Studies in the suitability of NPK-15-15-15 fertilizer, animal dung, and petroleum agar as Nutrient Supplements for growth of microorganisms

Yt Puyate,A Rim-Rukeh

doi:10.4314/gjpas.v14i3.16809

Abstract

The suitability of three nutrient supplements (NPK-15-15-15 fertilizer, petroleum agar, and animal (cattle) dung) in promoting growth of microorganisms in produced water and crude-oil-contaminated soil are investigated experimentally. The analysis involves monitoring the total microbial count (TMC) in produced water and crude-oil-contaminated soil samples treated with the different nutrient supplements. After a test period of 10 weeks, the TMC in produced water treated with NPK, petroleum agar, and cattle dung was 105 cfu/ml, 103 cfu/ml, and 102 cfu/ml respectively; while the TMC in soil treated with NPK, petroleum agar, and cattle dung was 104 cfu/g, 10 cfu/g, and 102 cfu/g respectively. NPK-15-15-15 fertilizer exhibits the best characteristics as nutrient supplement for the microorganisms in both the produced water and crude-oil-contaminated soil; followed by petroleum agar and then cattle dung for produced water, but followed by cattle dung and then petroleum agar for crude-oil-contaminated soil. Keywords: NPK fertilizer; Petroleum agar; Cattle dung; Microbes; Nutrient.Global Journal of Pure and Applied Sciences Vol. 14 (3) 2008: pp. 285-288

Highlights

Contamination of the biophysical environment by pollutants and the attendant potential effects on human and the ecosystems is a problem of global concern
The petroleum agar used as nutrient supplement in the experiments was procured from NEK Chemicals (Nig.) Ltd, Port Harcourt, and manufactured by BCH Chemicals, London; it contains 0.5g of ammonium chloride (NH4Cl), 2.5g of hydrated sodium hydrophosphate (NaHPO412H2O), 5g of potassium hydrophosphate (K2HPO4,) and 15g of Diefo agar powder, per litre of engine oil
The area was accidentally contaminated in June 2006 due to crude oil spill (NAOC, 2006), and the soil sample used in the study was collected in December 2006. (Note that collecting contaminated soil sample about six months after the spill is advantageous since the population of microorganisms in the soil would increase with time due to availability of nutrient)

Summary

Introduction

Contamination of the biophysical environment by pollutants and the attendant potential effects on human and the ecosystems is a problem of global concern. Various environmental effects of oil exploration and exploitation such as killing of marine organisms and damage to plants; making water unsafe for drinking, recreational activities, and domestic purposes; and destruction of natural components of soil are reported in literature (Joseph and others, 1996; Ojo, 1998). Environmental regulations require that contaminated area be cleaned to an acceptable and permissible level (DPR, 2002). Clean–up techniques which may be physical, chemical, or biological, are always applied to oil-degraded environment to restore its productivity. Physical and chemical clean-up methods are most widely used, they are not cost effective and sometimes result in further contamination of an environment (Stevens, 1991)

Methods

Results

Conclusion