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791.
792.
电-Fenton法预处理青霉素废水的降解规律研究 总被引:1,自引:0,他引:1
研究电-Fenton法预处理青霉素钠(penicillin G sodium,PGN)模拟废水的降解规律,分析预处理过程中PGN浓度、COD、TOC的变化情况及BOD5/COD改善情况.当T=20℃、pH=3时,投加0.5g/L FeSO4、0.2 mL/L H2O2,于0.3 A电流下降解浓度为100 mg/L的PGN废水,120 min后PGN去除97.9%,COD去除76.7%,TOC去除59.8%,BOD5/COD由0升至0.4,有效提高了废水的可生化性.以红外光谱(infrared spectrogram,IR)和液相色谱-质谱联用(Liquid chromatogramMass chromatogram,LC-MS)检测青霉素钠的降解产物,说明青霉素钠抑菌的关键结构b-内酰胺环被破坏,抗菌性消失,有助于生物处理有效去除. 相似文献
793.
Ying Hu Liu De Li Liu Min An Yin Lian Fu Ren Sen Zeng Shi Ming Luo Hanwen Wu Jim Pratley 《Ecological modelling》2009
Many plant species defend themselves against herbivorous insects indirectly by producing and releasing induced volatiles to attract natural enemies of the herbivores. In this paper, we consider the recruitment of natural enemies attracted by plant-induced volatiles and introduce the An–Liu–Johnson–Lovett model into the Lotka–Volterra model in an attempt to add this missing vital link in tritrophic interaction. Increase in attraction strength of plant-induced volatiles to the natural enemy leads to high fluctuation amplitude of plant biomass and herbivore population. When the attack strength of natural enemies reaches a certain level, fluctuation amplitude of plant biomass and herbivore population will decrease and plant biomass will approach to its environmental carrying capacity. The simulation demonstrates that plant volatile compounds induced by insects have led to the introduction of a third tritrophic level, e.g., natural enemies, into the plant–herbivore system, resulting in the coexistence of plants, insects, and natural enemies during the evolution process. 相似文献
794.
Zu Zeng Qin Zi Li Liu Yu Feng Zeng Jian Hua Sun Ke Di Yang 《Environmental Chemistry Letters》2009,7(2):149-153
Hydro-electric plasma technology in the presence of TiO2 catalyst used to treat 2,4-dinitrophenol (2,4-DNP) simulated wastewater is reported. The catalytic activity of TiO2 prepared by ammonia precipitation was greater than the activity of the TiO2 prepared by NaOH precipitation. The presence of chloride ions during the preparation process of TiO2 had a large negative effect on the catalytic activity. The catalytic activity of TiO2 calcined at 673 K was significantly higher than the activity of the TiO2 that was calcined at higher and lower temperatures. After being calcined at 673 K, TiO2 was mainly in the anatase phase and degraded 81% of the 2,4-DNP after 10 min of treatment. 相似文献
795.
采用不完全厌氧-好氧工艺处理印染废水,工程运行前在水解池中投入了主要用于脱色的优势菌群,经3年多的运行,系统的脱色率均稳定在90%以上。从池中取菌进行分离鉴定,并进行各单株菌脱色能力实验,对其中具有最佳脱色能力的菌株进行偶氮染料活性黑KNB的脱色产物的化学分析,从而探讨水解池中染料的脱色机理。结果发现:分离到的10株菌对试验染料有较好脱色效果,高效液相色谱检测发现产物只有苯胺类物质的存在。该菌的脱色作用主要是破坏了染料的发色基团——偶氮双键。 相似文献
796.
Phosphorus recovery from fosfomycin pharmaceutical wastewater by wet air oxidation and phosphate crystallization 总被引:1,自引:0,他引:1
Fosfomycin pharmaceutical wastewater contains highly concentrated and refractory antibiotic organic phosphorus (OP) compounds. Wet air oxidation (WAO)-phosphate crystallization process was developed and applied to fosfomycin pharmaceutical wastewater pretreatment and phosphorus recovery. Firstly, WAO was used to transform concentrated and refractory OP substances into inorganic phosphate (IP). At 200 °C, 1.0 MPa and pH 11.2, 99% total OP (TOP) was transformed into IP and 58% COD was reduced. Subsequently, the WAO effluent was subjected to phosphate crystallization process for phosphorus recovery. At Ca/P molar ratio 2.0:1.0 or Mg/N/P molar ratio 1.1:1.0:1.0, 99.9% phosphate removal and recovery were obtained and the recovered products were proven to be hydroxyapatite and struvite, respectively. After WAO-phosphate crystallization, the BOD/COD ratio of the wastewater increased from 0 to more than 0.5, which was suitable for biological treatment. The WAO-phosphate crystallization process was proven to be an effective method for phosphorus recovery and for fosfomycin pharmaceutical wastewater pretreatment. 相似文献
797.
As human populations expand and nonhuman animals decline, understanding the interactions between people and wildlife is essential.
For endangered species, appreciating the effect of human disturbance can be important for their conservation. However, a human
disturbance angle is often absent from ecological research, despite growing evidence of the negative impact of nonfatal human
interference. Here, we monitored Hainan Eld’s deer living within a reserve and translocated animals living amongst villagers.
We show that translocated deer deviated from a crepuscular activity pattern and became increasingly nocturnal, and most active
when villagers were not. It appears that translocated deer adapted over time to human disturbance and this pattern is similar
to that of other species during periods of hunting. People do not pose an actual threat to Eld’s deer, but their presence
triggered a response akin to predator avoidance and may be interfering with broader aspects of their biology and conservation. 相似文献
798.
799.
800.
Luo SL Chen L Chen JL Xiao X Xu TY Wan Y Rao C Liu CB Liu YT Lai C Zeng GM 《Chemosphere》2011,85(7):1130-1138
This study investigates the heavy metal-resistant bacterial endophytes of Cd-hyperaccumulator Solanum nigrum L. grown on a mine tailing by using cultivation-dependent technique. Thirty Cd-tolerant bacterial endophytes were isolated from roots, stems, and leaves of S. nigrum L. and classified by amplified ribosomal DNA-restriction analysis into 18 different types. Phylogenetic analysis based on 16S rDNA sequences showed that these isolates belonged to four groups: Actinobacteria (43%), Proteobacteria (23%), Bacteroidetes (27%) and Firmicutes (7%). All the isolates were then characterized for their plant growth promoting traits as well as their resistances to different heavy metals; and the actual plant growth promotion and colonization ability were also assessed. Four isolates were re-introduced into S. nigrum L. under Cd stress and resulted in Cd phytotoxicity decrease, as dry weights of roots increased from 55% to 143% and dry weights of above-ground from 64% to 100% compared to the uninoculated ones. The total Cd accumulation of inoculated plants increased from 66% to 135% (roots) and from 22% to 64% (above-ground) compared to the uninoculated ones. Our research suggests that bacterial endophytes are a most promising resource and may be the excellent candidates of bio-inoculants for enhancing the phytoremediation efficiency. 相似文献