Development of methane emission factors for Indian paddy fields and estimation of national methane budget.

A state-wise assessment of methane (CH(4)) budget for Indian paddies, based on a decadal measurement data across India is presented for the calendar year (CY) 1994, the base year for India's Initial National Communication (NATCOM) to the United Nations Framework Convention on Climate Change (UNFCCC), along with national trend from CY 1979 to 2006. The NATCOM CH(4) emission factors (EFs) for Indian paddy cultivation areas, generally having less than 0.7% of soil organic carbon (SOC), have been estimated as 17.48+/-4 g m(-2) for irrigated continuously flooded (IR-CF), 6.95+/-1.86 g m(-2) for rain-fed drought prone (RF-DP), 19+/-6 g m(-2) for rain-fed flood prone (RF-FP) and deep-water (DW), 6.62+/-1.89 g m(-2) for irrigated intermittently flooded single aeration (IR-IF-SA) and 2.01+/-1.49 g m(-2) for IR-IF multiple aeration (MA) paddy water regimes. The state-wise study for 1994 has indicated national CH(4) budget estimate of 4.09+/-1.19 Tg y(-1) and the trend from 1979 to 2006 was in the range of 3.62+/-1 to 4.09+/-1.19 Tg y(-1). Four higher emitting or "hot spot" states (West Bengal, Bihar, Madhya Pradesh and Uttar Pradesh) have accounted for 53.9% of total CH(4) emission with RF-FP paddy water regime as the major contributor. CH(4) emissions were enhanced by factors such as SOC ( approximately 1.5 times due to increase in SOC by approximately 1.8 times), paddy cultivars (approximately 1.5 times), age of seedlings (approximately 1.4 times), and seasons (approximately 1.8 times in Kharif or monsoon than in Rabi or winter season).

Possible ecological consequences from the Sethu Samudram Canal Project, India.

The Sethu Samudram Canal Project (SSCP), considered as a harbinger of economic growth in India, is a mega engineering project being developed to provide a 260 km long, 300 m wide and 12 m deep shipping channel between the Arabian Sea and the Bay of Bengal. This project impacts the unique biota and biodiversity of a 10,500 km(2) Marine Biosphere Reserve. This man-made link facilitates exchange of water masses between the less saline Bay of Bengal and the more saline Arabian Sea. Initial construction, subsequent dredging for channel maintenance, and the associated ship traffic would result in irreversible changes to the already over-exploited and stressed environment. Additionally, the channel would form a deep ocean route for future tsunamis. However, to provide assurance to the public, particularly the 50,000 fishing folk, in 47 villages in this area, it would be crucial that a long-term environmental monitoring program is instituted. A thorough evaluation of the impending environmental impacts, similar to those addressed by a Before/After and Control/Impact (BACI model) is recommended.

Evaluation of the marine algae Ulva fasciata and Sargassum sp. for the biosorption of Cu(II) from aqueous solutions.

In this study, the adsorption properties of two different marine algae (Ulva fasciata (green algae) and Sargassum sp. (brown algae)) were investigated. Equilibrium isotherms and kinetics were studied to evaluate the relative ability of the two algae to sequester Cu(II) from aqueous solutions. The maximum biosorption capacity obtained was 73.5 mg g(-1) for U. fasciata and 72.5 mg g(-1) for Sargassum sp. at a solution pH of 5.5 +/- 0.5. A significant fraction of the total copper(II) uptake was achieved within 30 min. The copper(II) uptake by the biosorbents was best described by pseudo-second-order rate model.

Ion chromatographic determination of thyroxine in urine.

Thyroxine (3,5,3',5'-tetraiodo thyronine) is administered to patients suffering from endemic goiter as also in cases of non-iodine deficient ethiology and hypothyroidism. It is suggested that the uptake of thyroxine can be monitored by assessing the levels of the same in the urine of patients under treatment. For the purpose, a highly sensitive and selective ion chromatographic procedure is developed. The sample of urine is treated with sodium hydroxide and UV irradiated to convert iodine in thyroxine to iodide. Subsequently, iodide is separated on an anion exchanger AS 4A column using 50 mM NaOH as the eluent and determined spectrophotometrically at 226 nm.

Ion chromatographic separation and determination of phosphate and arsenate in water and hair.

A simple and sensitive method for the sequential determination of phosphate and arsenate was developed based on initial ion chromatographic separation followed by detection as the ion-association complex formed by heteropolymolybdophosphate and arsenate with bismuth. With 200 microl sample injection and separation on a AS4A-SC column using an eluent of 3.5 mM sodium hydrogen carbonate-10.0 mM sodium hydroxide, the detection limits which are calculated as the concentration equivalent to twice the baseline noise, were found to be 0.8 microg/l and 4.2 microg/l for P and As, respectively. Spiked samples were analyzed and recoveries were found to be satisfactory in the range of 95-105% for phosphate and 90-105% for arsenate. Samples of water and hair were analyzed by the proposed method.