Helen Julian

• Doctor of Philosophy
• Lecturer at Bandung Institute of Technology

With 80% of wastewater globally discharged untreated and non-renewable energy resources rapidly depleting, the call for sustainable solutions has never been louder. Nature-Based Technologies for Wastewater Treatment and Bioenergy Production explores the groundbreaking integration of natural systems and advanced technologies to address critical glob...

Oil palm empty fruit bunch (OPEFB) is one of the wastes that has high hemicellulose composition and potentially processed into xylitol via biotransformation route. This study explores the effectiveness of ultrafiltration (UF) and nanofiltration (NF) in purifying and concentrating xylitol from OPEFB hydrolysate-fermentation broth. Various UF membran...

An HF-sAnMBR-DHS system was examined for enhanced RB5 diazo dye synthetic textile wastewater treatment. Natural aeration was provided during Phase-1 (51 days), while intermittent forced aeration (2 l/min for 5 min ON/OFF cycle) was purged into the DHS in Phase-2 (66 days). The mean tCOD and sCOD removal at P-1 were 88.43 ± 1.84% and 90.82±0.78%, re...

The present study investigated the effect of operational flux on the performance of hollow fiber anaerobic membrane bioreactors (HF-sAnMBR) during treatment of synthetic wastewater containing diazo dye. Two extreme operational flux value, which were 56.92 LMH and 3.21 LMH in reactor 1 (R-1) and reactor 2 (R-2), respectively, were chosen and the sys...

The applicability of microfiltration (MF) and osmotic membrane distillation (OMD) for sterilization and concentration of traditional functional drink constituents, such as Curcuma xanthorrhiza, ginger, lime, Java tea, and sappan wood extracts, was evaluated in this study. MF showed excellent performance in microorganisms elimination, turbidity redu...

Wastewater treatment and reuse using membrane distillation (MD) are applicable to produce freshwater, wastewater volume reduction, and nutrient recovery. MD can be well operated at high concentration feed and possess 100% theoretical rejection rate, thus simultaneously producing high-quality water and retaining valuable components in the wastewater...

This study explored the applicability of chemical cleaning and air-backwash to alleviate biofouling on seawater membrane distillation (SWMD). Membrane performance and wettability properties maintained at optimum duration and frequency of the treatments, as indicated by low permeate conductivity throughout the tests. The cleaning of the membrane usi...

Sugar alcohols, such as sorbitol, xylitol, and arabitol, are natural sweeteners with comparable sweetness to sucrose but have lower calories. Besides, they have unique characteristics such as teeth-friendly and low glycemic index, which are attractive for food industries. The vast availability of lignocelluloses biomass waste offers the potential o...

Membrane distillation (MD) has excellent potential for wastewater treatment, and studies on this subject have increased recently. The unique features of MD to pass only volatile component through the pores has led to the exploration of hybrid MD, particularly membrane distillation bioreactor (MDBR) and osmotic membrane bioreactor-membrane distillat...

Seawater membrane distillation (SWMD) is a promising separation technology due to its ability to operate as a stand-alone desalination unit operation. This paper reviews approaches to improve laboratory-to-pilot-scale MD performance, which comprise operational strategies, module design, and specifically tailored membranes. A detailed comparison of...

The applicability of EDI for organic acid removal in pineapple juice was investigated in this study. Using a bench-scale EDI, the influence of operation parameters, such as current density and feed flow rate, were evaluated against the ion transport flux and current efficiency. It was suggested that more acid removal and higher current efficiency w...

The performance of Submerged Vacuum Membrane Distillation and Crystallization (SVMDC) for cane sugar concentration and crystallization was investigated in this study. Using hollow fiber membrane, the effect of operation parameters, such as feed concentration, feed temperature, and feed agitation were evaluated against the permeate flux. Following t...

Simultaneous fruit juice concentration and preservation of the heat-sensitive sensorial and nutritional components is a challenging topic in food processing. Forward-osmosis (FO) membrane is one of the promising alternatives to concentrate juice at low temperature and pressure. There are a number of negative propensities in FO operation, inter alia...

The applicability of SDCMD technology using polypropylene membrane for apple juice concentration was explored in this study. The effect of feed temperature, draw solution flowrate, and draw solution concentration against the permeate flux and nutrient content were investigated. The results suggested a noticeable trade-off between the permeate flux...

In this work, polysulfone (PSF)-based ultrafiltration (UF) membrane with antibacterial and antifouling properties was prepared by phase inversion technique. ZnO and eugenol were used as additives and introduced into membrane matrix via additive blending method. The additives could improve the performance of PSF membrane due to their hydrophilic nat...

Nano-sized silica/polysulfone (PSf) flat sheet asymmetric MMMs with high CO2 permeance for CO2/N2 separation were fabricated by dry/wet phase inversion method using N, N-dimethylacetamide (DMAc) and tetrahydrofuran (THF) as solvents and ethanol as additives. The results indicated that the addition of nano-silica on the polymer matrix resulted on re...

The applicability of periodic air-backwash to alleviate crystal fouling in submerged VMDC for inland brine water treatment was investigated in this study. Using polypropylene membrane and modelled inland brine solution at very high concentrations, the effect of air-backwash was evaluated against water production for operation parameters, such as ba...

Membrane distillation-crystallization process has great potential to recover high quality water and valuable precipitates from inland brine water. Incorporation of submerging membrane in a feed tank with agitation provides opportunity to reduce temperature and concentration polarization and energy consumption. This study evaluated membrane transver...

This paper reports the effects of pH, gas–liquid flow rate ratio, membrane length, and membrane contactor configuration on the oxidation of iodide by ozone. Comparison between membrane contactor and bubbling technology was also conducted and the application of membrane contactor is confirmed to improve the iodide oxidation process. The best configu...

CO2removal conventional technologies have some disadvantages, for example huge amount of chemical needed and high energi demand for chemical regeneration or to achieve cryogenic condition. To overcome those disadvantages, membrane technology can be used for CO2 removal.The most populer membrane type for CO2separation is asymmetric membrane but it h...

The world market for CO 2 /CH 4 separation using membrane technology is getting bigger and polysulfone (PSf) is one of the most widely investigated polymer membrane materials. However, the existing PSf membranes performances are insufficient to fully exploit these opportunities. Therefore, modification that would produce membrane that fit the needs...

The oxidation of iodide by ozone in membrane contactor was studied in the pH range 1–3. Iodine (I2) concentration was detected in the brownish solution using spectrophotometer. The best configuration for iodide oxidation process is the liquid (acidic iodide solution) flows through the shell side and the gas (ozone) flows through the tube side. In t...