光纤传导可见光降解亚甲基蓝

针对浓度大、色度高的印染废水难以处理的情况,选用加入光纤的光催化体系进行研究。采用溶胶凝胶法制备了Ag+/TiO2粉体光催化剂,用固体紫外可见光谱、X射线衍射对其进行表征。选用亚甲基蓝溶液作为目标降解物,评价了Ag+/TiO2在可见光下的光催化活性。分别考察了加入石英芯侧光光纤与塑料侧光光纤反应体系下,催化剂量、光纤数量、光照强度和pH值等因素对亚甲基蓝降解实验的影响。结果表明,选用20 mg/L的亚甲基蓝,采用催化剂量为11.67 g/L,500根侧光光纤,300 W的外部光源,pH值约为11时,光催化降解效果最佳,均能达到90%以上。     

微生物制剂与玄武岩纤维联用处理城市废水

为了探索一种新型的去除水体中有机物的工艺,以模拟城市废水为研究对象,研究不同工况条件下,复合微生物制剂、组合双环玄武岩纤维填料以及复合微生物制剂与组合双环玄武岩纤维填料结合对模拟城市废水中COD的去除情况。实验结果表明,复合微生物制剂与组合双环玄武岩纤维填料结合在曝气的情况下对COD的去除能力较高。在复合微生物制剂与组合双环玄武岩纤维填料结合的条件下,对COD浓度为500 mg/L左右的模拟城市废水的去除效率可达 97.22%;影响模拟城市废水中COD去除效果的各因素的主次顺序依次为反应时间>曝气时间>投加量=pH;得出最佳工况参数是:复合微生物制剂的投加量为0.05 g/L,曝气时间为72 h,反应时间为96 h,pH为7。     

崇明东滩盐沼表层沉积物有机碳空间分布特征及其来源示踪研究

沉积物有机碳空间分布特征及其来源是盐沼碳循环研究的一个关键问题。该研究分析了长江口崇明东滩盐沼表层沉积物样品总有机碳(TOC)、总氮(TN)和稳定碳同位素(δ13C)等参数。研究表明:东滩表层沉积物TOC和TN的平均值分别为7. 70±3. 74和0. 74±0. 32 g/kg,两者均表现为自北向南减少的分布趋势。沉积物δ13C平均值为-25. 05±1. 21‰,三元混合模型模拟计算结果表明东滩沉积物有机碳主要来源于悬浮颗粒物(43. 53±22. 44%)和植被(43. 29±24. 82%),底栖微藻贡献率较低(13. 20±8. 40%)。东滩北部沉积物表现为高悬沙贡献-低植被贡献-高有机碳含量特征,中南部表现高植被贡献-低悬沙贡献-低有机碳含量的特点。     

调理剂对堆肥产品重金属生物有效性的影响

城市污泥中重金属含量及其生物有效性是限制污泥农用的主要因素,因此,研究污泥堆肥化处理过程中重金属生物有效性,对污泥的农用具有重要意义。实验以城市污泥为原料,以菌菇渣和秸秆为调理剂,设置4个处理:A(污泥∶菌菇渣∶秸秆=1∶0.4∶0.025)、B(污泥∶菌菇渣∶秸秆=1∶0.3∶0.025)、C(污泥∶秸秆=1∶0.12)和D(污泥∶秸秆=1∶0.09),进行好氧堆肥实验,采用BCR顺序提取法测定各种形态的重金属,研究堆肥前后重金属形态的变化规律。结果表明,城市污泥中Cu、Ni、Pb和Cr主要以可氧化态及残渣态存在,生物有效性较低,而Zn和Cd主要以酸溶态和可还原态存在,生物有效性较高;堆肥过程显著降低了Cu、Zn、Ni和Pb的生物有效性,并改变了Cu、Zn、Ni、Pb、Cr和Cd的形态分布,使污泥中的Cu、Zn、Ni、Pb和Cd向着更稳定的可氧化态或残渣态转变;污泥经过堆肥处理后,Cu、Zn和Ni 3种重金属生物有效性关系为:ABCD,与其他处理相比,处理A残渣态的Pb和Cr增加比例较多,综合来看,处理A对重金属生物有效性的降低最为明显,重金属钝化效果最佳。     

多级厌氧法处理螺旋霉素工业发酵菌渣效果的研究

通过自主设计的多级厌氧反应器系统来考察半连续处理螺旋霉素工业发酵菌渣的效果。该系统总反应体积为44L,由4个11L的升流式厌氧反应罐组成,罐体间采用串联方式连接。121d的连续运行周期分为3个阶段,各阶段的有机负荷率分别为1．27、1．82和2．73kgCOD／（m3·d）。全过程中主要监测了各级罐体的产气量和螺旋霉素的降解。结果表明,多级厌氧反应器系统启动初期会出现产气不稳定现象,经过2个月的运行之后系统达到稳定状态。在有机负荷达到2．73kgCOD／（m3·d）时,各级罐体仍能稳定运行,总产气的45％集中在1号罐。在系统启动初期,螺旋霉素不能被明显降解。运行约80d后,整个体系达到了快速降解螺旋霉素的状态,在2．73kgCOD／（m3·d）的有机负荷率下,螺旋霉素降解率达到97％,同时可溶性COD降解率也达到了90％。     

Di-n-butyl phthalate degrading endophytic bacterium Bacillus amyloliquefaciens subsp. strain JR20 isolated from garlic chive and its colonization in a leafy vegetable

The bioconcentration and elimination of racemic benalaxyl (BX) in trout liver microsomes and in juvenile rainbow trout (Oncorhynchus mykiss) were investigated to determine whether the fish can bioconcentrate and degrade this fungicide enantioselectively. Both enantiomers of BX were extracted with organic solvents and evaluated using high-performance liquid chromatography. In the microsomes, BX degradation followed first-order kinetics, and the S?(+) enantiomer of BX was eliminated twice as rapidly as the R?(?) enantiomer, resulting in residues enriched for R?(?)?BX. In vivo experiment, chiral analysis showed an obvious selective bioconcentration of BX based on statistically altered enantiomer fractions (EFs) in the fish compared with the values in the water. The R?(?)?BX was initially preferentially bioconcentrated by rainbow trout and then dissipated more slowly than its antipode. The mean half-lives for individual enantiomers were calculated as 31.6 h for R?(?)?BX and 20.3 h for the S?(+)?form. The results of the study showed that the degradation of BX enantiomers was stereoselective in rainbow trout.     

Removal of SO2 and NOX from Stack Gas by Reaction with Calcium Hydroxide Solids

Previous workers have shown that simultaneous SO₂/NO_X removal can be obtained in a dry scrubbing system with Ca(OH)₂ promoted by an additive such as NaOH, and that fly ash and product recycle improve the reactivity of the solids toward SO₂. To test SO₂/NO_X removal with fly ash and product recycle, bench-scale experiments with a packed bed reactor were performed at bag filter conditions. The most reactive solid for NO_X removal was prepared by slurrying Ca(OH)₂ with fly ash, CaSO₃, and NaOH. The best conditions for NO_X removal were the greatest temperature (125°C) and greatest concentrations of SO₂ (1500 ppm) and O₂ (20 percent). At the best conditions, NO_X removed in 1 hour was 3-4 moles per 100 moles Ca(OH)₂, compared to 5-10 moles SO₂ removed per 100 moles Ca(OH)₂. The best SO₂ removal was obtained at the highest relative humidities/lowest temperatures (55% RH/ 65°C) with solids prepared by slurrying Ca(OH)₂ with fly ash and NaOH. At these conditions, SO₂ removed In 1 hour was 60-80 moles per 100 moles Ca(OH)₂, compared to 0.5 to 1 moles NO_X removed per 100 moles Ca(OH)₂.     

固态碳源去除地下水硝酸盐的模拟实验

选取了5种研究较少的固体材料,棉花、丝瓜络、甘蔗渣、可降解餐盒、木屑作为去除地下水硝酸盐的外加碳源。在锥形瓶中进行反硝化对比实验,研究了不同固态碳源下NO3--N、NO2--N、NH4+-N及pH的变化情况,分析了NO3--N及总氮的去除率。研究结果表明,反硝化过程中pH呈升高趋势,在6.9～8.5范围内浮动。可降解餐盒和丝瓜络相对于其他的固态碳源来说,对NO3--N和总氮有较高的去除率,但丝瓜络的总氮去除率明显低于可降解餐盒。可降解餐盒的硝酸盐去除率达到98.28%,总氮去除率达到93.48%。可降解餐盒能够有效地去除地下水硝酸盐,达到以废治废的效果,是经济有效的最佳固态碳源。     

气液混合脉冲放电体系中偶氮染料的脱色效果

为了深入探究水包气式气液混合脉冲放电体系中各参数对有机物降解效果的影响,建立了多针一板电极形式的气液混合脉冲放电等离子体体系,以典型的偶氮染料——酸性橙Ⅱ（A07）为目标物,考察该体系中影响染料脱色效果的关键因素。研究结果表明,气液混合脉冲放电体系中与脉冲电源输入功率有关的因素（脉冲电压峰值和脉冲频率）对A07脱色效果影响明显。随着脉冲电压峰值和脉冲频率的增加,A07溶液的脱色效率和相应的准一级降解动力学常数增加。在较高的脉冲电压峰值（30kV）和脉冲频率（75Hz）条件下,10mg／LA07溶液的脱色效率和准一级降解动力学常数分别达到r92．7％和3．50×10～／min。同时,研究证明酸性溶液条件较利于染料脱色。     

Arsenite-oxidizing and arsenate-reducing bacteria associated with arsenic-rich groundwater in Taiwan

Drinking highly arsenic-contaminated groundwater is a likely cause of blackfoot disease in Taiwan, but microorganisms that potentially control arsenic mobility in the subsurface remain unstudied. The objective of this study was to investigate the relevant arsenite-oxidizing and arsenate-reducing microbial community that exists in highly arsenic-contaminated groundwater in Taiwan. We cultured and identified arsenic-transforming bacteria, analyzed arsenic resistance and transformation, and determined the presence of genetic markers for arsenic transformation. In total, 11 arsenic-transforming bacterial strains with different colony morphologies and varying arsenic transformation abilities were isolated, including 10 facultative anaerobic arsenate-reducing bacteria and one strictly aerobic arsenite-oxidizing bacterium. All of the isolates exhibited high levels of arsenic resistance with minimum inhibitory concentrations of arsenic ranging from 2 to 200 mM. Strain AR-11 was able to rapidly oxidize arsenite to arsenate at concentrations relevant to environmental groundwater samples without the addition of any electron donors or acceptors. We provide evidence that arsenic-reduction activity may be conferred by the ars operon(s) that were not amplified by the designed primers currently in use. The 16S rRNA sequence analysis grouped the isolates into the following genera: Pseudomonas, Bacillus, Psychrobacter, Vibrio, Citrobacter, Enterobacter, and Bosea. Among these genera, we present the first report of the genus Psychrobacter being involved in arsenic reduction. Our results further support the hypothesis that bacteria capable of either oxidizing arsenite or reducing arsenate coexist and are ubiquitous in arsenic-contaminated groundwater.