排序方式: 共有51条查询结果,搜索用时 15 毫秒
31.
G. Sekaran S. Karthikeyan K. Ramani B. Ravindran A. Gnanamani A. B. Mandal 《Environmental Chemistry Letters》2011,9(4):499-504
This is the first report on the heterogeneous oxidation of dissolved organics in wastewater with little consumption of Fenton’s
reagent and without sludge production. The salt-laden wastewater discharged from leather industry has poor biodegradability
due to the presence of high total dissolved solids. This wastewater is evaporated in solar evaporation pans. The evaporated
residue faces disposal problem due to high concentration of organic and inorganic salts. The present study demonstrates the
preparation, characterization and application of mesoporous activated carbon matrix along with Fenton’s reagent for the removal
of dissolved organics in wastewater. Free electron-rich mesoporous activated carbon matrices (MAC700, MAC800 and MAC900) were prepared and characterized for surface area, C, H, N, ash content, free electron density and energy gap value. Results
show that heterogeneous catalytic oxidation of dissolved organics in the wastewater decreased biochemical oxygen demand, chemical
oxygen demand, total organic carbon and dissolved protein, respectively, by 74, 69, 61 and 80% at optimum pH (3.5), H2O2 (7.5 mmol/l), FeSO4.7H2O (0.3 mmol/l) and MAC800 (10 g/l). 相似文献
32.
S. M. Lipson G. Karalis L. Karthikeyan F. S. Ozen R. E. Gordon S. Ponnala J. Bao W. Samarrai E. Wolfe 《Food and environmental virology》2017,9(4):434-443
Epigallocatechin gallate (EGCG) of green tea and the nutraceutical CystiCran®-40 (containing 40% proanthocyanidins) of the cranberry plant have been associated with antiviral activity. The purpose of this work was to determine the mechanism of antiviral synergy between each compound. Coliphage T4II (phage T4) and the rotavirus strain SA-11(RTV) were used as model virus systems. Individual and combined flavonoids structural and molecular weight analyses were performed by NMR and HPCL/MS, respectively. A suboptimal concentration of EGCG or C-40 alone or in combination reduced phage infectivity by ≤10%. Similarly, EGCG (30 µg/ml) and C-40 (25 µg/ml), respectively, reduced RTV titers by 3 and 13%. However, RTV titers were reduced by 32% (p < .05) with both flavonoids used in combination. RTV was not recognized in host cells by electron microscopy 24-h post-inoculation. NMR and HPLC/MS findings revealed significant structural and potential changes in molecular weight of the flavonoids in complex. 相似文献
33.
Karthikeyan Sivakumar Arumugam Shanmugasundaram Muthumanickam Jayaprakash Kulandaisamy Prabakaran Subramanian Muthusamy Annadurai Ramachandran Senapathi Venkatramanan Sekar Selvam 《Environmental science and pollution research international》2021,28(15):18651-18666
Environmental Science and Pollution Research - Groundwater is the major freshwater resource in urban and rural areas of India that provides potable water. The quality evaluation of existing... 相似文献
34.
Jidapa NithikulObuli. P. Karthikeyan C. Visvanathan 《Resources, Conservation and Recycling》2011,55(4):417-422
The potential reuse of rejects from upstream and downstream process of Mechanical-Biological-Treatment (MBT) plant for the production refuse derived fuel (RDF) was investigated in the present study. Since, the rejects were characterized with the high calorific values of approximately 21 kJ/kg for upstream process and 29.5 kJ/kg for downstream process, both can be considered for RDF production. Further, heavy metal contents were also not exceeding the European standards for using it as RDF is additional benefit. But, RDF production from upstream process rejects showed maximum energy supply of 3.20 × 106 MJ/d with less ash (11.8%), chlorine (0.6%) and sulfur (0.2%) contents than the downstream process rejects. Among the three potential RDF users surveyed, the cement industries showed positive interest to burn RDF in their cement kiln with the energy supply cost of <2.1 USD/GJ. Few technical, economical and safety barriers were also identified with the RDF end users and potential suggestions were discussed for thriving RDF market in Thailand. 相似文献
35.
Treatment of simulated Reactive Yellow 22 (azo) dye effluents using Spirogyra species 总被引:3,自引:0,他引:3
Mohan SV Rao NC Srinivas S Prasad KK Karthikeyan J 《Waste management (New York, N.Y.)》2002,22(6):575-582
The potential of commonly available green algae belonging to Spirogyra species was investigated as viable biomaterials for biological treatment of simulated synthetic azo dye (Reactive Yellow 22) effluents. The results obtained from the batch experiments revealed the ability of the algal species in removing the dye colour and was dependent both on the dye concentration and algal biomass. Maximum dye colour removal was observed on the third day for all the system conditions. Monitoring of ORP values helped to understand the overlying biochemical mechanism of algal-dye system. Based upon the results, the dye-algal treatment mechanism was attributed to biosorption (sorption of dye molecules over the surface of algal cells), bioconversion (diffusion of dye molecules into the algal cells and subsequent conversion) and biocoagulation (coagulation of dye molecules present in the aqueous phase onto the biopolymers released as metabolic intermediates during metabolic conversion of dye and subsequent settlement). 相似文献
36.
Complexation by humic acid (HA) of basic (quinoline) and neutral (naphthalene) polycyclic aromatic compounds (PACs) was compared using fluorescence spectroscopy and equilibrium dialysis (ED). These compounds sorb to HA via cation exchange and hydrophobic interactions, respectively. Ionization of quinoline strongly affects its sorption to HA; maximum sorption is observed at pH close to logKb (4.92), and competition with H+ and electrolyte cation (Li+) is evident. Spectroscopic experiments indicate that quinolinium (QH+) cation fluorescence is quenched via a static mechanism (i.e., a dark complex is formed) when the protonated form is adsorbed via ion exchange to HA. The extent of sorption, calculated from fluorescence data using the Stern-Volmer equation, was compared to independent ED measurements. Although both methods indicated the same trends with solution chemistry, fluorescence quenching data suggested more extensive complexation than that measured using ED. In contrast to ionizable PACs, studied here and previously, interaction of naphthalene with HA is unaffected by changes in solution conditions (pH, ionic strength). 相似文献
37.
Batch adsorption studies were undertaken to assess the suitability of aluminium titanate (AT) and bismuth aluminate (BA) to remove
fluoride ions from water. The e ect of pH, dose of adsorbent, contact time, initial concentration, co-ions and temperature on fluoride
removal e ciency were studied. The amounts of fluoride ions adsorbed, at 30°C from 4 mg/L of fluoride ion solution, by AT and BA
were 0.85 and 1.55 mg/g, respectively. The experimental data fitted well to the Freundlich and Langmuir isotherms. Thermodynamic
parameters such as H0, S 0 and G0 indicated that the removal of fluoride ions by AT was exothermic and non-spontaneous while
that by BA was endothermic and spontaneous. Fourier transform infrared (FT-IR) analysis and X-ray di raction (XRD) patterns of the
adsorbent before and after adsorption indicated that fluoride ions were chemisorbed by these adsorbents. 相似文献
38.
This communication presents a preliminary study conducted to investigate dye (Direct Brown 2‐Diazo) colour removal using viable algae Spirogyra species. The results indicate the ability of algae Spirogyra species to remove dye colour and found to be dependent on the contact time and biomass. Colour removal mechanism by algae Spirogyra species may be attributed to biosorption and/or bioconversion and/or biocoagulation. 相似文献
39.
Tamilarasi S Nanthakumar K Karthikeyan K Lakshmanaperumalsamy P 《Journal of environmental biology / Academy of Environmental Biology, India》2008,29(1):127-134
The total heterotrophic bacteria, actinomycetes and fungus were enumerated from the rhizosphere and non-rhizosphere soil of 50 selected locally available medicinal plants in and around Bharathiar University. In all the plants, population of microorganism were higher in the rhizosphere soil than in the non rhizosphere soil. Among the microorganisms, bacterial population was higher in number followed by fungus and actinomycetes. Of the medicinal plants, the maximum rhizosphere effect was observed in Annona squamosa and the minimum effect was seen in Eclipta alba and Cassia auriculata. Among the bacteria the dominant species was Bacillus followed by Pseudomonas, Enterobacter, Corynebacterium, Micrococcus and Serratia. The Streptomyces species was found to be dominant followed by Deuteromycetes and Frankia among the actinomycetes. Among the fungal isolates Rhizopus was found to be higher in number followed by Aspergillus, Penicillium, Mucor and Fusarium. About 70.96% of the bacterial isolates were found to be nitrate reducers and 90.60% of the bacteria solubilised phosphate. The rhizosphere bacterial isolates were also capable of hydrolyzing starch, cellulose, casein, urea and gelatin. The isolates of bacteria, actinomycetes and fungus were also able to produce phytohormone Indole-3-acetic acid (IAA). The maximum IAA production was recorded by Fusarium sp (5.8 mg/l). The rhizosphere bacterial isolates showed resistance to 14 commercially used antibiotics. In an attempt to check the influence of these plant growth promoting microorganisms on the antimicrobial property of Coriandrum sativum against Escherichia coli MTCC-443 and Aeromonas hydrophila MTCC-646, the results observed was not encouraging since the inoculants did not influence the antibacterial property. However extensive and in depth study is required to find out the influence of rhizomicroorganisms on the antibacterial property of medicinal plants. The other results clearly indicated that the rhizosphere microorganisms could be exploited for its innumerable properties and active metabolites. 相似文献
40.
In this study, the rice bran oil (RBO) has been converted into methyl ester with an aid of transesterification reaction. Chemically, transesterification means conversion of triglyceride molecule or a complex fatty acid into alcohol and ester by removing the glycerin and neutralizing the free fatty acids. The B20 blend samples [80% diesel + 20% biodiesel] were prepared for each methyl ester obtained from RBO and then the cerium oxide (CeO2) nanoparticles were added to the each B20 blend samples at a dosage of 50 ppm and 100 ppm with an aid of ultrasonicator. Moreover, in the absence of any engine modifications, the performance and emission characteristics of those blend samples have been investigated from the experimentally measured values such as density, viscosity, cloud point, pour point, and calorific value while the engine performance was also analyzed through the parameters like exhaust gas temperature (EGT), brake specific fuel consumption (BSFC), brake thermal efficiency (BTE), exhaust emission of carbon monoxide (CO), hydrocarbon (HC), and nitrogen oxide (NOx). The experimental results reveal that the use of CeO2 blended biodiesel in diesel engine has exhibited good improvement in performance characteristic and reduction in exhaust emissions. 相似文献