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

Full Length Research Paper Receptor Modeling Application on Surface Water Quality and Source Apportionment

Abstract. There is need for regular monitoring of river water quality to determine specific pollutants in order to aid amelioration schemes. In this study, Principal Component Analysis (PCA) was applied on eighteen water quality parameters; pH, conductivity, dissolved oxygen(DO), turbidity, temperature ,total dissolved solids (TDS), total solids (TS),total hardness (TH), biochemical oxygen demand (BOD), carbon dioxide (CO 2 ), ammonia (NH 3 ), nitrate (NO 3 -), chloride (Cl -), lead (Pb), iron (Fe), chromium (Cr), copper (Cu) and manganese (Mn) to identify major sources of water pollution of river Asa. The generated Principal Components (PCs) were used as independent variables and water quality index (WQI) as dependent variable to predict the contribution of each of the sources using multiple linear regression model (MLR). The PCs results showed that the sources of pollution are storm water runoff, industrial effluent, erosion and municipal waste, while MLR identified storm water runoff (0.786) and industrial effluent (0.241) as the respective major contributors of pollution. The study showed that PC-MLR model gives good prediction (R 2 =0.8) for water quality index

Karakteristike sabijenosti nekih poljoprivrednih zemljišta u državi Niger u Nigeriji

The movement of farm tractors and other heavy duty machineries leads to soil compaction. The dry density, penetration resistance and hydraulic conductivity are seriously influenced as a result of this, thus affecting plant physiology. In this study, soil samples were collected from three locations in Niger state, Nigeria namely Gidan kwano, Maikunkele and Maizube farms. Particle size analysis showed the textural class of the soils as sandy clay loam, loamy sand and clay loam, respectively. Atterberg limits of the soils samples were determined using the consistency test. The soils were characterized for their compaction behavior using 5, 10, 15, 20 and 25 blows compactive efforts of a proctor hammer in the moisture range of 8 to 26% (wet basis). The results of the compaction test showed that dry density increased with increase in compactive efforts, and that loamy sand had the highest dry density with accompanying low moisture content at all compaction levels. The result of the consistency test revealed that the optimum moisture content required for machinery traffic occurred between the plastic and liquid limits for all the three soil samples. Consequently, the use of tractors in carrying out farming operations is better suited when the soils are not too wet, so that the soil can support the machinery and hence avoiding wheel skidding. Predictive equations were established to relate the dry density of the different compactive efforts with moisture content of the three soils.Kretanje poljoprivrednih traktora i drugih teških mašina uzrokuje sabijanje zemljišta. Zapreminska težina, otpor penetracije i hidraulična provodljivost su pod značajnim uticajem sabijanja, što ugrožava i fiziologiju biljaka. U ovom istraživanju sakupljeni su uzorci zemljišta sa tri lokacije u državi Niger u Nigeriji, farme: Gidan kwano, Maikunkele i Maizube farms. Analiza dimenzija čestica pokazala je da teksture zemljišta pripadaju klasama peskovito-glinovita ilovača, pesak i glina ilovastog sastava, redom. Atterberg granice uzoraka ovog zemljišta određene su testom konzistentcije. Uzorci zemljišta su bili karakterisani koristeći intervale za sabijanje od 5, 10, 15, 20 i 25 udaraca Proctor čekića u opsegu vlage od 8 do 26% (mokra osnova). Rezultati testa sabijanja pokazuju da se zapreminska težina suvog uzorka povećava sa povećanjem broja udaraca i da frakcija ilovasti pesak ima najveću gustinu koja prati nizak nivo vlage na svim nivoima sabijanja. Rezultat testa konzistencije je pokazao da je optimalna vlažnost potrebna za saobraćaj mašina bila između plastične i tečne granice za sva tri uzoraka zemljišta. Shodno tome, upotreba traktora u obavljanju poljoprivrednih radova je bolje prilagođena kada zemljišta nisu prevlažena, tako da zemljište može da izdrži opterećanje mašina, a da pri tome bude izbegnuto proklizavanje točka. Postavljene su jednačine za predviđanje odnosa zapreminske težine suvog uzorka za različit broj udaraca čekića sa sadržajem vlage kod tri uzorka zemljišta

Assessment of Mechanical Properties of Soil-Lime-Crude Oil-Contaminated Soil Blend Using Regression Model for Sustainable Pavement Foundation Construction

Oil pollution causes deterioration of the physical, chemical, mechanical, and geotechnical characteristics of affected soil leading to loss of soil productivity for engineering purposes. Different stabilization methods serve as a remedy for such soil to regain its loss engineering properties. This study was concerned with the utilization of lime to stabilize crude oil contaminated soil and to investigate its efficacy for soil stabilization. The study also focused on determining the geotechnical properties of crude oil contamination and matching the result with standard specifications established for engineering works. Hydrated lime, expansive clayey soil, contaminated soil, and potable water were the materials used for the experimental investigation. The contaminated soil was treated with 6.5% lime and 0–20% crude oil contaminated materials obtained from oil exploration sites in North-Eastern Nigeria and per standard test method for laboratory evaluation of consistency limits, compaction properties, California bearing ratio (CBR), and microstructural and mineralogical assessments. The experimental results obtained were further tested statistically through one-way ANOVA and F-statistics to establish the source of variation for the geotechnical properties, while multiple linear regression and correlation statistics helped draw the connection between the consistency limits, compaction, and CBR properties of the soil-lime-COCM blend. Results indicated a coefficient of determination of 99.86. The contaminated soil materials were found to show optimal performance at a 5% ratio and 6.5% of lime for civil construction purposes