The effect of acidogenic and methanogenic conditions on the availability and stability of carbon, nitrogen and phosphorus in a digestate

Acidification and drying of digestate are important post-treatment for, respectively, improving nutrient availability and hygiene. These approaches are expected to reduce digestate soil application mass and increase its value. This study compared eleven organic feedstocks under acidogenic and methanogenic conditions as a sustainable approach to improving phosphorus availablity, organic carbon and stabilising ammoniacal nitrogen of the resulting digestate under thermal drying. The result showed increases in phosphate concentration under acidogenic conditions and reduction in ammonium nitrogen after drying at 100 °C. The highest phosphate values of 3.2 ± 0.38 g/kg were achieved using whey permeate substrate while the effect of drying on ammonium nitrogen concentration was lowest for acidogenic bird seed fermentation with an ammonium loss of 59.7%. Both results were facilitated by high total volatile fatty acid concentration produced from available organic carbon which reached a maximum value of 5.71 ± 0.53 g/L, respectively. Increases in phosphate and ammonium nitrogen stability under acidogenic conditions was a consequence of lower pH, a condition synonymous with acidogenic only fermentation. The accumulated volatile fatty acid contributed to higher carbon to nitrogen ratio under acidogenic fermentation. Higher labile carbon to nitrogen ratio can trigger immobilization of ammonium nitrogen in the soil and this presents a case for subsequent experimentation into acidogenic digestate application in soil

Optimisation of small scale anaerobic digestion technology

The recent advances in anaerobic digestion (AD) technology and changes in government policies have contributed to the gradual increase in the establishment of on-site smallscale anaerobic digesters in developed regions, particularly in Europe. However, these advances have not completely eradicated some of the challenges with operating AD system. The project is aimed at investigating the potential of optimizing small-scale AD through high solid digestion (HSAD) and reduction of substrate induced inhibition (SII). The study of different inocula, changes to environmental conditions, adsorption of inhibitors and reactor modification was explored. To investigate these possibilities, an onsite mono-substrate such as citrus fruit waste (CFW) with an average dry matter of 16% was used as the substrate, biochar material (rice husk, coconut shell and wood biochar) were used as adsorbent while an operating temperature from 35 - 55 ⁰C were also investigated. Limonene is an inhibitory compound and a constituent of CFW, this was used as the inhibitor, a compartmentalized anaerobic reactor (CAR) was designed to improve HSAD while selected inocula from digested sewage sludge, compost and landfill leachate and their mixture were used as an inoculant. In the first study, the acclimation rate of different inocula to increasing concentration of limonene compound was investigated and the mixed inocula recorded the highest recovery rate and methane yield with a value of 544 ± 21 ml CH4. The mixed inocula benefited from the synergistic effect of using a broader microbial community to mitigate limonene inhibition. This was followed up with the biochar study on AD of CFW and the result showed that microbial lag phase reduced by 50% which was attributed to sorption of limonene compound and biofilm formation on the biochar material. The study on AD of CFW at a different operating temperature of 35-55 ⁰C showed that the higher temperature of 45 and 55 ⁰C outperformed the other incubation with no detectable microbial lag phase. Finally, the optimization option for HSAD was investigated using a CAR and compared against the conventional continuous stirred tank reactor and a 34%, 43.3%, 48.5% and 79.9% higher cumulative methane production for organic loading rates of 1.42, 2.85, 4.00 and 5.00 gVSL-1 day -1 , respectively was achieved. This performance was attributed to the lower compartment of the CAR which facilitated leachate treatment and distribution. The result showed that limonene a constituent of CFW and an example of SII can be counteracted by (i) inoculating with a mixture of inocula (ii) addition of biochar (iii) operation at high temperature of 45 and 55 ⁰C and (iv) the single stage compartmentalized reactor improved HSAD and reduced limonene suppression

A survey of bird species in Abigi Metropolis, Ogun water side LGA, Ogun state Nigeria

Assessment of the bird species diversity and abundance in Abigi metropolis was carried out in this study. Data were collected during the rainy season (May, June, July and August 2018) and dry season (December 2018, January, February and March 2019 - ). Eight-point counts were used with a distance of 400 m apart. Birds were recorded by sightings or calls and local abundance status of the birds’ species were determined. A total of 28 bird species belonging to 15 families were recorded. Hirundinidae had the highest number ofspecies (six), Ploceidae, Pycynonotidae and Columbidae have three species each while Bucerotidae and Nectaranidae have two species each. All the other families have 1 species each. Fifty percent of the species recorded were classified to be locally rare. The results of this work suggest that a relatively good number of bird species still exist in this community, though human interference like intense farming leading to deforestation has led to the disturbance that caused migration of the bird species within the area. The resultsobtained from this study will provide information for further research. Keywords: Birds, Survey, Abigi metropoli

Perceptions of major stakeholder on pangolin (Phataginus spp) ecology, marketing and utilization in southwest Nigeria

This study assessed the perception of major stakeholders on the ecology and exploitation, marketing and utilization of pangolin in southwest  Nigeria. Qualitative sampling method was employed to elicit information from the respondents. This involved the use of informal interviews with unprepared interview guide. The interest groups such as hunters, wildlife vendors (marketers) and traditional medical practitioners were interviewed. In this study, 34 hunters, 76 marketers and 19 traditional medical practitioners were interviewed. Majority (91.18%) of the hunter agreed that bush burning and deforestation are the major cause of vulnerability of pangolin. All marketers agreed that sudden and high demand of pangolin contribute to its scarcity. All traditional medical practitioners believed that disobedient of pangolin is the cause of its vulnerability. However, conservation program should primarily focus on these major stakeholders to forestall extinction of pangolin in Nigeria. There should be advocacy and capacity building program to discourage them from hunting pangolins. Keywords: Hunters, marketers, pangopup, scales, termites, ants, nocturna

A checklist of angiosperm diversity surrounding Awba Dam: an important reservoir in Ibadan, Nigeria

The present study undertakes an enumeration of the existing flora species around Awba dam, located within the University of Ibadan, Ibadan, Nigeria. Methods followed conventional practice as reported by previous authors of related studies. Findings showed that the study area is very rich in biodiversity. A total of 119 species in 47 families were recorded. The large number of species recorded, especially herbs which contribute 37% of the total enumeration suggest that the site may be further accessed for medicinal plant species which could possess beneficial health properties. Nonetheless, the presence of fauna and phytoplankton species also indicates their role in ecosystem balancing and thus sustaining human livelihood. With the continuous developmental activities, practical conservation approaches is ideal if the study area is to be saved from total loss of species

Contributions of some non-timber forest products to household income of rural dwellers in Onigambari Forest Reserve, Oyo State, Nigeria

The communities surrounding the forest reserve get their daily income from the sales of some of the non-timber forest products (NTFPs) as a means of survival for them and their house hold without proper documentation. The study described the socio-economic characteristics of the rural dwellers in the study area and determined the income made from some of these NTFPs. Data was generated through the use of structured questionnaires administered to 120 randomly selected rural household heads. Data obtained were described using frequency counts, percentages and mean scores; the relationship between dependent variables and independent variables of the study was tested using binomial test and logistic regression. Finding reveal that, non-timber forest products gathering in Onigambari was male dominated (72.3%), 78.1% were married and 38.1% had formal education. Contribution of income from non-timberforest products to total income of respondents in the State was 59.46%. It was concluded that the non-timber forest products  contribute significantly to rural household income at Onigambari forest Reserve Area of Oyo State, Nigeri

Evaluation of some heavy metals bio-accumulation in meat and haemolymph of african landsnail (Archachatina Marginata Swainson)

The impact of captive rearing of snails (Archachatina marginata) on the bio-accumulation of some heavy metals (HMs) (Fe, Mn, Cu, Pb, Co, Ni, Cd and Cr) in the meat and haemolymph was evaluated in a two treatment trial (snails from the wild, (SW) and captive reared snails, (SC), each comprised of sixty snails of three replicates. Alldata collected (using standard analytical procedures) were subjected to ANOVA and significant means separated by Duncan Multiple Range Test. The trial revealed that the meat of SC had outstanding (P>0.05) Fe (22.30mg/kg) and Mn(4.79mg/kg), with no significant variation for DM, while the haemolymph recorded non-significant (P< 0.05) concentration for (Mn, Pb, Co, Ni, Cd and Cr). Its levels of Fe (3.50mg/kg) and Cu (2.06mg/kg) were however significantly (P>0.05) impacted by captive rearing. Generally the level of Cr in the meat and haemolymph were higher than 0.05mg/kg recommendation by WHO, hence snail meat and haemolymph must be consumed with caution and guidance

Effect of captive rearing on meat and haemolymph nutritional characteristics of snail (Archachatina marginata swainson)

An experiment was conducted to investigate and compare the impact of treatment, which is the source of snail (wild and captive reared) on the proximate and mineral composition (Na, K, Ca, Mg, P, Fe and Mn) of the meat and haemolymph of African land snails (Archachatina marginata). Ninety (90) adult snails (250.00 + 0.5g) were randomly distributed into two (2) treatments, each of three replicates, (15 snails per replicate), in a Complete Randomized Design. Samples of meat and haemolymph collected using standard procedures were subsequently analyzed for their nutritional qualities, using standard chemical analytical procedures. All data collected were statistically analyzed using ANOVA, while significant variation were separated with Duncan Multiple Range Test of the same package. The proximate composition of the meat revealed higher (P>0.05) DM (26.00%), Ether extract (2.17%) and NFE (3.57%) in SC, while there was a non-significant variation (P<0.05) in most proximate factors for haemolymph, except NFE (4.27%), which was higher (P>0.05) in SW. The mineral profiling of the meat revealed  elevated (PP>0.05) levels of Fee (22.30mg/kg) and Mn (4.79mg/kg) of SC, the haemolymph recorded improved levels (P>0.05) for all mineral elements in SC. In conclusion, the captive rearing of snail had improved impact on thenutritional qualities of SC