Effects of ozone on growth, yield and leaf gas exchange rates of two Bangladeshi cultivars of wheat (Triticum aestivum L.)

To clarify the effects of O₃ on crop plants cultivated in Bangladesh, two Bangladeshi wheat cultivars (Sufi and Bijoy) were grown in plastic boxes filled with Andisol and exposed daily to charcoal-filtered air or O₃ at 60 and 100 nl l⁻¹ (10:00-17:00) from 13 March to 4 June 2008. The whole-plant dry mass and grain yield per plant of the two cultivars at the final harvest were significantly reduced by the exposure to O₃. Although there was no significant effect of O₃ on stomatal diffusive conductance to H₂O of flag leaf, net photosynthetic rate of the leaf was significantly reduced by the exposure to O_3. The sensitivity of growth, yield, yield components and leaf gas exchange rates to O₃ was not significantly different between the two cultivars. The results obtained in the present study suggest that ambient levels of O₃ may detrimentally affect wheat production in Bangladesh.     

Environmental planning and management

Environmental Science and Pollution Research -     

Improved power density and Cr/Pb removal using ozone in a microbial desalination cell

Environmental Chemistry Letters - Microbial desalination cells are promising bio-electrochemical technologies for water desalination, treating wastewater and bioelectricity production. In this...     

Removal of malachite green from water samples by cloud point extraction using Triton X-100 as non-ionic surfactant

A surfactant mediated cloud point extraction (CPE) procedure has been developed to remove color from wastewater containing malachite green using Triton X-100 as non-ionic surfactant. The effects of the concentration of the surfactant, temperature and salt concentration on the different concentrations of dye have been studied and optimum conditions were obtained for the removal of malachite green. The concentration of malachite green in the dilute phase was measured using UV–Vis spectrophotometer. It was found that the separation of phases was complete and the recovery of malachite green was very effective in the presence of NaCl as an electrolyte. The results showed that up to 500 ppm of malachite green can quantitatively be removed (>95%) by CPE procedure in a single extraction using optimum conditions.     

Environmental kuznets curve and causal links between environmental degradation and selected socioeconomic indicators in Bangladesh

Environment, Development and Sustainability - This study has investigated the Environmental Kuznets Curve (EKC) hypothesis and focuses on the resource stock of the country in relation to the...     

Laboratory waste minimization by recovery of silver as nano-silver colloidal dispersion from waste silver chloride

The use of cyclic experiments, where the product of one reaction becomes the starting material for the next experiment, was proposed as an effective protocol for waste minimization in an educational lab. A simple, cheap and pollution-free method was developed for recovering silver as nano-silver colloidal dispersion from waste silver chloride in the laboratories of the Faculty of Health, Safety and Environment. Silver nanoparticles of the size 5–18 nm were recovered in the presence of sodium borohydride as a reducing agent and polyvinylpyrrolidone as a stabilizer agent. The nano-silver particles were studied for their formation, structure, stability and size using UV–Vis spectroscopy, transmission electron microscopy and dynamic light scattering techniques. The antibacterial assays of nanoparticles showed satisfactory results for Escherichia coli ATCC25922, Staphylococcus aureus ATCC 29213, and Acinetobacter baumanii (Clinical isolate). A laboratory experiment was designed in which students synthesize yellow colloidal silver solution from chemical waste silver chloride and estimate particle size using visible spectroscopy.     

Zero valent nano-sized iron/clinoptilolite modified with zero valent copper for reductive nitrate removal

Nitrates constitute one of the main toxic contaminants of groundwater. On the other hand, groundwater may be considered anoxic (oxygen concentration less than 9 μg L^?1). This fact justifies the use of nano zero valent metals for nitrate removal. In such conditions, zero valent metals are quite stable against oxidation due to the very low level of dissolved oxygen concentration. It has been shown that the performance of zero valent iron coated clinoptilolite zeolite for the reduction of nitrate anion in un-buffered conditions may be enhanced by coating small amounts of Cu⁰ onto the freshly prepared Fe⁰/zeolite composite. An optimum loading of Cu⁰ exists for which the rate of nitrate removal is maximal. For this optimal composition, the nitrite anion production curve with time passes through a maximum. Nitrite production, however, is slightly higher for the Cu modified zeolite. It has been shown that the nitrate removal process is only slightly dependent on the initial solution pH. In the temperature range of 20–60 °C, the process is controlled by both the liquid phase mass transfer and intrinsic reaction rate resistances. FESEM analysis of the zero valent metal/zeolite composite showed that upon the metal reduction reaction, an egg-shell distribution of zero valent metal in the zeolite agglomerate particle is produced.     

Community attitudes toward forest conservation programs through collaborative protected area management in Bangladesh

The formulation of conservation policies with options for creating protected areas is significantly influenced by the social factors of the surrounding communities. Therefore, indigenous knowledge, attitudes and perceptions of the local communities need to be explored during the planning and implementation stages of conservation projects. A government-initiated experiment in co-management was conducted in the Rema-Kalenga Wildlife Sanctuary, Bangladesh. This paper analyzes the attitudes toward conservation by members of local communities living in and around the wildlife sanctuary. Training incentives on alternative income-generating (AIG) activities and allotment of agricultural lands were distributed among the Forest User Groups. It is of interest to policy makers and resource managers whether this technique leads to improved attitudes on the part of local people. Although there were different attitudes toward protected areas and conservation, overall, a favorable attitude of the respondents was observed. The opinions of respondents also varied based on factors such as village position, village dependency level on forest resources, ethnicity and gender. Increase in annual income resulting from the augmented skills by trainings on AIG activities and getting agricultural lands leased from the Forest Department contributed significantly to the variation in respondents’ conservation attitudes. It is suggested that eliminating inequity and inequality in incentive distribution, discovering and launching training on more need-based livelihood activities, and liberalizing the restriction of resource extraction from the protected area by fixing the harvesting limit would encourage the community to be more cordially and actively involved in the conservation efforts of the sanctuary.     

The effect of distance on the adherence to postpartum follow-up in women with gestational diabetes

Environmental Science and Pollution Research - Despite the increasing prevalence of gestational diabetes mellitus and well-known long-term metabolic consequences, a low rate of postpartum screening...