Hazard estimation in urban home garden soils in an industrial area using microarthropods, soil properties and GIS modelling: an integrated approach.

The use of soil microarthropods as indicators of soil pollution in home gardens of an industrial area has been covered in this study. Soil samples were collected from 25 home gardens in three zones in Eloor during summer and North East monsoon from 2014 to 2018, for the study of soil microarthropods, soil properties, soil nutrients, and trace elements. The relationships among QBS-ar, microarthropod abundance, soil properties, and soil nutrients, were used to estimate the pollution hazard of the industrial area. The microarthropods present in the study area were Coleoptera, Hymenoptera, Diplopoda, and Araneae. A prominent study area feature was the absence of Collembola and Acari. The QBS-ar index score in these regions showed that the home gardens located adjacent to the industrial area showed low soil quality, with soil quality class values ranging from 1 to 2 throughout the study period. Discriminant analysis of soil nutrients with soil properties and microarthropod abundance showed that in Zone 1 and Zone 2, the data in 2018 was very well discriminated compared to other years. The hazard assessment in the Eloor region showed various levels of hazard zonation: Zone 1 with high-hazard and medium-hazard areas, Zone 2 with medium-hazard areas, and Zone 3 with low- and medium-hazard areas. The study is one of the first kinds that have used QBS-ar scores and soil properties along with soil nutrients and trace elements for estimating the level of hazard in home garden agroecosystems and thus points to an easy, simple, and practical approach in the monitoring and management of soil ecosystems.

Hydrochemical assessment of tropical springs--a case study from SW India.

The paper deals with the hydrochemical characterization and water quality assessment of springs emerging from the Archaean crystalline basements at the foothills of Western Ghat mountains in the highlands and Neogene sedimentary formations in the coastal lowlands of Kerala in south west India. A total of 19 springs from two important river basins of southern Kerala such as Ithikkara and Kallada river basins were studied for 18 physico-chemical (temperature, pH, electrical conductivity (EC), total dissolved solids (TDS), dissolved oxygen (DO), total hardness (TH), Na(+), K(+), Ca(2+), Mg(2+), CO3 (2-), HCO3 (-), Cl(-), SO4 (2-) , NO3 (-), SiO2, Fe(2+), and F(-) ) as well as bacteriological parameters. The discharge computations show that free-falling type of springs in the area discharge about 256.23 million liters of water a year. A comparative study between the spring water samples of highland and lowland regions reveal that the quality of spring water, except pH and bacteriological contents, satisfies the standards set by the Bureau of Indian Standards and World Health Organization for drinking water. Spring water samples collected from the lowlands register high value of Na(+) and Cl(-) compared with the highlands. Bicarbonate, Ca(2+), Mg(2+), and K(+) values are high in highland than lowland springs. The present study reveals that the spring water sources in the region can be developed as an alternate source for drinking water, provided pH correction and proper disinfection are done prior to its end use.

Microbial enhanced separation of oil from a petroleum refinery sludge.

Petroleum refineries around the world have adopted different technological options to manage the solid wastes generated during the refining process and stocking of crude oil. These include physical, chemical and biological treatment methods. In this investigation bacterial mediated oil separation is effected. Two strains of Bacillus were isolated from petroleum-contaminated soils, and inoculated into slurry of sludge, and sludge-sand combinations. The bacteria could effect the separation of oil so as to form a floating scum within 48h with an efficiency of 97% at < or =5% level of sludge in the sludge-sand mixture. The activity was traced to the production of biosurfactants by bacteria.

Ecology and seasonal variation of microalgal community in an oil refinery effluent holding pond: monitoring and assessment.

The microalgal community as primary producers has to play a significant role in the biotic and abitoic interactions of any aquatic ecosystem. Whenever a community is exposed to a pollutant, responses can occur because individuals acclimate to pollutant caused changes and selection can occur favouring resistant genotypes within a population and selection among species can result in changes in community structure. The microalgal community of industrial effluent treatment systems are continuously exposed to pollutants and there is little data available on the structure and seasonal variation of microalgal community of industrial effluent holding ponds, especially of a complex effluent like that of refinery. The aim of the present study was to investigate the annual variation in the ecology, biomass, productivity and community structure of the algal community of a refinery effluent holding pond. The results of the study showed the pond to be a eutrophic system with a resistant microalgal community with distinct seasonal variation in species composition.