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The feasibility and performance of Jicama peroxidase (JP) immobilized Buckypaper/polyvinyl alcohol (BP/PVA) membrane for methylene blue (MB) dye removal was investigated in a customized multi-stage filtration column under batch recycle mode. The effect of independent variables, such as influent flow rate, ratio of H2O2/MB dye concentration, and contact time on the dye removal efficiency, were investigated using response surface methodology (RSM). To capture the inherent characteristics and better predict the removal efficiency, a data-driven adaptive neuro-fuzzy inference system (ANFIS) is implemented. Results indicated that the optimum dye removal efficiency of 99.7% was achieved at a flow rate of 2 mL/min, 75:1 ratio of H2O2/dye concentration with contact time of 183 min. The model predictions of ANFIS are significantly good compared with RSM, thus resulting in R2 values of 0.9912 and 0.9775, respectively. The enzymatic kinetic parameters, Km and Vmax, were evaluated, which are 1.98 mg/L and 0.0219 mg/L/min, respectively. Results showed that JP-immobilized BP/PVA nanocomposite membrane can be promising and cost-effective biotechnology for the practical application in the treatment of industrial dye effluents.

A technical and feasibility assessment has been conducted for gasification of solid agricultural residue to produce hydrogen in Malaysia. The availability and current technologies for using biomass has been reviewed. Flow sheet for the process has been conceptualized and the material and energy balances for the process along with a plant-wide simulation using the software ASPEN Plus have been undertaken. Powdered Nickle Oxide (NIO-B) has been proposed as catalyst to give approximately 95% purity. Furthermore, the economic analyses worst, base and best financial scenarios have been done and in all cases, the rates of investment (ROI) analysis have been undertaken. From the economic analysis, it has been observed that the total estimated cost for a base scenario, the plant would be USD $52,413,276 for an annual feed rate of 241,938,900 kg. Based on current market of hydrogen and carbon dioxide the payback period for the base case plant would be 1.51 years with the total annual profit of USD $11,045,497.79, which corresponds to a ROI of 12.43%.

Dye effluents released from numerous dye-utilizing industries are harmful towards the environment and living things. Consequently, existence of dye effluent in environmental water bodies is becoming a growing concern to environmentalists and civilians. A long term sustainable and efficient dye effluent treatment method should be established to eliminate this issue. Dye wastewater should be treated first before release to minimize its negative impacts towards the environment and living things. However, due to lack of information on efficient dye removal methods, it is difficult to decide on a single technique that resolves the prevailing dye effluent issue. Therefore, this paper reviews existing research papers on various biological, chemical and physical dye removal methods to find its efficiency through percentage of dye removal. Although there are numerous existing tried and tested methods to accomplish dye removal, most of them have a common disadvantage which is the generation of secondary pollution to the environment. This paper highlights enzyme degradation (biological) and adsorption (physical) dye removal as these are known as one of the most efficient dye removal techniques these days. This paper also suggests the usage of a combined adsorbent as it is envisioned that this technique has better efficiency and is able to remove dyes at a faster rate.

The introduction of aptameric ligands onto disk-monolithic adsorbent, representing a unique strategy for convective isolation of target molecules with high specificity and selectivity, is investigated for the first time. Experimental results showed that the disk monolith possessed a good permeability of 1.67 ± 0.05 × 10–14 m2 (RSD = 3.2%). The aptameric ligand density for the aptamer-modified disk monolith was 480 pmol/uL. Chromatographic analysis of the aptamer disk-monolith efficiency showed an optimum linear velocity of 126 cm/min (≈0.25 mL/min) at room temperatures 25 ± 2°C. The theoretical number of plates corresponding to the optimum linear velocity was 128.2 with an height equivalent to the theoretical plate of 0.022 mm. The disk aptamer-immobilised monolithic system demonstrated good selectivity and isolation of thrombin from non-targets.

The search for effective and sustainable methods to degrade and remove recalcitrant dyes from textile effluents is a major research endeavor, owing to the escalating environmental and health concerns arising from the discharge of coloured effluents into water bodies. Plant-based peroxidases represent a reliable bio-resource for sustainable treatment of coloured effluents with the capacity to offer a continuous process for high throughput operation. The present study investigates the potential use of soybean peroxidase and Luffa acutangula (luffa) peroxidase, extracted from bio-wastes of soybean hulls and luffa skin peels respectively, for enzymatic degradation of azo dye methyl orange from liquid effluents. The enzymatic dye removal process was studied based on the consistent enzymatic activities of crude soybean peroxidase and luffa peroxidase extracts, which were 0.373 U mL −1 and 0.355 U mL −1 respectively. The effects of several process parameters including reaction time, pH, temperature, enzyme dosage, initial dye concentration and hydrogen peroxide concentration were investigated to optimise the performance of the enzymatic treatment process. Soybean peroxidase demonstrated a maximum dye decolourisation efficiency of 81.4% under the conditions of 1 h incubation at 30 °C using 2 mM of hydrogen peroxide, 0.5 mL crude soybean peroxidase and 30 mg L −1 methyl orange at pH 5.0. Also, luffa peroxidase yielded a maximum decolourisation efficiency of 75.3% under the conditions of 40 min at 40 °C using 2 mM hydrogen peroxide, 1.5 mL crude luffa peroxidase and 10 mg L −1 methyl orange at pH 3.0.

Microalgae are an excellent source of bioactive compounds for the production of a wide range of vital consumer products in the biofuel, pharmaceutical, food, cosmetics, and agricultural industries, in addition to huge upstream benefits relating to carbon dioxide biosequestration and wastewater treatment. However, energy-efficient, cost-effective, and scalable microalgal technologies for commercial-scale applications are limited, and this has significantly impacted the full-scale implementation of microalgal biosystems for bioproduct development, phycoremediation, and biorefinery applications. Microalgae culture dewatering continues to be a major challenge to large-scale biomass generation, and this is primarily due to the low cell densities of microalgal cultures and the small hydrodynamic size of microalgal cells. With such biophysical characteristics, energy-intensive solid–liquid separation processes such as centrifugation and filtration are generally used for continuous generation of biomass in large-scale settings, making dewatering a major contributor to the microalgae bioprocess economics. This article analyzes the potential of electroflotation as a cost-effective dewatering process that can be integrated into microalgae bioprocesses for continuous biomass production. Electroflotation hinges on the generation of fine bubbles at the surface of an electrode system to entrain microalgal particulates to the surface. A modification of electroflotation, which combines electrocoagulation to catalyze the coalescence of microalgae cells before gaseous entrainment, is also discussed. A technoeconomic appraisal of the prospects of electroflotation compared with other dewatering technologies is presented.

Enzymes are known to catalyze reactions at high efficiency, operate at milder conditions and are biodegradable. Due to enzyme limitations such as sensitivity to environmental conditions, enzyme immobilization is often used. The commonly employed immobilization methods include adsorption, entrapment, covalent attachment and cross-linking. Many research works have now focused on the immobilization of enzymes on nanoscale support due to the higher surface area to volume ratio, effective enzyme loading, significantly enhanced mass transfer efficiency and minimization of diffusional problems. The application of enzyme incorporated nanotechnology in the treatment of dye wastewater is thus, of high interest. Therefore, this paper has critically reviewed (1) the current technologies available for dye wastewater treatment; (2) different methods utilized for enzyme immobilization; and (3) the application and performance of enzyme incorporated nanotechnology for dye wastewater treatment. We identified that there is high potential for enzyme incorporated nanotechnology to be implemented in dye wastewater treatment due to the high decolorization performance (e.g. laccase immobilized on Fe3O4/SiO2 nanoparticles achieved 99% decolorization of Procion Red MX-5B in 20 min). We have also identified the key challenges faced by enzyme incorporated nanotechnology in dye wastewater treatment that includes: (i) realization of lab scale experiments to industrial applications; (ii) lack of understanding of enzymes incorporated nanotechnology; (iii) recovery of immobilized enzyme; (iv) synthesis of hybrid nanoflowers; and (v) sustainability of the nanomaterials used.

Phenol and its derivatives exist in various types of industrial effluents, and are known to be harmful to aquatic lives even at low concentrations. Conventional treatment technologies for phenol removal are challenged with long retention time, high energy consumption and process cost. Enzymatic treatment has emerged as an alternative technology for phenol removal from wastewater. These enzymes interact with aromatic compounds including phenols in the presence of hydrogen peroxide, forming free radicals which polymerize spontaneously to produce insoluble phenolic polymers. This work aims to extract peroxidase from agricultural wastes materials and establish its application for phenol removal. Peroxidase was extracted from jicama skin peels under varying extraction conditions of pH, sample-to-buffer ratio (w/v %) and temperature. Experimental results showed that extraction process conducted at pH 10, 40% w/v and 25oC demonstrated a peroxidase activity of 0.79 U/mL. Elevated temperatures slightly enhanced the peroxidase activities. Jicama peroxidase extracted at optimum extraction conditions demonstrated a phenol removal efficiency of 87.5% at pH 7. Phenol removal efficiency was ~ 97% in the range of 30 - 40oC, and H2O2 dosage has to be kept below 100 mM for maximum removal under phenol concentration tested.