The Use of Fibre Waste as Complement in Concrete for a Sustainable Environment

One of the many challenges faced in developing world is the issue of waste management. Organic fibres forms major percentage of waste produced from agricultural products and should be of great concern. Fibres have been used to reinforce composites concrete to obtain lighter weight, reduce shrinkage effects which serve to reduce environmental waste. Natural fibre is 100% bio-degradable and recyclable, thereby eliminate pollution, promote biodiversity and conservation of natural resources and thus environmentally friendly.This paper focuses on utilization of some fibres as solid wastes for making economically-friendly and affordable green environment. Three fibres: Jute, Oil palm and Polypropylene fibres were used as complement in concrete and its suitability, durability and influence on the properties of concrete were assessed. The percentages of fibre used were 0.25 and 0.5 of cement content by weight. A total of 84 concrete cube specimens were prepared for standard tests which include compression test, slump test and compaction factor test. The compression test was carried out at concrete ages of 7, 14, 21 and 28 days. As the percentage of the fibre increases, the tendency for fibre to ball up becomes higher in water. The test results showed that for Jute and Oil palm fibres, the optimum fibre content was 0.25% and for Polypropylene fibre, the optimum fibre content was 0.5%. They all yielded increase in strength when compared to the control specimen and has proven to reduce reasonable environmental waste pollution. Keywords: Environmental Pollution, Fibre, Concrete strength, Jute, Waste reductio

Qualitative Assessment of Effects of Encroachment on Water Resources of Agba Dam, Ilorin Nigeria

The city of Ilorin in Nigeria has experienced high population growth and rapid urbanization. Agba Dam is one of the major sources of potable water in Ilorin, and currently been threatened by anthropogenic induced encroachment activities, with potential for significant derogatory effects on its quality. Therefore, this paper assesses the qualitative impact of encroachment on the water resources regime of Agba Dam, Ilorin, Nigeria. Field survey was carried out to scope proximal anthropogenic activities and to delineate historical and current extent of the encroachment area of the dam. Representative water samples were collected from locations within the dam catchment, and subsequently analyzed for alkalinity, dissolved carbondioxide, chloride, total iron, copper, sulphate, colour, calcium, dissolved oxygen and turbidity. In addition, historical physical and chemical data of water samples obtained from the dam were also acquired, and analyzed to determine temporal variation in the quality. The results show a reduction of 0.89 km2 or 63% in the historical buffer boundary of the dam. The values of the measured physico-chemical parameters were generally similar to that obtained for the historical values and therefore suggest limited impact of the anthropogenic activities on the water quality. However, slight increases were observed in the measured concentrations of the alkalinity, dissolved carbondioxide, chloride, iron, copper and sulphate, and this indicates possibilities of water quality alteration, with potential consequences for ecosystem and aquatic life if the trend is unabated. Keywords: Anthropogenic, Water quality, Agba dam, Ilorin Nigeri

Viability of Recycled Concrete Waste as Construction Material for a Sustainable Environment

A major source of environmental burden in construction industries is concrete waste because its generation and accumulation start from the time fresh concrete are produced on-site or off-site till its hardens. This made concrete the largest portion of solid waste stream by weight in the construction industries. Recycling of these waste materials into new form as well as appropriate reuse could therefore conserve natural resources, reduce the space required for land filling and the cost of transportation. This paper assesses the viability of reusing aggregates obtained from concrete waste collected from four different construction sites by comparing compressive strength of concrete made with the recycled concrete waste aggregate with concrete made with natural fresh aggregate as control specimens using an aggregate size not greater than 25mm. A total of 60 cubes of size 150mm x 150mm were cast and cured for different maturity age of 7, 14, 21 and 28 days before crushing.  Laboratory results revealed that there was little variation in strength as the cubes matures. Average compressive strength of concrete made with recycled concrete waste aggregates obtained from two of the site were 22.8 N/mm2 and 24.3 N/mm2 and these were almost the same with the control test cubes with average compressive strength of 24.4 N/mm2. However, test cubes obtained from the other two sites had concrete strength lower than 20 N/mm2. Hence, concrete produced with recycled concrete waste aggregate though exhibiting lower compressive strength could be used for walkways and kerbs production in road construction, backfilling, and in concrete production for light load bearing structural components so as to achieve a sustainable environment and conserve natural resources

Viability of Recycled Concrete Waste as Construction Material for a Sustainable Environment

A major source of environmental burden in construction industries is concrete waste because its generation and accumulation start from the time fresh concrete are produced on-site or off-site till its hardens. This made concrete the largest portion of solid waste stream by weight in the construction industries. Recycling of these waste materials into new form as well as appropriate reuse could therefore conserve natural resources, reduce the space required for land filling and the cost of transportation. This paper assesses the viability of reusing aggregates obtained from concrete waste collected from four different construction sites by comparing compressive strength of concrete made with the recycled concrete waste aggregate with concrete made with natural fresh aggregate as control specimens using an aggregate size not greater than 25mm. A total of 60 cubes of size 150mm x 150mm were cast and cured for different maturity age of 7, 14, 21 and 28 days before crushing.  Laboratory results revealed that there was little variation in strength as the cubes matures. Average compressive strength of concrete made with recycled concrete waste aggregates obtained from two of the site were 22.8 N/mm2 and 24.3 N/mm2 and these were almost the same with the control test cubes with average compressive strength of 24.4 N/mm2. However, test cubes obtained from the other two sites had concrete strength lower than 20 N/mm2. Hence, concrete produced with recycled concrete waste aggregate though exhibiting lower compressive strength could be used for walkways and kerbs production in road construction, backfilling, and in concrete production for light load bearing structural components so as to achieve a sustainable environment and conserve natural resources

Evaluation of the cytotoxic potential of Securidaca longepedunculata on human breast adenocarcinoma (MCF-7) cells

The prevalence of cancer has increased interest in the role of complementary and alternative medicine, employing the use of plant products. Securidaca longepedunculata (SL) is an example of plant product which serves as a major component of anticancer decoctions in Nigeria. In other to scientifically ascertain this claim, this study was carried out to evaluates the cytotoxic potential of the crude extract and fractions of SL root bark against human breast adenocarcinoma (MCF-7) cell line. The root back of SL was pulverized and extracted with 80% methanol to yield a crude extract which was then submitted to liquid–liquid fractionation with dichloromethane (DCM) and butanol (BUT). The extract and fractions were subjected to Gas Chromatography-Mass Spectrometry (GC-MS). MCF-7 cell line was treated with graded concentrations (9.77 – 5000 μg ml-1) of the aqueous methanol crude extract as well as the DCM and BUT fractions for 24 or 48 hours. Cell viability was thereafter measured by XTT proliferation assay. The inhibitory activities of the aqueous methanolic crude extract was found to be both dose-dependent and time independent with IC50 values of 2241 μg ml-1 and 1808 μg ml-1 after 24 and 48 hours respectively. The DCM and BUT fractions were significantly (p < 0.05) cytotoxic with IC50 values of 86.27 μg ml-1 and 12.08 μg ml-1 respectively after 48 hours of treatment. The study provide evidence that BUT fractions of SL has the highest potential to significantly show anticancer properties

Solid Waste Management in a Leprosarium in Southwestern Nigeria

Waste from healthcare institutions generally ought to be treated and disposed hygienically. However, the type of institution normally determines the material component and the nature of the waste generated whether it is hazardous or non-hazardous, infectious or non-infectious waste. Also health status of an individual or community is a function of standard of living, medical services available, social amenities and hygienic environment normally determined through impact assessment. These have been examined in relation to the leprosarium in Ogbomosho, Southwestern Nigeria. The leprosarium under study consists of a clinic and three camps located at about 1000m from the clinic. The leprosarium housed 30 patients, while the camps served as home for about 140 people under rehabilitation together including their children. As one of the health institutions, it is apparent that the waste generated is heterogeneous mixture of both general municipal waste and bio-medical waste. The percentage of biomedical waste which is hazardous in nature is low about 1.0% with average generation rate of 0.13kg/day while that of non-hazardous, non-infectious general waste is 0.288kg/person/day. The average waste generation rate in term of mass is determined to be between 0.084 – 0.095kg/person/day which reveals the poor status and rural nature of these leper settlements. The waste components consist of bandages and swabs, paper, nylon and plastic, domestic waste, animal waste (mostly goat manure), wood ash and yard trimmings which are being disposed on open dump sites and sometimes by open burning which are unhygienic causing health hazards. Accumulation of these waste components without proper disposal initiates its putrefaction which produces offensive odour. In addition, absence of adequate sanitary facilities has promoted open defecation which is a source of infectious, diseases. As an economical, appropriate and useful method of waste disposal, composting was proposed since it is found relevant and acceptable  for the leprosarium and the settlements around as the waste generated is predominantly biodegradable and decomposable materials. Key words: Solid waste, bio-medical waste, characterization, waste disposal, compostin

PILOT STUDY ON LOW COST DOMESTIC SLOW SAND FILTER FOR GROUNDWATER QUALITY IMPROVEMENT

Most waterborne diseases can be prevented using simple, low cost water filtration techniques. The aim of this study is to design a low cost domestic slow sand filter, which can be operated and maintained effectiveness at household level by a member of the family, and determine its effectiveness in removing selected contaminants from the raw groundwater. Fine sand, activated charcoal, coarse sand, and gravel were used as media column for the developed slow sand filtration media. Common selected physico-chemical and microbial water parameters were examined before and after filtration with the slow sand filtration system. The filter was able to remove turbidity of the raw groundwater in the range of 86 - 92% without hampering the pH value or the temperature below the acceptable standards set by the Nigerian standards for drinking water quality. The filter media was able to reduce an average of 44 - 82%, 29 - 53% and 60 – 66% of total hardness, calcium hardness and chloride content, respectively from the chemical composition of the groundwater samples.  The media also showed high effectiveness in reducing biological impurities from the groundwater.  It was able to remove effectively the concentration of E-Coli and coliform counts. The average percent removal of E-coli and coliforms was found to be 100%. These were achieved with the aid of the bio-film layer that developed on the topmost part (fine sand layer) of the filter which was able to predate on the microbes in the groundwater samples. Slow sand filters are a sustainable means of water treatment when applied to appropriate source waters and when designed and operated properly.&nbsp

SUSTAINABLE MANAGEMENT OF COW DUNG FROM SLAUGHTER HOUSES

Large amount of cattle dung are generated daily from slaughter houses which are not only of environmental concern due to methane emission but also present a significant health risk if not adequately managed.  In this study, cow dung obtained from slaughter house was anaerobically digested and its composition evaluated.8 kg of the collected cow dung was mixed with water using a mechanical stirrer set at a speed of 150 rpm to form slurry before pouring it into a laboratory scale digester affixed with stirrer, inlet and outlet ports and temperature detector. The set up was left for 3days for microbial activation to take place, before daily stirring.  Average weekly temperature of the slurry inside the digester tank was observed. Biogas produced was collected in a rubber tube and trapped with activated charcoal dissolved in 500 ml of carbon disulphide (CS2) for 120 minutes in an open air. The liquid filtrate was then analysed using a Gas Chromatography. The optimum temperature was observed at 36.5 OC. The digestion temperature variation was between 0.5 to 2 OC. Methane bacteria worked best in the temperature ranges between 34 and 37 OC. After the liquefaction process, 30 cm3 of biogas was generated. Out of which, methane occupied 25.002 cm3 (83.34 %), carbon dioxide 4.467 cm3 (14.89 %), nitrogen 0.468cm3 (1.56 %) while carbon monoxide generated was 0.063 cm3 (0.21 %). The result clearly show that methane has the highest yield, the energy contained in methane can be used as domestic gas.Cow dung is an excellent substrate for biogas production in anaerobic digesters instead of indiscriminate disposal. Bio-digestion of cow dung is a viable and sustainable solution to the problem of waste pollution, disposal, control and management

Effects of a Mathematics Cognitive Acceleration Program on Student Achievement and Motivation

This paper presents the effects of a cognitive acceleration program in mathematics classes on Tongan students’ achievements, motivation and self-regulation. Cognitive Acceleration in Mathematics Education (CAME) is a program developed at King’s College and implemented worldwide with the aim of improving students’ thinking skills, mathematics performance and attitudes. The first author adapted the program materials to Tongan educational context and provided support to participating teachers for 8 months. This study employed a quasi-experimental design with 219 Year 8 students as the experimental group and 119 Year 8 students as the comparison group. There were a significant differences in the mean scores between the pre-test and post-test of the three instruments that were employed in the study, indicating that learning mathematics under the CAME program had a positive effect on levels of students’ self-regulation, motivation and mathematics achievement. Students also reported changes to the ways they learn mathematics