Ecotoxicological effects of discharge of Nigerian petroleum refinery oily sludge on biological sentinels

Abstract

Ecotoxicological effects of the discharge of Nigerian petroleum refinery oily sludge on biological sentinels were examined. The ecotoxicological effects examined included acute toxicity tests on Nitrobacter sp., fresh water shrimp (Desmoscaris trispinosa) and brackish water shrimp (Palaemoneles africanus) from the aquatic environment. It also covered chronic toxicity tests on microbial nitrogen transformation activity in soil and the growth of the terrestrial fauna, earthworm (Apporectoda longa) in pristine soils spiked with predetermined concentrations of the sludge. Analysis of the Nigerian petroleum refinery oily sludge used in this study indicated that the sludge is slightly acidic with a high total petroleum hydrocarbon (TPH) content of 340,000 mg/kg made up mainly between 10-40 carbon unit compounds. The sludge reduced the growth of Nitrobacter sp. in aqueous medium and also caused chronic effect on microbial nitrogen transformation activity in soil because it exceeded the 25% inhibition limit for chemicals with the potential to cause chronic effects on soil microbial activities. Similarly, the sludge exhibited toxicity on fresh and brackish shrimp. The freshwater shrimp was however more affected with an LC 50 of 1097.375 ± 0.62 mg/kg when compared with an LC 50 of 1590. 37±0.92 mg/kg obtained for the brackish water shrimp. It also reduced the growth rate of the earthworm (A. longa) progressively as the sludge concentration increased.

Heavy Metals in Black Crabs in the Atlantic Coast (Tenerife, Spain) – Human Risk Assessment

“…In order to demonstrate that the highest Pb concentrations found in the metropolitan area were a result of the influence of the refinery, selected samples from the metropolitan area with differences between metallic concentrations were analyzed and the crabs from the refinery area had the highest Pb concentrations (Fig. 3), which confirms the lead pollution from the oil refining operations [32]. Black crabs could also be useful biomarkers of environmental pollution and could be used to monitor the metal pollution in the areas where they live and to study the evolution of such pollution.…”

Evaluation of Bioaccumulation and Toxicity of Bisphenol-A and Phthalates on Earthworm and Nitrifying Bacteria from Soil Collected in Waste Management Landfill, Kaduna State, Nigeria

“…The total organic carbon content recorded for the plastic composted soil was also high which is as a result of the release of carbon from carbon containing compounds from the plastic contaminants. The moisture content of the plastic composted soil sample recorded a low value, this is because soil water and oxygen are used up during combustion and degradation of these contaminants thereby leaving the soil with low percentage moisture content (Atuanya et al, 2014). It was observed that the plastic composted soil sample had a lower pH value than the control soil sample (Okpamen et al, 2013).…”

Co-Compost Biotreatment of Drilling Muds Contaminated Sites

“…This could be attributed to the observed high percentage TPH degradation by the NPK + soil treatment. According to [18] large quantities of carbon tend to result in rapid depletion of the available pools of major inorganic nutrients such as N and P. Hence the soil treated with NPK recording a very high amount of nutrient that resulted in the corresponding TPH degradation. This is despite recording lower total viable bacterial count.…”

“…Enhanced biodegradation through composting systems have shown great promise in the treatment of the drilling wastes associated with oil based mud drilling, and are now moving to become a mainstream option [16]. The process of composting reduces organic matter into carbon dioxide, water, heat, and humus [18]. The composting process is also, by definition, a 'self-heating' process, whereby the decomposition process releases energy in the form of heat.…”