Environmental Burden of Heavy Metal Contamination Levels in Soil from Sewage Irrigation Area of Geriyo Catchment, Nigeria

The heavy metal concentration levels and contamination/pollution index of agricultural soils taken from 0 – 30 cm depth from site I and II of sewage irrigation area and from a control site of Geriyo catchment in Adamawa State, Nigeria was determined using atomic absorption spectrophotometer standard method. The mean concentration levels of trace and heavy metals (Fe, Zn, Mn, Cu, Cd, Cr and Pb) at site I are 89.90 mg/kg for Fe, 74.39 mg/kg for Zn, 12.79 mg/kg for Mn, 15.09 mg/kg for Cu, 9.86 mg/kg for Cd, 11.2 mg/kg for Cr and 7.18 mg/kg for Pb, while at site II, the concentrations levels of  294.7 mg/kg for Fe, 310.2 mg/kg for Zn, 131.9 mg/kg for Mn, 254.8 mg/kg for Cu, 240.2 mg/kg for Cd, 199.6 mg/kg for Cr and 159.2 mg/kg for Pb were observed. The concentration levels of trace and heavy metals of site II soil is significantly higher than site I and the control site with values of (Cu, Cd, Cr and Pb) mostly above the maximum permissible heavy metal concentration levels in soil set out by EU, UK and USA. The contamination/pollution index assessment of the soils revealed that the soils belong to slight pollution to excessive heavy metal pollution soil category with the potentials of negative effect on plants and ground water reserve contamination. Leaching and liming of the soil to reduce the level of metals is recommended in the context of very high land competition for sustainable agricultural productivity. Keywords: Sewage irrigation, heavy metal, pollution index, soil, Geriyo catchmen

Heavy metal concentration levels in soil at Lake Geriyo irrigation site, Yola, Adamawa state, North Eastern Nigeria

The study assessed the physicochemical parameters and mean concentration levels of heavy metals in soil at two selected wastewater receiving sites and control site of Lake Geriyo irrigation project in order to determine the extent of heavy metal pollution due to wastewater irrigation using standard methods. The pH values at the River Benue, Shinko and control site soils were slightly acidic to neutral with mean value of 6.85, 5.75 and 7.0 respectively. Mean electrical conductivity values were 1.08μs/cm, 1.54μs/cm and 1.95μs/cm and organic matter levels are 0.75%, 2.11% and 3.5%. The textural classification of the soils revealed that the soils are predominantly sandy in nature with 56.4%, 55.6% and 50.4% sand, 20%, 16.0% and19% are clay, while 24.0%, 28.4% and 30.0% are silt. The mean concentrations of heavy metals (Fe, Zn, Mn, Cu, Cd, Cr, Pb and Ni) recorded in River Benue site soil are 86.89mg/kg, 74.38mg/kg,12.76mg/kg, 15.08mg/kg, 9.83mg/kg, 11.0mg/kg, 7.17mg/kg and 18.73mg/kg. Shinko site recorded concentration levels of 292.7mg/kg, 309.2mg/kg, 130.9mg/kg, 253.8mg/kg, 199.2mg/kg, 158.7mg/kg and 74.43mg/kg respectively, while the control site soil had concentration levels of Fe 58.48mg/kg, Zn 39.44mg/kg, Mn 7.13mg/kg, Cu 9.40mg/kg, Cd 7.62mg/kg, Cr 9.82mg/kg, Pb 6.28mg/kg and Ni 17.62mg/kg. The result showed that the concentrations of heavy metals at River Benue and Shinko site soils are more polluted than the control site soil with Shinko site soil exhibiting high levels of heavy metals concentration. Comparative analysis of this study and International threshold values of heavy metals concentration levels in soil revealed that most of the parameters at Shinko site soil are elevated above the EU, USA and UK Standards. Future study is hereby recommended to focus on the impact of heavy metal concentration on irrigated vegetables as some may find their way into the food chain and cause public health hazards to consumers

Engineering Mathematics I: A Case Study of First Year Students at Faculty of Engineering, UNIMAS

The subject of mathematics is important as a prerequisite and requirement as most topics in engineering courses widely employ these fundamentals. The paper will describe an analysis based on Engineering Mathematics I course results for first year student of Semester I 2009/2010 academic year at the Faculty of Engineering, University of Malaysia Sarawak (UNIMAS). The aim is to identify the topics within Engineering Mathematics I, which may cause some difficulties for new students to understand. The performance that directly related to the students’ weaknesses is obtained from the continuous assessments of the course, end of semester report analysis based on course outcomes and item analysis. The results will be used as the basis for improving the teaching and learning process for this course

Effect of temperature to the properties of sago starch

Recently, the importance of sago starch has increased, as it has become one of the main economically important agricultural crops to the most Southeast Asia countries. In the present work, an analysis on drying process of sago starch (Metroxylon sagu Rottb.) underwent various temperature has been made by using four empirical equations. The main goal of this analysis is to suggest the most accurate equation, in order to model and simulate the mechanical drying of sago starch. The experimental investigations were carried out in a gravity convection lab oven; and ±50g of sago starch (sample heights of 1 cm) was dried through four different temperatures, which were 50, 60, 70 and 80ºC. The effect of drying temperature on the drying kinetics, as well as various qualities attributes of sago starch, such as microstructure, colour and functional properties were investigated. The results suggested that drying temperature has significant effect on sago starch drying kinetic; therefore, drying temperature would be the basis to select drying condition. Meanwhile, it was found that the various drying temperature ranging from 50 to 80ºC affected the product quality especially in term of colour

Flood estimation at ungauged river basins in Sarawak by regionalisation technique

This study is about flood estimation at ungauged basin in Sarawak by utilizing the regionalization technique. There are 21 major river basins in Sarawak. Being the largest state in Malaysia and still not fully developed, Sarawak has only about 60 gauging stations distributed throughout the state. However, due to limited records and tidal influence, discharges records from only 19 stations could be used in this study

Evaluation of Critical Parameters to Improve Slope Drainage System

This study focuses on identifying and evaluating critical parameters of various drainage configurations, arrangement, and filter which affect the efficiency of water draining system in slopes. There are a total of seven experiments with different types of homogeneous soil, drainage envelope, filter material, and quantity of pipes performed utilizing a model box with a dimension of 0.8 m × 0.8 m × 0.6 m. The pipes were orientated at 5 degrees from the horizontal. Rainfall event was introduced via a rainfall simulator with rainfall intensity of 434.1 mm/h. From the experiments performed, the expected outcomes when utilizing double pipes and geotextile as envelope filter were verified in this study. The results obtained from these experiments were reviewed and compared with Chapter 14 “Subsurface Drainage Systems” of DID’s Irrigation and Agricultural Drainage Manual of Malaysia and the European standard. It is recommended that the pipe installed in the slope could be wrapped with geotextile and in tandem with application of granular filter to minimize clogging without affecting the water discharge rate. Terzaghi’s filter criteria could be followed closely when deciding on new materials to act as aggregate filter. A caging system could be introduced as it could maintain the integrity of the drainage system and could ease installation

Comparison of wave hindcasting of linear wave theory and SWAN modelling at Batu Pahat River Estuary

Estuary, like other coastal systems, is ephemeral; undergo continuous geological evolution and very active coastal region. Batu Pahat river estuary is chosen, togather information on wave conditions nearshore. Estuary of Sungai Batu Pahat is exposed to high energy wave conditions from the Strait of Melacca. Offshore wave data is analyzed for design wave nearshore and wave height is the most important parameters observed. Wave height transformation nearshore was predicted from linear wave theory and SWAN nearshore wave modeling. Regular Waves theory of small-amplitude or linear wave theory developed by Airy (1845) and numerical wave models SWAN (acronym for Simulation Waves Nearshore) developed by the Delft Institute of Technology in the Netherlands using spectral method of Irregular Waves theory are adopted for wave hindcasting. Linear wave theoiy is often used due to its simplicity and easily applied. SWAN (acronym for Simulation Waves Nearshore) is a phase averaging wave model designed to obtain realistic estimates of wave parameters in coastal areas, lakes and estuaries from given wind, bottom, and current conditions. SWAN is one of the most widely applied spectral wave models at present in coastal engineering studies and is freely available for both research and consultancy studies. Offshore wave data are analyzed for various wave heights of average one third of maximum wave heights (H1/3 ) and extreme value of Gumbel and Weibull statistical distribution with three wave scenarios of Annual, Northeast Monsoon and Southwest Monsoon. The differences in the analysis are inspected. Both mefliods agreed well with the theoiy where wave heights decreases when it reach estuary, but SWAN gives smaller results of wave height at shallower location. Waves are irregular in nature; linear wave theory is based on Regular Waves theory while SWAN based on spectral methods and deal with complex bathymetry nearshore from Irregular Waves theory. Thus, SWAN gives more dependable answer compared to linear wave theory for design purposes