N. Al-Awadhi

White rot fungi and their role in remediating oil-contaminated soil

White rot fungi, which utilize lignin as an energy source, possess the ability to degrade a wide spectrum of environmental pollutants using peroxidases enzymes. This ability led to several studies that focused on the development of bio-treatment systems using white rot fungi. Three strains of white rot fungi, namely Phanerochaete chrysosporium, Pleurotus ostreatus, and Coriolus versicolor, have been tested for their ability to degrade oil in contaminated soil. A soil microcosm test was designed to study the effect of strain used, inocula concentration, and the addition of nitrogen on bioremediation efficiency. Coriolus versicolor showed the highest degradation rate, as the total petroleum hydrocarbon (TPH) concentration decreased from 32 g/kg to reach 7 g/kg within 12 months. The increase in the inocula concentration enhanced substantially TPH degradation. The nutrient rich conditions initiated the growth of other soil existing microorganisms enabling them to degrade different compounds synergistically with some white rot fungal strains. Because of their unique biodegradative abilities, white rot fungi are considered potentially useful microorganisms for bioremediation applications.

Isolation and Characterization of Biosurfactant-Producing Bacteria from Oil-Contaminated Soil

Two biosurfactant-producing Pseudomonas aeruginosa strains (KISR C1 and KISR B1) were isolated from Kuwaiti oil-contaminated soil, which resulted from the Gulf War. The optimum environmental conditions that supported the growth and surfactant production of both isolates were examined. The two isolates differed in their biosurfactant-stimu-lating carbon source, nitrogen concentration, and the pH of the medium. C-1 isolate produced two types of rhamnolipids with a final concentration of 98.4 g/l after spiking the nitrogen-limited medium with 10 mg/ml olive oil. The other isolate (B-1) produced only one type of rhamnolipid (5.9 g/l) after spiking the medium with crude oil. The biosurfactant produced by this strain was found to be very effective in the emulsifica-tion of crude oil. The result suggests that this isolate can potentially be used to enhance bioremediation of oil-contamination and enhanced oil recovery.

Plants‐associated microflora and the remediation of oil‐contaminated soil

Abstract The use of plants and their rhizospheric microorganisms is a promising emerging technology for remediating contaminated soils. The degradation of total petroleum hydrocarbon (TPH) in the rhizospheric and nonrhizospheric soil of three domestic plants, namely, alfalfa (Medicaga sativa) broad beans (Vicia faba) and ryegrass (Lolium perenne) was investigated. The experimental data from the studies of plantmicrobe‐soil interactions implicated the enhancement of TPH degradation by the rhizospheric microbial community. Although the three domestic plants exhibited normal growth in the presence of ∼1.0% TPH, the degradation was more profound in the case of leguminous plants. The TPH degradation in the soil cultivated with broad beans and alfalfa was 36.6 and 35.8%, respectively, compared with 24% degradation in case of ryegrass. Such a high correlation between plant type and TPH degradation rates indicate that selection for enhanced rhizosphere degradation may be accomplished by selecting leguminous plants.

Compost Soil Piles for Treatment of Oil-Contaminated Soil

A number of diverse technological options are being considered for the remediation of soil contaminated with weathered crude oil in Kuwait. The bioremediation technique involving the use of composting soil piles was selected from among the most appropriate methods and evaluated on a pilot scale. The field test was conducted from November 1992 to September 1993 at the Burgan oil field. Soil piles were constructed from the contaminated soil after amendment with necessary soil additives. The piles were subjected to regular irrigation and turning, and a monitoring program was carried out, including monthly soil sample collection from each pile for the measurement of petroleum hydrocarbon PAHs, soil microbial counts, mineral and metal concentrations. The results obtained showed that the composting soil pile treatment resulted in the reduction of up to 59% total extractable matter of oil contamination within 8 months. This article describes the technology used and summarizes the results obtained.

Growth of Tomato Plants in Soil Contaminated with Kuwait Crude Oil

This laboratory study measured growth of one plant species, Lycopersicon esculentum Big Girl (tomato), that is sensitive to the presence of soil contamination, in Kuwait soil amended with crude-oil-contaminated soil. Germinated tomato seeds were placed in containers with soil containing 0, 0.12, 0.24, 0.36, 0.48, 0.60, 1.2, and 2.4% crude oil and were grown in an indoor growth chamber. Plants grew in Kuwait soil containing up to 0.36% crude oil; however, growth and fruit production were compromised at crude oil concentrations greater than 0.12% when compared with control plants. Plants did not grow in Kuwait soil amended with 0.48% crude oil or higher.

Bioremediation of Oil Contaminated Soil in Kuwait

During the Gulf crisis, the State of Kuwait was subjected to environmental hazards during oil well fires. The discharged oil formed over 300 oil lakes covering land areas in excess of 49 km2, besides aerial fall-out deposits which covered Kuwait desert soil. The density of oil contamination ranged from oil lakes, heavy contaminated soil > 10% oil, medium and light contaminated soil < 10% oil. For the latter area, landfarming might be one of the most effective technologies for cleaning the contaminated soil.

Kuwait Integrated Environmental Information Network (KIEIN-IV): a way of developing national environmental indicators for better environmental information dissemination

One of the main challenges that face Kuwait is the development of environmental indicators for sustainable development. For this purpose, the Kuwait Integrated Environmental Information Network (KIEIN) multi-phase project was initiated in 1994 with the main goal of developing an interactive environmental information platform. The final KIEIN-IV aims at developing the national environmental indicators, which will be embedded in a web service interface. Key issues behind this project are the dissemination of these indicators among society to maximise the societal benefits and foster the synergy and integration between different users to obtain the utmost benefit. The six main thematic areas, atmosphere and climate change, land, coastal and marine environment, fresh water, biodiversity, and waste management, were developed for the KIEIN GeoPortal. These themes are key environmental issues that are broken down into indicators. In this regard, six Themes, 22 Issues and 65 Indicators were listed.