Study on adsorption behavior of alkaline protease on poly(ether sulfone) integrated with fish scale hydroxyapatite as self organized in ion exchange membrane

This study was performed to investigate the physiochemical effect on the protease adsorption produced by Bacillus sp. using highly specific ion exchange membrane (IExM). Effects of pH solution (adjusted with HCl and NaOH), ionic strength (adjusted by NaCl), and initial concentration on adsorption study were performed by using affinity polyethersulfone (PES) membrane integrated with fish scale hydroxyapatite (FSHAp), FSHAp/PES IExM. At 1.0 M, the maximum adsorption capacity was recorded by 0.229 mg/cm2 in 90 minutes incubation time. The optimum pH was found to be at pH 8 with adsorption capacity of 0.211 mg/cm2 in 90 minutes incubation time. The optimum adsorption capacity with 0.204 mg/cm2 was observed when adsorption study performed with initial concentration at 0.9 mg/ml. Experimental data showed the protease adsorbed higher in alkaline condition compared to acidic solution. Further experiment showed that increase in ionic strength leads to noticeable increase in adsorption capacity which is due to aggregation of enzyme molecules in solution. The adsorption study also showed great adsorption behavior when high initial concentration applied as high number of free enzyme molecule to be adsorbed

Fouling evaluation for ultrafiltration of protein-based washwater: a resistance-in-series model approach

A comprehensive understanding of fouling mechanisms throughout the separation system process is crucial in designing a desired bio-separation system. In this research, we have adopted a resistance-in-series model to determine magnitude of four major resistances that govern in fouling mechanisms namely membrane hydraulic (Rm), adsorption (Rad), pore plugging (Rpp) and cake formation (Rc) resistances. The experiments were conducted using a tubular ultrafiltration Polyvinylidene (PVDF) membrane with surimi wash water as model protein-solution. Two main operating parameters of trans-membrane pressure (TMP) and cross-flow velocity (CFV) were chosen to study the effects of operating conditions towards fouling mechanisms evaluated using resistance-in-series model. The resistance magnitudes were in the following sequence: Rpp >Rad > Rc > Rm. The growth kinetics of each phase on resistances and the kinetic constants represent the extent of flux drop were quantified. Permeate obtained from the filtration process produced the clarified washwater with satisfactory quality physically and physico-chemically based water on national water quality standard

Characterization assessment on nanofiltration membrane using steric-hindrance pore (SHP) and teorell-meyer-sievers (TMS) models

Interfacial polymerization (IP) is a simple process for modifying thin-film composite (TFC) polymers that can be used as separation membranes in water treatment. This work describes the IP process for the preparation of polyester TFC membranes using organic monomers, in particular triethanolamine (TEOA) and trimesoyl chloride (TMC). This work includes an evaluation of monomer concentration and polymerization reaction time as variables to determine the membrane properties and its performance as acid humic removal. The characterization of TFC membranes was investigated using field emission scanning electron microscopy (FESEM), steric hindrance pore (SHP) and Teorell-Meyer-Sievers model (TMS). This IP technique resulted in the membrane (NF-PES8-35) having the lowest contact angle (θ=34.0±0.35) and lower hydrophobicity (θ=62.6 ± 0.33) compared to the unmodified membrane. The rejection of NaCl by NF-PES8-35 membrane showed the highest 0.001 M NaCl (62.42%), while NF-PES4-15 membrane showed the lowest (2.4%). The highest removal of humic acid (97.8%) was achieved when separation was performed with the NF-PES6-35 membrane and the high performance polyester TFC membranes were exhibited in the water purification filtration system

Properties and evaluation of functionalized mixed membrane adsorbents for the adsorption of vanillic acid from palm oil waste

Identifying factors that can improve the ability of mixed matrix membrane (MMM) adsorbents to isolate phenolic chemicals from palm oil waste is a major challenge. This study prepared a mixed matrix membrane with improved efficiency using a quaternary doping solution and a hydroxyapatite (HAp) filler and denoted as modified mixed matrix membrane (MMMHAp). Prior to use, HAp powder obtained from eggshells calcined at different temperatures was evaluated as an absorbent for the desired phenolic compounds. All the prepared HAp and MMMHAp powders were evaluated for their properties by Fourier transform infrared spectroscopy (FTIR), scanning electron microscope (SEM) and X-ray diffraction (XRD). For this study, vanillic acid was selected as a phenolic chemical because it is widely used in the pharmaceutical, biomedical and food industries. The optimal adsorption and vanillic acid isolation from crude palm oil samples by MMMHAp occurred using an acetate buffer solution with a pH of 8. The data from the equilibrium adsorption study were also in agreement with the Freundlich isotherm, as the R2 value was 0.9900 suggesting heterogeneous adsorption of vanillic acid on the surface of MMMHAp. The kinetic adsorption study clearly shows a pseudo-second-order fit (R2=0.9992), suggesting that chemisorption occurs between the adsorbed substance and the adsorbent. The modified membrane (MMMHAp) has characteristics of its finger-like structures is more elongated and connected to the porous layer, indicating that the incorporation of hydroxyapatite nanoparticles into the membrane enhances the adsorption of vanillic acid from real sample and has the highest adsorption capacity of 170.8 mg/g. These results show that this improved MMMHAp can be developed and used for waste utilization to obtain useful materials

Environmental Performance of Small-Scale Seawater Reverse Osmosis Plant for Rural Area Water Supply

Seawater desalination is an alternative technology to provide safe drinking water and to solve water issues in an area having low water quality and limited drinking water supply. Currently, reverse osmosis (RO) is commonly used in the desalination technology and experiencing significant growth. The aim of this study was to analyze the environmental impacts of the seawater reverse osmosis (SWRO) plant installed in Kampung Pantai Senok, Kelantan, as this plant was the first installed in Malaysia. The software SimaPro 8.5 together with the ReCiPe 2016 database were used as tools to evaluate the life cycle assessment (LCA) of the SWRO plant. The results showed that the impact of global warming (3.90 kg CO2 eq/year) was the highest, followed by terrestrial ecotoxicity (1.62 kg 1,4-DCB/year) and fossil resource scarcity (1.29 kg oil eq/year). The impact of global warming was caused by the natural gas used to generate the electricity, mainly during the RO process. Reducing the environmental impact can be effectively achieved by decreasing the electricity usage for the seawater desalination process. As a suggestion, electricity generation can be overcome by using a high-flux membrane with other suitable renewable energy for the plant such as solar and wind energy

Improving Prediction Accuracy of Socio-Human Relationships in a Small-Scale Desalination Plant

This study examines who are the social actors in coordinating the environmental hot spots along the process of desalination. The integrated model design of life cycle modeling and Social Network Analysis is evaluated holistically by the inventory of life cycle and actor engagement ratings. Instances of the first small-scale reverse osmosis desalination plant project in Kelantan, Malaysia were used to meet the demands of this study. Environmental performance is measured through the Eco-Indicator 99 method in the Life Cycle Assessment Principles. Meanwhile, the network analysis of the actors’ networks involves stakeholders visualized through the UCINET software. The results show three hotspot points of membrane and brine disposal, the use of electrical energy, and the use of chemicals. The results acknowledged that 87 percent of the actors’ involvement from the dominant stakeholder group has been in control of the management and of the aforementioned hotspot. Undoubtedly, the results of this study can provide a better understanding of the potential market of actors to work with a more accurate and polycentric information flow for the development of more established desalination systems. This intriguing research will require further exploration in future studies

Adsorption of trypsin onto chitosan/Psf affinity membranes: Effects of physio-chemical environment

This study aimed to investigate the significance of the physico-chemical environment during trypsin adsorption onto a highly bio-specific affinity membrane. The affinity matrix polysulfone (PSf) membranes were prepared via a simple dry/wet phase inversion technique. Surface modification of PSf membranes was employed using chitosan in order to improve membrane hydrophilicity. Glutaraldehyde and ovomucoid were used as the membrane activator and affinity ligand, respectively. Inspection of membrane morphology was done using scanning electron microscopy. The functional groups on the membrane surface were determined using Fourier-transform infrared spectroscopy equipped with attenuated total reflection (ATR-FTIR). In order to determine the optimum conditions for the maximum adsorption capacity of trypsin, adsorption studies were performed at different pH levels (5, 7, 8, 10, 12), ionic strengths (0.01, 0.05, 0.1, 0.3 and 0.5 M) and initial trypsin concentrations (0.1, 0.3, 0.5, 0.7 and 0.9 mg/ml). The optimum adsorption was obtained with a 0.9 mg/ml initial trypsin solution at pH 7 and an ionic strength of 0.1

A theoretical approach on membrane characterization: the deduction of fine structural details of asymmetric nanofiltration membranes

In this study, the effects of polymer concentration on the performances and fine structural details of asymmetric nanofiltration (NF) membranes were investigated. Based on the well known models/equations on pore flow, solution diffusion and extended Nernst–Planck, the experimental data (electrolyte/ions rejection) has been modeled. Spielger– Kedem equations were used to determine the membranes parameters such as reflection coefficient, solute permeability and steric hindrance effects. Employing steric hindrance pore model (SHP) model and Teorell–Meyer Sievers (TMS) model, important membranes structural details in terms of effective pore radius, effective charge density and ratio of effective membrane thickness to membrane porosity have been measured. From the modeling results, it was found that the polymer concentration can influence the membrane performances by varying of structural details. Through the observation using scanning electron microscopy (SEM), it was shown that the produced membranes exhibited a finger-like structure. According to the results obtained from the modeling, these membranes are in range of the commercially available NF membranes