Current Issue : April - June Volume : 2019 Issue Number : 2 Articles : 5 Articles
This document presents the technical description and cost comparison of\nfour rainwater harvesting systems for homes, the method for its hydraulic design\nand an equation to estimate the minimum catchment area, with the goal\nto supply drinking water to segregated small communities in Mexico considering\nclimate change effects, both natural and anthropogenic. The four\nRainwater Harvesting Systems (RHS) introduced in this work are the following:\ntwo rigid, one system built with ferrocement and the other built with clay\nbricks, and two flexible: one is a commercial collector while the other is a\nsystem built with a 3/8-inch reinforcing bar mesh and covered with a linear\nlow-density polyethylene geomembrane. The RHS consist in cylindrical containers\nbuilt with diverse materials, and in the case of rigid RHSs, they can\nstore up to 50,000 liters of water. Also, rigid RHSs have a longer useful life\nand are more resistant than flexible RHSs, but their cost is notably higher. Rigid\nRHSs compete in price with commercial rainwater harvesting system\nbrands like Rotoplas , but commercial RHSs disadvantages are their lower durability,\nstorage capacity, and resistance. On the other hand, flexible RHSs are\nless durable than rigid ones, although, in the case of the rainwater harvesting\nsystem made with a 3/8-inch reinforcing bar mesh, the system can be rebuilt\nand reused and the cost is much lower. The design of the collectors takes into\nconsideration the climate variability of the study area, natural or anthropogenic....
Elemental analysis of sewage effluents in Kibabii sewage treatment system\nwas achieved via Energy-Dispersive X-Ray Fluorescence (EDXRF) spectroscopy\nwith the aim of assessing the efficacy of the treatment system. Concentrations\nof lead (Pb), mercury (Hg), cadmium (Cd) and arsenic (As) were\nmeasured based on clay soil â??standardsâ? in concentration range for Pb, Hg\nand As as 12.7 ppm, 14.3 ppm and 8.83 ppm respectively for certification.\nAmong other probable reference materials, clay soil â??standardsâ? were used\nfor certification in this work because of similarity in matrix composition with\nthe sediments. The concentration for Hg, Pb, and As in the sewage sediments\nwere................
Environmental determinants causing unexpected disease rampant are seemed\nmajor challenges to be protective from inevitable hazards and to deal the future\nconsequences in terms of human health loss. This paper explores the\nmajor environmental determinants stimulating disease prevalence in western\nhilly areas of Nepal. Cross-sectional analytical research design for household\nlevel primary data was treated with the binary logit regression model to identify\nthe determinants of disease prevalence. Extreme winter temperature, decreasing\nwinter rainfall, sporadic rain, drying spout and decreasing the tree\nspecies are the major environmental determinants; hand washing, proper\nmanagement of solid waste from kitchen and habit of drinking boiled water\nare as household behavioral determinants; and adequate family members,\nhigher education, use of pesticide to control the insects and use of clean\ncooking fuels are socioeconomic determinants encouraging disease prevalence.\nPlantation of large perennial and medicinal plants, proper management\nof warm clothes or heaters especially for old people and children having respiratory\nproblems for extreme winter; management of water tank for long\ndrought in winter and community awareness campaign for the protection of\nspout are urgent needs for the prevention of current disease prevalence. Ergo,\nthe recommendations are made accordingly....
The present study assesses the physicochemical and bacteriological quality of\nthe drinking water used by the population of So-Ava based on the Beninese\nstandards and those established by the World Health Organization (WHO).\nIn rural and peri-urban areas of Benin where public water supply systems are\ninadequate or almost non-existent, the population consumes water of various\nsources of unknown qualities. A total of 67 water samples were analyzed during\nthe rainy season (July 2017) and in the dry season (January 2018) for certain\nphysical, chemical and bacteriological parameters using the standard\nmethods. The results of the analyses reveal that the physicochemical characteristics\nof the water used for consumption in So-Ava comply with the drinking\nwater standards of the World Health Organization and those in force in\nBenin except for the percentages of the following parameters: pH (41.80%);\nturbidity (25.37%); the color (16.42); ammonium (17.91%); iron (40.30%);\nNitrites (4.48%); Residual chlorine (91.05). Bacteriologically, the analyses\nshowed a high total aerobic mesophilic flora contamination, faecal coliforms,\nE. coli , faecal enterococci respectively in 89.55%, 82.09%, 50.75% and 70.15%\nof the analyzed water samples. The ratio of faecal coliforms to faecal enterococci\nindicated that the origin of faecal contamination was human in 59.7% of\nthe samples and animal in 40.3% of the samples. The adoption of hygiene\nmeasures at the water point, during the transport and storage of water, including\nthe treatment by chlorination of drinking water at the family level was\nrecommended for the population concerned and household awareness on the adoption of basic hygiene and sanitation measures have been recommended for hygiene and sanitation services....
Subcritical water extraction (SCW) was used to extract oil from Chlorella pyrenoidosa. The operational factors such as reaction\ntemperature, reaction time, and biomass loading influence the oil yield during the extraction process. In this study, response surface\nmethodology was employed to identify the desired extraction conditions for maximum oil yield. Experiments were carried out in\nbatch reactors as per central composite design with three independent factors including reaction temperature , reaction time (1, 5, 10, 15, and 20 min), and biomass loading (1, 3, 5, 10, and 15%). A maximum oil yield of 12.89 wt.%\nwas obtained at 320 degree Centigrade and 15 min, with 3% biomass loading. Sequential model tests showed the good fit of experimental data to the\nsecond-order quadratic model. This study opens the great potential of SCW to extract algal oil for use in algal biofuel production....
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