Volume 5 Issue 1

Authors: Simeon Taole; Nnenesi Kgabi; Amanda Bubu

Abstract: In this study, the sampling of size segregated particulates was performed by using a three-stage Dekati PM10 Cascade Impactor. The concentration of toxic elements in the different particle sizes was determined using Particle Induced X-ray Emission. This study focused on determination of the concentration of toxic elements in different particle sizes. The highest level of particulate matter (PM) at daytime was 90 μg.m-3 while at night-time, the concentrations ranged between 0.04 µg.m-3 and 0.8 μg.m-3. The toxic elements Cr, Ni, V and Pb were identified in the PM10, PM2.5, PM1.0 and PM<1 samples. The Cr concentrations exceeded the limits of 1 μg.m-3 for NIOSH and also the 1.5 μg.m-3 limit for APCEL. The WHO standards of 0.5 μg.m-3 and 1 μg.m-3 for Pb and V respectively were not exceeded. The study suggests the need for more prolonged, continuous studies so as to establish trends and seasonal variations in particulate matter and toxic metals.

Keywords: Toxic Metals; Particulate Matter; Size Distribution; Sources of Atmospheric Particles; Particle Induced X-Ray Emission


Authors: Asha B. Chelani

Abstract: Monthly aerosol optical depth (AOD) data over central India during 2001-2010 obtained from Moderate Resolution Imaging Spectroradiometer are analyzed for trend and periodicity. For this purpose, spectral analysis and linear trend analysis are performed. High AOD during monsoon followed by summer months are observed. Spatial analysis did not show any significant spatial variations in AOD levels. Spectral analysis suggested two dominant periods; 12 months and 6 months consistent with the annual and seasonal patterns. Trend analysis showed an insignificant trend at all the locations. Decadal change in AOD is the highest in Nagpur, which is an urban agglomeration station. Less developed and nonurban areas, however show decreasing or insignificant trend in AOD levels. Correlation with change in population over the last decade at different locations showed significant positive relationship with percentage change in AOD levels suggesting the effect of urban agglomeration on AOD in central India.

Keywords: Aerosol Optical Depth; Periodicity; Trend; Population


Authors: Nestor Jaime Aguirre; Carlos Alberto Palacio; Lina Claudia Giraldo

Abstract: This work aims at determining the effect of wastewater input and hydrologic regimes on the epilithic algal colonization over artificial substrates in the Aburrá–Medellin River. For this purpose, at eight stations in the river were installed 14 polypropylene baskets with 2000 grams of gravel as substrates in order to know the algae response to changes in water quality (reflected in changes in biological indices and also affected by fluctuations in water levels; i.e., flow rates, and therefore changes in its composition according to the hydrological cycle). Alterations generated in the composition and abundance of algae by wastewater discharges and change in water levels did not produce a pattern of colonization. Based on the above, it allowed to conclude that algae are sensitive organisms to particular events that affect water quality in the Aburrá–Medellín River.

Keywords: Epiphyton; Colonization; Algae; Water Quality of Aburrá-Medellín River


Authors: Juan Pablo Arrigoni; Gabriela Paladino; Francisca Laos

Abstract: Decentralized composting has become a powerful option for municipal organic waste management. This technology, not only is an effective tool to treat organic waste, producing compost as a valuable by-product, but also represents an innovative way to involve waste generators in treatment operations. Decentralized composting contributes to reducing waste transportation, treatment costs and landfilling volumes thus resulting in a positive impact on municipal waste management programs. In this work, three low-tech composter prototypes were designed and built using discarded metallic oil drums and recycled plastic materials. The composting experience was carried out at an oilfield, using food waste from a catering service for 65 people. Temperature was used as the main indicator of the composting process, and final product quality was characterized through the following variables: total nitrogen, total phosphorous, extractable phosphorous, pH, organic matter and electrical conductivity. Results confirm the effectiveness of this composting technology for organic waste treatment: thermophilic temperatures were reached in all prototypes, and final products obtained from all composters showed high nutrient and organic matter contents, but also high pH and electrical conductivity values, which frequently appear in decentralized composting product; however, obtained values are still adequate for agronomic applications. Nevertheless, some significant differences were found for these variables among the prototypes, possibly related to design characteristics. Finally, composters construction could be optimised by recycling other waste, as shown in this experience (metallic drums, high density polyethylene and accessories), in order to improve the strategies for decentralised composting.

Keywords: Decentralised Composting; Composter; Organic Waste; Oilfield Solid Waste


Authors: Bimal Aryal

Abstract: In developing countries, such as Nepal, the expansion of cities produces parallel growth of large informal settlements, in which aspects the qualities of life are threatened. This study focuses on prioritizing 6 different environmental issues (Health and sanitation, Water availability, Solid waste disposal, Food, Flood and Transportation) observed in one informal settlement. Two focus group discussions were conducted, one with 12 and the other with 14 participants. One hundred and twenty respondents (out of 700 households) were selected through proportional stratified sampling based on gender and age strata. Water shortage was found to be the major environmental issue in the settlement. The study describes the livelihood challenges in the settlement, such as water shortages, solid waste disposal, health and sanitation. It also proposes alternative solutions for managing the enclave’s infrastructure, while addressing changing climate.

Keywords: Water; Health and Sanitation; Informal Settlement; Flood


Authors: Subin Kalu; Madan Koirala; Udhab Raj Khadka; Anup K C

Abstract: Soil quality management helps to maintain biological productivity; air and water quality; and human habitation and health. As improper land management can deteriorate soil function, the evaluation of soil quality for different land use is necessary. To evaluate soil quality for different land use types in the Panchase area, soil quality index was computed on the basis of the soil management assessment framework. Protected forest has the highest soil quality index (0.95) followed by community forest (0.91), pasture (0.88), khet (0.81), and bari (0.79). Available phosphorus and soil organic carbon play major roles in making significant differences in the SQI among the different land use types. Less anthropogenic impact and vegetation in forest land result in better soil quality, whereas attempts to increase productivity in cultivated land degrade the soil quality. The proper application of fertilizer and giving priority to organic farming is recommended to improve soil quality.

Keywords: Land Use; Soil Management Assessment Framework (SMAF); Soil Quality; Soil Quality Index (SQI)


Authors: E. E. Awokunmi; S. S. Asaolu; S. O. Adefemi; A. Y. Gbolagade

Abstract: The levels of heavy metals in water and soil have increased due to the indiscriminate dumping of domestic and industrial wastes. This research was conducted to examine the contributions of municipal solid waste disposal to the concentrations of heavy metals in water sources near Oke-Ese Dumpsite in Ilesha, Osun State. Soil samples were collected from Oke -Ese Dumpsite at intervals of 10 m, at depths of 0-15 cm using calibrated soil auger. A control soil sample was also collected at a distance of 200 m from the last sampling point at the dumpsites. Water samples were randomly collected from five water sources (river and wells). Physicochemical parameters, sequential extraction and heavy metals analyses were conducted on collected samples. Results indicate that pH (6.20 ± 0.11), organic matter content (8.60 ± 0.16) and Cation Exchange Capacity (78.4 ± 0.17) of the control sample were greater than 5.70 ± 0.12, 7.62 ± 0.14 and 56.26 ± 0.24 respectively. Heavy metals were observed at elevated concentrations at dumpsites locations with average values in the following order: Pb (22.7), Fe (134.9), Cd (42.7), Cu (9.0), Zn (116.0), Mn (15.5), Ni (27.7) and Cr (11.0). However, the results of sequential extraction revealed that these heavy metals were distributed in considerable proportions in the exchangeable fraction of soil (11.2 – 89.3 mg/kg). Both Sequential Extraction Procedures (SEPs) employed, indicated the possibility of these metals leaching into the surrounding water sources. In addition, these heavy metals were found in greater concentrations than the limit set by World Health Organisation (WHO) in all water sources near the Oke-Ese Dumpsite. In conclusion, there is need to cite dumpsite away from residential area and contaminated water sources should be treated before domestic applications.

Keywords: Contributions; Municipal; Heavy Metals; Dumpsites; Concentrations


Authors: E. E. Awokunmi; O. A. Ibigbami; S. S. Asaolu; O. S. Adefemi; A. Y. Gbolagade

Abstract: Heavy metal pollution is of great concern due to their potential harmful effects on man and the environment, as soil and sediment are their primary repositories. Anthropogenic activities such as agricultural practices, industrial activities, and waste disposal have contributed to increases in heavy metal concentrations in soil. It is important to determine the effect of agricultural input on the heavy metal concentrations, mobility and bioavailability on cocoa farms by analyzing soil samples collected from selected locations to determine pH, content of organic matter, presence of water-soluble heavy metals and sequential extraction of heavy metals using standard analytical procedures. Results indicate random variation in the pH and organic matter content of soil with average values of 6.49 ± 0.12 and 2.30 ± 0.11%, respectively. The acid digestion of heavy metals was relatively higher than water-soluble heavy metals with the following mean values: Zn (33.70 > 11.30), Fe (111.71 > 4.58), Mn (1.84 > 1.24), Cd (2.16 > 0.95) and Co (1.66 > 1.01). However, sequential extraction revealed that the heavy metals were distributed in all extractive steps, with the non-residual phase dominating and resulting in possible mobility and bioavailability of those heavy metals.

Keywords: Sequential Extraction; Heavy Metals; Cocoa; Farms