Abstract : The present review deals with the maternal transfer of lead through the placenta during pregnancy and its deleterious effects on developing gastrointestinal tract. Exposure to lead is more dangerous for young and unborn children. It is well known that lead passes through the placenta of mother to fetus and accumulates in fetal tissues during gestation and it can be obtained through the milk during lactation .Lead may be released from maternal bone reserves during pregnancy and thus it becomes a major source of intoxication for the fetus. Prenatal exposure to low lead levels may increase the risk of reduced birth weight and premature birth. Lead is poorly absorbed from the GI tract; however, toxic effects can result from the relatively small amount of lead that is absorbed. There have been very few studies designed to evaluate consequences of lead toxicity during developmental stages, although this is the most sensitive period. The absorption of lead is influenced by many factors such as chemical form of the lead, diet, presence of food in GI tract, calcium status, vitamin D and iron. The mechanisms by which these interactions occur and induce histopathological changes in developing fetus are not fully understood. This reflects a lack of understanding of the mechanism by which lead is absorbed in the GI tract of mother and influence the developing fetus during gestation and lactation. Although threshold levels have been derived from the animal data, factors such as size, relative difference in consumption in proportion to size especially during infancy, and variable histopathological changes in GI tract are not well investigated during different developmental stages.
Abstract : Property use changes continuously, hence planning based on this information is a continuous process that can be very critical. In Nigeria, information depicting past and present changes in property use for environmental planning, monitoring and socio-economic development is often inadequate. Therefore, there is a need of new tool such as GIS, to analyze changes in properties in Apapa, Nigeria. The method adopted in achieving the result of this work includes collection of both spatial and ancillary data of year 1968 and 2007. Both spatial data with GPS locations of additional information were integrated using ArcGIS to update the 2007 data. The study revealed that initial plan for each property as at 1968 showed that 136 were been used for properties. Year 2007 information revealed 246 existing properties when query analysis was performed to display property information or status. Changes in property uses between 1968 and 2007 were identified in the study; some plots were merged while others have more than two properties within a single plot. The rate of change was simply determined by few parameters in last 39 years. Total properties and individual properties changes, percent dynamics change and rate of changes have been demonstrated in the study.
Abstract : The West Bengal part of the Ganges-Brahmaputra delta, popularly known as the Sundarban delta, is a system where intricate estuarine and coastal processes are influenced by adjacent marine, terrestrial and meteorological systems and the dynamic interface amongst the three, being the center of population growth, coastal sea, ponds/wetlands, estuarine Islands in this area are to sustain the negative impact caused by society's commercial, recreational, and residential activities. Additionally, natural forcing like sea level rise or climate change is a prime issue of concern for this vulnerable tract. Presently, this deltaic system is facing degradation due to natural and anthropogenic causes. Degradation of this littoral tract is manifested in terms of frequent embankment failures, submergence & flooding, beach erosion, siltation within embankment, saline water intrusion in the agricultural field etc. The present study demonstrates the potential of Geospatial and statistical technique for monitoring the climate changes of eastern part of Indian Sundarban, India since such kind of changes stand as a testimony for the past and present coastal environment. In the present study, multi resolution and multi temporal satellite images of Landsat have been utilized to demarcate climate change of weather data between 1990 to 2013. The Statistical techniques called as linear regression and regression coefficient have been used for find out the change rate during the period of 1990 to 2013 weather change and environment impact assessment of the study area. Finally, an attempt has been made to find out any interactive relationship between the climates changes in the concerned area.
Abstract : Reproduction has vital role to maintain the biodiversity and ecobalance in nature. In present investigation major physico-chemical parameters like chloride, sodium, COD, TS, TDS and SS has induces histopathology of oocytes in crab Barytelphusa cunicularis. In which, ovary showed disturbed epithelial layer with degenerated oocytes. Vacuolization was appeared at the periphery of the oocyte cells due to high concentration of COD. In conclusion, physico-chemical parameters caused histopathology on developing oocytes under stressful conditions.
Abstract : Photo-catalysis of wastewater using titanium dioxide is an advanced oxidation process (AOP) for environmental remediation. Advanced Oxidation Process can mineralize a wide range of organic compound and convert it into carbon dioxide, water and inorganic ions. Recently Advanced Oxidation Process is an emerging technology for the water purification. Advanced Oxidation Process uses different type of oxidants. Titaniumdioxide has been widely studied on lab scale for decontamination of drinking water. This paper deals with the problem of water contamination due to the sewage and also relates with the photo-catalysis of sewage using titanium dioxide as an oxidant. Photo-catalysis of sewage is mainly depending on the oxidation reduction reaction. For the removal of organic waste form the sewage oxidation reduction reaction is used and this reaction is accelerated using titanium dioxide as a strong oxidizing agent. Changes in different physical and chemical characteristics of sewage after application of Advanced Oxidation Process were observed using titanium dioxide as a strong oxidizing agent. The photo catalysis of sewage has been studied for removal COD reduction. The influence of TiO2 catalyst and pH on COD removal efficiency was recorded. Maximum COD removal of the sewage achieved was 78% after catalyst dosage of 0.25 g/50ml at alkaline pH 8 and at ambient temperature. Effective contact time is 50 minutes for 80% COD removal with optimum catalyst and pH. The photocatalytic degradation process using TiO2 as an irradiation source showed potential application for the COD removal of the sewage.
Abstract : External carbon sources can enhance denitrification rates and thus improve nitrogen removal in wastewater treatment plants. When external carbon sources are added, no severe effect could be observed from an operational point of view. Denitrification is a process in which the oxidized nitrogen substances, i.e. nitrates and nitrites are reduced to nitrogen gas, such as N2O and N2, when a proton donor (energy source) is available. Nitrogen in groundwater results from human excreta, ground garbage and industrial effluents, particularly from food processing plants. The addition of external carbon source helps in increasing denitrification rates and enhances the nitrogen removal. In most biological denitrification systems, the nitrate polluted wastewater (e.g. domestic sewage) contains sufficient carbon source to provide the energy source for the conversion of nitrate to nitrogen gas by the denitrifying bacteria. The groundwater, in which the nitrate contents may be as high as 100 mg/L with low dissolved carbon content, an additional proton acceptor is required. This project work discusses the successful implementation of methanol as carbon sources for Wastewater Treatment Facility utilizing upflow deep bed continuous filter. This work will describe the methodology employed to implement methanol carbon sources, the modifications required to utilize methanol carbon sources in deep bed filter technologies.