改性粉煤灰基吸附剂烟气脱汞

改性粉煤灰基吸附剂作为烟气脱汞吸附剂,具有成本低的特点。为进一步研究改性粉煤灰基吸附剂脱汞的工业运行状况,设计了最大烟气流量为2 000 Nm3/h的中试实验。首先通过数值模拟方法研究燃煤烟气过程中吸附剂脱汞性能,分别研究了吸附剂粒径、烟气流量以及吸附剂料层厚度对脱汞效率的影响。研究发现,随着烟气流量的增加脱汞效率降低,烟气流量为2 000 Nm3/h时脱汞效率为74.26%。在中试实验中采用三段式脱汞工艺,脱汞吸附剂为卤素元素浸渍改性的粉煤灰基吸附剂,根据模拟结果设计了吸附剂粒径为25 mm,料层厚度为400 mm的实验参数。实验结果表明,三段式脱汞工艺在烟气流量为2 000 Nm3/h,其脱汞效率为78.8%,其中吸附剂的脱汞效率为68.90%,证明了改性粉煤灰基吸附剂在工业烟气脱汞工艺中具有良好作用。     

不同粒径高浓度粉末活性炭组合UF膜工艺特征和过滤效果

采用一体式高浓度粉末活性炭-超滤(HCPAC-UF)组合工艺,处理高氨氮微污染水源水。选取3种不同粒径(50、3和0.2 μm)的粉末活性炭考察PAC粒径变化对组合工艺处理效果的影响。结果表明,PAC粒径改变分别对UV254表征的腐殖质类有机物和DOC表征的溶解性有机物的去除影响较小;PAC粒径显著影响系统中的微生物的生长环境,PAC粒径越小,系统中微生物的生长受抑制越明显,同时,PAC的粒径越小对减缓HCPAC-UF工艺的膜污染越显著。研究结果对于优化HCPAC-UF工艺参数具有一定参考价值。     

Photodegradation of PCDD/Fs adsorbed on spruce (Picea abies (L.) Karst.) needles under sunlight irradiation

Spruce (Picea abies (L.) Karst.) needles were exposed to exhaust gas containing polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) generated by combustion of polyvinyl chloride, wood, high-density polyethylene, and styrene. Photodegradation of PCDD/Fs adsorbed on spruce needles under sunlight irradiation was studied. The photodegradation of PCDD/Fs follows pseudo-first-order reaction kinetics, with photolysis half-lives ranging between 40 and 100 h. The photolysis rates of PCDF congeners are higher than PCDD congeners with the same chlorinated substitutions. Higher chlorinated PCDD/Fs tend to photolyze slowly. The wax components in spruce needles may act as proton donors and accelerate the photolysis rate. C-Cl cleavage through the addition of protons to PCDD/F molecules may be an important route for PCDD/Fs photodegradation.     

Photolysis of polycyclic aromatic hydrocarbons adsorbed on spruce [Picea abies (L) Karst] needles under sunlight irradiation

Photolysis of polycyclic aromatic hydrocarbons (PAHs) sorbed on surfaces of spruce [Picea abies (L.) Karst.] needles under sunlight irradiation was investigated. PAHs were produced by combustion of polyvinyl chloride (PVC), wood, high-density polyethylene (HDPE), and styrene in a stove. The factors of sunlight irradiation on the surfaces of spruce needles were taken into consideration when investigating the kinetic parameters. The photolysis of the 18 PAHs under study follows first-order kinetics. The photolysis half-lives range from 15 h for dibenzo(a,h)anthracene to 75 h for phenanthrene. Photolysis of some PAHs on surfaces of spruce needles may play an important role on the fate of PAHs in the environment.     

活性红BF-3BN脱色菌群的构建及特性研究

采用梯度压力式驯化法,从河南某印染厂的活性污泥中富集筛选一组活性红BF-3BN高效脱色菌群AR1。经菌株分离和16S rDNA测序分析,确定菌群内微生物分别归属Clostridium sp.、Pseudomonas sp.和Shewtnella sp.等3个属。染料脱色实验结果表明,在活性红BF-3BN起始浓度为200...     

等离子体与光催化复合空气净化技术研究

尝试了一种新的等离子体-光催化复合方式进行空气净化,研究表明该种复合方式具有较显著的协同促进效应,通过改变等离子体发生单元与光催化单元的距离以及在两者之间放置网状物,可消除等离子体单元产生的负电荷对光催化单元的不利影响,进一步提高其复合效应.还对这一复合方式产生协同效应的机理进行了分析.     

Health risk assessment of exposure to organic matter from the use of reclaimed water in toilets

To estimate the carcinogenic and non-carcinogenic risks of six volatile organic compounds (VOCs) found in reclaimed water used for flushing toilets, a probabilistic health risk assessment based on Monte Carlo simulations was used. Before Monte Carlo simulations, the contaminant volatilization model was applied to estimate the concentration of the pollutants in air. Moreover, a questionnaire was used to acquire daily exposure time and the Batch Fit tool of Crystal Ball software was applied to find the best-fitting distribution of a part of the input parameters. The risk analysis indicated that the health risks from six VOCs were lower than the negligible risk level (1?×?10^?8) in all cases, and the health risk for females was slightly higher than that for males. Overall, exposure to organic pollutants in reclaimed water during toilet flushing does not currently pose a significant carcinogenic risk to humans. In this study, we want to provide some information on the health risk from reclaimed water used for toilet flushing in China and hope that it will be useful to promote the application of reclaimed water in water-deficient areas.     

吸附-预沉淀MBR工艺处理生活污水及膜污染控制效果

膜污染是限制膜生物反应器（MBR）广泛应用的主要因素之一。针对MBR处理生活污水过程中存在的硝化效果不稳定与膜污染问题,提出了一种新型的MBR系统：通过吸附-预沉淀实现进水中碳氮的分离和单独处理,不仅提高了污染物去除效果,且能够有效控制膜污染。研究结果表明,吸附-预沉淀可以去除进水中约89.7%的有机物,系统出水COD、NH4+-N平均浓度为24 mg/L、0.78 mg/L,去除率分别为95.9%和98.1%。MBR中碳氮比的降低和硝化细菌比例的增加大大降低了MBR内MLSS、EPS和SMP含量,平均浓度分别为5 185 mg/L、41 mg/g MLSS和2.62 mg/g MLSS。在膜通量为4 L/（m2·h）条件下,TMP可稳定保持在20 kPa左右。通过吸附-预沉淀过程可有效控制MBR中的膜污染。     

Physiological and biochemical responses of rice seeds to phosphine exposure during germination

Rice seeds (Tianyou, 3618) were used to examine the physiological and biochemical responses to phosphine exposure during germination. A control (0 mg m⁻³) and four concentrations of phosphine (1.4 mg m⁻³, 4.2 mg m⁻³, 7.0 mg m⁻³ and 13.9 mg m⁻³) were used to treat the rice seeds. Each treatment was applied for 90 min once per day for five days. The germination rate (GR); germination potential (GP); germination index (GI); antioxidant enzymes, including superoxide dismutase (SOD), peroxidase (POD), and catalase (CAT); and lipid peroxidation measured through via malondialdehyde (MDA) were determined as indicators of the physiological and biochemical responses of the rice seeds to phosphine exposure. These indicators were determined once per day for five days. The results indicated that the GR, GP and GI of the rice seeds markedly decreased after phosphine exposure. The changes in the activities of the antioxidant enzymes due to the phosphine exposure were also significant. The exposure lowered the CAT and SOD activities and increased POD activity in the treated rice seeds compared with controls. The MDA content exhibited a slow increase trend with the increase of phosphine concentration. These results suggest that phosphine has inhibitory effects on seed germination. In addition, phosphine exposure caused oxidative stress in the seeds. The antioxidant enzymes could play a pivotal role against oxidative injury. Overall, the effect of phosphine on rice seeds is different from what has been reported previously for insects and mammals.