F. A. Aisien

Potential Application of Recycled Rubber in Oil Pollution Control

The abundance and indiscriminate disposal of scrap tyres inurban areas in Nigeria create serious health and environmentalproblems. The potential of using rubber recycled from scraptyres as an absorbent in crude oil clean up was investigated.Rubber particles of mesh sizes within the range of 0.15 to2.36 mm were used to absorb crude oil at different temperatures(5 to 40 °C). The rapid increase in oil absorption withinthe first 20 min was followed by a much slower rate, with theequilibrium absorption being attained after 30 min. Theequilibrium absorption increased with decreasing particle sizeand decreasing temperature of absorption. At 30 °C, the oil absorption for the 0.15 mm rubber particles was more than twice that of the 2.36 mm particle size. When regenerated recycledrubber was used, the equilibrium absorption decreased by about15–40%. The extent of reduction was higher for the largerparticles and at lower temperature of absorption.

A comparative study of effect of oral chronic cyanide administration on some rabbit tissue ATPases.

The effect of oral KCN administration on Na(+)-K(+)-ATPase, Ca(2+)-ATPase and Mg(2+)-ATPase activities was studied in some rabbit tissues. Generally, the order of activity of the enzymes was kidney > liver > ileum > colon. There were significant decreases (P < 0.05) in the activities of all the ATPases in the tissues of KCN-treated rabbits relative to controls. The decreases in Na(+)-K(+)-ATPase and Ca(2+)-ATPase activities were most pronounced in liver and kidney. The decreases in ATPases suggest impairment of membrane function as a result of the toxic effect of cyanide.

Levels of Heavy Metals in and Around Scrap Car Dumpsite at Uwelu, Nigeria

Soil contaminated with heavy metals can result to very serious environmental hazard. As a result of this problem, this research was carried out to investigate the concentration of heavy metals (Fe, Zn, Pb, Cu and Cr) in and around Uwelu scrap car dumpsite in Benin City, southern Nigeria. In carrying out this research, a total of 36 soil samples were taken for laboratory analysis . The soil samples were collected at various depths at the dumpsite, and at various horizontal distances from the dumpsite includin g human settlements close to the dumpsite, in order to ascertain the levels of toxic heavy metal concentration on human living habitat around the dumpsite. The heavy metals in the waste soils samples were sequentially extracted and measured using atomic ab sorption spectrometry(AAS). The results show that Fe had the highest concentration of 515mg/kg, followed by Zn, 236.8mg/kg, Cu, 78.61mg/kg and Cr, 0.94mg/kg at the dumpsite surface, where all the metals recorded their highest concentration. The level of F e and Pb were above the Federal Environmental Protection Agency (FEPA) minimum acceptable limit. Besides, the concentrations of these heavy metals decreased with increased vertical depth at the dumpsite and with increased horizontal distance from the dump site. Similar

Toxicity Assessment of some Crude Oil Contaminated Soils in the Niger Delta

This paper considered the toxicity assessment of some crude oil contaminated soils in Niger Delta areas. The soil samples were collected from different horizontal distances, vertical depths and contaminated soil of different ages. The heavy metals in the contaminated soils were digested and extracted using di-acid digested and DTPA extraction methods respectively. The physiochemical parameters (moisture content, pH, N, P and heavy metals (Ni, Pb and Cd) were analysed with APHA method. The heavy metals concentration was determined using atomic absorption spectrophotometer (AAS). The results show that the metals concentration decreased with the age of the contaminated soil and with increased vertical depths. However, the metals concentrations were almost constant at different horizontal distances. Similar trend was observed for the moisture content, pH, N, P and K.

Improved Quality of Abattoir Wastewater Through Phytoremediation

The effectiveness of abattoir wastewater purification using macrophytes such as water hyacinth (Eichhornia crassipes), water spinach (Ipomoea aquatica) and microalgae, Closterium turgidum, Chlorella vulgaris was investigated in laboratory scale. The cascade was a semi-continuous study performed in four stages: first water hyacinth culture, algae culture, water spinach culture and second water hyacinth culture. The retention time for each stage was 7 days. The physiochemical and bacteriological properties (water quality indicators) of the raw abattoir wastewater and the treated abattoir wastewater at the end of each stage was carried out using APHA standard methods of analysis. The efficiency of reduction of the soluble anions and other parameters (DO, BOD, COD, TDS, TSS, temperature, turbidity alkalinity, conductivity, pH and total hardness) at the end of the last treatment stage ranged from 71.2 to 90 % and 20 to 98.3 %, respectively. The heavy metals and bacteria counts were completely removed (100 % efficiency). However, the efficiency of increase temperature and DO were 6.67 % and 81 %, respectively. There was a strong correlation between water quality indicators and the R 2 ranged from 0.96 to 1.0 and −0.96 to −0.99 for linear and inverse linear, respectively. It was concluded that the water quality of the abattoir wastewater was greatly improved by phytoremediation with macrophytes and microalgae as evidence by virtually all water quality indicators falling either below or within the WHO/FEPA permissible limits for the discharge of wastewater into surface water.

Phytoremediation of Petroleum-Polluted Soils

Soil pollution from the discharge of petroleum and its products is among the most extensive environmentally damaging pollution problem in the world today. The presence of toxic organics in the soil and surrounding water bodies constitutes potential threats to humans and the ecosystem. The potential of using phytoremediation, a process whereby green vegetation is used to remediate petroleum-polluted soils, is examined. Considerable attention has been focused on hydrocarbons linked with phytoremediation, categories of phytoremediation, enhancement of phytoremediation, environmental factors affecting phytoremediation, plants/legumes associated with phytoremediation and advantages and limitations of phytoremediation. In spite of these, several methods have been used in the past to remediate petroleum-polluted soils. The application of phytoremediation has proven to be one of the most efficient, cost-effective and environmentally friendly technologies. Phytoremediation with enhancement should be strongly encouraged.

Bio-Treatment of Brewery Effluent Using Enzymes

The feasibility of treating brewery effluent using bio-catalysts (enzymes) was investigated. Carbohydrase, lipase, protease and a mixture enzyme made of carbohydrate and lipase were used. Brewery wastewater samples were collected and analyzed for 96 hrs, at intervals of 12 hrs. The physiochemical properties: biological oxygen demand BOD, chemical oxygen demand COD, total suspended solid (TSS), total dissolved solid TDS, pH, phosphorus (PO4), ammonium nitrogen (NH4-N), total hydrocarbon (THC) were determined using APHA standard method of analysis. The concentrations of the physiochemical properties of the brewery effluent decreased with increasing biodegradation time, for the various enzymes used. However, the different enzymes gave different percentage reductions of each of the physiochemical properties. The order of percentage reduction for the enzyme systems is mixed enzyme > carbohydrase > lipase > protease > control. Hence, the mixed enzyme gave the best results of 90%, 90%, 50%, 100%, 91.6% and 100% reductions for COD, BOD, TSS, NH4-N, PO4 and THC, respectively after 96 hrs. of biotreatment. However, the control gave the least percentage reductions of 6.9%, 5.3%, 16.4%, 7.1%, 5.8% and 50.0% for COD, BOD5, TSS, PO4, NH4-N, and THC respectively.

Effects of Linear Alkyl Benzene Sulfonate Detergent on the Activity of Cassava Fermenting Enzyme

The effect of linear alkyl benzene sulfonate (LAS) detergent on the activity of cassava fermenting enzymes was investigated for 72 hrs. Enzymatic assay methods were used to determine the activity of cassava fermenting enzymes: cellulase, α-amylase, pectin methyl esterase and phosphorylase. The cassava fermenting media were made up of LAS detergent concentration of between 1g/L to 5g/L. The results show that the LAS detergent of 2g/L and 3g/L gave optimum enzyme activity. The order of enzyme activity was pectin methyl esterase > α-amylase > phosphorylase > cellulase.

Batch Treatment of Palm Oil Mill Effluent

Batch treatment of palm oil mill effluent (POME) was investigated using physical, chemical and biological methods. Physiochemical parameters such as pH, sulphate (SO42-), total dissolved solids (TDS), total suspended solid (TSS), chloride ion (Cl-), biological oxygen demand (BOD), chemical oxygen (COD) and metals (Fe2+, Zn2+, Ca2+ and Mg2+) concentrations were determined using American Public Health Association (APHA) methods. The results revealed that significant treatment was achieved at each stage. However, the biological method proved to be the best with percentage reductions of 45.6%, 97.6%, 71,0%, 50.1%, 80.4%, 93.8%, 72.0%, 85.4%, 93.2%, 77.7%, 86.2% and 85.7% for pH, SO42-, TS, TDS, TSS, Cl-, BOD, COD, Fe2+, Zn2+, Ca2+ and Mg2+ respectively. The concentrations after treatment were in conformity with the minimum acceptable standard of FEPA and WHO.

Design, Fabrication and Performance Test of a Prototype Biogas Digester

The search for alternative sources of energy from organic waste has been on in Nigeria. This report focuses on a simple design, fabrication and performance test of a prototype biogas digester. The volume of the digester was 340dm3 and that of the absorber/adsorber was 12.5dm3. The digester was fabricated using mild and stainless steels, styrofoam, polythene sheets and other materials. The digester can be moved about and agitated manually. In the performance test, 8.134L of biogas was generated within 14 days of anaerobic digestion of palm oil mill effluent (POME). The optimum pH and temperature for biogas production were 6.2 and 29oC respectively.