Leachate characterization of active and closed dump sites in Port Harcourt metropolis, Nigeria

Leachates are said to have the capacity of polluting environmental media such as air, soil, surface and ground water. The knowledge of the composition of leachates is important to determine the dump sites that require immediate remediation attention and their effective treatment approach. This study characterizes the  leachate quality of both active and closed dump sites in Port Harcourt City. Leachates were sampled from the base of the dum psites and analysed, pH, dissolved oxygen (DO), electrical conductivity and total dissolved solids were determined on the samples in-situ. While chloride, sulphate, phosphate, chemical oxygen  demand (COD), biochemical oxygen demand (BOD), lead, zinc, iron, chromium, copper, cadmium and nickel were analyzed in the laboratory. The sample  locations were Nkpolu Junction along East-West Road (LS1), Chindah Borrow Pit, off Chindah Road, Mile 4(LS2) and Rumuepirikom Community, off Iwofe Road  (LS3). Locations 1 & 3 are closed dump sites, while location 2 is an active dump site. The mean pollution indices for Locations 1, 2 & 3 include; pH (7.96, 6.55 & 7.43), BOD (mg/l) (1.24, 5.95 & 2.94), COD (mg/l) (3.10, 14.87 & 7.35) and DO (mg/l) (2.3, 0.85 & 0.56). Heavy metals analyses reveals Iron (mg/l) having the highest concentration (0.176, 0.461 & 0.253 for LS1, LS2 & LS3 respectively) which exceeds the maximum contaminant levels of 0.05 mg/l prescribed by the Federal Ministry of Environment, which is a regulatory body in Nigeria. The ratio of BOD5/ COD was less than 0.5 for leachates from all sample locations, an  indication of dump site stabilization while the pH values indicated that all sample locations in terms of age of the dump site vary partially from being young to mature in age. The study recommends continuous monitoring of leachates for the active dump site, as the concentration of individual parameters that make up the leachate is quite variable.Keywords: Leachate quality, dump sites, remediation, BOD5/COD ratio

Physico-Chemical Characterization and Pollution Index Determination of Leachates from Warri Waste Dumpsite, Southern Nigeria

This study characterizes the leachates quality of an active dumpsite in Warri, Delta State and also analyses its contamination or pollution potential. Leachate Pollution Index (LPI) - a tool for quantifying pollution potential of leachates generated from dumpsites - has been used to quantify the leachates contamination potential of the dumpsite. The LPI values for the different sample locations L1, L2 and L3 were computed to be 5.69, 6.18 and 5.89 respectively with a mean value of 5.80, while the control had a value of 4.82. These LPI values were also compared with the LPI standard (7.38) for treated leachates. Comparison of the mean LPI  value (5.80) with the standard (7.38) indicated a relatively low contamination potential of the leachates. Moreover, it was observed that the concentration of the  individual parameters of the leachates is quite variable. The organic strength (BOD5 divided by COD) of the dumpsite was less than 0.5, while the pH values  indicated that all sample locations in terms of age was mature, an indication of dumpsite stabilization. The study recommends continuous monitoring of leachates and upgrade to an engineered landfill to forestall possible pollution problems in future.Keyword: Dumpsites, Leachates, Leachate Pollution Index, Leachates Quality, Municipal Solid Waste, Physico-chemical Parameters, Warr

Batch adsorption of heavy metals (Cu, Pb, Fe, Cr and Cd) from aqueous solutions using coconut husk

No Abstrac

Bioaccumulation Of Heavy Metals In The Catfish Chrysicthys Nigrodigitatus From Taylor Creek, Southern Nigeria

The discharge of liquid effluents either untreated or with only primary treatment into Etelebou Creek, a tributary of Taylor Creek has led to the extensive contamination of Taylor Creek by heavy metals. The catfish species, C. nigrodigitatus and other environmental segments were collected from five sites along Taylor Creek, southern Nigeria, and some metals determined by flame atomic absorption spectrophotometry. The concentration levels of the metals in C. nigrodigitatus were higher than values reported in the literature for fresh fish and may lead to a higher risk and harmful effects. The bivariate regression models relating metals in C. nigrodigitatus and metals in the surface waters were significant (R2 ≥ 0.7134). The Log (bio-concentration factors or BCF) of Cr and Zn in C. nigrodigitatus were the highest, whereas Ni was the lowest. The ecological distribution of the log (BCF) values was, for all the heavy metals, moderately stable over the Creek. All log-transformed biomagnification factors (BMF) in the Creek were positive, which indicates that the metal concentration was higher in C. nigrodigitatus than in suspended particulate matter (SPM). The absolute log (BMF) values of heavy metals can therefore be ranked in order of decreasing magnitude: Fe (4.06) > Zn (2.87) > Mn (2.59) > Cr (1.95) > Pb (1.90) > Ni (1.82) > Cd (1.55). This sequence indicates that toxic metals such as Cd, Cr and Pb are undergoing significant bio-reduction from SPM to C. nigrodigitatus. The degree ofcorrelation between the metals was different in C. nigrodigitatus, which suggests that the sources of the metals, polluting Taylor Creek were diverse

Influence of vehicular density on the distribution pattern of lead and cadmium in road dust of Port Harcourt city, Nigeria

No Abstract.International Journal of Natural and Applied Sciences Vol. 4 (1) 2008: pp. 29-3

Temporal trends of heavy metals in shrimps (Macrobrachium macrobrachion) from a non-tidal freshwater ecosystem

No Abstract.International Journal of Tropical Agriculture and Food Systems Vol. 2 (1) 2008: pp. 60-6

Human exposure to organochlorine pesticides in vegetables from major cities in south-south Nigeria

Contamination of vegetables with organochlorine pesticides (OCPs) during cultivation could affect their nutritional value and also results in adverse health effects to consumers. Thus, this study evaluates human exposure to OCPs in vegetables from major cities in south-south Nigeria. A total of eighty vegetables consisting of Vernonia amygdalina, Telfairia occidentalis, Desmodium intortum cv and Talinum triangulare obtained from four major cities (Warri, Benin, Yenagoa and Port-Harcourt) in south-south Nigeria were analysed for OCPs using a gas chromatograph coupled with a mass selective detector. The results showed that the mean concentration of ∑20 OCPs in the vegetables ranged from 11.6 to 37.7 ng g−1 fresh wt for Vernonia amygdalina, 2.48–37.0 ng g−1 fresh wt for Telfairia occidentalis, 7.63–54.2 ng g−1 fresh wt for Desmodium intortum cv and 27.3–57.3 ng g−1 fresh wt for Talinum triangulare. The concentrations of OCPs were generally lower than their respective Maximum Residue Limits (MRLs). The EDI values of the ∑20 OCPs in the vegetables ranged from 141 to 464 ng kg−1 bw day−1 for children and 26.5–87.0 ng kg−1 bw day−1 for adults. The EDI of ∑Drins, ∑Chlordanes and ∑DDTs for the vegetables were below their respective acceptable EDI values set by FAO/WHO Joint Meeting on Pesticide Residue. The hazard index values for children and adults were generally <1 suggesting that there is no potential non-carcinogenic risk for children and adults consuming the vegetables. The total cancer risk values were above 1 × 10−6 and indicated that children and adults have moderate and low carcinogenic risks respectively from ingestion of these vegetables. The isomeric ratios and principal component analysis result showed that OCPs in these vegetables originated from both historical and recent usage in vegetable cultivation