With a 270 million Indonesian population, domestic wastewater is one of the major contributors to wastewater generated from human activities. This review aimed to give an overview of the current state of domestic wastewater generation, characteristics and treatment systems in Indonesia. Overall, grey water quantity in Indonesia was 1 to 4 times higher than black water quantity, while the quantity of untreated grey water was 3 to 6 times higher than untreated black water. Parameters of concern include suspended solids, biochemical oxygen demand, chemical oxygen demand, oil and grease, nitrogen and coliforms. Our analysis shows that grey water can be a significant source of water pollution due to the large quantity and lack of treatment. In addition, black water treatment that relies mainly on on-site treatment is often inadequate due to the lack of quality control for the infrastructure, operation and maintenance. An incentive or penalty scheme to build and ensure the quality of domestic wastewater treatment is required and can be applied at the household, community or central (city) level.

Combination of electrokinetic soil flushing and bioremediation (EKSF-Bio) technology has attracted many researchers attention in the last few decades. Electrokinetic is used to increase biodegradation rate of microorganisms in soil pores. Therefore, it is necessary to use solubilizing agents such as surfactants that can improve biodegradation process. This paper describes the basic understanding and recent development associated with electrokinetic soil flushing, bioremediation, and its combination as innovative hybrid solution for treating hydrocarbon contaminated soil. Surfactant has been widely used in many studies and practical applications in remediation of hydrocarbon contaminant, but specific review about those combination technology cannot be found. Surfactants and other flushing/solubilizing agents have significant effects to increase hydrocarbon remediation efficiency. Thus, this paper is expected to provide clear information about fundamental interaction between electrokinetic, flushing agents and bioremediation, principal factors, and an inspiration for ongoing and future research benefit.

Production of omega-3 fatty acids from lemuru fish by-products was studied by enzymatic hydrolysis using a lipase enzyme in one liter of the batch reactor. The hydrolysis temperature of fish oil was set at 45 to 55 ℃ for 0 to 24 h, whereas agitation from 50 to 150 rpm. RSM-Box Bhenken was used to study the effect of these parameters on omega-3 (EPA, docosahexaenoic acid (DHA), and α-linolenic acid (ALA)) content. The % free fatty acid (FFA), acid index, peroxide index, iodine index, and saponification index of lemuru fish oil was 0.925, 2.52, 42.5, 97.28, and 160.11%, respectively. GC-MS analysis results showed that unsaturated fatty acids content (62.34%), which are consisted of omega-3 (EPA, DHA, and ALA), omega-6 and omega-9, was much higher than saturated acids (12.97%). The experiment data showed that the highest EPA (1.221%) and DHA (0.312%) content were reached at 50 ℃ and 24 h with 150 rpm of agitation. However, through the RSM-Box Bhenken analysis and 3D surface plot, it was suggested that the optimum condition was obtained at 45 ℃ and 24 h with 150 rpm of agitation with the content of EPA, DHA, and ALA were 1.709, 0.49, and 1.237%, respectively.

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Carbaryl, one of the carbamate insecticides are used extensively for pest control in agriculture. The chemical is highly valued for its rapid action and relatively short environmental persistence. Because of its widespread and intensive use, residues of carbaryl have the potential to contaminate the environment. This study aims to formulate a system dynamics model to simulate a degradation process of carbaryl. Since carbaryl was not readily volatilizing, this study only estimates the concentration and degradation of carbaryl in soil and water. The result revealed that carbaryl degraded rapidly, with a half-life of 7 days in soil and two days in water. The model was validated with a laboratory experiment using solid phase extraction reversed-phase high-performance liquid chromatography to determine carbaryl concentration. 12.82 % percentage error compared to the experimental value indicated that the developed model’s prediction was acceptable. The model can be used to estimate the presence of carbaryl pesticide in soil and water. Findings from this study can be used to assess the fate and the impact of carbaryl pesticide in the environment.