Accumulation and release of petroleum-derived aromatic hydrocarbons by four species of marine animals

Survival of Ctenodiscus crispatus during exposure to hypoxia (P _{O 2}<3 mm Hg) at 5°C is greater than that of any echinoderm reported in the literature, the LT₅₀ being 248 h; this is reduced to 236 h in the presence of hydrogen sulfide. Unlike Asterias vulgaris and A. forbesi, both of which lose the tube foot response to tactile stimulation long before death from hypoxia occurs, C. crispatus remains responsive until death. The extension of the highly protrusible epiproctal cone, which occurs in 75% of the mud stars simultaneously exposed to hypoxia and H₂S, serves to maintain burrow contact with the overlying water. The rate of oxygen consumption remains constant down to an ambient oxygen partial pressure of 10 to 25 mm Hg, becoming more oxygen-dependent after prior exposure of the asteroids to hypoxia. C. crispatus exhibits a clear oxygen-debt phenomenon as well as a compensatory reduction in the residual P _{O 2} (oxygen partial pressure at which oxygen consumption ceases) from 2.4 to 0.2 mm Hg after hypoxic exposure.     

Safety evaluation of flubendiamide and its metabolites on cabbage and persistence in soil in different agroclimatic zones of India

Supervised field trials following good agricultural practices were conducted at the research farms of four agricultural universities located at four different agroclimatic zones of India to evaluate the persistence and dissipation of flubendiamide and its metabolite, des-iodo flubendiamide, on cabbage. Two spray applications of flubendiamide 480 SC of standard and double dose at the rate of 24 and 48 g a.i. ha^?1 were given to the crop at a 15-day interval, and the residues of flubendiamide 2 h after spray were found in the range of 0.107–0.33 and 0.20–0.49 mg kg^?1 at respective doses. Residue of des-iodo flubendiamide was not detected in any cabbage sample during study period. No residues were found in the soil samples collected from all treated fields after 15 days of application. On the basis of data generated under All India Network Project on Pesticide Residues, a preharvest interval (PHI) of 10 days has been recommended, and the flubendiamide 480 SC has been registered for its use on cabbage by Central Insecticide Board and Registration Committee, Ministry of Agriculture, Government of India. The maximum residue limit (MRL) of flubendiamide on cabbage has been fixed by the Ministry of Health and Family Welfare, Government of India, under Food Safety Standard Authority of India as 0.05 μg/g after its risk assessment.     

Effects of Regional Reductions in Sulphur Deposition on the Chemical and Biological Recovery of Lakes within Killarney Park, Ontario, Canada

The lakes in KillarneyProvincial Park, located 40–60 km southwest ofSudbury, Ontario, were some of the first lakesin North America to be acidified by atmosphericpollutants. Acidification affected thousandsof fish and invertebrate populations in dozensof lakes. Since the 1970's, water quality hasimproved in response to atmospheric pollutionreductions and some lakes have alreadyrecovered to approximately their pre-industrialpH levels, as inferred from diatom microfossilsin lake sediments. Since the 1970's, fishspecies richness has not changed substantially,but zooplankton species richness has increasedin acidified lakes. The critical sulphur load,the amount of SO₂-derived acid depositionthat can occur while still maintaining suitable water quality, was estimated to beexceeded in 38% of the park area in 1997. Depending on which of four possible NorthAmerican emission control scenarios (CLR =currently legislated reduction; CLR + 25%; CLR+ 50%; CLR + 75%) is achieved by 2010, theprojected critical loads will be exceeded inabout 0-30% of the park area in the future. There are many factors that can affectbiological recovery rates of damaged lakes, butit is expected that biological recovery willlag considerably behind observed chemicalrecovery rates.     

酸沉降作用的降低和安大略省基拉尼湖泊的化学恢复

毗邻加拿大安大略省萨德伯里市的基拉尼公园中的湖泊都表现出明显的水质变化,其中包括pH值和碱度的普遍增加,SO2- 4、碱基阳离子和金属浓度的减少.经过数十年的改善,尽管一些湖泊的pH值已经大于6,但仍有许多湖泊的湖水酸度却一直很高.过去,萨德伯里金属冶炼厂排放引起的过高的硫沉降左右了这一地区的酸化过程.然而,自从冶炼厂的硫排放被严格控制之后(排放量降低了90%),萨德伯里地区的硫排放就不再是该地区最主要的硫沉降源了.目前,基拉尼地区的SO2- 4湿沉降和湖水中SO2- 4浓度已经十分接近约200km外的安大略省多赛特地区,这就表明基拉尼地区的硫沉降现在主要来自于长距离传输,而不是当地污染源.对基拉尼湖泊的研究揭示了化学恢复过程的复杂本质.一旦湖水的酸度降低,就会引起一系列的变化,包括Ca2+浓度的减少,透明度增加和热力学状态改变.这些变化可能会潜在地影响一些生态体系.因此很明显需要对基拉尼湖泊的恢复在多胁迫因子的框架内继续进行评价.     

Ipomoea dasysperma seed gum: an effective natural coagulant for the decolorization of textile dye solutions

An investigation of dye decolorization from synthetic dye solutions using the non-ionic, water-soluble, high molecular weight seed gums Ipomoea dasysperma and guar gum as coagulants was undertaken. The use of galactomannans derived from plants in this system presents a sustainable method of textile effluent treatment. These natural coagulants extracted from plants proved to be workable alternatives to conventional coagulants like polyaluminum chloride, as they are biodegradable, safe to human health, are cost effective when compared to imported chemicals and have a wider effective dosage range for flocculation of various colloidal suspensions. Coagulant dose and coagulation pH are important factors influencing the mechanism of coagulation. Also the type and chemical structure of the dye plays an important role in the coagulation process. The seed gums alone were found to be effective for decolorization of direct dye and in combination with PAC their coagulation efficiency was well extended even for reactive and acid dyes.     

Effect of crude oil contamination on the chlorophyll content and morpho-anatomy of Cyperus brevifolius (Rottb.) Hassk

Chlorophyll plays a pivotal role in the plant physiology and its productivity. Cultivation of plants in crude oil contaminated soil has a great impact on the synthesis of chlorophyll pigment. Morpho-anatomy of the experimental plant also shows structural deformation in higher concentrations. Keeping this in mind, a laboratory investigation has been carried out to study the effect of crude oil on chlorophyll content and morpho-anatomy of Cyperus brevifolius plant. Fifteen-day-old seedling of the plant was planted in different concentrations of the crude oil mixed soil (i.e., 10,000, 20,000, 30,000, 40,000, and 50,000 ppm). A control setup was also maintained without adding crude oil. Results were recorded after 6 months of plantation. Investigation revealed that there is a great impact of crude oil contamination on chlorophyll content of the leaves of the experimental plant. It also showed that chlorophyll a, chlorophyll b, and total chlorophyll content of leaves grown in different concentrations of crude oil were found to be lower than those of the control plant. Further, results also demonstrated that chlorophyll content was lowest in the treatment that received maximum dose of crude oil. It also showed that chlorophyll content was decreased with increased concentration of crude oil. Results also demonstrated that there was a reduction in plant shoot and root biomass with the increase of crude oil concentration. Results also revealed that the shoot biomass is higher than root biomass. Morphology and anatomy of the experimental plant also show structural deformation in higher concentrations. Accumulation of crude oil on the cuticle of the transverse section of the leaves and shoot forms a thick dark layer. Estimation of the level of pollution in an environment due to oil spill is possible by the in-depth study of the harmful effects of oil on the morphology and anatomy and chlorophyll content of the plants grown in that particular environment.     

Impact Assessment and Recommendation of Alternative Conjunctive Water Use Strategies for Salt Affected Agricultural Lands through a Field Scale Decision Support System – A Case Study

Conjunctive use of saline/non-saline irrigation waters is generally aimed at minimizing yield losses and enhancing flexibility of cropping, without much alteration in farming operations. Recommendation of location-specific suitable conjunctive water use plans requires assessment of their long-term impacts on soil salinization/sodification and crop yield reductions. This is conventionally achieved through long-term field experiments. However such impact evaluations are site specific, expensive and time consuming. Appropriate decision support systems (DSS) can be time-efficient and cost-effective means for such long-term impact evaluations. This study demonstrates the application of one such (indigenously developed) DSS for recommending best conjunctive water use plans for a, rice-wheat growing, salt affected farmer’s field in Gurgaon district of Haryana (India). Before application, the DSS was extensively validated on several farmers and controlled experimental fields in Gurgaon and Karnal districts of Haryana (India). Validation of DSS showed its potential to give realistic estimates of root zone soil salinity (with R = 0.76–0.94; AMRE = 0.03–0.06; RMSPD = 0.51–0.90); sodicity (with R = 0.99; AMRE = 0.02; RMSPD = 0.84) and relative crop yield reductions (AMRE = 0.24), under existing (local) resource management practices. Long term (10 years) root zone salt build ups and associated rice/wheat crop yield reductions, in a salt affected farmer’s field, under varied conjunctive water use scenarios were evaluated with the validated DSS. It was observed that long-term applications of canal (CW) and tube well (TW) waters in a cycle and in 1:1 mixed mode, during Kharif season, predicted higher average root zone salt reductions (2–9%) and lower rice crop yield reductions (4–5%) than the existing practice of 3-CW, 3-TW, 3-CW. Besides this, long-term application of 75% CW mixed with 25% TW, during Rabi season, predicted about 17% lower average root-zone salt reductions than the cyclic applications of (1-CW, 1-TW, 2-CW) and (2-CW, 1-TW, 1-CW, i.e., existing irrigation strategy). However, average wheat crop yield reductions (16–17%) simulated under all these strategies were almost at par. In general, cyclic-conjunctive water use strategies emerged as better options than the blending modes. These results were in complete confirmation with actual long-term conjunctive water use experiments on similar soils. It was thus observed that such pre-validated tools could be efficient means for designing, local resource and target crop yield-specific, appropriate conjunctive water use plans for irrigated agricultural lands.     

Multivariate analysis of drinking water quality parameters in Bhopal, India

Pollution of water bodies is one of the areas of major concern to environmentalists. Water quality is an index of health and well being of a society. Industrialization, urbanization and modern agriculture practices have direct impact on the water resources. These factors influence the water resources quantitatively and qualitatively. The study area selected were the Upper lake and Kolar reservoir of Bhopal, the state capital of Madhya Pradesh, India. The Upper lake and Kolar reservoir both are the important sources of potable water supply for the Bhopal city. The physico–chemical parameters like temperature, pH, turbidity, total hardness, alkalinity, BOD, COD, Chloride, nitrate and phosphate were studied to ascertain the drinking water quality.     

Statistical evaluation of hydrobiological parameters of Narmada River water at Hoshangabad City, India

Narmada is considered to be the lifeline of the state of Madhya Pradesh in Central India. The Narmada water is used for bathing, drinking, irrigation and industrial purposes. The city sewage and industrial effluent from Security paper mill at Hoshangabad drains in the Narmada River and pollutes the water quality. Urban sewage enters into Narmada through main nallas. River water quality at Hoshangabad has become a matter of concern due to continuous changing environment and increasing social and industrial activity that influence the water quality directly or indirectly. The present investigation is undertaken to study the effect of domestic sewage and effluent from Security paper Mill on the water quality and ecology of river Narmada at Hoshangabad. The study is carried on at four sites along with the bank of river Narmada. Water samples from four stations were collected, out of which three main sewage mixing points of the city and one fresh water site are taken into account. The samples collected were analyzed, as per standard methods parameters such as Temperature, pH, were measured in-situ. The statistical evaluations were also made. The result showed increase in BOD, Nitrates, Phosphates and Total Coliforms, No. of phytoplanktons. The results revealed that most of the water samples were below or out of limited; according to the WHO, BIS standards.