The management of brine produced by the reverse osmosis process is challenging due to its high salt and organic content. Limitations in brine disposal options sometimes necessitate the use of zero ...liquid discharge (ZLD) approach. ZLD systems may include a membrane process – which is used to recover water and to further concentrate brine – followed by thermal treatment. In such systems, a high-water recovery rate is difficult to achieve due to the early onset of membrane scaling and fouling. Brine pre-treatment is therefore necessary to protect the membrane and facilitate ZLD. Literature shows that the most common brine pre-treatment process, chemical precipitation, is generally costly because of high chemical consumption and hazardous sludge production. Moreover, its performance may be hindered by the temporal fluctuations in brine chemistry and the occurrence of residual antiscalants in the brine. A critical evaluation of alternative pre-treatment options was performed. It was found that electrocoagulation and nanofiltration processes have promising performance in terms of hardness and organic removals. Meanwhile, coagulation and adsorption processes show potential for organic removal. Further studies should be performed on process optimization and cost analysis to determine the feasibility of applying these technologies in ZLD systems.
•The occurrence of antiscalants in brine could hinder chemical precipitation.•Chemical precipitation has poor silica and organic removal.•Ion exchange and nanofiltration show potential to manage brines with high hardness.•Coagulation and adsorption can achieve high organic removal.•Biological processes are not suitable in ZLD due to narrow scope of treatment.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK, ZRSKP
•Electrodialysis reversal was applied to concentrate industrial RO brine.•The RO brine contained high levels of dissolved solids, hardness and organics.•Water recovery of 85% was achieved and ...concentrated RO brine up to 6.5 times.•Calcium carbonate scaling was observed in the electrodialysis reversal process.•Low molecular weight neutral organics in the RO brine did not cause fouling.
Reverse osmosis (RO) brine typically contains high salinity and dissolved organics. Among the different approaches for RO brine management, electrodialysis reversal (EDR) offers high potential due to its moderate energy consumption, anti-scaling and anti-fouling properties, ability to produce highly concentrated brine and ease of operation. However, despite the potential benefits associated with EDR, its application for industrial RO brine management has yet to be adequately explored. This study aimed to evaluate the feasibility of a lab-scale EDR system for water recovery from industrial RO brine and minimizing the volume of the resulting concentrated brine. The relatively high concentration of organic and inorganic foulants such as hardness, sulfate and alkalinity in the industrial RO brine necessitate the assessment of anti-fouling and anti-scaling properties of the ion exchange membranes. In this study, it was noted that the limiting current to prevent polarization during electrodialysis process, in the lab-scale EDR system, was 0.89 A. Total organic carbon (TOC) removal efficiency was about 7.1% and no organic fouling was observed even after 6 d of continuous operation. This observation was probably attributed to the nature of organic foulants present in the industrial RO brine, the majority of which were low molecular weights (LWMs). However, the resistance of the EDR system increased during 8 h of operation due to high scaling potential of the EDR concentrate stream. Overall, the EDR process was able to achieve 85% water recovery and the volume of industrial RO brine was reduced by approximately 6.5 times.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
•Membrane fouling rate was reduced by 35% with iron addition.•Addition of iron enhanced biomass activity and enlarged flocs size.•SMP and DOMs concentrations in mixed liquor reduced remarkably by ...iron addition.•Relative abundance of biofilm-forming related bacteria decreased in Fe-MBR compared with Co-MBR.
Membrane fouling is considered as a main drawback for MBR technology especially treating industrial wastewater. Therefore, this study aimed to investigate the effect of fouling in membrane bioreactor (MBR) treating pharmaceutical wastewater with the addition of ferric hydroxide. Two identical lab-scale MBRs, namely, a control MBR (Co-MBR) and an enhanced MBR dosed with ferric hydroxide (Fe-MBR), were operated in parallel. The results demonstrate membrane fouling was retarded by 35% with the addition of iron. Further exploration of membrane fouling mechanisms showed iron addition resulted in increase in biomass floc size, enhancement of bacteria activity and reduction of dissolved organic concentration, especially carbohydrate, biopolymer and low molecular weight compounds concentrations in mixed liquor. There was also lower abundance of bacterial associated with biofilm formation in the Fe-MBR compared with the Co-MBR. These findings collectively contributed to the positive impacts on membrane fouling mitigation.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
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•High TN removal (93.2%) under high saline condition was achieved by FAF-SMBR.•Seawater activated sludge dominated by abundant marine bacteria was acclimated.•Carriers reconstructed ...polymeric structure of disintegrated sludge under saline stress.•Nitrifiers and denitrifiers were enriched under high saline stress based on bio-carriers.•Marine bacteria capable of degrading EPS and SMP were identified in bio-carriers.
The application of MBR in high saline wastewater treatment is mainly constrained by poor nitrogen removal and severe membrane fouling caused by high salinity stress. A novel carriers-enhanced MBR system was successfully developed for treating saline mariculture wastewater, which showed efficient TN removal (93.2%) and fouling control. High-throughput sequencing revealed the enhancement mechanism of bio-carriers under high saline condition. Bio-carriers substantially improved the community structure, representatively, nitrifiers abundance (Nitrosomonas, Nitrospira) increased from 2.18% to 9.57%, abundance of denitrifiers (Sulfurimonas, Thermogutta, etc.) also rose from 3.81% to 14.82%. Thereby, the nitrogen removal process was enhanced. Noteworthy, ammonia oxidizer (Nitrosomonas, 8.26%) was the absolute dominant nitrifiers compared with nitrite oxidizer (Nitrospira, 1.13%). This supported the finding of shortcut nitrification–denitrification process in hybrid system. Moreover, a series of biomacromolecule degraders (Lutibacterium, Cycloclasticus, etc.) were detected in bio-carriers, which could account for the mitigation of membrane fouling as result of EPS and SMP degradation.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
The mobility of children going to school plays an important role in their quality of life. Hence, spatial planning and the development of city infrastructure should meet the needs of children. Home, ...school, and the surrounding city influence children’s character and growth. Children’s spatial mobility in the Archipelago of Indonesia is still not fulfilling the framework of a child-friendly environment. This study aims to review the parameters of children’s spatial mobility in Indonesia’s archipelago, suggesting the degree of fulfilment of a child-friendly environment. A review of seven local and national electronic media coverages to elicit the parameters of Indonesia’s children’s environment. The coverages include Liputan6, Radar Sriwijaya, Medan Headlines, Detiknews, Hipwee, CNN Indonesia, and Merdeka.com from 2015 to 2021. Three themes were identified from the coverage, including (1) basic services (education and transport), (2) safety and security, (3) family, kin, peers, and community. It is found that education and transport are the essential services that are not equipped for the children’s mobility, especially those living on the islands. Thus, the lack of transportation infrastructure is a strong influence and appears in the dynamics of the development of the spatial mobility of children in the Indonesian Archipelago.
The issues of community resilience arise from the need to develop an understanding of how people would respond to internal and external disturbances. In-depth discussion towards the impact of a city ...to a neighbouring district has little been discussed. The District of Pontian is located west of Iskandar Malaysia. It has received an unprecedented level of infrastructural development to boost the economy of Iskandar Malaysia. This study examines the land use pattern change of Pontian District impacted by Iskandar Malaysia. Additionally, the study aims to assess the social, economic and environmental capital and the factors that contribute to the adaptabilities and resilience of farmer communities in Pontian. Build-up area for each period using Google earth satellite imagery from the year 2005 to 2015, was classified to analyze the change of build-up area. Markov Chains technique is applied to predict changes of land use. Next, survey questionnaires were utilized to measure the levels of community resilience. Subsequently, an interview was employed to identify the factors that contribute to the stresses. The results indicate that rapid development of Iskandar Malaysia gave an impact to agricultural land and changed the land use pattern of Pontian. The findings revealed the perspective of individuals, community, and system resilience capacity to survive. It was found that farmers were able to adapt to various stresses. The result indicates that individuals and communities can be adaptive, absorptive, and transformative. The findings can assist in formulation of strategies for communities to be better prepared for the current and future impact of the triple threat of urbanization, globalization and climate change.
Aluminum-based water treatment residue (Al-WTR) generated during the drinking water treatment process is a readily available recycled material with high phosphorus (P) adsorption capacity. The P ...adsorption capacity of Al-WTR generated from Singapore’s water treatment plant was evaluated with reference to particle size range, adsorption pH and temperature. Column tests, with WTR amendments in sand with and without compost, were used to simulate the bioretention systems. The adsorption rate decreased with increasing WTR sizes. Highest P adsorption capacity, 15.57 mg PO43−-P/g WTR, was achieved using fine WTR particles (>50% particles at less than 0.30 mm). At pH 4, the contact time required to reduce effluent P concentration to below the detectable range was half compared with pH 7 and 9. The adsorption rate observed at 40 ± 2 °C was 21% higher compared with that at 30 ± 2 °C. Soil mixes amended with 10% WTR and compost were able to maintain consistently high (90%) total phosphorus (TP) removal efficiency at a TP load up to 6.45 g/m3. In contrast, TP removal efficiencies associated with columns without WTR amendment decreased to less than 45% as the TP load increased beyond 4.5 g/m3. The results showed that WTR application is beneficial for enhanced TP removal in bioretention systems.
Thermal-based Zero Liquid Discharge (ZLD) process has been used for managing industrial brine. However, conventional thermal ZLD process is very energy intensive. In view of this, pre-concentration ...techniques have been applied prior to thermal process to reduce energy consumption of ZLD systems. Capacitive Deionization (CDI) is an emerging desalination technique and has yet to be extensively explored for the treatment of industrial brine especially for ZLD applications. High concentration of total dissolved solids (TDS) and high fouling potential of industrial brine are two major challenges in CDI process. This paper reviews the possible factors for optimizing CDI process in industrial brine treatment, namely, cell architectures, strategies in operation and fouling control. Cell architectures of membrane CDI (MCDI) and flow-electrode CDI (CDI) are preferred options for treating industrial brine compared with classic CDI in terms of energy consumption and fouling propensity. There are other operational strategies that could enhance the feasibility of using CDI process for ZLD application. These include reversed voltage desorption, multi-stage operation, brine recirculation and fouling control. Fouling control methods comprise pretreatment, antifouling modification, antiscalant and chemical cleaning. These methods could be integrated to optimize fouling mitigation. In addition to providing insights on feasibility of using CDI to concentrate industrial brines, this review also proposed guidelines for optimizing CDI process applied to treat industrial brines for ZLD applications.
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•Total dissolved solids and foulants in industrial brines are challenging for CDI process.•Possible factors for optimizing CDI process are reviewed for industrial brine treatment.•Guidelines of designing CDI process for brine treatment are suggested.•Future study required on CDI fouling mechanism and mitigation for ZLD applications.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
E-learning is useful to help students gaining digital and data literacy during their studies particularly in the era of Industrial Revolution 4.0 (IR 4.0). E-learning which is characterized by time ...and place flexibility should be utilized as a tool for self-learning. In Universiti Teknologi Malaysia (UTM), e-learning plays an important role as a supplementary tool for effective web-based learning. The purpose of this study is to examine what are the factors that drive students’ satisfaction in e-learning. A total of 194 samples were collected from undergraduate students in UTM using quantitative method. Purposive sampling technique was used to select the respondents. Statistical Package for the Social Sciences (SPSS) was utilized for data analysis. The findings showed that delivery method and con-tent have a positive and significant relationship with satisfaction of using e-learning. However, system operations has no impact on students’ satisfaction in e-learning. In conclusion, the finding of this study is expected to provide an effective teaching model for general education schools.
In recent years, many studies have been conducted on using different filter media in bioretention systems for stormwater runoff treatment. This critical review paper provides a comprehensive review ...on the current state of water treatment residual (WTR), a recycled material that can be used as bioretention filter media for removals of key stormwater runoff pollutants (especially phosphorus) and future perspectives with innovative modification on WTR applied for pathogen removal from stormwater runoff. This review paper comprised (i) a brief summary of the reported WTR characteristics, (ii) a thorough evaluation of WTR performance on major pollutants removal from stormwater runoff (iii) a discussion on phosphorus removal mechanisms by WTR applied in the stormwater runoff treatment, and (iv) a review of the future perspectives of WTR for pathogen removal and other potential practical application in the field of stormwater treatment. As outlined in this review, WTR in stormwater runoff treatment has yet to be fully explored. The possible enhancements, especially metal surface modification on WTR are reviewed to bring about the widespread use of WTR in stormwater reuse practices.
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•Water treatment residual (WTR) could be used as filter media to treat stormwater.•WTR was evaluated for its performance of pollutants removal from stormwater runoff.•Phosphorus removal mechanisms by WTR and similar filter media were reviewed.•Future perspectives on pathogen removal by surface modified WTR were proposed.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
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