Relative effectiveness of biogas production using poultry wastes and cow dung

A comparative study of biogas production of different proportions of poultry wastes  and cow dung was conducted under the same operating conditions.  The study was based on Completely Randomsied Design replicated three times.  Three different mix ratios of poultry wastes and cow dung were tested (namely 3:1, 1:1 and 1:3) and all of them were diluted with the same amount of water.  Each treatment was replicated three times.  Biogas production was measured for a period of seven days and volume of gas produced was determined by water displacement method at room temperature of 25 – 30oC.  Biogas production started on the second day, and  reached apex on the sixth day for Digester A (cow dung:poultry wastes r = 1:3).  Production reached its peak on the seventh day for Digester B (cow dung:poultry wastes r = 2:2).  For Digester C (cow dung:poultry wastes r = 3:1), biogas production started on the second day and attained maximum on fifth day.  The average gas production for Digesters A, B and C were 3.84, 3.55, and 3.19 mL respectively.  The study shows that the largest volume of biogas production was obtained using the 3:1 mix ratio of poultry wastes to cow dung.  Poultry wastes therefore are effective for production of biogas than cow dung.  Statistical analysis reveals that wastes fed into the digester and days of experiment were significant at 99% confidence level.  The volumes of wastes generated by the digesters were statistically different from each other.  Digester A produced the highest mean biogas of 4.48 mL/day and this value was significantly higher than ones produced by Digesters B and C (4.26 and 3.72 mL/day respectively).  Finaly, for a developing country like Nigeria, where wastes are not productively used, wastes generated from animal wastes can be effectively managed through conversion into biogas.  Wastes are therefore turned to wealth, which increases the income of the society.   Keywords: biogas production, bio-digester, poultry wastes, cow dung, biogas volume and yiel

A global horizon scan of the future impacts of robotics and autonomous systems on urban ecosystems

Technology is transforming societies worldwide. A major innovation is the emergence of robotics and autonomous systems (RAS), which have the potential to revolutionize cities for both people and nature. Nonetheless, the opportunities and challenges associated with RAS for urban ecosystems have yet to be considered systematically. Here, we report the findings of an online horizon scan involving 170 expert participants from 35 countries. We conclude that RAS are likely to transform land use, transport systems and human–nature interactions. The prioritized opportunities were primarily centred on the deployment of RAS for the monitoring and management of biodiversity and ecosystems. Fewer challenges were prioritized. Those that were emphasized concerns surrounding waste from unrecovered RAS, and the quality and interpretation of RAS-collected data. Although the future impacts of RAS for urban ecosystems are difficult to predict, examining potentially important developments early is essential if we are to avoid detrimental consequences but fully realize the benefits

Effects of electromagnetic irrigation water on lagos spinach evapotranspiration using lysimetric method

The study was conducted to determine the effect of magnetic treatment of water on the evapotranspiration of Lagos Spinach – simply called Celosia, at different growing stages up until harvest, with varying magnetic flux densities and non – magnetic water as the control experiment. Flux densities of T1 = 719 G using 12 V terminal, T2 = 443 G using 8 V terminal, T3 = 319 G using 6 V, T4 = 124 G using 4 V and T5 = 0 G (control) obtained from the electromagnet, were used in treating irrigation water. Equal volume of water (1.3 litres) was used to irrigate the plants every irrigation session. Each treatment was replicated ten times to make a total number of 50 buckets of celosia plants laid out in a Completely Randomized Design (CRD) layout. Celosia seeds were planted in the 50 buckets in a transparent screenhouse for 42 days (08-May-2018 to 18 - June – 2018). Lysimetric method was used to compute water lost due to evapotranspiration per day by weight loss in buckets. The mean values of daily evapotranspiration of two celosia plants per bucket over a – 42 – day period of growth for T1, T2, T3, T4 and T5 were 7.49 mm/day, 7.55 mm/day, 7.76 mm/day, 8.36 mm/day and 7.68 mm/day respectively. Daily values of evapotranspiration subjected to Analysis of Variance (ANOVA) at a confidence interval of 95% (i.e. α ≤ 0.05) using the IBM Statistical Package for Social Science Students version 22 (SPSS) showed that the rate of water absorption by celosia plants for evapotranspiration was statistically significant. The percentage increment of evapotranspiration of celosia irrigated with magnetic water compared with that of ordinary water varied from 1.04 % to 8.85 %. This implies that magnetically – treated celosia plants absorbed water more easily than those of ordinary water, and this might be responsible for the former’s enhanced growth

Relative Coagulation Effectiveness of <i>Jatropha curcas</i> Press Cake (Physic Nut) and Aluminium Sulphate in Purifying Domestic Sewage

An investigation was conducted on the relative effectiveness of using press cake of dried Jatropha curcas (Physic nut) seed and alum (Aluminium sulphate) for the purification of domestic sewage. The experimental design used was Completely Randomized Design (CRD) replicated three times. Physical and chemical properties of domestic sewage were investigated before and after the purification exercise. Treatments imposed included: the control culture (no alum and Jatropha), 10 mg/l of Aluminium Sulphate (alum) treatment, 80 mg/l of J. curcas treatment, 100 mg/l of J. curcas treatment and 120 mg/l of J. curcas treatment. The results showed that for the total dissolved solids, cultured tanks treated with 80 mg/l of J. curcas reduced the sewage concentration from 30.1 mg/l to 23.20 mg/l, Biological Oxygen Demand (BOD) was reduced from 30.55 mg/l to 30.10 mg/l, increased acidity from 5.33 mg/l to 5.66 mg/l, reduced alkalinity from 6.35 mg/l to 6.0 mg/l, reduced pH from 7.6 to 6.55, and likewise 10 mg/l of alum also reduced pH from 7.6 to 6.55. The cultured tanks treated with 120 mg/l of J. curcas performed best in reducing turbidity and Chemical Oxygen Demand (COD) of the sewage. The turbidity was reduced from 5.99 NTU to 5.6 NTU; 120 mg/l of J. curcas also reduced total hardness from 9.6 mg/l to 7.15 mg/l, total solids from 55.6 mg/l to 55.17 mg/l. Cultured tanks treated with 10 mg/l of alum reduced total dissolved solids from 30.1 mg/l to 24.30 mg/l, while those treated with 80 mg/l of J. curcas reduced it from 30.1 mg/l to 23.20 mg/l, 100 mg/l and 120 mg/l of J. curcas reduced it to 25.20 mg/l. Total suspended solids increased from 25.5 mg/l to 30.96 mg/l for 10 mg/l of alum, to 30.22 mg/l for 80 mg/l of J. curcas, 30.26 mg/l for 100 mg/l of J. curcas and 30.38 mg/l for 120 mg/l of J. curcas. Conductivity increased withion the study period from 525 μS/cm to 830 μS/cm for 10 mg/l of alum, to 590 μS/cm for 80 mg/l of J. curcas, 634 μS/cm for 100 mg/l of J. curcas and finally to 662 μS/cm for 120 mg/l of J. curcas. The results show that, within the reduction of BOD, pH, alkalinity and total solids, 80 mg/l of J. curcas performed best, while for reduction of COD and turbidity, 120 mg/l of J. curcas gave the best results. The study showed that Jatropha curcas was effective in purifying domestic sewage with little or no harmful effect on the ecology

Effects of Electromagnetic Treatment of Irrigation Water on Growth and Yield of Lagos Spinach (Celosia argentae)

The effects of magnetic treatment of irrigation water on growth and yield of potted celosia plants (Celosia argentae) grown inside a screen house were investigated. The study was carried out using Completely Randomised Design replicated five times. Water was allowed to pass through five different flux densities of 719, 443, 319, 124 and 0 Gausses (non – magnetized water). Analysis of selected 25 samples of the magnetic flux density experiment (at 6 WAP) showed that mean stem girth irrigated with ordinary water recorded the highest value of 1.95 mm. Mean leaf area of plants irrigated with magnetic flux density of 719 G had a percentage increase of 24.97 %; mean bulk weight of 172.72 g; biomass weight of 133.48 g; and root weight of 39.24 g, when compared with plants treated with ordinary water (0G), with a bulk weight of 158.08 g; biomass weight of 124.22 g; and root weight of 33.86 g. Analysis of Variance (ANOVA) at a confidence interval of 95% showed that effects of varying magnetic treatments of water on bulk yield, edible weight, root weight, total leaf area and average plant height were significant at P ≤ 0.05. This implies that magnetic technology contributed to the result of the aforementioned growth indices. Effect of magnetic treatment of water on number of leaves was not significant at P ≤ 0.05. Further analysis of results using Duncan New Multiple Range Test (DNMRT) showed that the effects of 719, 443, and 319 Gauss were statistically and significantly different from one another on bulk yield of sampled plants. Memory (residual) effect of irrigation water was also enhanced by magnetic treatment. Magnetic treatment of water also reduced sodium hazard and salinity effect on crop yield. The study shows that magnetic treatment of irrigation water increases crop growth and yield

SARS-CoV-2 vaccination modelling for safe surgery to save lives: data from an international prospective cohort study

Background: Preoperative SARS-CoV-2 vaccination could support safer elective surgery. Vaccine numbers are limited so this study aimed to inform their prioritization by modelling. Methods: The primary outcome was the number needed to vaccinate (NNV) to prevent one COVID-19-related death in 1 year. NNVs were based on postoperative SARS-CoV-2 rates and mortality in an international cohort study (surgical patients), and community SARS-CoV-2 incidence and case fatality data (general population). NNV estimates were stratified by age (18-49, 50-69, 70 or more years) and type of surgery. Best- and worst-case scenarios were used to describe uncertainty. Results: NNVs were more favourable in surgical patients than the general population. The most favourable NNVs were in patients aged 70 years or more needing cancer surgery (351; best case 196, worst case 816) or non-cancer surgery (733; best case 407, worst case 1664). Both exceeded the NNV in the general population (1840; best case 1196, worst case 3066). NNVs for surgical patients remained favourable at a range of SARS-CoV-2 incidence rates in sensitivity analysis modelling. Globally, prioritizing preoperative vaccination of patients needing elective surgery ahead of the general population could prevent an additional 58 687 (best case 115 007, worst case 20 177) COVID-19-related deaths in 1 year. Conclusion: As global roll out of SARS-CoV-2 vaccination proceeds, patients needing elective surgery should be prioritized ahead of the general population