Edwan Kardena

Strategies toward commercial scale of biosurfactant production as potential substitute for it's chemically counterparts

In the past few decades natural emulsifiers/biosurfactants have been intensively studied for their ability as potential substitute for synthetic surfactant usage. Biosurfactants are valuable microbial amphipathic compounds with effective surface active and biological properties which are applicable to several industries and process materials. Several biosurfactants properties are low toxicity, higher biodegradability and ecological acceptability, also synthesised from wide range of raw materials. At present, biosurfactant are unable to compete with the synthetic surfactant due to their high production cost, specific functionality and production capacity to meet the need of intended applications. A considerable number of researches and studies have been published in order to eliminate the economical bottleneck of biosurfactants production process. This review describes alternatives strategies toward commercialisation of biosurfactants on a large scale that might be able to replace their chemical counter parts.

Scanning electron microscopy and magnetic characterization of iron oxides in solid waste landfill leachate

Leachate sludge samples were taken from two municipal solid waste sites of Jelekong and Sarimukti in Bandung, Indonesia. Their magnetic mineralogy and granulometry were analyzed to discriminate the sources of magnetic minerals using X-ray diffraction (XRD), scanning electron microscopy equipped with energy-dispersive X-ray spectroscopy (SEM-EDX) and rock magnetism. SEM-EDX analyses infer that the main magnetic minerals in the leachate sludge are iron oxides. In terms of their morphology, the grains from Jelekong are mostly octahedral and angular, which are similar to the general shapes of magnetic grains from the local soils. The grains from Sarimukti, on the other hand, are dominated by imperfect spherule shapes suggesting the product of combustion processes. Hysteresis parameters verify that the predominant magnetic mineral in leachate sludge is low coercivity ferrimagnetic mineral such as magnetite (Fe(3)O(4)). Furthermore, comparisons of rock magnetic parameters show that the magnetic minerals of soil samples from Jelekong have higher degree of magnetic pedogenesis indicating higher proportion of superparamagnetic/ultrafine particles than those of soil samples from Sarimukti. The plot of susceptibilities ratio versus coercive force has a great potential to be used as a discriminating tool for determining the source of magnetic minerals.

Petroleum Oil and Gas Industry Waste Treatment; Common Practice in Indonesia

The demand for oil, gas, and other energy sources are growing dramatically with the worldwide energy consumption that projected to increase by 37 percent in 2035. Rising demand driven by world’s population which predicted to increase by 25 percent in the next 20 years [1]. Indonesia as the fourth largest population in the world, known to its total primary energy consumption increased by more than 50 percent between 2000 and 2010. Currently, Indonesia’s oil production reached nearly 860,000 barrels of oil per day [2]. Oil and gas exploration and production (E and P) activities aside from a necessity, are responsible for various environmental accidents around the world, e.g.: Oil spills during transportation and distribution; Waste from the E and P operations in the form of oil sludge, waste drilling fluid/mud; Waste treatment plant residue (oil separator, oil catcher, dissolved air flotation); Leakage from floating storage, tankers, storage tanks; Residue from cleaning activities; Work over wastes, well completion, treatment, and stimulation fluid; Produced water; Offshore wells drilling leakage as well as the distribution of oil spilled from the well to the tanker and from the ship to the mainland [3,4]. Inadequate treatment of those wastes can threaten the human health and safety as well as the environment.

Biological Treatment of Synthetic Oilfield-Produced Water in Activated Sludge Using a Consortium of Endogenous Bacteria Isolated from A Tropical Area

The aim of this study was to investigate the biological treatment of synthetic oilfield-produced water in activated sludge in an attempt to remove the organic compounds using endogenous bacteria; we also hope to determine the biokinetic coefficients. The activated sludge was operated with various hydraulic retention times (HRT=20 hours, 12 hours, 8 hours), solid retention times (SRT=25 days, 20 days, 15 days, 10 days), and substrate concentrations (500 mg L-1 to 1,100 mg L-1). The endogenous bacterial strains, which were isolated from existing wastewater treatment facilities, were identified as Pseudomonas sp., Enterobacter sp., Bacillus sp1., and Bacillus sp2. It was observed that the highest COD removals were obtained in reactors A (80.7%) and B (82.4%), which had high SRTs (25 days and 20 days) and HRT (20 hours). At shorter SRTs (15 days and 20 days), the concentration of the COD effluent did not comply with the Indonesian regulations for oilfield-produced water quality standards, which means that these SRTs were not recommended as appropriate operational conditions. Furthermore, the results showed that the yield (Y), decay coefficient (kd), maximum specific growth rate (k), and saturation constant (Ks) were 0.533 mg MLVSS mg-1 COD, 0.167 day-1, 0.985 day-1, and 255.46 mg COD L-1, respectively. These biokinetic coefficients (obtained from the Y and Ks values) indicated that although the strains of bacteria can grow well in the reactor, they had low affinities to the substrate, which caused the concentration of the COD effluent to be relatively high.

Preliminary Study on Climate Change Biomitigation by Improving CO2 Removal and CO2 Utilization Efficiency Using Microalgae Culture in Photobioreactor

Culture conditions are very important to CO2 bio-fixation related with the CO2 removal efficiency through biological process by microalgae photosynthesis activities. The aim of the research was to study how high CO2 utilization efficiency could reach in mix culture that supplied high CO2 concentration (2%, 5%, and 7%) continuously from the bottom of photobioreactor. The mix microalgae culture containing of Chlorella sp, Scenedesmusobliquus and Ankistrodemus sp. were cultivated in photobioreactor with various environmental treatments i.e light intensities, light periodism and temperatures whereas the fixed CO2 gas flow rate of 8 L.min-1. The results showed that microalgae growth was best at light intensity of 4000 lux for 16/8 hours light/darkness cycling, 30°C and 5% CO2 supplied, indicated by the highest dried biomass (g.L-1), the highest Carbon content was g.d-1 and highest CO2 removal efficiency (%) that were 2.7, 11.9, 49, respectively. However the highest CO2 utilization efficiency for bio-fixation phenomenon was obtained from culture that supplied by 2% CO2 concentration, the value was almost 2 fold than 5% CO2 supplied and 4 fold than 7% CO2 concentration supplied, respectively. Biological fixation of CO2 are greatly affected by the characteristics of the microalgae strains and their tolerance to environmental conditions.