Although fly ash disposal is of environmental concern the quality of residues can be improved wit... more Although fly ash disposal is of environmental concern the quality of residues can be improved with respect to high value applications. Fly ash is considered as a potential source of aluminium and other strategic metals. Leaching and metal extraction behaviour of fly ash collected from Talcher Thermal Power Station have been thoroughly studied using sulphuric acid as extractant. The chemical
The Mineral phosphate solubilization (MPS) was studied in five Aspergillus niger strains. MPS act... more The Mineral phosphate solubilization (MPS) was studied in five Aspergillus niger strains. MPS activity was measured in solid (Pikovskaya's medium) as well as liquid media using different phosphate sources (dicalcium phosphate, tricalcium phosphate aluminium phosphates, and Rock phosphate). All the strains showed a zone of clearance of tricalcium phosphate in Pikovskaya's medium in plates and solubilized tricalcium phosphates in broth efficiently. Solubilization was lower in aluminium phosphates and Rock phosphate. Among the carbon sources the fungi preferred sucrose for higher P solubilization. Nitrogen in the form of nitrate was very effective in solubilizing inorganic phosphates. Xylose and urea were the poorest sources of carbon and nitrogen for all the strains of Aspergillus. Phosphate release was associated with reduction in pH.
There is a great potential of carbon sequestration under different plantations in about 7500 km l... more There is a great potential of carbon sequestration under different plantations in about 7500 km long coastline of India. The objectives of this study were to examine the carbon sequestration dynamics under different age Casuarina plantation at Sagar Island, West Bengal. The organic carbon content in surface and sub-surface soil ranged from 25.8 58.8 and 12.1 25.7 tonn/hectare, respectively. Soil organic carbon under old Casuarina showed 15 times more value than the unplanted soil of the Sand Dunes. Rate of carbon sequestration was observed to be the maximum ( 4.3 tonn/ year) under new Casuarina plantation near to the tree. izLrkouk oS f'od dkcZ u pØ es a ènk&ouLifr iz .kkfy;k¡ egRoiw .kZ Hkw fedk fuHkkrh gSa rFkk e`nk dkcZfud dkcZu dk lcls cM+k HkaMkj gSA e`nk dkcZ u la p;u dkcZ u MkbvkW DlkbM 1⁄4CO 2 1⁄2 dh òf) dks jks dus vkS j oS f'od gfjr x̀g iz Hkko dks de djus gs rq fofHkUUk ykxr iz Hkkodkjh ek/;eksa esa ls ,d gSA jk"Va h; Lrj ij gfjr x̀g xS l CO 2 dk ènk dkcZ u r...
A novel technique has been developed to prepare refractory grade magnesia from sea bittern, which... more A novel technique has been developed to prepare refractory grade magnesia from sea bittern, which is a heterogeneous precipitation method to precipitate magnesium as double salt by a suitable career reagent. Prepared double salt is converted to magnesium carbonate, which on further calcination gives rise to MgO. The powdered samples of prepared magnesium carbonate and magnesium oxide are characterized by elemental analysis, X-ray powder diffraction, IR, TG/DTA, Particle size analyser and SEM. Commercially available Fluka magnesium carbonate and its calcined product have also been simultaneously characterised for comparison. Prepared boron free magnesia shows high purity of 99.08%, which can be used as basic refractory material.
Abstract This study examines the possible sources of ambient pollutants and seasonal variations w... more Abstract This study examines the possible sources of ambient pollutants and seasonal variations within the nine selected stations, including the residential, commercial, and industrial sites from January 2016 to December 2018 in Paradip city. The particulate matter (PM) like PM10 and PM2.5 and gaseous pollutants like sulphur dioxide (SO2), nitrogen dioxide (NO2), and ammonia (NH3) samples were collected in four different seasons such as pre-monsoon, monsoon, post-monsoon, and winter. The seasonal average concentrations of PM10 and PM2.5 showed the highest levels in winter and the lowest in monsoon. The seasonal average concentrations of SO2, NO2, and NH3 were within the permissible limits at all the sites. The seasonal air quality index (AQI) shows that industrial sites were under the “severe air pollution” category in the winter season while all residential and commercial sites (except AG) under the “light air pollution” category in all seasons. The correlation such as, PM10 with PM2.5 and SO2 with NO2, showed a significant positive relation in all seasons. Principal component analysis (PCA) identified two major factors, with a total variance of 47.995% and 25.821%, respectively. Hierarchical cluster analysis (HCA) was used to explain the pollutants dispersion and spatial variations.
Abstract Mahanadi estuary is situated in the eastern part of India with several industries along ... more Abstract Mahanadi estuary is situated in the eastern part of India with several industries along its bank, which makes the system highly vulnerable to different types of pollutants. To assess the coastal pollution due to possible heavy metal contamination in the surface sediment of the estuary, seasonal observations (pre-monsoon, post-monsoon, and winter) were made from a time-series monitoring station near the estuary mouth. The study showed that the average concentrations of nine heavy metals were in the order of Fe> Pb> Cr >Zn >Co> Cu> Ni> Cd> Hg in both pre-monsoon and post-monsoon, whereas in winter their order was Fe >Pb >Cr> Zn> Ni> Cu> Co> Cd> Hg. The one-way ANOVA of metal concentrations shows significant seasonal variations (p geo ), and Pollution Load Index (PLI) along with Potential Ecological Risk Assessment (PERI) were used for the environmental assessment of Mahanadi estuary sediment collected during pre-monsoon, post-monsoon, and winter season. The high EF of Pb and Cd shows contamination of sediments by these metals from external sources such as industrial and other anthropogenic activities. Pollution indices showed that the sediment of the Mahanadi estuary is not contaminated with respect to metals except Cd. Numerical Sediment Quality Guidelines, applied to assess adverse biological effects of these metals, suggested possibilities of occasional biological effect due to Cd.
Estuaries receive the anthropogenic pollutants of their watershed area. Dhamra estuary, on the ea... more Estuaries receive the anthropogenic pollutants of their watershed area. Dhamra estuary, on the east coast of India, is such an estuary that receives a huge amount of pollutants, and it will eventually pose a threat to the ecological sensitive areas in its vicinity. Therefore, a study was carried out on physico-chemical parameters and chlorophyll-a to delineate the sources of variation during pre-monsoon and post-monsoon seasons. Surface water sampling was carried out from 12 stations in the estuarine and coastal area. Factor analysis and cluster analysis were applied to seasonal data to understand the sources of variation. From the study, it was observed that the chemical parameters are severely affected by anthropogenic influences such as sediment dredging, aquaculture effluent, and waste from industry and sewage from upstream. In the long run, this will affect the nearby nesting ground of vulnerable Olive Ridley turtles, high bio-diverse mangrove forests, and saltwater crocodile habitat. Estuaries and their adjacent coastal ecosystems around the world show escalating signs of deterioration, primarily due to anthropogenic actions (Borja et al., 2010). During the past century, increasing nutrient runoff has provoked an increase in phytoplankton production in different coastal areas of the world (Caddy, 2000; Nixon and Buckley, 2002). The increased primary production has surpassed the assimilative capability of these ecosystems, which has led to the global expansion of marine dead zones, habitat loss for seagrasses, demersal fish, and shellfish, and shifts in fish communities (
Abstract The biogeochemical characteristics of Mahanadi estuarine system in eastern India were in... more Abstract The biogeochemical characteristics of Mahanadi estuarine system in eastern India were investigated to understand the seasonality in carbon parameters and their influence on sea–air CO2 gradient. In general, the stations close to the estuary had higher salinity and total alkalinity; and lower pCO 2 (water) relative to the inner most stations. In contrast, the riverine stations had low pH and high pCO 2(water) and lower total alkalinity. The chlorophyll a values ranged between 0.27 to 11.22 mg m−3 during this investigation. We found that the seasonal oscillations in sea–air CO2 gradient ( Δ pCO2 = pCO 2(water) –pCO 2(air) ) were negative during winter and positive during summer, wherein the estuary acted as a weak source. The average air–water CO2 flux density values varied between −5.65 to 13.11 μ mol m−2 h − 1 throughout the study period. Two-way ANOVA showed strong seasonal control on environmental variables. The relationships observed between pH and salinity with pCO2 suggest that fluvial inputs of nutrients and the accompanying heterotrophic processes may possibly control the sea–air CO2 gradient in the surface waters of the Mahanadi estuary.
Surface water partial pressure of carbon dioxide [pCO 2 (water)], total alkalinity (TA), dissolve... more Surface water partial pressure of carbon dioxide [pCO 2 (water)], total alkalinity (TA), dissolved inorganic carbon (DIC), and air-water CO 2 flux were measured in two estuaries of the Bay of Bengal namely Mahanadi and Dhamra. Though the annual average air-water CO 2 fluxes at the Mahanadi and the Dhamra Estuaries were − 3.9 ± 21.4 (mean ± standard deviation) µmol m −2 h −1 and − 2.9 ± 11.6 µmol m −2 h −1 , respectively, the intra-annual variation of air-water CO 2 fluxes in the two estuaries was contrasting. Nonetheless, from the perspective of net primary productivity, the surface water of both the estuaries were found autotrophic throughout the study period with varying rates at different seasons and highest during summer months. Mahanadi Estuary acted as a CO 2 source toward atmosphere during monsoon months, whereas, Dhamra Estuary acted as a source during pre-monsoon months. On the contrary, Mahanadi and Dhamra Estuaries acted as CO 2 sink during pre-monsoon months and monsoon months, respectively. The salinity in Mahanadi Estuary was much lower compared to Dhamra, which indicated significant freshwater discharge rich in organic carbon, and the remineralization of this carbon to DIC during summer and monsoon months explained the CO 2 source character. Whereas, in Dhamra, reduced freshwater flow and high turbidity were held accountable for net heterotrophic character of the water column during the post-monsoon months. The annual data set of air-water CO 2 fluxes from these two estuaries produced from this study could be utilized in future to fill the data gap and upscale the Indian estuaries scenario from the perspective of blue carbon budgeting.
Journal of the Indian Society of Remote Sensing, 2019
Short-term variability in physico-chemical properties of Dhamra estuarine system located in north... more Short-term variability in physico-chemical properties of Dhamra estuarine system located in northeastern India was investigated to understand the inter-seasonal variability. The oxygen data show 89-92% saturation in winter months compared to 60-70% during summer. Overall, the nitrate ranged between \ 1.0 and 22.0 lmol l-1 ; however, phosphate concentrations never exceeded 1 lmol l-1 during the whole study period. In general, the lowest nutrient values were recorded during March and December irrespective of the year sampled. Pearson correlation matrix shows poor relationships between inorganic nitrate and phosphate suggesting decoupling in the Dhamra estuary. However, relationship between surface chlorophyll and nitrate was significant highlighting modest control on phytoplankton population. Interestingly, pCO 2(air) exhibited considerable monthly variability during the sampling period, thereby accentuating the sea-air CO 2 gradient. The pCO 2(air) varied between 370 and 421 latm, whereas pCO 2(water) ranged between 146 and 751 latm. The DpCO 2 therefore showed monthly fluctuation and acted as a weak to moderate source to the immediate atmosphere. Our observation from Dhamra estuary suggests large inter-annual variability which therefore necessitates the need for near real-time measurements which is now a possibility with emerging coastal biogeochemical buoys.
A highly lead(II) resistant (up to 2200 mg/l) bacterium PbRPSD202 was selected among 210 lead res... more A highly lead(II) resistant (up to 2200 mg/l) bacterium PbRPSD202 was selected among 210 lead resistant bacteria isolated from marine environment of Paradeep Port, Odisha for possible biosoption of toxic Pb (II) ions from metals polluted environments. The bacterium was identified as Bacillus xiamenensis following the phenotypic as well as 16S rRNA gene sequence analysis. In addition to Pb(II), it also showed resistance towards other heavy metals like Cd(II), Cr(VI), As(III), Cu(II), Ni(II) and Zn(II). Batch biosorption of Pb(II) using both live and dead biomass of this strain was investigated under different operational parametric conditions such as pH, temperature, NaCl concentration, shaking speed, treatment time, biomass concentration and initial Pb(II) concentration. The maximum Pb(II) uptake of 216.75 and 207.4 mg/g biomass was obtained with live and dead biomass, respectively, at the optimum condition (4% w/v NaCl, pH 6.0, 35°C, 140 rpm and 1 g/l biosorbent dose). Both active as well as passive Pb(II) bio-sorption process showed best fit with the pseudo-second-order kinetic model. The sorption mechanism was favoured with Langmuir isotherm model indicating monolayer type adsorption. FTIR and FESEM-EDX analysis further ensured the possible interactions of Pb(II) with bacterial cell surface ligands like hydroxyl, carbonyl, carboxyl and amine groups during surface adsorption. TEM analysis revealed the intracellular accumulation of lead ions. This investigation highlights the potential application of this bacterium for bioremediation of lead(II) from the multiple metals contaminated saline environment through biosorption.
An assessment of the water quality of Mahanadi and its distributary rivers and streams, Atharaban... more An assessment of the water quality of Mahanadi and its distributary rivers and streams, Atharabanki river and Taldanda Canal adjoining Paradip was studied in three different seasons namely summer, premonsoon and winter. Four parameters namely pH, Dissolved Oxygen, Biochemical Oxygen Demand and Fecal Coliform were considered to compute Water Quality Index based on National Science Foundation studies. Our findings highlighted the deterioration of water quality in the rivers due to industrialisation and human activities.
Hexavalent chromium-tolerant (1500 mg/L) bacterium MW1 was isolated from harbour water of Paradip... more Hexavalent chromium-tolerant (1500 mg/L) bacterium MW1 was isolated from harbour water of Paradip Port and evaluated for Cr (VI) reduction potential. The isolate was identified as Exiguobacterium indicum by biochemical and 16S rRNA gene sequence methods. Salt tolerance of the bacterium was evaluated in a wide range of NaCl concentrations (0.5-13%, w/v). The Cr(VI) reduction of the strain was evaluated and optimised with varied Cr(VI) concentrations (100-1000 mg/L), pH (5.0-9.0), temperature (30-40°C) and shaking velocity (100-150 rpm) in two different minimal media (M9 and Acetate). Under optimised conditions, after 192 h of incubation nearly 92%, 50% and 46% reduction in the M9 minimal medium and 91%, 47% and 40% reduction in the acetate minimal medium were observed for 100, 500 and 1000 mg/L of Cr(VI), respectively. The exponential rate equation for Cr(VI) reduction yielded higher rate constant value, that is, 1.27 × 10 −2 h −1 (M9) and 1.17 × 10 −2 h −1 (Acetate) in case of 100 mg/L and became lower for 500 and 1000 mg/L Cr(VI) concentrations. Further, the association of bacterial cells with reduced product was ascertained by Fourier transform infrared spectrometer, UV-Vis-DRS and field-emission scanning electron microscope-energy-dispersive X-ray analyses. The above study suggests that the higher reducing ability of the marine bacterium E. indicum MW1 will be suitable for Cr(VI) reduction from saline effluents.
Journal of Applied Sciences and Environmental Management, 2011
Dhamra estuarine ecosystem is a hotspot of rich biological diversity which supports a patch of ma... more Dhamra estuarine ecosystem is a hotspot of rich biological diversity which supports a patch of mangrove along with unique flora and fauna. In this study, the diversity of phytoplankton population and other factors that control their growth and biodiversity were investigated. The samples were collected monthly from Dhamra estuary of Bay of Bengal at 6 different stations (grouped under three regions) from March-2008 to February-2009. A total of 41 genera of phytoplankton species belonging to 4 classes of algae were identified. The maximum value of 9.3 X 10 4 cells l-1 was recorded in post monsoon season. Phytoplankton of Bacillariophyceae, appearing throughout the year, and represent majority of population (75-94%) at all the sampling stations, followed by Dinophyceae (3-14%), Cyanophyceae (3-8%) and Chlorophyceae (0-4%) classes. The Shannonweavers diversity index (H) remains between 0.22 and 2.49. Based on the correlation coefficient data, phytoplankton shows positive relationship with DO, salinity, nutrients and negative relationship with temperature and turbidity. Present study shows that the occurrence and diversity of these primary producers do not subscribe to a single dimensional phenomenon of a single factor, rather than, a consequence of a series of supported factors which will help to maintain and balance such type of fragile ecosystem. @JASEM
Most agricultural soils contain large reserves of phosphorus (P), a considerable part of which ac... more Most agricultural soils contain large reserves of phosphorus (P), a considerable part of which accumulates as a consequence of regular applications of P fertilizers. However, a greater part of soil phosphorus, approximately 95-99% is present in the form of insoluble phosphates and hence cannot be utilized by the plants. In the present study phosphate solubilising activity of Pseudomonas fluorescence against three types of rock phosphate (RP) were studied with respect to different parameters like temperature, incubation period, pulp density and effect of different carbon and nitrogen sources. Results indicated that the lower the concentration of the phosphate in the leaching broth the greater was the dissolution percentage of P 2 O 5. A maximum of 44.70, 48.84 and 56.17(mg%) of P 2 O 5 solubilisation were obtained after 15 days of incubation at 35ºC from West valley, North valley and South valley rock phosphate, respectively at 0.5 % pulp density. Acidic pH medium was favourable for phosphate solubilisation in all the experiments. Among the carbon sources glucose followed by maltose and sucrose supported the maximum RP solubilization in the presence of 0.5% pulp density as the optimum concentration. Nitrogen in the form of ammonium was very effective in solubilizing rock phosphates by P. fluorescence.
Petroleum hydrocarbon (PHC) concentration was monitored in water of estuaries, ports, and coastal... more Petroleum hydrocarbon (PHC) concentration was monitored in water of estuaries, ports, and coastal transects up to 10-km distance in East Coast of India once in every year during 2002-2009. The highest concentration was observed at Haldia port (1.60-20.11 μg/l) due to the impact of hydrocarbon discharges from nearby oil refinery, petrochemical industries, handling of crude oils, etc. The concentration of PHC exhibited relatively higher values during low tide than the high tide in all the four estuaries indicating riverine inputs and land-based discharges, which contribute substantial amounts of PHC to the coastal water. Hoogly estuary recorded higher values of PHC (1.17-18.50 μg/l) due to the influence of industrial wastes, land runoff, and port activities. The spatial distribution of PHC estimated by the kriging method showed a variation in concentration of PHC over the whole region. To discriminate the dispersion pattern of PHC, principal component analysis (PCA) was performed usin...
The two major sources which are contributing to marine pollution are natural processes as well as... more The two major sources which are contributing to marine pollution are natural processes as well as anthropogenic activities. The natural process includes precipitation, erosion, weathering of crystal material whereas anthropogenic activities are urbanization, industrialization, mining and agricultural activities, etc. Mahanadi is the biggest river source of Odisha which joins the Bay of Bengal at Paradip. Paradip Township is an urbanized well-developed industrial township where various anthropogenic activities are contributing pollution to the water sources. In the present study, an attempt has been made to estimate and monitor the seasonal and spatial variation of physiochemical properties of the Mahanadi estuary, the East Coast coastal belt of India. The result revealed that there is a remarkable variation in the physiochemical parameters such as pH, salinity, TSS, DO, BOD, NO 2 N, NO 3 N, NH 4 N, TN, TP, SIO 4 and Chl-a which are attributed to the runoff water getting discharged to the coastal water sources. It is being recommended to treat waste water and materials before discharging them to the marine water medium.
Although fly ash disposal is of environmental concern the quality of residues can be improved wit... more Although fly ash disposal is of environmental concern the quality of residues can be improved with respect to high value applications. Fly ash is considered as a potential source of aluminium and other strategic metals. Leaching and metal extraction behaviour of fly ash collected from Talcher Thermal Power Station have been thoroughly studied using sulphuric acid as extractant. The chemical
The Mineral phosphate solubilization (MPS) was studied in five Aspergillus niger strains. MPS act... more The Mineral phosphate solubilization (MPS) was studied in five Aspergillus niger strains. MPS activity was measured in solid (Pikovskaya's medium) as well as liquid media using different phosphate sources (dicalcium phosphate, tricalcium phosphate aluminium phosphates, and Rock phosphate). All the strains showed a zone of clearance of tricalcium phosphate in Pikovskaya's medium in plates and solubilized tricalcium phosphates in broth efficiently. Solubilization was lower in aluminium phosphates and Rock phosphate. Among the carbon sources the fungi preferred sucrose for higher P solubilization. Nitrogen in the form of nitrate was very effective in solubilizing inorganic phosphates. Xylose and urea were the poorest sources of carbon and nitrogen for all the strains of Aspergillus. Phosphate release was associated with reduction in pH.
There is a great potential of carbon sequestration under different plantations in about 7500 km l... more There is a great potential of carbon sequestration under different plantations in about 7500 km long coastline of India. The objectives of this study were to examine the carbon sequestration dynamics under different age Casuarina plantation at Sagar Island, West Bengal. The organic carbon content in surface and sub-surface soil ranged from 25.8 58.8 and 12.1 25.7 tonn/hectare, respectively. Soil organic carbon under old Casuarina showed 15 times more value than the unplanted soil of the Sand Dunes. Rate of carbon sequestration was observed to be the maximum ( 4.3 tonn/ year) under new Casuarina plantation near to the tree. izLrkouk oS f'od dkcZ u pØ es a ènk&ouLifr iz .kkfy;k¡ egRoiw .kZ Hkw fedk fuHkkrh gSa rFkk e`nk dkcZfud dkcZu dk lcls cM+k HkaMkj gSA e`nk dkcZ u la p;u dkcZ u MkbvkW DlkbM 1⁄4CO 2 1⁄2 dh òf) dks jks dus vkS j oS f'od gfjr x̀g iz Hkko dks de djus gs rq fofHkUUk ykxr iz Hkkodkjh ek/;eksa esa ls ,d gSA jk"Va h; Lrj ij gfjr x̀g xS l CO 2 dk ènk dkcZ u r...
A novel technique has been developed to prepare refractory grade magnesia from sea bittern, which... more A novel technique has been developed to prepare refractory grade magnesia from sea bittern, which is a heterogeneous precipitation method to precipitate magnesium as double salt by a suitable career reagent. Prepared double salt is converted to magnesium carbonate, which on further calcination gives rise to MgO. The powdered samples of prepared magnesium carbonate and magnesium oxide are characterized by elemental analysis, X-ray powder diffraction, IR, TG/DTA, Particle size analyser and SEM. Commercially available Fluka magnesium carbonate and its calcined product have also been simultaneously characterised for comparison. Prepared boron free magnesia shows high purity of 99.08%, which can be used as basic refractory material.
Abstract This study examines the possible sources of ambient pollutants and seasonal variations w... more Abstract This study examines the possible sources of ambient pollutants and seasonal variations within the nine selected stations, including the residential, commercial, and industrial sites from January 2016 to December 2018 in Paradip city. The particulate matter (PM) like PM10 and PM2.5 and gaseous pollutants like sulphur dioxide (SO2), nitrogen dioxide (NO2), and ammonia (NH3) samples were collected in four different seasons such as pre-monsoon, monsoon, post-monsoon, and winter. The seasonal average concentrations of PM10 and PM2.5 showed the highest levels in winter and the lowest in monsoon. The seasonal average concentrations of SO2, NO2, and NH3 were within the permissible limits at all the sites. The seasonal air quality index (AQI) shows that industrial sites were under the “severe air pollution” category in the winter season while all residential and commercial sites (except AG) under the “light air pollution” category in all seasons. The correlation such as, PM10 with PM2.5 and SO2 with NO2, showed a significant positive relation in all seasons. Principal component analysis (PCA) identified two major factors, with a total variance of 47.995% and 25.821%, respectively. Hierarchical cluster analysis (HCA) was used to explain the pollutants dispersion and spatial variations.
Abstract Mahanadi estuary is situated in the eastern part of India with several industries along ... more Abstract Mahanadi estuary is situated in the eastern part of India with several industries along its bank, which makes the system highly vulnerable to different types of pollutants. To assess the coastal pollution due to possible heavy metal contamination in the surface sediment of the estuary, seasonal observations (pre-monsoon, post-monsoon, and winter) were made from a time-series monitoring station near the estuary mouth. The study showed that the average concentrations of nine heavy metals were in the order of Fe> Pb> Cr >Zn >Co> Cu> Ni> Cd> Hg in both pre-monsoon and post-monsoon, whereas in winter their order was Fe >Pb >Cr> Zn> Ni> Cu> Co> Cd> Hg. The one-way ANOVA of metal concentrations shows significant seasonal variations (p geo ), and Pollution Load Index (PLI) along with Potential Ecological Risk Assessment (PERI) were used for the environmental assessment of Mahanadi estuary sediment collected during pre-monsoon, post-monsoon, and winter season. The high EF of Pb and Cd shows contamination of sediments by these metals from external sources such as industrial and other anthropogenic activities. Pollution indices showed that the sediment of the Mahanadi estuary is not contaminated with respect to metals except Cd. Numerical Sediment Quality Guidelines, applied to assess adverse biological effects of these metals, suggested possibilities of occasional biological effect due to Cd.
Estuaries receive the anthropogenic pollutants of their watershed area. Dhamra estuary, on the ea... more Estuaries receive the anthropogenic pollutants of their watershed area. Dhamra estuary, on the east coast of India, is such an estuary that receives a huge amount of pollutants, and it will eventually pose a threat to the ecological sensitive areas in its vicinity. Therefore, a study was carried out on physico-chemical parameters and chlorophyll-a to delineate the sources of variation during pre-monsoon and post-monsoon seasons. Surface water sampling was carried out from 12 stations in the estuarine and coastal area. Factor analysis and cluster analysis were applied to seasonal data to understand the sources of variation. From the study, it was observed that the chemical parameters are severely affected by anthropogenic influences such as sediment dredging, aquaculture effluent, and waste from industry and sewage from upstream. In the long run, this will affect the nearby nesting ground of vulnerable Olive Ridley turtles, high bio-diverse mangrove forests, and saltwater crocodile habitat. Estuaries and their adjacent coastal ecosystems around the world show escalating signs of deterioration, primarily due to anthropogenic actions (Borja et al., 2010). During the past century, increasing nutrient runoff has provoked an increase in phytoplankton production in different coastal areas of the world (Caddy, 2000; Nixon and Buckley, 2002). The increased primary production has surpassed the assimilative capability of these ecosystems, which has led to the global expansion of marine dead zones, habitat loss for seagrasses, demersal fish, and shellfish, and shifts in fish communities (
Abstract The biogeochemical characteristics of Mahanadi estuarine system in eastern India were in... more Abstract The biogeochemical characteristics of Mahanadi estuarine system in eastern India were investigated to understand the seasonality in carbon parameters and their influence on sea–air CO2 gradient. In general, the stations close to the estuary had higher salinity and total alkalinity; and lower pCO 2 (water) relative to the inner most stations. In contrast, the riverine stations had low pH and high pCO 2(water) and lower total alkalinity. The chlorophyll a values ranged between 0.27 to 11.22 mg m−3 during this investigation. We found that the seasonal oscillations in sea–air CO2 gradient ( Δ pCO2 = pCO 2(water) –pCO 2(air) ) were negative during winter and positive during summer, wherein the estuary acted as a weak source. The average air–water CO2 flux density values varied between −5.65 to 13.11 μ mol m−2 h − 1 throughout the study period. Two-way ANOVA showed strong seasonal control on environmental variables. The relationships observed between pH and salinity with pCO2 suggest that fluvial inputs of nutrients and the accompanying heterotrophic processes may possibly control the sea–air CO2 gradient in the surface waters of the Mahanadi estuary.
Surface water partial pressure of carbon dioxide [pCO 2 (water)], total alkalinity (TA), dissolve... more Surface water partial pressure of carbon dioxide [pCO 2 (water)], total alkalinity (TA), dissolved inorganic carbon (DIC), and air-water CO 2 flux were measured in two estuaries of the Bay of Bengal namely Mahanadi and Dhamra. Though the annual average air-water CO 2 fluxes at the Mahanadi and the Dhamra Estuaries were − 3.9 ± 21.4 (mean ± standard deviation) µmol m −2 h −1 and − 2.9 ± 11.6 µmol m −2 h −1 , respectively, the intra-annual variation of air-water CO 2 fluxes in the two estuaries was contrasting. Nonetheless, from the perspective of net primary productivity, the surface water of both the estuaries were found autotrophic throughout the study period with varying rates at different seasons and highest during summer months. Mahanadi Estuary acted as a CO 2 source toward atmosphere during monsoon months, whereas, Dhamra Estuary acted as a source during pre-monsoon months. On the contrary, Mahanadi and Dhamra Estuaries acted as CO 2 sink during pre-monsoon months and monsoon months, respectively. The salinity in Mahanadi Estuary was much lower compared to Dhamra, which indicated significant freshwater discharge rich in organic carbon, and the remineralization of this carbon to DIC during summer and monsoon months explained the CO 2 source character. Whereas, in Dhamra, reduced freshwater flow and high turbidity were held accountable for net heterotrophic character of the water column during the post-monsoon months. The annual data set of air-water CO 2 fluxes from these two estuaries produced from this study could be utilized in future to fill the data gap and upscale the Indian estuaries scenario from the perspective of blue carbon budgeting.
Journal of the Indian Society of Remote Sensing, 2019
Short-term variability in physico-chemical properties of Dhamra estuarine system located in north... more Short-term variability in physico-chemical properties of Dhamra estuarine system located in northeastern India was investigated to understand the inter-seasonal variability. The oxygen data show 89-92% saturation in winter months compared to 60-70% during summer. Overall, the nitrate ranged between \ 1.0 and 22.0 lmol l-1 ; however, phosphate concentrations never exceeded 1 lmol l-1 during the whole study period. In general, the lowest nutrient values were recorded during March and December irrespective of the year sampled. Pearson correlation matrix shows poor relationships between inorganic nitrate and phosphate suggesting decoupling in the Dhamra estuary. However, relationship between surface chlorophyll and nitrate was significant highlighting modest control on phytoplankton population. Interestingly, pCO 2(air) exhibited considerable monthly variability during the sampling period, thereby accentuating the sea-air CO 2 gradient. The pCO 2(air) varied between 370 and 421 latm, whereas pCO 2(water) ranged between 146 and 751 latm. The DpCO 2 therefore showed monthly fluctuation and acted as a weak to moderate source to the immediate atmosphere. Our observation from Dhamra estuary suggests large inter-annual variability which therefore necessitates the need for near real-time measurements which is now a possibility with emerging coastal biogeochemical buoys.
A highly lead(II) resistant (up to 2200 mg/l) bacterium PbRPSD202 was selected among 210 lead res... more A highly lead(II) resistant (up to 2200 mg/l) bacterium PbRPSD202 was selected among 210 lead resistant bacteria isolated from marine environment of Paradeep Port, Odisha for possible biosoption of toxic Pb (II) ions from metals polluted environments. The bacterium was identified as Bacillus xiamenensis following the phenotypic as well as 16S rRNA gene sequence analysis. In addition to Pb(II), it also showed resistance towards other heavy metals like Cd(II), Cr(VI), As(III), Cu(II), Ni(II) and Zn(II). Batch biosorption of Pb(II) using both live and dead biomass of this strain was investigated under different operational parametric conditions such as pH, temperature, NaCl concentration, shaking speed, treatment time, biomass concentration and initial Pb(II) concentration. The maximum Pb(II) uptake of 216.75 and 207.4 mg/g biomass was obtained with live and dead biomass, respectively, at the optimum condition (4% w/v NaCl, pH 6.0, 35°C, 140 rpm and 1 g/l biosorbent dose). Both active as well as passive Pb(II) bio-sorption process showed best fit with the pseudo-second-order kinetic model. The sorption mechanism was favoured with Langmuir isotherm model indicating monolayer type adsorption. FTIR and FESEM-EDX analysis further ensured the possible interactions of Pb(II) with bacterial cell surface ligands like hydroxyl, carbonyl, carboxyl and amine groups during surface adsorption. TEM analysis revealed the intracellular accumulation of lead ions. This investigation highlights the potential application of this bacterium for bioremediation of lead(II) from the multiple metals contaminated saline environment through biosorption.
An assessment of the water quality of Mahanadi and its distributary rivers and streams, Atharaban... more An assessment of the water quality of Mahanadi and its distributary rivers and streams, Atharabanki river and Taldanda Canal adjoining Paradip was studied in three different seasons namely summer, premonsoon and winter. Four parameters namely pH, Dissolved Oxygen, Biochemical Oxygen Demand and Fecal Coliform were considered to compute Water Quality Index based on National Science Foundation studies. Our findings highlighted the deterioration of water quality in the rivers due to industrialisation and human activities.
Hexavalent chromium-tolerant (1500 mg/L) bacterium MW1 was isolated from harbour water of Paradip... more Hexavalent chromium-tolerant (1500 mg/L) bacterium MW1 was isolated from harbour water of Paradip Port and evaluated for Cr (VI) reduction potential. The isolate was identified as Exiguobacterium indicum by biochemical and 16S rRNA gene sequence methods. Salt tolerance of the bacterium was evaluated in a wide range of NaCl concentrations (0.5-13%, w/v). The Cr(VI) reduction of the strain was evaluated and optimised with varied Cr(VI) concentrations (100-1000 mg/L), pH (5.0-9.0), temperature (30-40°C) and shaking velocity (100-150 rpm) in two different minimal media (M9 and Acetate). Under optimised conditions, after 192 h of incubation nearly 92%, 50% and 46% reduction in the M9 minimal medium and 91%, 47% and 40% reduction in the acetate minimal medium were observed for 100, 500 and 1000 mg/L of Cr(VI), respectively. The exponential rate equation for Cr(VI) reduction yielded higher rate constant value, that is, 1.27 × 10 −2 h −1 (M9) and 1.17 × 10 −2 h −1 (Acetate) in case of 100 mg/L and became lower for 500 and 1000 mg/L Cr(VI) concentrations. Further, the association of bacterial cells with reduced product was ascertained by Fourier transform infrared spectrometer, UV-Vis-DRS and field-emission scanning electron microscope-energy-dispersive X-ray analyses. The above study suggests that the higher reducing ability of the marine bacterium E. indicum MW1 will be suitable for Cr(VI) reduction from saline effluents.
Journal of Applied Sciences and Environmental Management, 2011
Dhamra estuarine ecosystem is a hotspot of rich biological diversity which supports a patch of ma... more Dhamra estuarine ecosystem is a hotspot of rich biological diversity which supports a patch of mangrove along with unique flora and fauna. In this study, the diversity of phytoplankton population and other factors that control their growth and biodiversity were investigated. The samples were collected monthly from Dhamra estuary of Bay of Bengal at 6 different stations (grouped under three regions) from March-2008 to February-2009. A total of 41 genera of phytoplankton species belonging to 4 classes of algae were identified. The maximum value of 9.3 X 10 4 cells l-1 was recorded in post monsoon season. Phytoplankton of Bacillariophyceae, appearing throughout the year, and represent majority of population (75-94%) at all the sampling stations, followed by Dinophyceae (3-14%), Cyanophyceae (3-8%) and Chlorophyceae (0-4%) classes. The Shannonweavers diversity index (H) remains between 0.22 and 2.49. Based on the correlation coefficient data, phytoplankton shows positive relationship with DO, salinity, nutrients and negative relationship with temperature and turbidity. Present study shows that the occurrence and diversity of these primary producers do not subscribe to a single dimensional phenomenon of a single factor, rather than, a consequence of a series of supported factors which will help to maintain and balance such type of fragile ecosystem. @JASEM
Most agricultural soils contain large reserves of phosphorus (P), a considerable part of which ac... more Most agricultural soils contain large reserves of phosphorus (P), a considerable part of which accumulates as a consequence of regular applications of P fertilizers. However, a greater part of soil phosphorus, approximately 95-99% is present in the form of insoluble phosphates and hence cannot be utilized by the plants. In the present study phosphate solubilising activity of Pseudomonas fluorescence against three types of rock phosphate (RP) were studied with respect to different parameters like temperature, incubation period, pulp density and effect of different carbon and nitrogen sources. Results indicated that the lower the concentration of the phosphate in the leaching broth the greater was the dissolution percentage of P 2 O 5. A maximum of 44.70, 48.84 and 56.17(mg%) of P 2 O 5 solubilisation were obtained after 15 days of incubation at 35ºC from West valley, North valley and South valley rock phosphate, respectively at 0.5 % pulp density. Acidic pH medium was favourable for phosphate solubilisation in all the experiments. Among the carbon sources glucose followed by maltose and sucrose supported the maximum RP solubilization in the presence of 0.5% pulp density as the optimum concentration. Nitrogen in the form of ammonium was very effective in solubilizing rock phosphates by P. fluorescence.
Petroleum hydrocarbon (PHC) concentration was monitored in water of estuaries, ports, and coastal... more Petroleum hydrocarbon (PHC) concentration was monitored in water of estuaries, ports, and coastal transects up to 10-km distance in East Coast of India once in every year during 2002-2009. The highest concentration was observed at Haldia port (1.60-20.11 μg/l) due to the impact of hydrocarbon discharges from nearby oil refinery, petrochemical industries, handling of crude oils, etc. The concentration of PHC exhibited relatively higher values during low tide than the high tide in all the four estuaries indicating riverine inputs and land-based discharges, which contribute substantial amounts of PHC to the coastal water. Hoogly estuary recorded higher values of PHC (1.17-18.50 μg/l) due to the influence of industrial wastes, land runoff, and port activities. The spatial distribution of PHC estimated by the kriging method showed a variation in concentration of PHC over the whole region. To discriminate the dispersion pattern of PHC, principal component analysis (PCA) was performed usin...
The two major sources which are contributing to marine pollution are natural processes as well as... more The two major sources which are contributing to marine pollution are natural processes as well as anthropogenic activities. The natural process includes precipitation, erosion, weathering of crystal material whereas anthropogenic activities are urbanization, industrialization, mining and agricultural activities, etc. Mahanadi is the biggest river source of Odisha which joins the Bay of Bengal at Paradip. Paradip Township is an urbanized well-developed industrial township where various anthropogenic activities are contributing pollution to the water sources. In the present study, an attempt has been made to estimate and monitor the seasonal and spatial variation of physiochemical properties of the Mahanadi estuary, the East Coast coastal belt of India. The result revealed that there is a remarkable variation in the physiochemical parameters such as pH, salinity, TSS, DO, BOD, NO 2 N, NO 3 N, NH 4 N, TN, TP, SIO 4 and Chl-a which are attributed to the runoff water getting discharged to the coastal water sources. It is being recommended to treat waste water and materials before discharging them to the marine water medium.
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