Distribution of Phosphorus along a Toposequence on an Alfisol in Minna, Niger State

The distribution of various forms of phosphorus was evaluated along a toposequence located in an Alfisol in Teaching and Research Farm of the Federal University of Technology, Minna. The toposequence was delineated into different topographic units (Crest, Upper slope, Middle slope and Lower slope). Soil samples were collected from identified horizons in profile pits in each topographic unit. The soil samples were analyzed for organic, total, available and various active P forms. The results obtained showed that distribution of phosphorus varied widely with each topographic unit. Total P ranged from 102 ug g-1 at the lower shope to 422 ug g-1 at the upper shope, with a mean of 236.95μg g-1. Organic P also ranged from 21 - 132μg g-1 with a mean of 55.8μg g-1. Organic P was highest at the lower slope and lowest at the upper slope. Available P ranged from 0.4 – 5.54μg g-1 with a mean of 2.47μg g-1. The active P forms was in the order of Fe-P > Al-P > Ca-P, with Fe-P varying from 19 - 95μg g-1, Al – P ranged from 1.75 – 22μg g-1 and Ca – P ranged from 1.12- 4.3μg g-1. There was a positive correlation between organic P and clay (r = 0.56*) and between organic P and organic carbon (r = 0.52*). However, organic P correlated negatively with sand (r= -0.49*).Fe – P and Al – P correlated with magnesium (r = 0.51*) and sand (r = 0.45*) respectively. Available P also correlated positively with clay (r = 0.43*) and organic carbon (r = 0.52*).Keywords: Toposequence, Alfisol, Crest, Active P and Organic P

Smoked cigarette butt leachate impacts survival and behaviour of freshwater invertebrates

Smoked cigarette filters a. k.a. “butts”, composed of plastic (e.g. cellulose acetate) are one of the world’s most common litter items. In response to concerns about plastic pollution, biodegradable cellulose filters are being promoted as an environmentally safe alternative, however, once smoked, both contain toxins which can leach once discarded. The impacts of biodegradable butts as littered items on the receiving environment, in comparison with conventional butts has not yet been assessed. A freshwater mesocosm experiment was used to test the effects of leachate from smoked cellulose acetate versus smoked cellulose filters at a range of concentrations (0, 0.2, 1 and 5 butts L−1) on the mortality and behaviour of four freshwater invertebrates (Dreissena polymorpha, Polycelis nigra, Planorbis planorbis and Bithynia tentaculata). Leachate derived from 5 butts L−1 of either type of filter caused 60–100% mortality to all species within 5 days. Leachate derived from 1 butt L−1 of either type resulted in adults being less active than those exposed to no or 0.2 butts L−1 leachate. Cigarette butts, therefore, regardless of their perceived degradability can cause mortality and decreased activity of key freshwater invertebrates and should always be disposed of responsibly

Acetylation of Amaranthus viridis starch: Modeling and process parameters optimization

The optimum reaction conditions for the derivation of acetylated (esterified) starch using response surface methodology (RSM) and artificial neural network (ANN) were studied. All the independent variables (starch solids, acetic anhydride concentration, and reaction time) were of significant (p < .05) importance in achieving esterified starch of Amaranthus viridis. Optimum conditions of 152.46 g of starch, 11 ml of acetic anhydride and time of 2.92 min with corresponding acetyl content and degree of substitution (DS) of 1.74% and 0.06, respectively, were established for ANN. The RSM gave optimum conditions of 149.57 g (starch), 10.38 ml (acetic anhydride) and 3 min (time) with corresponding acetyl content and DS of 1.61% and 0.06, respectively. The order of priority of the process variables was established as acetic anhydride (42.59%), starch solids (33.90%), and reaction time (23.51%). The results provided useful information on development of economic and efficient acetylation process for modification of A. viridis starch