循环流化床烟气脱硫机理研究

对影响脱硫效率的关键因素进行了分析,同时进行了实验验证,认为水分的蒸发是主要影响因素,而流化床的运行温度和床内的相对湿度则是影响循环床脱硫效率的主要运行参数,对排烟循环流化床的床料进行了电镜扫描分析。结果表明,床料的再循环,一方面为脱硫剂的再循环提供了载体,另一方面,扩大了脱硫反应的面积,提高了脱硫效率。     

重庆缙云山四川大头茶常绿阔叶林重金属元素的累积与生物循环

四川大头茶,常绿阔叶林,重金属,循环,净化     

Ferric citrate-induced photodegradation of dyes in aqueous solutions

The photooxidation of dye solutions containing Fe(III)-citrate complexes was studied. The photodegradation under near-UV light of the five dyes, C. I. reactive red 2, C. I. reactive blue 4, C. I. reactive black 8, C. I. basic red 13 and C. I. basic yellow 2, in aqueous solutions at pH2.0 containing Fe(III)-citrate complexes was found to follow pseudo-first order kinetics. The photodegradation rates of the dye, C. I. reactive red 2, decreased with increasing the initial dye concentration in range of 20 – 60 mg/L . A comparatively higher photodegradation efficiency of the dye was gained under the condition of pH2.0 and the Fe(III) to citrate ratio 1:2.     

Metal accumulation in sediments and benthic invertebrates in lakes of Latvia

The concentrations of cadmium, lead, nickel and copper in waters, sediments (total metal concentrations and their speciation forms) and benthic macroinvertebrates in 11 lakes of Latvia were determined using atomic absorption spectroscopy. Metal concentrations in lake waters, sediments and biota were compared with water chemistry. Compared to total concentrations, metal speciation forms in sediments were better correlated with respective metal concentrations in invertebrates. Therefore, the evaluation of potential metal bioaccumulation should consider metal speciation. The mean concentrations of trace metals in benthic invertebrates in Latvia were much lower than in other countries, which can be explained by comparatively lower anthropogenic loads. However, local areas of anthropogenic impacts were evident.     

反硝化型甲烷厌氧氧化(DAMO)系统pH值耦合模型研究

对3个具有不同优势菌种反应器中厌氧氧化(DAMO)过程与pH值进行动力学耦合,结果表明,在25℃,Anammox-DAMO混培系统最大脱氮速率、硝酸盐初始抑制浓度和铵盐初始抑制浓度分别为3.95mg/(L·d),182.63,196.40mg/L;Nitrate-DAMO系统最大脱氮速率、硝酸盐初始抑制浓度分别为4.3...     

睾丸酮丛毛单胞菌对喹啉类化合物的降解

对喹啉、异喹啉、2-甲基喹啉、3-甲基喹啉、4-甲基喹啉和6-甲基喹啉在睾丸酮丝毛单胞菌(Comamonas testosteroni Q10)作用下的降解及底物之间的相互作用进行研究．结果表明,喹啉和3-甲基喹啉不仅能有效地被降解,而且细菌也有明显的生长,而其它化合物虽有部分降解但没有观察到细胞生长．底物初始浓度的增加对菌Q10有一定抑制作用．喹啉的存在对其它化合物的降解具有不同的促进效应,其中尤以6-甲基喹啉和4-甲基喹啉最为明显．能在较短时间内得到完全去除,而在各二元体系中喹啉的降解受到这些化合物的抑制作用．     

还原铁粉/紫外光体系对活性艳红X-3B溶液的脱色

研究了在紫外杀菌灯（λmax=253．7nm,30W）照射下,添加还原铁粉的活性艳红X－3B水溶液的脱色作用。当pH=3．5,铁粉投加量为2．0g／L时,20mg／L活性艳红X－3B溶液在光照180min后的脱色率为79％。脱色为动力学零级反应。染料溶液的pH、铁粉投加量、活性艳红初始浓度对脱色有影响。初步探讨了脱色反应的机理。     

茚虫威对斑马鱼的急性毒性及遗传毒性

茚虫威属噁二嗪类新型广谱高效杀虫剂,在农业生产中有着重要作用,近年来随着用量的增加,由此产生的对水生生物的影响越来越受到重视。使用斑马鱼进行茚虫威的急性毒性作用实验,并采用微核试验、彗星试验、Annexin V-FITC/PI双染色检测观察染毒后的斑马鱼是否被诱导产生遗传毒性。结果表明:在24 h、48 h、72 h、96 h,茚虫威LC50值分别为2.263mg·L-1、2.184 mg·L-1、2.184 mg·L-1、2.133 mg·L-1。茚虫威对斑马鱼急性毒性属中等毒性。96 h茚虫威浓度为1.98 mg·L-1和2.16 mg·L-1时,斑马鱼的微核率与对照组相比达差异极显著水平(P0.01)。采用彗星试验检测斑马鱼肝脏DNA损伤,结果显示斑马鱼暴露于高浓度1.98 mg·L-1和2.16 mg·L-1茚虫威后,与对照组相比,斑马鱼的DNA损伤均表现为极显著差异(P0.01)。采用Annexin V-FITC/PI双染色流式细胞仪法检测,结果表明染毒后24 h斑马鱼肝细胞出现细胞凋亡现象。实验结果进一步表明,茚虫威对斑马鱼短期染毒后诱导细胞凋亡,表现出遗传毒性。     

Microbial community functional structure in response to micro-aerobic conditions in sulfate-reducing sulfur-producing bioreactor

Limited oxygen supply to anaerobic wastewater treatment systems had been demonstrated as an effective strategy to improve elemental sulfur(S0) recovery, coupling sulfate reduction and sulfide oxidation. However, little is known about the impact of dissolved oxygen(DO) on the microbial functional structures in these systems. We used a high throughput tool(GeoChip) to evaluate the microbial community structures in a biological desulfurization reactor under micro-aerobic conditions(DO: 0.02–0.33 mg/L). The results indicated that the microbial community functional compositions and structures were dramatically altered with elevated DO levels. The abundances of dsrA/B genes involved in sulfate reduction processes significantly decreased(p 0.05, LSD test) at relatively high DO concentration(DO: 0.33 mg/L). The abundances of sox and fccA/B genes involved in sulfur/sulfide oxidation processes significantly increased(p 0.05, LSD test) in low DO concentration conditions(DO: 0.09 mg/L) and then gradually decreased with continuously elevated DO levels. Their abundances coincided with the change of sulfate removal efficiencies and elemental sulfur(S0) conversion efficiencies in the bioreactor. In addition, the abundance of carbon degradation genes increased with the raising of DO levels, showing that the heterotrophic microorganisms(e.g., fermentative microorganisms) were thriving under micro-aerobic condition. This study provides new insights into the impacts of micro-aerobic conditions on the microbial functional structure of sulfatereducing sulfur-producing bioreactors, and revealed the potential linkage between functional microbial communities and reactor performance.