对该电化学氧化过程的运行成本进行了评估．     

富铁酸性硫酸盐体系施氏矿物附着包裹硫杆菌的Fe2+氧化能力研究

探究富铁酸性硫酸盐体系次生铁矿物附着包裹硫杆菌的Fe~(2+)氧化活性,对揭示次生铁矿物调控酸性矿山废水形成过程具有指导意义.本研究首先采用摇瓶实验合成次生铁矿物—施氏矿物,然后将脱水后的0.1、0.2、0.3及0.4 g施氏矿物直接或溶解后加入到pH为2.50的富铁酸性硫酸盐体系(改进型9K液体培养基)中进行Fe~(2+)氧化,分析体系pH、Fe~(2+)氧化率、次生铁矿物产生量等相关指标.研究表明,氧化亚铁硫杆菌在脱水施氏矿物的附着包裹量为2×10~8cells·g~(-1).0.1、0.2、0.3及0.4 g施氏矿物直接加入体系经过108 h培养,pH分别下降至2.28、2.25、2.24及2.22;Fe~(2+)氧化速率随着施氏矿物加入量的增加而增加,且各体系Fe~(2+)氧化率在108 h均达到100%,此时次生铁矿物产生量分别是3.05、3.30、3.61与3.70 g·L~(-1).然而,0.1、0.2、0.3及0.4 g施氏矿物溶解后进入的相应体系经过108 h培养后,pH分别下降至2.19、2.18、2.10及2.02;Fe~(2+)氧化速率随着施氏矿物溶解量的增加而增加,各体系Fe~(2+)氧化率在96 h均达到100%,各体系次生铁矿物在108 h时的产生量分别是6.16、6.44、6.76与7.89 g·L~(-1).可见,施氏矿物对硫杆菌的吸附包裹作用致使体系Fe~(2+)氧化效率降低,次生铁矿物合成量减少,酸化程度减弱.     

Treatment of 2-phenylamino-3-methyl-6-di-n-butylaminofluoran production effluent by combination of biological treatments and Fenton＇s oxidation

High strength refractory organic stream is produced during the production of 2-phenylamino-3-methyl-6-di-n-butylaminofluoran （One Dye Black 2, abbr. ODB 2）, a novel heat-sensitive material with a promising market. In this study, a combination of acidificationprecipitation, primary biological treatment, Fenton＇s oxidation and another biological treatment was successfully used for the removal of COD from 18000-25000 mg/L to below 200 mg/L from the ODB 2 production wastewater in a pilot experiment. A COD removal of 70%-80% was achieved by acidification-precipitation under a pH of 2.5-3.0. The first step biodegradafion permitted an average COD removal of 70% under an hydraulic residence time （HRT） of 30 h. By batch tests, the optimum conditions of Fenton＇s oxidation were acquired as： Fe^2＋ dose 6.0 mmol/L; H2O2 dose 3000 mg/L; and reaction time 6 h. The second step biological treatment could ensure an effluent COD below 200 mg/L under an HRT of 10 h following the Fenton＇s treatment.     

Arsenic redox transformation by Pseudomonas sp. HN-2 isolated from arsenic-contaminated soil in Hunan, China

A mesophilic,Gram-negative,arsenite[As(Ⅲ)]-oxidizing and arsenate[As(V)]-reducing bacterial strain,Pseudomonas sp.HN-2,was isolated from an As-contaminated soil.Phylogenetic analysis based on 16 S r RNA gene sequencing indicated that the strain was closely related to Pseudomonas stutzeri.Under aerobic conditions,this strain oxidized 92.0%(61.4 μmol/L) of arsenite to arsenate within 3 hr of incubation.Reduction of As(V) to As(Ⅲ) occurred in anoxic conditions.Pseudomonas sp.HN-2 is among the first soil bacteria shown to be capable of both aerobic As(Ⅲ) oxidation and anoxic As(V) reduction.The strain,as an efficient As(Ⅲ) oxidizer and As(V) reducer in Pseudomonas,has the potential to impact arsenic mobility in both anoxic and aerobic environments,and has potential application in As remediation processes.     

一株具砷氧化和反硝化功能的无色杆菌的筛选和鉴定

利用含As3+肉汤培养基,从广西河池砷污染地区水样和沉积物样中通过多次分离、纯化获取砷耐受菌.进一步从砷耐受菌中筛选出在好氧条件下可以同时进行砷氧化和反硝化的多功能菌株cll-35. 对该菌株进行形态观察,并利用16S rDNA序列分析方法进行鉴定,发现该菌株为革兰氏阴性菌,与Achromobacter denitrificans strain 22426和Achromobacter xylosoxidans strain C8B的同源性均达99%;该菌株在NO₃-和As3+同时存在的条件下好氧反硝化能力和砷氧化速率均得到提高;在只含NO₃-的条件下,NO₃-的去除率为53.65%,而在As3+和NO₃-同时存在的条件下,NO₃-的去除率为75.27%.在不含NO₃-和含NO₃-的条件下,As3+的转化率都在99%以上,而在含NO₃-的条件下,As3+的氧化速率更快.这种相互促进可能与反硝化过程中的电子传递和砷氧化过程中的动态平衡有关.      

亚氧化钛膜电极电化学特性及其处理印染工业废水的效能研究

电化学氧化法具有稳定高效、操作灵活、集成度高等特点,在处理难降解有机废水领域具有独特优势.电化学废水处理过程通常受限于传质速率,而膜电极有望解决这一瓶颈问题.亚氧化钛膜电极（TiSO-ME）的化学结构与电化学性质结果显示,经过高温还原法制备的TiSO-ME电极主要由Ti₄O₇和少量Ti₅O₉组成,大孔体积占总孔体积的92.7%,平均孔径为0.508 μm.电化学测试结果表明,TiSO-ME具有良好的导电性、高析氧电位和电化学稳定性.过滤试验结果表明,在0.82×10^-3~3.14×10^-3 mL·cm^-2·s^-1范围内膜通量与传质系数成正比.在电流密度为8 mA·cm^-2,膜通量为2.31×10^-3 mL·cm^-2·s^-1的条件下,电解1.5 h即可有效处理实际印染工业废水,sCOD去除率高达96.07%,电流效率可达24.22%,电能消耗较不存在膜通量时降低了32.99%.TiSO-ME能够实现废水在膜孔结构内部的穿流式操作,有效克服旁流式操作传质受限的问题,在小规模分散式工业废水处理中有着重要的研究价值和发展潜力.     

疏水型H-ZSM-5分子筛上NO氧化反应的研究

针对NO低温氧化催化剂的抗水汽性差的问题,以疏水型高硅H-ZSM-5分子筛为NO氧化催化剂,在温度为10~90℃、NO进口浓度为0.05%~0.08%,及相对湿度为0~100%条件下,考察了NO的氧化反应.结果表明,H-ZSM-5分子筛的硅铝比由50提高至300时,湿气条件(水汽含量1.18%)下,NO氧化率由20%升高至56%;干气下,低温有利于NO氧化;湿气下(水汽含量1.18%),NO氧化率随着温度的升高先增加后减少,最佳反应温度为20℃,与NOx工业废气的排放温度相近.200h的稳定性试验结果显示,在30℃、NO进口浓度0.08%、空时0.5s、保持相对湿度为50%或100%时,NO氧化率可维持在60%和50%,催化剂具有良好的稳定性.     

Oxidation inhibition of sulfite in dual alkali FGD system

A laboratory-scale well-mixed thermostatic reactor with continuously blasting air was used to investigate the oxidation inhibition of sulfite in dual alkali flue gas desulfurization （FGD） system. The effects of operating parameters such as pH value and catalyst concentration on the oxidation were studied. Sodium thiosulfate was used in the system, and was found that it significantly inhabited the sulfite oxidation. In the absence of catalyst, sodium thiosulfate at 12.67 mmol/L had an inhibition efficiency of approximately 98%. While in the presence of catalyst, sodium thiosulfate at 26.72 mmol/L had an inhibition efficiency less than 85.0%. The oxidation reaction order of sulfite in the sodium thiosulfate was determined to be -1.90 and 4）.55 in the absence and presence of the catalyst, respectively. Apparent activation energy of oxidation inhibition was calculated to be 53.9 kJ/mol. Pilot tests showed that the consumption rate of thiosulfate agreed well with the laboratory-scale experimental results.