Sources, distribution, and risk assessment of organochlorine pesticides in Nairobi City, Kenya

The distribution and sources of organochlorine pesticides (OCPs) in air and surface waters were monitored in Nairobi City using triolein-filled semipermeable membrane devices (SP-MDs).The SPMDs were extracted by dialysis using n-hexane,followed by cleanup by adsorption chromatography on silica gel cartridges.Sample analysis was done by GC-ECD and confirmed by GC–MS.Separation of means was achieved by analysis of variance,followed by pair-wise comparison using the t-test (p≤0.05).The total OCPs r...     

Synthesis of 2,5‐diaryl‐2,4‐pentadienenitriles and their spectral,fluorescence and mutagenic properties

The condensation of substituted cinnamaldehydes and arylacetonitriles using sodium ethoxide in ethanol at room temperature afforded 2,5‐diaryl‐2,4‐pentadienenitriles in good yield. The structure of the reaction products was established on the basis of their infrared, nuclear magnetic resonance and elemental analysis data. Two representative compounds were studied for their mutagenic activity. One of them showed a weak mutagenicity while the second showed a high mutagenic activity in TA97a Salmonella strain. Both were negative in TA100. Some of these pentadienenitriles showed fluorescence in solutions.     

Revalorization of Macadamia nutshell residue as a filler in eco-friendly castor polyol-based polyurethane foam

Journal of Material Cycles and Waste Management - The use of lignocellulosic fibers as fillers in polymer matrices has aroused the interest of the scientific community and industrial sectors. In...     

Conservation Genetics of the Endangered Isle Royale Gray Wolf

Abstract. The small group of wolves on Isle Royale has been studied for over three decades as a model of the relationship between large carnivores and their prey. During the last ten years the population declined from 50 individuals to as few as 12 individuals. The causes of this decline may be food shortages, disease, or reduced genetic variability. We address the issues of genetic variability and relationships of Isle Royale wolves using allozyme electrophoresis, mtDNA restriction-site analysis, and multilocus hypervariable minisatellite DNA analysis (genetic fingerprinting). Our results indicate that approximately 50% of the allozyme heterozygosity has been lost in the island population, a decline similar to that expected if no immigration had occurred from the mainland. The genetic fingerprinting data indicate that the seven sampled Isle Royale wolves are as similar as captive populations of siblings. Surprisingly, the Isle Royale wolves have an mDNA genotype that is very rare on the mainland, being found in only one of 144 mainland wolves ThFF suggests that the remaining Isle Royale wolves areprobably derived from a single female founder     

Woody residues of the grape production chain as an alternative precursor of high porous activated carbon with remarkable performance for naproxen uptake from water

Environmental Science and Pollution Research - Activated carbon prepared from grape branches was used as a remarkable adsorbent to uptake naproxen and treat a synthetic mixture from aqueous...     

Heavy metals' content of automotive shredder residues (ASR): evaluation of environmental risk

Every year between 8 and 9 millions of vehicles in the European Union arrive to their end of life. Car wastes can have a very high metal content, falling into hazardous waste class. A preliminary evaluation of these wastes could be made by metals' leaching test runs which is the main objective of the present study. Evaluation of the total metal content was carried out by X-ray fluorescence and the mobility of these metals using two simple standardized extractions such as the TCLP (Toxicity Characterisation Leaching Procedure) of the US EPA and the German leaching test DIN 38414-S4. Additionally, an extraction test with acetone was performed in order to recognise metals bounded to organic matter. The results show that the total metal content of the ASR can overpass the established values for inert residues. Lead and zinc contents are fairly well correlated with grain-size, whilst other metals' contents do not exhibit clear grain-size dependence.     

Current Levels and Management of Solid Wastes in Nigeria

Solid waste is of serious concern in developing countries because of its high rate of generation and the low‐end quality of its management. Inefficient handling of solid wastes may result in deterioration of environmental quality, but it can also result in loss of potential resources. This study reviews current solid waste generation and management in Nigeria and the need for an effective collection, recovery, and recycling policy. Our review is based on literature searches and personal field surveys. Observations showed that uncontrolled electronic waste (e‐waste), agricultural‐waste (agro‐waste), scrap metals, waste polymers, and waste from the transportation sector are prevalent in Nigeria. Recent collection rates were less than 50% of the total solid waste generated (i.e., approximately 40% was collected). With an effective collection system and appropriate policies, the abundance of solid waste in the country could present material recovery and recycling opportunities that would boost the economy and move Nigeria closer to sustainable resource management.