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Petroleum hydrocarbon waste is produced in worldwide refineries in significant amount. In Libya, approximately 10,000 tons of oil sludge is generated in oil refineries (hydrocarbon waste mixtures) annually. Insufficient treatment of those wastes can threaten the human health and safety as well as our environment. One of the major challenges faced by petroleum refineries is the safe disposal of oil sludge generated during the cleaning and refining process stages of crude storage facilities. This paper reviews the hydrocarbon sludge characteristics and conventional methods for remediation of oil hydrocarbon from sludge. This study intensively focuses on earlier literature to describe the recently selected innovation technology in oily hydrocarbon sludge bioremediation process. Conventional characterization parameters or measurable factors can be gathered in chemical, physical, and biological parameters: (1) Chemical parameters are consequently necessary in the case of utilization of topsoil environment when they become relevant to the presence of nutrients and toxic compounds; (2) Physical parameters provide general data on sludge process and hand ability; (3) Biological parameters provide data on microbial activity and organic matter presence, which will be used to evaluate the safety of the facilities. The objective of this research is to promote the bioremediating oil sludge feasibility from Marsa El Hariga Terminal and Refinery (Tobruk). [ABSTRACT FROM AUTHOR]

During pumping of groundwater to the surface, the reaction between dissolved iron (Fe2+) and oxygen causes oxidation to ferric iron (Fe3+), thereby increasing the concentration of Fe2+. In this research, the potential application of ozonation with limestone adsorption to remove Fe2+ from groundwater was investigated through batch ozonation and fixed-bed-column studies. Groundwater samples were collected from a University Science Malaysia tube well (initial concentration of Fe2+, Co = 1.563 mg/L). The effect of varying ozone dosages (10, 12.5, 15, 17.5, 20, 22.5, and 25 g/Nm3) was analyzed to determine the optimum ozone dosage for treatment. The characteristics of the column data and breakthrough curve were analyzed and predicted using mathematical models, such as Adam Bohart, Thomas, and Yoon- Nelson models. The data fitted well to the Thomas and Yoon-Nelson models, with correlation coefficient r2 > 0.93, but not to the Adam Bohart (r2 = 0.47). The total Fe2+ removed was 72% (final concentration of Fe2+, Ct = 0.426 mg/L) at the maximum dosage of 25 g/Nm3 through ozonation only. However, the efficiency of Fe2+ removal was increased up to 99.5% (Ct = 0.008 mg/L) when the hybrid treatment of ozonation with limestone adsorption was applied in this study. Thus, this integrated treatment was considerably more effective in removing Fe2+ than single ozonation treatment. [ABSTRACT FROM AUTHOR]

A study was conducted to investigate the efficiency of iron oxide nanoparticle (FeONPs) adsorption for removing of DOM in landfill leachate. FeONPs was directly prepared via sodium borohydride (KBH4) reduction method. Adsorption kinetics, isotherm and thermodynamic studies were developed to design the model for DOM removal. Pseudo first-order and pseudo second-order model have been studied to fit the experimental data. The regression results showed that the adsorption kinetics were more accurately represented by a pseudo second-order model. The Weber-Morris intraparticle diffusion model was used to analyze the adsorption kinetics data. The plot of qt versus t1/2 represents multi linearity, which showed that the adsorption processes occurred in more than one step. Adsorption isotherms were analyzed by Langmuir, Freundlich, Tempkin and Dubinin-Radushkevich, isotherms model. Equilibrium data were well fitted to the Dubinin-Radushkevich isotherm model. Maximum monolayer adsorption based on Langmuir was calculated to be 21.74 mg/g. Thermodynamic parameters such as free energy changes (ΔG°), enthalpy (ΔH°) and entropy (ΔS°) were evaluated between temperatures of 25 °C and 40 °C. The ΔG° was noticed progressively decrease from -9.620 -9.820 -10.021, and -10.222 kJ/mol as the temperature increase. The ΔH° and ΔS° values were found to be 2.350 kJ/mol and 40.165 J/mol.K respectively. The results showed that the overall adsorption process was endothermic and spontaneous. The results from this study suggested that FeNPs could be a viable adsorbent in managing higher DOM problems associated with landfill leachate. [ABSTRACT FROM AUTHOR]

In this study, composite adsorbent was produced from the combination of activated carbon (AC) and calcite by four (4) different mixing ratios (AC:Calcite) of 9:1, 7:3, 1:1, 3:7, 1:9. The mixture was mixed with alginate as the binder. The composite adsorbent was tested in batch of experimental study to observe the effectiveness of removing COD and Fe2+ from sample of leachate collected from semi-aerobic sanitary landfill at Pulau Burung, Penang, Malaysia. The effect on contact time was conducted to observe its impact on the adsorption of COD and Fe2+. Besides, the adsorption kinetic model was also conducted to study the mechanism of adsorption process by applying pseudo-first order and pseudo- second-order rate equations. Based on experimental results, optimum removal of COD and Fe2+ was obtained at mixing ratio of 7:3 with optimum removal of 54.6% for COD and 68.06% for Fe2+. This result indicates that high amount of AC in mixing ratio of adsorbent contributed to the highest removal of both COD and Fe2+. In addition, the study also proves that a combination of AC and calcite has improved the adsorption efficiency. The results of adsorption kinetic model indicate that both COD and Fe2+ followed the pseudo-second order kinetic model which means that the chemisorptions is the favorable mechanism of adsorption process. [ABSTRACT FROM AUTHOR]

The use of extracts from Diplazium esculentum leaves as coagulant and coagulant aid has not been discussed in literature. In this research, the capability of extracts from D. esculentum leaves, namely, D. esculentum aqueous (DEaqs) and D. esculentum powder (DEpowd), to act as coagulant aid in combination with polyaluminum chloride (PACl) was evaluated using stabilized leachate from the Kuala Sepetang Landfill Site (KSLS) and the Kulim Landfill Site (KLS) through a Jar test. Identified as polymers with high molecular weight, DEaqs (221 kDa) and DEpowd (275 kDa) act as anionic coagulants and are capable of promoting the coagulation process in leachate saturated with negative particles. The main functional groups that induce the coagulation-flocculation process by DEaqs and DEpowd are carboxyl, hydroxyl, and amine groups, which all contain hydrogen in their molecules. Jar test results were analyzed based on the removal efficiency (RE) of suspended solids (SS), turbidity, colour, chemical oxygen demand (COD), and ammonia-N. A 50% reduction in the volume of PACl from its optimum dosage, with the DEaqs and DEpowd dosages below 1000 mg/L, exhibited a synergic effect of all the measured parameters in KSLS leachates. [ABSTRACT FROM AUTHOR]

Coagulation-flocculation has been extensively applied for semi-aerobic landfill leachate treatment, prior to other treatment methods. Opting for alternative other than conventional aluminium-based coagulants, mechanically treated starch from oil palm trunk waste had been tested as coagulant for semi-aerobic landfill leachate treatment. FTIR and corresponding elemental analysis had revealed its dominant functional groups like hydroxyl, carboxyl and amine, insinuating existences of starch, fatty acids, proteins, phosphonates, ash and small traces of lignin. Jar test using partially stabilised semi-aerobic landfill leachate from Pulau Burung Landfill Site had shown that this particular botanical coagulant could remove suspended solids and COD in semi-aerobic landfill leachate, though the efficiencies were relatively much lower compared to those of polyaluminium chloride (PAC). Apparently, it was more suitable to be applied as coagulant aid in tandem with PAC, augmenting PAC coagulation performance with 12-16% of improvement. The findings of this first ever attempt had unravelled the potential of oil palm trunk waste in semiaerobic leachate treatment. [ABSTRACT FROM AUTHOR]