RESEARCH ARTICLES
Abstract : The present study provides a baseline data on ecological status of mangrove swamps and salt marshes for their conservation and management in Visakhapatnam coastal environments. An ecological survey of outer harbor mangrove swamps and salt marshes was conducted to generate baseline data on mangrove plant species and habitats status during the period from September 2014 to June 2015. This study on mangrove swamps of Visakhapatnam outer harbor indicates that rapid decline of mangrove species and habitat loss was observed in area wise and species composition that showed decline of 15-20 mangrove species during the year 1998 to 6 species at present. The study was extensively done concentrating on the degradation of mangroves in the particular area which was not done before.
Abstract : This paper presents particulate matter load at different aerodynamic diameter for two seasons of an urban industrial site in Delhi using portable aerosol spectrometer. The result showed that seasonal average concentration varied from 57 to 457µg m-3 for PM10 in the pre-monsoon and 78 to 900 µg m-3 in post-monsoon season. The fine particles with aerodynamic diameter less than 2.5µm were observed from 15 to 65 µg m-3 in pre monsoon and 16 to 772 µg m-3 in post monsoon. The mean concentration variation shows an expected weekly pattern of increased values on weekdays than weekend for pre-monsoon but in post monsoon the weekend concentration was found to be higher than weekday’s value. The mass fraction of PM10-2.5 shows greater variability in post monsoon season with 105µg m-3 and 81µg m-3 for pre-monsoon season. The size ratio fraction for PM2.5/PM10 ranged from 0.17 to 0.66 in two seasons. The seasonal variation for PM10 and PM2.5 showed a strong linear relationship for the weekly behavior with R2 from 0.48 to 0.99. The correlation matrix for weekday and weekend pattern shows that particulate matter of different aerodynamic diameter was positively correlated in two different seasons. The observation indicates that despite several measures of pollution abatement the people living in nearby areas are at significant risk of respiratory health problems.
Abstract : The objective of this study was to investigate the potential use of cassava steep liquor (CSL) alone and in combination with potassium phosphate and ammonium sulphate (inorganic nutrients) as biostimulation-bioaugmentation agent in the bioremediation of crude oil contaminated waters. Bioremediation was carried out for six weeks at ambient temperature in plastic bucket bioreactors containing water artificially contaminated with 10% (v/v) Bonny light crude oil. CSL alone and in combination with potassium phosphate and/or ammonium sulphate was added to each bioreactor. Similar contaminated water without CSL and potassium phosphate/ammonium addition served as control designated as natural bioattenuation. The results revealed that natural bioattenuation, CSL supplementation, CSL + potassium phosphate, CSL + ammonium sulphate, and combined CSL + potassium + ammonium sulphate remediation systems elicited 40%, 58.5%, 67.7%, 64.1% and 77.4% total petroleum hydrocarbon degradation and a corresponding biochemical oxygen demand (BOD) reduction of 52%, 62.7%, 71%, 66.7% and 81.7%, respectively. The microbial load in the contaminated water increased rapidly between days 0 and 7 and decreased between days 14 and 42 in all the remediation systems. A first-order kinetic model fitted well to the biodegradation data and the corresponding half-life time was also estimated. The model revealed that crude oil contaminated water under combined CSL + potassium + ammonium sulphate treatment strategy had higher biodegradation rate constants, as well as lower half-life times, than other remediation systems. Thus, the results suggest that CSL and in combination with inorganic nutrient could be an indispensable tool in bioremediation of petroleum hydrocarbons contaminated environment.
Abstract : A geodynamically active and geomorphologically sensitive study area (the Khairna river basin) lies between 290 23' to 29031' North latitudes and 790 25' to 79039' East longitudes in the Kumaun lesser Himalayas and covers an area of about 125 km2. The Khairna stream follows the NS tending strike dip Garampani fault and joins river Kosi at Khairna, which lies in District Nainital, Uttarakhand, India. Quantitative measurement of the mass wasting processes (From October 2004- 2007) reveals that about 105477432 m³ material is present as loose material in various forms within the watershed. Out of which is 95160819 m3 debris flow material; about 3544313 m3 is in the form of rock fall material disposed by the active process and about 6736170 m3 by landslide deposits, thus generating material at the rate of 843819 m3/km2 by the means of different mass wasting processes. These active processes in the study area add the mobilized material to the fluvial system and help estimate the denudation rate of the study area. All the processes are responsible for the occurrence of environmental hazards and in extreme conditions, disasters. Only understanding the ground truth related with the causes intensity and impact of these processes can help their planning, mitigation and prevention.
Abstract : The objective of this study was to evaluate the potential of green seaweed biomass to remove heavy metals such as iron (Fe), calcium (Ca), magnesium (Mg), potassium (K), silver (Ag) and chromium (Cr) present in textile wastewater. The wastewater sample was treated with the biomass at different contact time ranging from 10 to 90 minutes. The result showed that there was 87.5%, 99.9 %, 59.7 %, 57.2 %, 100% and 86.8% corresponding maximum reduction in the concentration of Fe, Ca, Mg, K, Ag and Cr at 60 min contact time, respectively. The experimental biosorption data fitted very well to both pseudo first-order and pseudo second-order kinetic models, however, the biosorpton kinetics of Fe, Ca, Mg, K, Ag and Cr followed a pseudo first-order kinetic model and the biosorption mechanisms were controlled by boundary layer surface diffusion. Thus green seaweed biomass has the potential to be used as a low cost biosorbent for the treatment of industrial wastewater that contains the presence of heavy metals.