Raka,VK; Agnihotri,AR; Thekdi,RJ; Shikrolkar,SB; Salunke,S (1999): Efficacy of rapid field test to detect facal pollution in drinking water. Pollution Research, 18(1): 37-42.

No simple, reliable and full proof method is available to check water quality al users level or at village water-supply level. Recently Manja et al. (1982) have developed a simple Field Test (FT) to detect faccal pollution in drinking water. It was felt necessary to assess the suitability and use fullness of this Field test developed by Manja et al. (1982) for screening large number of drinking water sources as a routine test.

A comprehensive study was carried out at sixteen District Public Health Laboratories situated at various parts of the State of Maharashtra. Each Public health laboratory was asked to examine about 100 water samples by field test and also by conventional most probable number method simultaneously. Composition of field test medium proposed by Manja et al. has been partially modified and employed for microbiological analysis. The modified field test was comparable to most probable number method based on presence of thermotolerant coliforms. It revealed that there was very good agreement between the results of both the methods. Positive field test revealed that hydrogen sulphide producing organisms are always present in association with thermotolerant coliforms in contaminated water.

The present paper describes the suitability of modified field test to assess microbiological quality of drn1killg water and its usefulness as routine screening test for large number of samples.

The modified field test was found to be more suitable, reliable, inexpensive, easy to perform and most useful to detect faecal contamination in drinking water within 24 hrs. It also proved suitable for routine analysis in laboratories. However it will be highly useful for screening rural water supply at village level where resources, time, manpower and laboratory facilities are not available.

Reckhow, KH; Chapra, SC (1999): Modeling excessive nutrient loading in the environment. Environmental Pollution, 100: 197-207.

Models addressing excessive nutrient loading in the environment originated over 50 years ago with the simple nutrient concentration thresholds proposed by Sawyer (1947. Fertilization of lakes by agricultural and urban drainage. New Engl. Water Works Assoc. 61, 109-127). Since then, models have improved due to progress in modeling techniques and technology as well as enhancements in scientific knowledge. Several of these advances are examined here. Among the recent approaches in modeling techniques we review are error propagation, model confirmation, generalized sensitivity analysis, and Bayesian analysis. In the scientific arena and process characterization, we focus on advances in surface water modeling, discussing enhanced modeling of organic carbon, improved hydrodynamics, and refined characterization of sediment diagenesis. We conclude with some observa-tions on future needs and anticipated developments.

Schroth,G; De Silva,LF; Seixas,R; Teixeira,WG; Jeferson,LVM; Zech,W (1999): Subsoil accumulation of mineral nitrogen under polyculture and monoculture palantations, fallow and primary forest in a Ferralitic Amazonian upland soil. Agriculture, Ecosystems and Environment, 75:109-120.

Central Amazonia is characterized by high and intensive rainfall and permeable soils. When rainforests are cleared for agricultural use, the efficient nutrient recycling mechanisms of the forests are disrupted and the nutrient availability in the topsoil is increased by fertilization, thereby increasing the potential for nutrient leaching. In this study, the distribution of mineral N in the upper two meters of a ferralitic upland soil was evaluated as an indicator for nutrient leaching and for the potential contribution of the subsoil to crop nutrition. A perennial polyculture system with four tree crops and a leguminous cover crop at two fenilization levels was compared with a vnoculture plantation of peach palm (Bactris gasipaes), spontaneous fallow and primary rainforest. Mineral N accumulated principally as nitrate in the subsoil under all ‘agricultural crops and also under the primary forest, although to a lesser extent. Within the polyculture system, there were significant differences in N accumulation between the tree crop species, and for one of the species (Theobroma grandiflorum) also between fertilization levels. The principal sources of subsoil N were mineral fertilizer and presumably N from the mineralization of leguminous biomass and soil organic matter. The N losses from the agricultural systems and the absence of yield responses of the tree crops to N fertilization indicated that agricultural production was not limited by N at this site, or that N was too rapidly leached to be taken up efficiently by the crops. None of the tree crop species seemed n he efficient in capturing leached N. Strategies are discussed for reducing N losses from agricultural systems with perennial crops, including the development of site and species-specific fertilizer recommendations, closer tree spacing and the encouragement of lateral and vertical tree root development.

Sharma,KP; Kushwaha,SP (1999): Nutrient dynamics in an Arundo donax wetland: Nutrient uptake, seasonal changes in Tissue concentrations, and release during in situ decomposition. International journal of Ecology and Environmental Sciences, 25: 1-20.

Total uptake of nitrogen, phosphorus, calcium, magnesium, sodium and potassium by a natural stand of Arundo donax L. growing in the marginal upland area of a sewage drain near Jaipur city (India) was estimated by following seasonal changes in nutrient concentrations in the live and dead parts of the above and belowground organs. Tissue concentrations of nutrients in live shoots were two to three times more than in the dead shoots, and aboveground organs contained two to three times more nutrients (except sodium) than the belowground organs. Nutrient concentrations were highest in the leaves and also exhibited larger seasonal variations than in other organs. Peak standing crops (gm^-2) of potassium (83.5), calcium (25.0) and magnesium (20.49) were larger in the aboveground organs and those of sodium (40.2) and phosphorus (17.45) in the belowground organs. Peak standing crops of nitrogen were similar in both the above-(72.86) and belowground (74.38) organs. Seasonal changes in the nutrient concentrations and their standing crops in different plant parts suggest that-the nutrients were translocated from the old shoots to the new shoots and there was relatively little internal cycling between above and belowground organs except that of phosphorus.

Decomposition of belowground and aboveground parts of A. donar was studied in situ for about nine months by litter bag method. Belowgroun organs decomposed faster than the aboveground organs. Decomposition rates of all plant parts were higher in the rainy season. The half lives of leaf, stem, rhizome and root litter were 198,330,144 and 224 days respectively. The order of nutrient disappearance from the decomposing litters was Na > IC > Mg > P > N > Ca.

The occurrence of A. donax only in habitats which are subjected to flooding for short periods, the internal translocation of nutrients from old shoots to new shoots, and the allocation of large amounts of nutrients to belowground organs which decompose faster than the stems, make it unsuitable for wastewater treatment systems where the sunstrata remain under water for most of the year.

Sheryl,AT; Simon,MWM; John,JE. Ross,JN (1999): Identification of Novel C₁₀H₆N₂Br₄Cl₂ heterocyclic compound in Seabird Eggs. A Bio-accumulating Marine Natural Product? Environmental Sciences & Technology, 33(1): 26-33.

A novel brominated and chlorinated compound, C₁₀H₆N₂Br₄Cl₂, bioaccumulating in seabird eggs was identified and characterized by low- and high-resolution electron impact ionization (El), electron capture negative ionization (ECNI), and ammonia positive chemical ionization (PCI) mass spectrometry. This compound is the major congener of a series of four hexahalogenated species. The major congener was determined in egg samples from Leach’s storm-petrel, rhinoceros auklet, glaucous-winged gull, and black-footed albatross from the Pacific coast area; Leach’s storm-petrel, Atlantic puffin, and herring gull from the Atlantic coast; and herring gull from the Great Lakes using GC-ECNI-MS. The concentrations of C₁₀H₆N₂Br₄Cl₂ in the Pacific Ocean samples ranged from 1.8 to 140 µg/g (wet weight), and were significantly higher than the Atlantic Ocean samples (p = 0.037). The Pacific Ocean samples contained levels of C₁₀H₆N₂Br₄Cl₂ approximately 1.5-2.5 times higher than in the Atlantic Ocean samples of the same or ecologically similar species. The compound was not detected in any of the samples from the Great Lakes. The Pacific Ocean offshore surface feeders had the highest concentrations 134-140 ng/g} when compared to the other samples (0.61-5.6 ng/g). Its strictly marine occurrence and relatively high nitrogen content indicate that C₁₀H₆N₂Br₄Cl₂ probably is a marine natural product, found at highest concentrations in the Pacific Ocean surface feeding birds. A possible structure of C₁₀H₆N₂Br₄Cl₂ is 1,1'-dimethyl-tetrabromodichloro-2,2'-bipyrrole.