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Biotechnological conversion of agro-industrial wastewaters into biodegradable plastic, poly b-hydroxybutyrate
No full textWaste activated sludge generated from a combined dairy and food processing industry wastewater treatment plant was evaluated for
its potential to produce biodegradable plastic, poly b-hydroxybutyric acid (PHB). Deproteinized jowar grain-based distillery spentwash
yielded 42.3% PHB production (w/w), followed by filtered rice grain-based distillery spentwash (40% PHB) when used as substrates.
Addition of di-ammonium hydrogen phosphate (DAHP) resulted in an increase in PHB production to 67% when raw rice grain-based
spentwash was used. Same wastewater, after removal of suspended solids by filtration and with DAHP supplementation resulted in lower
PHB production (57.9%). However, supplementing other wastes with DAHP led to a substantial decrease in PHB content in comparison
to what was observed in the absence of DAHP
Assessing Spatial Occurrence of Ground Level Ozone around Coal Mining Areas of Chandrapur District, Maharashtra, India
No full textStratospheric input and photochemical ozone formation in the troposphere are the two main sources determining the ozone levels in the surface layer of the atmosphere. Because of the importance of ozone in controlling the atmospheric chemistry and its decisive role in the heat balance of atmosphere, leading to climate change, the examination of its formation and destruction are of great interest. This study characterized the distribution of Ground level Ozone (GLO) in Chandrapur district is lying between 19°25′N to 20°45′N and 78°50′E to 80°10′E. Continuous ozone analyzer was used to quantify GLO at thirteen locations fixed by Global Positioning System (GPS) during the winter of 2005–2006. The daily GLO at all the locations ranged between 6.4 and 24.8 ppbv with an average and standard deviation of 14.9 ± 6.5 ppbv. The maximum and minimum concentration occurs during 1300–1600 h and 0300–0500 h may be due to high solar radiation facilitating photochemical production of O3 and downward mixing from the overlying air mass and in situ destruction of ozone by deposition and/or the reaction between O3 and NO. GIS based spatial distribution of GLO in Chandrapur district is indicates that the central core of the district and southern sites experienced elevated levels of GLO relative to the northern and western areas. The sites near by Chandrapur city are particularly affected by elevated GLO. The average variation of GLO with temperature shows a significant correlation of r = 0.55 indicating a direct relationship between GLO and temperature. Similarly an attempt has been made to compare the GLO monitored data in Chandrapur district with the reported values for other locations in Indian cities. This generated database helps regulatory agencies to identify locations where the natural resources and human health could be at risk
Catalytic properties of Ru-mordenite for NO reduction
No full textThe reduction of NO by CO over H and Na forms of Ru exchanged mordenite has been studied with ruthenium content of 0.2, 1 and 3 wt.%. The
catalysts were characterized with respect to X-ray diffraction, BET surface area, temperature programmed oxidation, and temperature programmed
desorption of ammonia. These catalysts have been evaluated for their activity for NO–CO reaction using a steady state gas laboratory evaluation
assembly. The catalysts show high activity for NO reduction and almost 100% conversion of NO to N2 was observed below 400 ◦C. The activity
was found to be a factor of ruthenium content, however, Ru-mordenite in Na form was observed to be relatively more active than Ru-mordenite
in H form, probably due to the electron donation from sodium to ruthenium sites. New zeolite phases with improved hydrothermal stability, high
surface area and reasonable cation exchange properties can be potential materials for catalytic reduction of NOx. Introduction of active metal ions
through ion exchange insures their high dispersion in zeolite supports, which also offer tailoring possibilities for DeNOx catalysts
Thermally stable metal ruthenate based soot oxidation catalyst for diesel exhaust emission control
No full textLanthanum ruthenate materials with perovskite type structure can be easily synthesized with ruthenium in 4+ oxidation state.
La3.5Ru4.0O13 type perovskite has been synthesized in unsupported and supported forms by using various methods. This perovskite
type La3.5Ru4.0O13 phase shows high thermal stability and can therefore be used as a catalyst for high temperature applications,
including those for auto-exhaust emission control. The material shows good catalytic activity for the carbon/soot oxidation in view
of its possible application in diesel soot oxidation for regeneration of Diesel Particulate Filter
Microbially-influenced degradation of solidified/stabilized metal waste
No full textIn the present study, a refined microbially-influenced degradation method was used to evaluate the stability of a solidified synthetic waste containing chromium salt, cement and fly ash in two different proportions. The experimental samples showed evidence of microbial growth by leaching of sulfate. Chromium leached by Thiobacillus thiooxidans from the experimental samples ‘C1’ (10.26% CrCl3 Æ6H2O; 89.74% cement) and ‘FC1’ (10.26% CrCl3 Æ6H2O; 10% fly ash; 79.74% cement), after 30 days of exposure was 14.53 mg/g and 9.53 mg/g, respectively. The corresponding concentration of chromium in the leachate was 0.189 mg/l and 0.124 mg/l, respectively, which was lower than the toxicity characteristic leaching procedure (TCLP), regulatory limit (5 mg/l). Replacement of cement by 10% fly ash in FC1
restricted the leaching of chromium more effectively. Model equations based on two shrinking core models namely, acid dissolution and bulk diffusion model, were used to analyze the kinetics of microbial degradation. Of the two approaches, the bulk diffusion model fit the data better than the acid dissolution model as indicated by the correlation coefficients of >0.97
Degradation of 4-nitroaniline by Stenotrophomonas strain HPC 135
No full textA bacterial strain HPC 135 capable of growing on 4-nitroaniline (NA) as a source of carbon and energy was isolated from contaminated site after enrichment. Experiments revealed that the strain HPC 135 utilized 4NA as analyzed by high-performance liquid chromatography (HPLC). The presence of acetate as co-substrate did not affect the utilization of 4-nitroaniline by the isolate but cell growth was increased. Oxygen consumption studies demonstrated that strain HPC 135 could utilize various substrates such as 4-chloro-2-nitrophenol, 4-chlorobenzonitrile, 4-nitrophenol as well as 4NA. On partial 16S rDNA sequence analysis, strain HPC 135 showed highest homology with Stenotrophomonas strain based on FASTA program
A study on major inorganic ion composition of atmospheric aerosols
Get PDFAbstract: Atmospheric aerosol samples were collected from Akola and Buldana region covering around 40 sqkm area during October-November 2002 and were analyzed for ten major inorganic ions namely F-, Cl-, NO3-, SO42-, PO42-, Na
+, K+, Ca2+, Mg2+ and NH using ion chromatographic technique. Theaverage mass of aerosols was found to be 225.81 µg/m3 4+ with standard deviation of 31.29 and average total water soluble load of total cations and
anions was found to be 4.32 µg/m3. The concentration of ions in samples showed a general pattern as SO42->NO3->Cl-
>PO>Ca2+> NH4+> Mg2+>K for cations. The overall composition of the aerosols was taken into account to identify the sources. The trend showed higher concentration of sodium followed by calcium, sulfate, nitrate, phosphate and ammoinum and found to be influenced by terrestrial sources. The presence of SO42- and NO3- in aerosols may be due to re-suspension of soil particles. Ca2+, Mg2+ and Cl are to be derived from soil materials. The presence of NH+4 may be attributed to the reaction of NH3- vapors with acidic gases may react or condense on an acidic particle surface of anthropogenic origin. Theatmospheric aerosol is slightly acidic due to neutralization of basicity by SO2 and NOx
Hazardous air pollutants in industrial area of Mumbai – India
No full textHazardous Air Pollutants (HAPs) have a potential to be distributed into different component of environment with varying persistence. In the current study fourteen HAPs have been quantified in the air using TO-17 method in an industrial area of Mumbai. The distribution of these HAPs in different environmental compartments have been calculated using multi media mass balance model, TaPL3, along with long range transport potential and persistence. Results show that most of the target compounds partition mostly in air. Phenol and trifluralin, partition predominantly into soil while ethyl benzene and xylene partition predominantly into vegetation compartment. Naphthalene has the highest persistence followed by ethyl benzene, xylene and 1,1,1 trihloro ethane. Long range transport potential is maximum for 1,1,1 trichloroethane. Assessment of human health risk in terms of non-carcinogenic hazard and carcinogenic risk due to exposure to HAPs. have been estimated for industrial workers and residents in the study area considering all possible exposure routes using the output from TaPL3 model. The overall carcinogenic risk for residents and workers are estimated as high as unity along with very high hazard potential
Monoethanol Amine Modified Zeolite 13X for CO2 Adsorption at Different Temperatures
No full textZeolite 13X has been modified with monoethanol amine (MEA). MEA loadings of 0.5–25 wt % have been
achieved using the impregnation method in different solvents. The mode of incorporation based on methanol
with stirring at room temperature appears to be the most feasible. The adsorbent has been characterized for
crystallinity, surface area, pore volume, and pore size. The thermal stability of the adsorbent is studied using
a thermal analyzer. The CO2 adsorption capacity of adsorbents is evaluated using the breakthrough adsorption
method with a packed column on a 10 g scale. The adsorption capacities of adsorbents are estimated in the
temperature range 30–120 °C. The adsorbents show improvement in CO2 adsorption capacity over the unmodified
zeolite by a factor of ca. 1.6 at 30 °C, whereas at 120 °C the efficiency improved by a factor of 3.5. For
adsorption at these temperatures, different MEA loading levels were found to be suitable as per the governing
adsorption phenomena, that is, physical or chemical. The adsorbent is also studied for CO2 selectivity over N2
at 75 °C. The MEA-modified adsorbent shows better CO2 selectivity, which was improved further in the
presence of moisture