Limnology of Kharland (saline) ponds of Ratnagiri, Maharashtra in relation to prawn culture potential

The coastal saline soils, Kharlands, have great potential for their use in aquaculture. This study has been taken up to understand the limnology of the ponds in Kharland area for assessing their prawn culture potential. This study was carried out during September, 1999 to August, 2001. Each Kharland pond has an area of 0.045 hectare. During the study, depth of pond water was 47.7 to 120.0 cm, temperature varied from 25.7 to 34.5 degrees C; transparency from nil to 65.0 cm; specific conductivity from 1.78 to 94.5 microS.cm(-1); total dissolved solids from 0.89 to 27.55 ppt; pH 5.42 to 8.25; dissolved oxygen 1.6 to 8 mg.l(-1); free carbon dioxide 10.00 to 44.00 mg.l(-1); total alkalinity 5.00 to 142.00 mg.l(-1); salinity 0.45 to 39.55 ppt; total hardness 245.00 to 5945.00; calcium 56.05 to 1827.6; magnesium 110.74 to 4507.75 mg.l(-1); dissolved organic matter 1.45 to 9.68 mg.l(-1); ammonia 1.00-8.00 microg.l(-1); nitrite nil to 20.00 micro l(-1) and nitrate 7.5 to 17.5 microg.l(-1). These Kharland ponds are unique in physio-chemical characteristics during their seasonal cycle. From July to October, these ponds have nearly freshwater while from November to May pond water becomes saline. Thus, there is a great possibility of taking up monoculture of both the freshwater and brackish water prawns as well as polyculture of prawns and fishes in the Kharland ponds.     

Dissipation and leaching of (14)C-monocrotophos in Soil Columns under subtropical climate

Dissipation and leaching behavior of 14C-monocrotophos was studied for 365 days under field conditions using PVC cylinders. The first set (24 cylinders) was spiked with 1.0 microCi 14C-labeled monocrotophos along with 1.06 mg unlabeled monocrotophos to give a concentration of 2 mg kg -1 in the soil up to 15 cm depth. The second set (24 cylinders) received 14C-labeled monocrotophos along with other non-labeled insecticides viz., dimethoate @ 300 g a.i ha-1, deltamethrin @ 12.5 g a.i ha-1, endosulfan @ 750 g a.i ha-1, cypermethrin @ 60 g a.i ha-1, and triazophos @ 600 g a.i ha-1 at an interval of 15 days each as recommended for the cotton crop. 14C-monocrotophos dissipated faster, up to 45% in first 90 days in columns treated with only monocrotophos compared to 25% in columns that received monocrotophos along with other insecticides. However, both the columns showed similar residues 180 days onward. After 180 days of treatment, 46% radiolabeled residues were observed, which reduced up to 39.6% after 365 days. Leaching of 14C-monocrotophos to 15-30 cm soil layer was observed in both the experimental setups. In the 15-30 cm soil layer of both soil columns, up to 0.19 mg 14C-monocrotophos kg-1d. wt. soil was detected after 270 days.     

Reduced downward mobility of metolachlor and metribuzin from surfactant-modified clays

The study aims to prepare the organoclay complexes of metolachlor and metribuzin so as to reduce their downward mobility in soil profile. The organoclays were preadsorbed with phenyltrimethylammonium (PTMA) (50% of cation exchange capacity [CEC]) and hexadecyltrimethylammonium (HDTMA) (100% of CEC). Four metolachlor formulations, two for each organoclay, were prepared having 1% and 2% load of herbicide and were called PTMA-Metol-1%, PTMA-Metol-2%, HDTMA-Metol-1% and HDTMA-Metol-2%. Two metribuzin formulations were prepared and were called PTMA-Metri-1% and HDTMA-Metri-1%. Soil column leaching experiment showed that compared to their commercially available formulations, organoclay complexes were effective in reducing the downward mobility of both herbicides. Organoclay complexes of metolachlor and metribuzin prepared using PTMA-Montmorillonite performed better than the HDTMA-Montmorillonite complexes.     

Application of a microscale emission factor model for particulate matter to calculate vehicle-generated contributions to fine particulate emissions

This paper discusses the evaluation and application of a new generation of particulate matter (PM) emission factor model (MicroFacPM). MicroFacPM that was evaluated in Tuscarora Mountain Tunnel, Pennsylvania Turnpike, PA shows good agreement between measured and modeled emissions. MicroFacPM application is presented to the vehicle traffic on the main approach road to the Ambassador Bridge, which is one of the most important international border entry points in North America, connecting Detroit, MI, with Windsor, Ontario, Canada. An increase in border security has forced heavy-duty diesel vehicles to line up for several kilometers through the city of Windsor causing concern about elevated concentrations of ambient PM. MicroFacPM has been developed to model vehicle-generated PM (fine [PM2.5] and coarse < or = 10 microm [PM10]) from the on-road vehicle fleet, which in this case includes traffic at very low speeds (10 km/h). The Windsor case study gives vehicle generated PM2.5 sources and their breakdown by vehicle age and class. It shows that the primary sources of vehicle-generated PM2.5 emissions are the late-model heavy-duty diesel vehicles. We also applied CALINE4 and AERMOD in conjunction with MicroFacPM, using Canadian traffic and climate conditions, to describe the vehicle-generated PM2.5 dispersion near this roadway during the month of May in 2003.     

Decolorization of triphenylmethane dye-bath effluent in an integrated two-stage anaerobic reactor

In the present study, decolorization of a simulated dye waste containing three different triphenylmethane (TPM) dyes--Magenta, Malachite Green and Crystal Violet, was investigated in a laboratory scale, two-stage anaerobic high-rate reactor. The effect of various parameters (influent dye concentration, hydraulic and co-substrate loading rates) on color and COD removal efficiency of the reactor has been studied. It has been shown that the influent dye concentration had little effect on overall COD and color removal efficiency. More than 99% color removal and 96% COD removal efficiency were maintained even at a dye concentration of 500 mg/l and a dye loading rate of 1000 mg/l day. However, a minimum level of glucose as supplementary carbon source is required to maintain the maximum color removal efficiency and it drops appreciably when no glucose is added to the influent. The study also showed that the acidogenic phase of the reaction plays an important role in decolorization of the TPM dyes. In addition, the two-stage anaerobic reactor was observed to have distinct advantages over the single-stage system, as the drop in color and COD removal efficiency of stage 1 are adequately compensated by stage 2 of the reactor especially under high dye loading rates accompanied by low co-substrate loading and under reduced HRTs.     

马来西亚油棕业：在环境无害与可持续作物生产方向上的进展

在社会经济上,油棕是马来西亚一种高度重要的作物.同热带雨林一样,它也是大气CO2的一种高效吸收者.其稠密的、伞一样的树冠提供有助于长期土壤稳定性的连续地面覆盖.棕榈油加工业有与环境保护有关的良好轨迹记录,其中包括废物管理以及废物和副产物利用.多年来,它已经采取了适当措施来防止土壤、空气和水体的退化.油棕是一种高能效作物.与其它主要一年生含油种子作物比较,它的栽培和加工需要投入较少的农业化学品和化石燃料就能生产一吨油,而且产生较少的排放.