REMOVAL OF CHROMIUM FROM AQUEOUS SOLUTION USING LOCALLY AVAILABLE INEXPENSIVE TARO AND WATER HYACINTH AS BIOSORBENT

In this investigation, locally available and inexpensive Taro and Water Hyacinth were used as biosorbents to remove chromium from synthetic wastewater. The removal of this metal ion from water in the batch and column method have been studied and discussed. Adsorption kinetics and equilibrium isotherm studies were also carried out. The material exhibits good adsorption capacity and the data follow both Freundlich and Langmuir models. Scanning Electronic Microscopic image was also used to understand the surface characteristics of biosorbent before and after biosorption studies. Effects of various factors such as pH, adsorbent dose, adsorbate initial concentration, particle size etc. were analyzed. The initial concentrations of chromium were considered 5-30mgL-1 in batch method and only 4mgL-1 in column method. The maximum chromium adsorbed was 1.64 mgg-1 and 4.44 mgg-1 in Batch method and 1.15 mgg-1 and 0.75 mgg-1 in Column method. Batch and Column desorption and regeneration studies were conducted. Column desorption studies indicated that both of these biosorbents could be reused for removing heavy metals. Results of the laboratory experiments show that the performance of Taro and Water Hyacinth prove that they can effectively be used as low cost biosorbents for the removal of chromium from wastewater. KEYWORDS:   adsorption; chromium removal; Taro; water hyacinth; batch method; column studie

Safe distances between groundwater-based water wells and pit latrines at different hydrogeological conditions in the Ganges Atrai floodplains of Bangladesh.

BACKGROUND: Groundwater drawn from shallow tubewells in Bangladesh is often polluted by nearby pit latrines, which are commonly used toilets in rural and sub-urban areas of the country. METHODS: To determine the minimum safe distance of a tubewell from a pit latrine in different hydrogeological conditions of Bangladesh, 20 monitoring wells were installed at three study sites (Manda, Mohanpur and Bagmara) with the vertical and horizontal distances ranging from 18-47 to 2-15 m, respectively. Water samples were collected three times in three seasons and tested for faecal coliforms (FC) and faecal streptococci (FS) as indicators of contamination. Soil samples were analysed for texture, bulk density and hydraulic conductivity following standard procedures. Sediment samples were collected to prepare lithological logs. RESULTS: When the shallow aquifers at one of the three sites (Mohanpur) were overlained by 18-23-m-thick aquitards, the groundwater of the monitoring wells was found contaminated with a lateral and vertical distances of 2 and 31 m, respectively. However, where the aquitard was only 9 m thick, contamination was found up to lateral and vertical distances of 4.5 and 40.5 m, respectively. The soil textures of all the sites were mainly composed of loam and sandy loam. The hydraulic conductivities in the first aquifer at Manda, Mohanpur and Bagmara were 5.2-7.3, 8.2 and 1.4-15.7 m/h, respectively. CONCLUSIONS: The results showed that the safe distance from the tubewell to the pit latrine varied from site to site depending on the horizontal and vertical distances of the tubewell as well as hydrogeological conditions of a particular area

Safe distances between groundwater-based water wells and pit latrines at different hydrogeological conditions in the Ganges Atrai floodplains of Bangladesh

Background: Groundwater drawn from shallow tubewells in Bangladesh is often polluted by nearby pit latrines, which are commonly used toilets in rural and sub-urban areas of the country. Methods: To determine the minimum safe distance of a tubewell from a pit latrine in different hydrogeological conditions of Bangladesh, 20 monitoring wells were installed at three study sites (Manda, Mohanpur and Bagmara) with the vertical and horizontal distances ranging from 18\u201347 to 2\u201315 m, respectively. Water samples were collected three times in three seasons and tested for faecal coliforms (FC) and faecal streptococci (FS) as indicators of contamination. Soil samples were analysed for texture, bulk density and hydraulic conductivity following standard procedures. Sediment samples were collected to prepare lithological logs. Results: When the shallow aquifers at one of the three sites (Mohanpur) were overlained by 18\u201323-m-thick aquitards, the groundwater of the monitoring wells was found contaminated with a lateral and vertical distances of 2 and 31 m, respectively. However, where the aquitard was only 9 m thick, contamination was found up to lateral and vertical distances of 4.5 and 40.5 m, respectively. The soil textures of all the sites were mainly composed of loam and sandy loam. The hydraulic conductivities in the first aquifer at Manda, Mohanpur and Bagmara were 5.2\u20137.3, 8.2 and 1.4\u201315.7 m/h, respectively. Conclusions: The results showed that the safe distance from the tubewell to the pit latrine varied from site to site depending on the horizontal and vertical distances of the tubewell as well as hydrogeological conditions of a particular area

Pigmentos lipossolúveis e hidrossolúveis em plantas de salvínia sob toxicidade por cromo

Devido à intensa utilização industrial, o cromo é considerado um importante poluente ambiental. O presente trabalho objetivou determinar os teores de pigmentos hidro e lipossolúveis em plantas de salvínia expostas a concentrações crescentes de Cr, visando estabelecer parâmetros bioquímicos para utilização dessa macrófita em programas de biomonitoramento e/ou fitorremediação da poluição causada por esse poluente metálico em ambientes aquáticos. As plantas foram submetidas a concentrações crescentes de Cr e avaliadas após quatro, seis e dez dias de tratamento. Os resultados dos ensaios permitiram concluir que plantas de salvínia sob condições de estresse por Cr apresentam reduções nas concentrações das clorofilas a, b e total e, em contraste, aumentos nas concentrações de antocianinas totais. Embora a concentração de carotenoides totais não tenha sido alterada em resposta ao Cr, as variações nas concentrações dos demais pigmentos lipossolúveis e dos pigmentos hidrossolúveis observadas nas folhas das plantas de salvínia podem ser utilizadas como parâmetros bioquímicos de biomonitoramento da poluição causada por esse elemento metálico em ambientes aquáticos.Due to widespread industrial use, chromium is considered a serious environmental pollutant. This study aimed to determine the content of hydrosoluble and liposoluble pigments in salvinia plants exposed to increasing concentrations of Cr, to establish biochemical parameters for the use of macrophyta in pollution bio-monitoring programs and/or phyto-remediation in aquatic environments by this pollutant metal. The plants were exposed to increasing concentrations of Cr and evaluated after four, six, and ten days of treatment. The test results showed that salvinia plants under stress conditions for Cr exhibit decreases in the concentrations of chlorophylls a, b, and total, and, in contrast, increases in anthocyanin concentrations. Although the concentration of carotenoids has not been altered in response to Cr, the variations in the concentrations of other liposoluble and hydrosoluble pigments found in salvinia plant leaves can be used as biochemical parameters for biomonitoring of pollution caused by this metallic element in aquatic environments

Production of He-4 and (4) in Pb-Pb collisions at root(NN)-N-S=2.76 TeV at the LHC

Results on the production of He-4 and (4) nuclei in Pb-Pb collisions at root(NN)-N-S = 2.76 TeV in the rapidity range vertical bar y vertical bar <1, using the ALICE detector, are presented in this paper. The rapidity densities corresponding to 0-10% central events are found to be dN/dy4(He) = (0.8 +/- 0.4 (stat) +/- 0.3 (syst)) x 10(-6) and dN/dy4 = (1.1 +/- 0.4 (stat) +/- 0.2 (syst)) x 10(-6), respectively. This is in agreement with the statistical thermal model expectation assuming the same chemical freeze-out temperature (T-chem = 156 MeV) as for light hadrons. The measured ratio of (4)/He-4 is 1.4 +/- 0.8 (stat) +/- 0.5 (syst). (C) 2018 Published by Elsevier B.V.Peer reviewe

Cotton spinning waste as useful compost for organic Indian Spinach (Basella alba ) production in Bangladesh

Purpose This study aims to ascertain the physiochemical characteristics of the compost made from recycled cotton spinning waste (CSW) for Indian Spinach cultivation in Bangladesh.Method The physiochemical characteristics of the compost made of fresh cotton spinning waste (CSW), cotton spinning waste ash (CSWA), rice husk (RH), rice husk ash (RHA) with varying ratios following open air composting method was determined. The utility of the resulting compost was justified by applying it to Indian Spinach cultivation compared with chemical fertilizer and control (no-compost) treatments.Results Among the several composting options, the compost prepared by mixing 87% CSW + 13% CSW ash (C3) and 87% CSW + 13% rice husk (C4) was found to be the quality compost with a higher C/N ratio, P, K, S and a lower Pb content. The vegetative growth, yield and nutritional qualities were significantly affected by the compost characteristics compared to chemical fertilizer because of increased nutrient uptake and biostimulation functions. Moreover, Indian Spinach cultivated with CSW compost provided 64 BDTk. profits compared to 28 BDTk. in case of control that indicates 128% increase in profit for the compost than that of control.Conclusion The compost derived from the mixture of CSW+CSWA+RH+RHA substrates possesses an optimum moisture content (31.2%), pH (7.5), C/N ratio (16.8:1), macronutrients, and micronutrients that enable it to act as an alternative to chemical fertilizer. When it comes to yield and nutrition quality of the grown Indian Spinach, CSW based compost fared much better than chemical fertilizer in field test

High pressure ultrafiltration CuO/hydroxyethyl cellulose composite ceramic membrane for separation of Cr (VI) and Pb (II) from contaminated water

A novel clay-alumina ceramic composite membrane has been fabricated comprising of hydroxyethyl cellulose and CuO nanoparticles for separation of Cr (VI) and Pb (II) from contaminated water. It was prepared by slurry casting method over low cost clay-alumina ceramic substrate. The active layer formation of the prepared membrane was confirmed by FESEM, EDX and XPS analysis. The pore structure of macroporous ceramic substrate was improved from 0.5 to 1.5 mu m to 3 nm by addition of CuO nanoparticles in combination with biopolymer which resulted in consequent improvement of heavy metal rejection rate. The permeability was determined as 34.99 Lm(-2) h(-1) bar(-1). The membrane exhibited significant performances and stability on rejection of toxic Pb (II) and Cr (VI) ions from spiked solution and simulated wastewater. Although the operational pressure range was 0-5 bar, maximum percentage of rejection achieved was 97.14% for Pb (II) at 2 bar transmembrane pressure from spiked water. Similarly maximum percentage of rejection was obtained at 2 bar transmembrane pressure for Cr (VI) was 91.44%. The reusability of the membrane was also studied and obtained results suggested that the prepared membrane may be used for real application. It is believed that this CuO nanoparticles containing clay-alumina ceramic composite membrane will be an effective solution for removal of heavy metals from contaminated water

Pattern of sexually transmitted infections: A profile from a rural- and tribal-based sexually transmitted infections clinic of a tertiary care hospital of Eastern India

Introduction: Prevalence of Sexually transmitted infections (STI's) in developing nations is very high where the measures for STI treatment and prevention are limited. Enormous variation in clinical presentation make STI's very difficult to be studied epidemiologically. To know the exact prevalence of STI's is very important for a region or community for planning preventive strategies. The aim of the present study is to observe the pattern of sexually transmitted infections among the tribal and non-tribal population attending a rural and tribal base tertiary care Centre. Method: All the consecutive STI patients irrespective of age and sex attending the STI clinic were included. Thorough clinical examination and relevant investigations were done to know the different STI's present in them. They were divided into tribal and non-tribal group as per history and comparison of patterns of STI's done among the two groups. Result: Around 34% of STI patients were tribal. Majority of patients belong to 20-40 years of age. Sex ratio of tribal group was 1:0.86 and non-tribal group was 1:2.64. The difference is statistically significant. Commonest STI in both the group was Genital ulcer disease Herpetic but the occurrence of urethral discharge, genital scabies, and inguinal bubo were among the tribal group. Per vaginal discharge was the commonest STI among the female in both the groups. VDRL positivity was 1.16% and HIV positivity was 0.36% among STI clinic attendees. Conclusion: Tribal females need special attention for prevention of STI in tribal community