EVALUATION OF WASTEWATER TREATMENT IN NUSA DUA TOURISM AREA AND THEIR CHALLENGES TO ALGAE BLOOM

<p>The wastewater treatment plant (WWTP) in the Nusa Dua area has implemented a stabilization pond to reduce organic matter and nutrients. Because it has been operating since 1980, it is necessary to evaluate the existing conditions. The aim of this study was to determine the percentage of organic and nutrient reduction from the WWTP system. Organic removal in the form of BOD and COD parameters were 71.84% and 75.11%, respectively. Meanwhile, nutrient parameters in the form of NH3-N, TN, and TP have a percentage of 83.64%; 59.41%, and -375.81%, respectively. TP is the only parameter that has increased, causing a problem which is caused by the explosion of algae population in the reservoir. TP allowance should be a concern in choosing advanced treatment.<em></em></p>

Organic pollutants removal from oilfield produced water using nano magnetite as adsorbent

<p>The current study investigates the ability of Nano magnetite as an adsorbent to remove organic materials from oilfield-produced water (PW). The effect of several variables on the removal procedure was investigated, such as nano magnetite dose, pH of solution and adsorption period. The adsorbent was carefully examined and completed using several approaches FTIR, SEM and surface area analyzer. The results show that the best organic removal reached more than 89 % at 0.8 g Nano magnetite dose in 120 min through pH = 6.0 at room temperature. Three mathematical isotherm models of adsorption were used in this study: Langmuir, Freundlich and Brunauer-Emmett-Teller. It seems that the Langmuir model and Brunauer-Emmett-Teller was best fitted model over the experimental variety with a correlation coefficient of 0.994 and 0.995 respectively.</p>

Application of Coagulation–Membrane Rotation to Improve Ultrafiltration Performance in Drinking Water Treatment

The combination of conventional and advanced water treatment is now widely used in drinking water treatment. However, membrane fouling is still the main obstacle to extend its application. In this study, the impact of the combination of coagulation and ultrafiltration (UF) membrane rotation on both fouling control and organic removal of macro (sodium alginate, SA) and micro organic matters (tannic acid, TA) was studied comprehensively to evaluate its applicability in drinking water treatment. The results indicated that membrane rotation could generate shear stress and vortex, thus effectively reducing membrane fouling of both SA and TA solutions, especially for macro SA organics. With additional coagulation, the membrane fouling could be further reduced through the aggregation of mediate and macro organic substances into flocs and elimination by membrane retention. For example, with the membrane rotation speed of 60 r/min, the permeate flux increased by 90% and the organic removal by 35% in SA solution, with 40 mg/L coagulant dosage, with an additional 70% increase of flux and 5% increment of organic removal to 80% obtained. However, too much shear stress could intensify the potential of fiber breakage at the potting, destroying the flocs and resulting in the reduction of permeate flux and deterioration of effluent quality. Finally, the combination of coagulation and membrane rotation would lead to the shaking of the cake layer, which is beneficial for fouling mitigation and prolongation of membrane filtration lifetime. This study provides useful information on applying the combined process of conventional coagulation and the hydrodynamic shear force for drinking water treatment, which can be further explored in the future.

Use of shredded tire chips and tire crumbs as packing media in trickling filter system for landfill leachate treatment

Scrap tire stockpiles are havens for pests and mosquitoes; thereby this poses a potential health risk. This research work was carried out in six stages to determine the use of scrap tire materials in trickling filter system to treat landfill leachate; 81 to 96% BOD₅, 76 to 90% COD and 15 to 68% NH₃-N from leachate were removed. Organic removal appears to be largely related with total dissolved solids reduction from leachate. Sudden increase in organic content of effluent from time to time could be attributed to biomass sloughing and clogging in trickling filters. However, tire crumbs exhibited more consistent organic removal through out the experiment. Because of high surface area of tire materials, a thick layer of biomass was attached on them and sloughed off at an interval of 21 days. Further research and practical applications are needed to establish usefulness of tire materials in this field.

Use of shredded tire chips and tire crumbs as packing media in trickling filter system for landfill leachate treatment

Scrap tire stockpiles are havens for pests and mosquitoes; thereby this poses a potential health risk. This research work was carried out in six stages to determine the use of scrap tire materials in trickling filter system to treat landfill leachate; 81 to 96% BOD₅, 76 to 90% COD and 15 to 68% NH₃-N from leachate were removed. Organic removal appears to be largely related with total dissolved solids reduction from leachate. Sudden increase in organic content of effluent from time to time could be attributed to biomass sloughing and clogging in trickling filters. However, tire crumbs exhibited more consistent organic removal through out the experiment. Because of high surface area of tire materials, a thick layer of biomass was attached on them and sloughed off at an interval of 21 days. Further research and practical applications are needed to establish usefulness of tire materials in this field.

Combined Effect of Activated Carbon Particles and Non-Adsorptive Spherical Beads as Fluidized Media on Fouling, Organic Removal and Microbial Communities in Anaerobic Membrane Bioreactor

The combined effect of acrylonitrile butadiene styrene (ABS) spherical beads and granular activated carbon (GAC) particles as fluidized media on the performance of anaerobic fluidized bed membrane bioreactor (AFMBR) was investigated. GAC particles and ABS beads were fluidized together in a single AFMBR to investigate membrane fouling and organic removal efficiency as well as energy consumption. The density difference between these two similarly sized media caused the stratified bed layer where ABS beads are fluidized above the GAC along the membrane. Membrane relaxation was effective to reduce the fouling and trans-membrane pressure (TMP) below 0.25 bar could be achieved at 6 h of hydraulic retention time (HRT). More than 90% of soluble chemical oxygen demand (SCOD) was removed after 80 d operation. Biogas consisting of 65% of methane was produced by AFMBR, suggesting that combined use of GAC and ABS beads did not have any adverse effect on methane production during the operational period. Scanning Electron Microscope (SEM) examinations showed the adherence of microbes to both media. However, 16S rRNA results revealed that fewer microbes attached to ABS beads than GAC. There were also compositional differences between the ABS and GAC microbial communities. The abundance of the syntrophs and exoelectrogens population on ABS beads was relatively low compared to that of GAC. Our result implied that syntrophic synergy and possible occurrence of direct interspecies electron transfer (DIET) might be facilitated in AFMBR by GAC, while traditional methanogenic pathways were dominant in ABS beads. The electrical energy required was 0.02 kWh/m3, and it was only about 13% of that produced by AFMBR.