Azo and reactive dyes are mostly used in various industries like textile, leather, paper, food, plastic, and printing of color products [1-3]. Dyes are toxic for humans as well as the environment, and must be treated before their discharge to reduce environmental pollution [4]. Several methods for removing dyes include membrane filtration [5], coagulation/flocculation [6], advanced oxidation [7], and phyto-catalytic degradation [8]. Biodegradation of dyes is difficult because of their stable and complex chemical structure. Therefore, the adsorption process has been adopted for removal of dyes due to its simplicity, flexibility, ease of operation, and cost effectiveness [9]. Various adsorbents have been utilized for dye removal, such as alumina, rice husk, banana peels, orange peels, coconut shells, peanut shells, and various clays, etc. [10]. Among these, carbon-based materials are more efficient adsorbents, comprising large numbers of pores and high surface area for adsorption of dyes, but due to their high preparation cost they can't be used
The present study investigates the noise pollution levels in public- and private-sector hospitals of Lahore. The noise pollution parameters were investigated from 20 public and 10 private hospitals. We observed that the equivalent continuous sound level (Leq) values varied significantly in different departments of the hospitals as well as at different times of the day. The public-sector hospitals had significantly higher noise pollution compared to the private-sector hospitals. The Wilcoxon Mann-Whitney two-sample rank-sum test revealed significant difference between noise levels in intensive care unit (ICU) during morning and in emergency, waiting area, intensive care unit (ICU), and reception during daytimes. However, no significant differences were found for any department during the evening. The Leq values were found to be higher than the international norms (WHO standards) for all hospitals, higher than USEPA for 29 hospitals and higher than local standards for 27 hospitals. Overall, significantly lower sound levels were always observed in private hospitals.
With the advancement in the technologies around the world over the past few years, the microelectromechanical systems (MEMS) have gained much attention in harvesting the energy for wireless, self-powered and MEMS devices. In the present era, many devices are available for energy harnessing such as electromagnetic, electrostatic and piezoelectric generator and these devices are designed based on its ability to capture the different form of environment energy such as solar energy, wind energy, thermal energy and convert it into the useful energy form. Out of these devices, the use of a piezoelectric generator for energy harvesting is very attractive for MEMS applications. There are various sources of harvestable energy including waste heat, solar energy, wind energy, energy in floating water and mechanical vibrations which are used by the researchers for energy harvesting purposes. This paper reviews the state-of-the-art in harvesting mechanical vibrations as an energy source by various generators (such as electromagnetic, electrostatic and piezoelectric generators). Also, the design and characteristics of piezoelectric generators, using vibrations of cantilevered bimorphs, for MEMS have also been reviewed here. Electromagnetic, electrostatic and piezoelectric generators presented in the literature are reviewed by taking into an account the power output, frequency, acceleration, dimension and application of each generator and the coupling factor of each transduction mechanism has also been discussed for all the devices.
Municipal solid waste (MSW) includes packaging waste, yard waste, wood, textile, newsprints, bottles, food waste, metals, and plastics. Trade, industry, and human population growth plus variations in living standards and in consumption patterns have been the main factors for progressive increase in generating MSW. As a consequence, management of MSW is one of the major challenges for municipalities in the 21st century [1][2]. In developing Asian countries, these factors are Pol. J. Environ. Stud. Vol. 26, No. 3 (2017) AbstractThis paper evaluates the environmental impacts of various municipal solid waste (MSW) treatment options produced on-site simultaneously with energy and material recovery. The results present a comparison of life cycle assessment (LCA) for municipal solid waste management (MSWM) in five different waste scenarios along with baseline scenario of the Defence Housing Authority (DHA) in Lahore. All scenarios were modeled using EaseTech software. Nine impact categories were assessed and results were presented based on the ASTM D5231-92(2003) characterization method. Results revealed that a material recovery facility (MRF) had low global warming potential (GWP), but lower avoided burdens in other impact categories. The incineration process indicated fewer burdens on the environment such as GWP (-2.086×10 7 kg CO 2 eq) as compared to landfills (2.461×10 7 kg CO 2 eq). This was due to lower avoided emissions in the landfill process compared to incineration. The negative values in results represented higher avoided emissions in treatment processes. Bio-gasification avoided CO 2 emissions (-8.053×10 5 kg CO 2 eq), but showed negative impacts in other categories. Almost all impact categories were high in composting except for freshwater eutrophication. LCA results provided good knowledge for decision makers as a tool to decide what alternative is a better change for sustainable waste management.
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