光生物反应器中活性污泥和藻类的共培养及微生物群落分析

利用污水处理厂好氧池活性污泥和来自二沉池壁的藻类构成菌藻生物反应器用以处理实际生活废水,探讨了不同泥藻接种比对废水处理效果的影响,并分析了稳定运行后的微生物群落组成。结果表明：泥/藻质量比为1∶0.75的混合系统对污染物质(COD、TN和TP)的去除效率最高;当HRT为2 d时,按泥/藻质量比为1∶0.75接种的光生物反应器(初始TSS为1.12 g·L−1)在搅拌和太阳光照射的条件下,对${{\rm{NH}}_4^ + }$-N的去除率可达99.7%,对${{\rm{PO}}_4^{3 - }}$的去除率约为70%。利用高通量测序技术对运行42 d后反应器内(SRT为15 d)的细菌群落进行分析发现,优势细菌为厚壁菌门的微小杆菌属(Exiguobacterium),蓝菌门的光合产氧蓝细菌属(Cyanobium)和变形菌门α-变形菌纲的不产氧光合好氧异养固氮红杆菌属(Rhodobacter),其相对丰度分别为23.32%、15.23%和5.77%。同时,反应器内还存在氧化亚硝酸盐的硝化螺旋菌(Nitrospira),以及除磷的不动杆菌(Acinetobacter)和能进行好氧反硝化的副球菌(Paracoccus),其相对丰度分别为1.19%、0.58%和0.35%。     

Immune responses,DNA damage and ultrastructural alterations of gills in the marine mussel Lithophaga lithophaga exposed to CuO nanoparticles

Environmental Science and Pollution Research - Nanoparticle (NP) pollution is a worldwide problem. Copper oxide nanoparticles (CuO NPs) are one of the most used NPs in a variety of applications,...     

Uptake and distributions of polycyclic aromatic hydrocarbons in cultivated plants around an E-waste disposal site in Southern China

Environmental Science and Pollution Research - Polycyclic aromatic hydrocarbons (PAHs) in air, soil, and cultivated plants at e-waste disposal sites in Taizhou, Zhejiang Province, were determined...     

Microwave regeneration of activated carbon used for removal of solvents from vented air

A microwave regeneration of activated carbon used to remove organic solvents from vented air has been investigated. Methyl ethyl ketone (MEK), acetone, and tetrachloroethylene (TCE) vapors were removed from vented air through adsorption onto granular activated carbon. The saturated carbon was then regenerated in a microwave field, where the solvent was quickly desorbed and recovered from the inner pores of the carbon granules. The microwave-induced regeneration restored the original adsorption capacity and surface area of the activated carbon.     

Effects of tri-o-cresyl phosphate on serum estrogen and progesterone concentration and ATPase activity in the shell gland of adult hens

The activities of calcium-activated ATPase (Ca2+-ATPase) and calcium magnesium-activated ATPase (Ca2+-Mg2+-ATPase) in the shell gland, and concentrations of 17beta-estradiol (E2) and progesterone in serum were monitored, respectively, from hens orally dosed with tri-o-cresyl phosphate (TOCP) (750 mg/kg). Treated birds were monitored daily for laying and development of delayed neurotoxicity, and activities of Ca2+-ATPase and Ca2+-Mg2+-ATPase were measured at 7 and 10 days after dosing. TOCP-treated birds manifested motor deficit by 7-9 days postdosing, while hens administered vehicle exhibited no signs of delayed neurotoxicity. Ca2+-ATPase and Ca2+-Mg2+-ATPase activities of shell glands from TOCP-dosed hens were not significantly affected (P > 0.05). The serum E2 concentration was significantly reduced in TOCP-treated hens (P < 0.01); however, progesterone levels were unaffected.     

Comparison of particulate mass, chemical species for urban, suburban and rural areas in central Taiwan, Taichung

Aerosol samples for PM2.5, PM(2.5-10) and TSP were collected from June to September 1998 and from February to March 1999 in central Taiwan. Ion chromatography was used to analyze the acidic anions: sulfate, nitrate and chloride in the Universal samples. The ratios of fine particle concentrations to coarse particle concentrations displayed that the fine particle concentrations are almost greater than that of coarse particle concentrations in Taichung area. The average concentrations of PM2.5, PM(2.5-10) and TSP in urban sites are higher than in suburban and rural sites at both daytime and night-time. Chloride dominated in the coarse mode in daytime and in fine mode in night-time. Nitrate can be found in both the coarse and fine modes. Sulfate dominated in fine mode in both daytime and night-time.     

Mutagenic nitrated benzo[a]pyrene derivatives in the reaction product of benzo[a]pyrene in NO2-air in the presence of O3 or under photoirradiation

In order to clarify the contribution of nitrated products to the direct-mutagenic activity of products of the reactions of benzo[a]pyrene in NO2-air under various conditions, heterogeneous reactions of BaP deposited on filter in the air containing 10 ppm of NO2 have been conducted in dark or under photoirradiation. The reaction products have been analyzed by gas chromatography and mutagenicity of the products fractionated by preparative HPLC was assayed for Salmonella typhimurium strains TA98 and YG1024 in the absence of S9 mix. 3,6-dinitrobenzo[a]pyrene and 1,3-dinitrobenzo[a]pyrene, which are strong direct-acting mutagens, largely contributed to the total direct-acting mutagenicity of the dark reaction products in NO2-air. On the other hand, both the dark reaction in the presence of O3 and the photoreaction in NO2-air resulted in the formation of much smaller amounts of nitrobenzo[a]pyrenes than that observed in the dark reaction in the absence of O3. These results show that the contribution of other direct-acting mutagens to the total direct-acting mutagenicity of the products in these reactions should be considered. Benzo[a]pyrene lactones were identified in a highly mutagenic fraction of the products of the dark reaction in the presence of O3 and photoreaction and a nitrobenzo[a]pyrene lactone was also identified in a highly mutagenic fraction of the dark reaction products in the presence of O3. Nitrated oxygenated benzo[a]pyrene derivatives such as nitrobenzo[a]pyrene lactone were considered to largely contribute to direct-acting mutagenicity of the products of the dark reaction in the presence of O3 and photoreaction.     

Genotoxicity of two novel pesticides for the earthworm, Eisenia fetida

In this paper, several studies were conducted to evaluate the genotoxicity of two pesticides, Imidacloprid and RH-5849, for earthworm (Eisenia fetida). Earthworms were exposed in different exposure systems to evaluate their acute toxicity and the genotoxicity of the two pesticides was evaluated by using the method of sperm deformity assessment, micronucleus test of root tip cells in Vicia faba, a mouse bone-marrow micronucleus test, and comet assay. LC(50) (interpolated concentration at which 50% mortality of test population occurs) for earthworms varied in different exposure systems. The results indicated that Imidacloprid was consistently more toxic than RH-5849 in all exposure systems. In this study, sperm deformity test was used to detect the potential adverse influences of pesticides on the reproduction of earthworms. The results demonstrated that significant induction of sperm deformity (p<0.01) and a dose-effect relationship displayed at Imidacloprid concentrations higher than 0.5 mg/kg dry soil. However, the sperm deformity frequency of groups exposed to RH-5849 did not show significant difference (p>0.05) from the control until the dose reached 100 mg/kg dry soil. The results of the V. faba micronucleus tests showed that micronuclei frequency of the exposed group did not show significant difference (p>0.05) from the control until the concentration of Imidacloprid and RH-5849 reached 100 mg/ml. The results of the mouse bone-marrow micronuclei test also indicate that two pesticides did not show significant effects (p>0.05) on the micronuclei frequency in mice bone-marrow cells until the dose reached 100 mg/kg for Imidacloprid and 300 mg/kg for RH-5849 (2/3 LD(50)). Although no genotoxicity was detected by using the micronucleus tests, the results of the comet assay showed that the two pesticides induce significant DNA damage (p<0.01) in earthworms and dose-effect relationships were displayed. The 'earthworm comet assay' is a rapid and sensitive way to screen chemicals or terrestrial environments for their DNA-damaging properties.     

异喹啉季铵盐在盐酸中对A3钢的吸附及其缓蚀作用

采用失重、电化学法研究了异喹啉季铵盐在 1mol/L盐酸溶液中对A3钢的缓蚀行为及吸附规律。实验表明 ,异喹啉季铵盐是一种阴、阳极混合型缓蚀剂 ,其缓蚀性能优良 ,在A3钢表面产生化学吸附 ,吸附过程为放热反应。