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LIST OF VOLUME ONE, NUMBER TWO ARTICLES
VOL. 1, No. 2 , ARTICLE 1 Effects of water soluble fractions of crude oil on growth of the catfish, Clarias gariepinus By Ofojekwu P. C. & Onah J. A. (Burchell, 1822)
The effect of sublethal concentrations of water soluble fractions (WSFs) of the Bonny light crude oil on the growth of the African catfish, Clarias gariepinus fingerlings (mean weight: 2.02 + 0.04g) was investigated under laboratory conditions during a 10-week exposure period. The nominal concentrations used were 0.00 (control), 0.035, 0.070, 0.140, 0.280 and 0.560 ml.1-1. There was no mortality in the exposed fish throughout the exposure period, but results obtained indicated that growth and feed utilization were significantly reduced. The group of fish exposed to 0.560ml.1-1 had the most severe depression in growth. The consequences of WSFs of crude oil as it affects growth, feed utilization and survival of fish in a crude oil-polluted environment are discussed FOR FULL ARTICLE: SEND E-MAIL TO ekomrob@yahoo.com
VOL. 1, No. 2 , ARTICLE 2 Effect of kerosene on tailing flotation in the separation process of quartz from Osu gold waste by Adewuyi B. O. & Opafunso Z. O.
Tailing flotation is carried out to minimize the amount of gold being wasted in the Osu gold mine. This work was carried out in order to determine the efficiency of kerosene in the separation process of Si02 from gold waste. Tailings were successively refloated with kerosene addition to recover the SiO2. The weight of SiO2 recovered reduced with increasing rate of agitation. The % of silica removed increases with increasing frother volume. FOR FULL ARTICLE: SEND E-MAIL TO ekomrob@yahoo.com
VOL. 1, No. 2 , ARTICLE 3 A preliminary checklist of the macrobenthic fauna offshore, Niger Delta, Nigeria by Imoobe T. O. T.
One hundred and twenty (120) taxa of marine macrobenthic invertebrates made up of Mollusca (46 taxa), Polychaeta (32 taxa), Crustacea (24 taxa), Minor phyla (8), Chordata (4), Cnidaria (3) and Echinodermata (3) were collected from the seabed between July 1998 and July 1999. These included Capitella capitata, a small polychaete and a “universal indicator of organic pollution.” 45% of these macrobenthic fauna have probably not been previously reported from Nigeria.
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VOL. 1, No. 2 , ARTICLE 4 Long-term effects of mineral oil-based muds on the macrobenthic invertebrates in the Gulf of Guinea. by Imoobe T. O. T.
The impact of discharged oil based mud on the macrobenthic fauna was investigated, three years after drilling ceased in an offshore location in the Gulf of Guinea. During this survey macrobenthic fauna species richness and abundance were determined at distances of 0m, 100m, 200m, 500m, 800m, 1200m, 2500m and 8,000m from the well in the direction of the prevailing bottom water current, 800m and 1000m on the reverse side of the current after the well location. A low species richness and abundance was observed within a distance of £200m from the well. Six species showed abundance gradient, increasing with distance from the well. Although the result indicate that effect had not completely disappeared after three years it is obvious that recovery has set in, because a number of sensitive species were encountered around £200m of the well. Capitella capitata which usually signifies impacted sediment was not found at all in the area. FOR FULL ARTICLE: SEND E-MAIL TO ekomrob@yahoo.com
VOL. 1, No. 2 , ARTICLE 5 Effects of Qua-Iboe (Nigerian) crude oil on the germination and growth of okra (Abelmoschus esculentus, L) and fluted pumpkin (Telferia occidentalis, L) in tropics by Asuquo F. E., Ibanga I. J. & Idungafa N.
Field studies to ascertain the effects of crude oil spillage on agricultural crops and soil environments are few. A greenhouse experiment was carried out using zero % (control), 2%, 4% and 8% v/w levels of Qua Iboe crude oil treated soils to investigate the response of Okra (Abelmoschus esculentus ) and fluted pumpkin (Telferia occidentalis) to crude oil contamination. The results showed that redox potential, pH, temperature, electrical conductivity, organic carbon, total nitrogen and total hydrocarbon contents of the contaminated soils increased with increase in crude oil concentrations. In contrast, available phosphorus, effective cation exchange capacity, exchangeable bases and acidity decreased with increase in crude oil concentrations. Okra and Telferia seeds showed a delayed germination in the 2% and 4% treated soils and total inhibition of germination in the 8% treated soils. The growth of Okra and Telferia seedlings decreased significantly (P < 0.05) with increase in crude oil concentrations. The amount of heavy metals and THC absorbed by Okra and Telferia shoots increased with increase in crude oil concentrations. However, Okra absorbed more Fe, Ni, and Cd while Telferia absorbed more Cu, Zn, and THC. This study recommends Telferia for a long term bioremediation of oil polluted sites after accidental spillage on land. FOR FULL ARTICLE: SEND E-MAIL TO ekomrob@yahoo.com
VOL. 1, No. 2 , ARTICLE 6 Marine garbage composition and dynamics: A case study of Ibeno beach, Nigeria by Asuquo F. E.
Oil related environmental degradation in the coastal regions of Nigeria have been a subject of intermittent civil disorder because of apparent and perceived negative impacts on the lives of the coastal dwellers. In this study, beach contamination by oil and non-oil materials collectively called garbage is reported. Data was collected fortnightly over a period of 7 months (Dec. 2000 – June 2001) along Ibeno-Okposo, one of the most popular beach resorts on the southeast coast of Nigeria. Results show that the beach garbage is composed of hydrocarbon residues (tar balls), plastics/ leather products, Nypa fructicans fragments, fishing materials, oyster shells and wood fragments. Concentration of tar balls ranged from 1 to 6 g/m2. The non-hydrocarbon components were typically <20 g/m2 and dominated by Nypa fructicans fragments (65%). Beach use was largely responsible for the plastic and other exotic wastes on the beach. The distribution of garbage on the beach is determined by a combination of climatic and hydrodynamic conditions. During the rainy season (April-October), surface run-off and river discharge as well as the wave energy are high and accumulation of garbage on the beach is low. The population of beach users is noticeably low and tourism-related contribution to beach garbage budget is also low due to the unfavorable weather conditions for beach use. In the dry season (November- March) when wave conditions are mild and beach tourism is intense, garbage concentration is high. Apart from garbage contribution by beach users, the high garbage concentration during the dry season is attributed to the net onshore transport of materials by waves. This study provides some baseline data for the modelling of environmental aesthetics of the Ibeno-Okposo beach with regards to tourism and recreation.
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VOL. 1, No. 2 , ARTICLE 7 Distribution and characteristics of solid wastes and waste disposal sites in Port Harcourt Municipality, Rivers State, Nigeria by Igwe C., Isirimah N. O. & Teme S. C.
A survey of waste dumpsites was conducted in Port Harcourt City, Nigeria. Waste disposal and collection sites are distributed throughout Port Harcourt municipality. Five approved waste collections zones with about 38 subdivisions and 12 major waste disposal sites were characterized after drying, sorting and weighing of waste materials. Variations in the physical properties and, distribution of solid waste materials from site to site and within site were assessed. The compositions of waste materials are reported. Compostable wastes which are food remains, leaves and treeprunings constitute about 74.53% with very high distribution in Nkpolu Rumuigbo (98.9%) and Marine base (87.2%) waste disposal sites. Polyethylene distribution is high (74.5 and 64.2%) in Nkpolu Rumuigbo and Marine base, and moderate (42.5%) in Diobu axis. The recalcitrants - metals, glass, polyethylene and plastics and trash make up 25.47% of wastes in the study area. Polyethylene and plastics are moderately distributed in all waste dumpsites. Polyethylene distribution is low (30.7%) in Diobu axis and very low (1.9, 9.0, 5.1and 0.0%) in Marine base, Elekohia, Nkpogu and Nkpolu Rumuigbo respectively. The utility and hazards of the different waste components are discoursed. FOR FULL ARTICLE: SEND E-MAIL TO ekomrob@yahoo.com
VOL. 1, No. 2 , ARTICLE 8 Performance evaluation of some natural fibres for slow sand filter protection by Sanyaolu B. O., Malgwi D. I. & Mashauri D. A.
This study constitutes an additional step in the water pollution research for alternative methods of pretreatment to cope with the highly turbid tropical surface water in developing countries.The extent to which the natural fibres, coir and kapok can protect the slow sand filter unit particularly, the household Slow Sand Filter (SSF) was investigated. Laboratory and field tests were conducted at a filtration rate of 0.08 m/hr. Analyses were conducted on in let water and filtrate from SSF units to determine water quality changes. Majority of impurities were concentrated in the fabric layers such that routine maintenance will only involve cleaning of the fabrics at the end of the run. The low rate of degradation observed in the coir protected SSF compared with the Kapok protected SSF is attributed to the high lignin content of coir (45%). High microbiological degradation in the Kapok protected SSF resulted in higher head loss development. Coir protected SSF thus afforded good protection to the SSF with a filter run time extension of a factor of 1.25 over the reference filter. Coir and other locally available vegetable fabrics can be further exploited since they are abundant as wastes hence more economical in protecting the conventional SSF. FOR FULL ARTICLE: SEND E-MAIL TO ekomrob@yahoo.com
VOL. 1, No. 2 , ARTICLE 9 Mangrove mapping in Cross River Estuary, Nigeria by Holzlöhner S., Nwosu F. M. & Akpan E. R.
A survey was conducted along the banks and coast of the Cross River Estuary between December 1996 and July 1999 to classify the mangrove formations. Ten different vegetation categories were identified and mapped, viz: (a) only mangrove; (b) mangrove with fringing nypa palm; (c) mangrove with extended nypa belt; (d) mixed mangrove and other trees, no nypa; (e) young mangrove in front, nypa in the middle, mangrove behind; (f) no mangrove, no nypa, only other trees; (g) mixed mangrove, nypa and other trees; (h) mixed forest with Pandanus palm in front, no nypa; (i) nypa in front, other trees behind, no mangrove; (j) only nypa over wide areas. This classification will facilitate management and conservation programmes for the Cross River mangrove by distinguishing between mangrove-rich and mangrove-poor parts, hence identifying areas for restoration measures. Significant positive correlations were found between the size of the villages and the occurrence of nypa (r = 0.5212) and also between the age of the villages and the occurrence of nypa (r = 0.5539). Obviously with increasing size and age of the villages, the mangrove stocks decrease because of utilization by man, and therefore the less exploited nypa palm increases its stands. Based on the results of this survey also, sites for a possible development of the first mangrove national park in Nigeria have been identified. FOR FULL ARTICLE: SEND E-MAIL TO ekomrob@yahoo.com
VOL. 1, No. 2 , ARTICLE 10 Preliminary investigations of acid mine drainage (AMD) problems in the Ishiagu lead/zinc pit mines, Ebonyi State, Nigeria by Eze C. L. & Uko E. D.
Open-pit mining of lead/zinc in the Ishiagu region of Ebonyi State from 1965 to 1982 has exposed large volumes of previously unoxidized sulphides to weathering. Abandoned mine waste of shale, sulphide and carbonate minerals presently occupies an area of approximately five hectares in the area. Water in the open mine pits was sampled in July 2001 and December 2002 and analysed for the general chemical characteristics of mine drainage water which include pH, alkalinity, acidity, iron, manganese and sulphate. The sulphides have been oxidized and contributed to acid mine drainage in the area. The Ishiagu lead/zinc mine drainage water is slightly acidic with an average pH of 5.6 in the wet season and 5.1 in the dry season. The average for the other parameters in the wet season are alkalinity 160 mg/l CaCO3, acidity 45 mg/l CaCO3, manganese 28.52 mg/l, iron 4.83 mg/l and sulphate 923 mg/l. During the dry season acidity slightly increased to 46 mg/l, iron to 6.2 mg/l while sulphate increased to 996 mg/l. Manganese did not show any significant change between the two seasons. The carbonate minerals in the mine spoil exert a buffering effect on the mine drainage water. Evaporation slightly increased the concentration of acid and metals in open-pit waters during the dry periods. Large amounts of unweathered sulphides are dispersed throughout the site. These are long-term sources of metals and acid that will be difficult to remediate if not controlled at this stage. Presently, the level of acidity of the mine drainage waters is within tolerable limit for terrestrial and aquatic life. FOR FULL ARTICLE: SEND E-MAIL TO ekomrob@yahoo.com
VOL. 1, No. 2 , ARTICLE 11 Environmental fate and effects of pulp and paper mill effluents: A case study of Jebba Paper Mill in Kwara State, Nigeria by Shallsuku P. & Hassan S.
The distribution of chlorinated organic compounds in River Niger, Nigeria which receives pulp and paper mill effluents was studied. The release of chlorocatechols from the sediment was examined. Significant mobilization and release of chlorocatechols from the sediment phase into water mass occurred. The chlorocatechols were bound to particulate matter which could be removed from the extracts by centrifugation as well as by dialysis. Over 70% of the 3,4,5-trichlorocatechols and 3,4,5,6- tetra-chlorocatechols was contained in particulate fraction (0.2-10mm). The amounts of 3,4,5-trichlorocatechol and 3,4,5,6-tetrachlorocatechol released at pH 11 were greater than those released at pH 7. The environmental consequences of the mobilization of these potentially toxic chlorcatechols from the sediment phase into the overlying water mass are discussed. The chlorinated catechols and guaiacols were transformed into chlorinated anisole and chlorinated veratroles in the River water collected downstream from the paper and pulp mill. Their potential for causing off- flavors in the receiving water was evaluated. The average concentration of 2,4,6-trichloroanisole was about 1.0g/L, close to the odour threshold concentration in water. The average concentrations of 4,5-dichloroveratrole, 3,4,5-trichloroveratrole, and 2,3,4,6-tetrachloroveratrole were 4.1, 7.7, and 1.0g/L, respectively, representing 2-4 orders of magnitude below their odour threshold concentration in water. Chemical structure appears to be more important than volatility from water (Henry`s constant) in determining odour threshold concentration. Olfactory gas chromatography showed several odour peaks in these extracts in addition to the chlorinated anisole and veratroles. Several of these compounds were found downstream from the paper and pulp mill, consistent with field observations of odour in this river during the study period.FOR FULL ARTICLE: SEND E-MAIL TO ekomrob@yahoo.com |
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