Status of Potentially Harmful Elements (PHEs) in Soils around the Vicinity of a Newly Constructed Sporting Facility in Omagwa, Nigeria

A study, intended to generate pre- urbanization baseline data of the soils at the Greater Port Harcourt site of the new stadium, the Adokiye Amiesimaka Stadium, has been conducted. Concentrations of heavy metals (Cd, Cr, Cu, Ni and Pb) and physicochemical properties of surface and sub-surface soils at the study sites have been determined using spectrophotometric and other standard methods. The results indicate that the pH of the soil ranged between 5.3 and 6.2 while the percent organic carbon ranged between 1.73 – 2.50 %. The ranges of the percentages of total organic matter and total nitrogen in the soil were 2.98 – 4.31% and 0.24 – 0.34% respectively. The particle size distribution results obtained for sand, silt and clay were 59.0 – 74.0 %, 3.8 – 6.0 %, and 21.2 – 37.2 %, respectively. The mean concentrations of the metals for surface and sub-surface soils were respectively as follows: Cd (0.21±0.05 mg/kg and 0.24±0.15mg/kg); Cr (1.98 ± 1.07 mg/kg and 2.23 ± 1.67 mg/kg); Cu (11.8 ± 4.48 mg/kg and 12.4 ± 5.40 mg/kg); Ni (2.39 ± 0.66 mg/kg and 2.46 ± 0.53 mg/kg) and Pb (1.32 ± 0.87 mg/kg and 1.23 ± 0.88 mg/kg). The results indicate that the levels of the physicochemical characteristics in the soils of the study area are, in general, lower than soils in the city that have long been disturbed as a result of anthropogenic inputs. On the other hand, the heavy metal levels were similar in both surface and sub- surface soil samples. This may be as a result of the geogenic nature of the sites. However, the pristine nature of the study sites may be responsible for the relatively lower metal levels compared with disturbed soils in the city. These values thus provide baseline data for the study area. @JASE

Bio-Diesel Production from Oil of Orange (Citrus Sinensis) Peels as Feedstock

Although, in Nigeria orange peels are considered as a waste, this study is intended to convert the waste into wealth by establishing the production of biodiesel with oil obtained from orange peels; using transeterification process. Oil from sun-dried/ ground orange peels were extractedusing n-hexane. Transesterification process was done at a temperature range of 80 - 83 °C with oil to ethanol mole ratio of 1:3 respectively and sodium hydroxide as catalyst. The parameters analyzed included: Viscosity, Density and the concentrations of K, Na, Ca, Mg and P.The viscosity and density of the biodiesel obtained were 2.1 stand 825 kg/m3 respectively. The mean concentrations of K, Na, Ca, Mg and P in the biodiesel were 4 ppm, 7 ppm, 3 ppm, 3 ppm and 8 ppm respectively. These results are in close agreement with ASTM standards requirement for biodiesel. The glycerol was recycled trice before it finally lost potent.It is thus apparent that the locally-sourced feedstock (orange peels) would be a good source for the production of biodiesel. @JASE

Assessment of Physicochemical Characteristics of Produced Water from Terminals of Some Oil Industry Facilities in Nigeria

This study evaluated the physico-chemical characteristics, total hydrocarbon concentration (THC) and some heavy metal levels of produced water from terminals of two oil industry facilities in Nigeria, using standard methods. Appropriate sample bottles were used in the collection of samples for analyses of BOD, other  physico-chemical characteristics, total hydrocarbon and heavy metals. The samples were preserved accordingly and transported to the laboratory in ice - packed coolers. The levels of the physico-chemical properties of produced water in the two locations, showed that mean temperature, pH, TDS, TSS, salinity and turbidity levels were: 24.40± 0.35oC – 25.50 ± 0.35oC; 7.49 ± 0.28 – 7.89 ± 0.30; 8428 ±2332mg/l – 9205 ± 2100mg/l; 8.50 ± 3.40mg/l – 14.30 ± 5.10mg/l; 6108± 1250mg/l – 7422 ± 2280mg/l and 16.00 ± 5.00 NTU – 37.00 ± 9.60 NTU respectively. DO and BOD levels were respectively 3.07 ± 0.40mg/l – 3.29 ± 0.40mg/l and 1.46 ± 0.38mg/l – 1.72 ± 0.48mg/l. COD levels did not vary between the two locations. Mean TOC levels ranged between 0.05 ± 0.02mg/l and 0.06 ± 0.02mg/l while mean THC ranged between 4.72 ± 1.59mg/l and 36.90 ± 3.03mg/l. The levels of the nutrient characteristics of nitrate, phosphate and sulphate ranged as  follows: NO3 - (1.90 ± 1.16mg/l – 2.50 ± 0.26mg/l); PO4 3- (0.52 ± 0.12mg/l – 1.07 ± 0.12mg/l) and SO4 2- (14.40 ± 4.57mg/l – 21.70 ± 2.75mg/l). Levels of trace metals ( Pb, Ni, V, Cd, Hg and Cr) were below detection limits. However, the concentration of Fe ranged between 0.53 ± 0.11mg/l 1.06 ± 0.26mg/l. With the exception of salinity, TDS and TSS, the levels of other physico- chemical characteristics including the trace metals were within the permissible limits set out by Nigeria’s Department of Petroleum Resources (DPR).KEY WORDS: Physico- chemical characteristics, Produced water, oil terminals, Heavy metals, oil industryfacility

Removal of Reactive Red 1 dye from aqueous solution using gypsum

In order to establish the capacity of gypsum in the removal of dyes from aqueous solutions, the adsorption behaviour of Reactive Red 1 (RR1) from aqueous solution onto gypsum was investigated under several different operating parameters namely, contact time, adsorbent dosage, pH, particle size, and adsorbate dosage, at ambient temperature. The study employed the batch experiment method and utilized two differentparticle sizes (150 ìm and 300 ìm) of the adsorbent. Two portions of each particle size were subjected to two different treatments (acid and base) while a third portion remained untreated. Acidic medium favoured the dyeremoval at an optimal pH of 2 and an optimal contact time of 25-35 minutes. Optimal adsorption was also recorded at an adsorbent dosage of 0.8 g. Under optimal conditions, 89.8% adsorption was recorded with the150 ìm particle size of the adsorbent in the acid-treated medium. Both Langmuir and Freundlich isotherms could be used to describe adsorption of the dye, with the value of the separation factor of the Langmuir isotherm (RL) lying well in between 0 and 1. The Freundlich isotherm intensity parameter (1/n) also fell in between 0 and 1- indicating that both isotherm processes are favourable. The experimental data fitted well to the pseudo-second-order kinetics model with R2>0.99 indicating that chemisorption was the rate-controlling step in the adsorption of the dye. The smaller particle size (150 ìm) adsorbed higher amount of the dye because of its larger surface area. Acid treated adsorbents yielded higher dye removal than the untreated and the base treated. Keywords: Reactive Red 1 dye; Adsorption; Isotherms; Kinetics; Gypsum

Effects of physical variables on settling velocities of calcium and strontium phosphates in mother solution

Settling velocity is an important parameter used in modeling solid-liquid flow operations and for evaluating tank volumes in water treatment technology. In the present study, series of bench-scale batch-wise precipitation and settling tests were performed to evaluate the effect of some physical variables such as precipitate concentration, temperature and stirring on settling velocity of tricalcium diphosphate (TCDP) and tristrontium diphosphate (TSDP) in mother solution. Various amounts of TCDP and TSDP precipitates were generated in reaction mixtures, by mixing sub-saturated equi-molar solutions (0.1M) of the respective ions in various metal to phosphate (M/P) volume ratios (10:90ml; 20:80ml; 30:70ml; 40:60ml; 50:50ml; 60:40ml; 70:30ml; 80:20ml; 90:10ml). Settling velocity diagrams of TCDP and TSDP were obtained as functions of M/P volume ratio, temperature, and repeat stirring. The results showed that whereas temperature and stirring variables had a linear relationship with precipitate settling velocity, a non-linear relationship was observed between the precipitate concentration variable and settling velocity. When the temperature of the mixtures were raised from 30oC to 50oC, 0.76- and 0.45- fold increases in settling rate were recorded for TCDP and TSDP, respectively. On the other hand, with repeated stirring of TSDP precipitate, 83% increase in settling velocity was recorded between the first and third stirrings. The results may be employed in settling tank designs for the removal of phosphates in water treatment process. Keywords: settling velocity, mother solution, batch-wise precipitation, temperature, amount of precipitates, Ca3(PO4)2, Sr3(PO4)2

Evaluation of Water Quality Index Using Physicochemical Characteristics of Ogbor River in Aba, Abia State, Nigeria

The study was carried out to evaluate water quality index (WQI) of Ogbor River, a freshwater system flowing through the commercial city of Aba, Southern Nigeria using selected physicochemical parameters. The levels of the physicochemical parameters were determined using standard analytical procedures in the Laboratory. The values obtained were subjected to statistical analysis using Excel spreadsheet (Version 16).Water Quality index was calculated using mean values of the selected nine parameters and the World Health Organisation standard for drinking water. The result of physicochemical parameters used showed that Dissolved Oxygen (DO) with mean 4.44 \ub1 0.70 mg/L, and Nitrate (NO3-) with mean 7.58 \ub1 6.25 mg/L were below National and International standards. The value of WQI calculated was 83.05. The result revealed that Ogbor River water quality was very poor, so it is unfit for human consumption, and should be treated to avoid water related diseases

Impact of sawdust on the water quality of Elechi creek in Port Harcourt municipality

The impact of sawdust on the water quality of Elechi creek, in Port Harcourt municipality, has been investigated. Three sampling stations were established – upstream, vicinity and downstream of the main dump site of the sawdust in the water body. Various physiochemical characteristics, including temperature, Electrical conductivity, pH, Dissolved Oxygen, and Biochemical Oxygen Demand (BOD) as well as nutrients and heavy metal concentrations, of the water body have been measured using standard methods. The investigation revealsthat sawdust may have altered the quality of water in the creek as changes in electrical conductivity and metal concentrations were observed