Ma An Fahmi Rashid Al-Khatib

Turbidity and suspended solids removal from high-strength wastewater using high surface area adsorbent: Mechanistic pathway and statistical analysis

Abstract In this study, the potential of an improved empty fruit bunch-based powdered activated carbon (PAC) with high surface area was employed in removing suspended solids and turbidity from a high-strength wastewater. Also, the effects of operating parameters, such as PAC dosage, contact time and mixing speed on sorption trends of the two pollutants from the wastewater—biotreated palm oil mill effluent using a full factorial experimental design was investigated. Adsorption efficiency of 89.1 and 91.4% were observed for suspended solids and turbidity, respectively, at the operating condition of 3.5 g PAC dosage, 45 min contact time and 150 rpm mixing speed. The analysis of variance also revealed that the actual and model predicted values were in agreement with R 2 values of 0.9949 and 0.9991 for suspended solids and turbidity, respectively. The three operating factors had similar significance on the sorption of both pollutants with an increasing sequence of significance: contact time < mixing speed < PAC dosage. This is indicative of their similar mechanistic pathway and response trends to the adsorption process. The Freundlich and pseudo-second-order models also predicted the experimental data in describing the adsorption behaviour with R 2 values of 0.9057 and 0.9998.

Studies on pore blocking mechanism and technical feasibility of a hybrid PAC-MF process for reclamation of irrigation water from biotreated POME

ABSTRACT An integrated low-cost adsorption (with powdered activated carbon, PAC) and cross-flow membrane filtration (with microfiltration membranes of 0.1 and 0.2 μm pore sizes) process was employed for the treatment of biotreated palm oil mill effluent (POME) to produce irrigation water that is fully benchmarked with water-quality standards. The permeate quality was within the recommended standard for irrigation water, as the concentrations of all critical constituents were well below their recommended values. Sustainability of the process integration was further confirmed with the domination of cake filtration over other blocking mechanisms with higher R2 values at all trans-membrane pressures. Suitable extended usage of permeate was found for toilet/urinal flushing.

Synthesis and Characterization of Carbon Nanofibers Grown on Powdered Activated Carbon

Carbon nanofibers (CNFs) were synthesized through nickel ion (Ni2+) impregnation of powdered activated carbon (PAC). Chemical Vapor Deposition (CVD) using acetylene gas, in the presence of hydrogen gas, was employed for the synthesis process. Various percentages (1, 3, 5, and 7 wt. %) of Ni2+ catalysts were used in the impregnation of Ni2+ into PAC. Field Emission Scanning Electron Microscope (FESEM), Fourier Transform Infrared (FTIR) Spectroscopy, Energy Dispersive X-Ray Analyzer (EDX), Transmission Electron Microscopy (TEM), Thermal Gravimetric Analysis (TGA), zeta potential, and Brunauer, Emmett, and Teller (BET) were utilized for the characterization of the novel composite, which possessed micro and nanodimensions. FESEM and TEM images revealed that the carbonaceous structure of the nanomaterials was fibrous instead of tubular with average width varying from 100 to 200 nanometers. The PAC surface area increased from 101 m2/g to 837 m2/g after the growth of CNF. TGA combustion temperature range was within 400°C and 570°C, while the average zeta potential of the nanocomposite materials was −24.9 mV, indicating its moderate dispersive nature in water.

Zero liquid discharge and water conservation through water reclamation & reuse of biotreated palm oil mill effluent: A review

World natural resources are now going into extinction as evident from the accelerating depletion of our water resources through the persistent but exorable pollutions confronting our water environment daily. Despite this, some part of the world still witnesses overwhelming wastage of fresh water due to lack of proper motivation towards water management policies from the policy makers as well as professionals. Malaysia as a country was known as a place of huge amount of fresh water coupled with regular rainfalls around the year but now witnessing depletion in its fresh waters due to environmental pollution. One of the main causes of this pollution is the palm oil industry which discharges its Biotreated Palm Oil Mill Effluent (BPOME) into the rivers after little but insufficient treatments. This paper reviews the status, rationale and potential of water reuse in Malaysia. The piece further reflects the potential of advanced technologies to produce regenerated water offering specific solutions to industrial or agricultural reuse needs from BPOME, thus suggesting potential, affordable and cost effective water conservation systems through zero liquid discharge (ZLD) technology and water reclamation from BPOME discharge.

Production of sugar by hydrolysis of empty fruit bunches using palm oil mill effluent (POME) based cellulases: Optimization study

The utilization of lignocellulosic materials such as empty fruit bunches (EFB) from palm oil plant for bioethanol production attract increasing attention as an abundantly available and cheap renewable residue, especially in Malaysia where palm oil production is the major agricultural industry. The most challenging part in conversion of lignocellulosic materials to bioethanol is the hydrolysis process in order to obtain a reducing sugar. In this study, cellulase enzyme used for the hydrolysis was produced from palm oil mill effluent (POME), whose cost of production was considerably low as compared to commercial cellulases. The hydrolysis of EFB for sugar production as an initial step was statistically optimized based on agitation speed, EFB and cellulase concentrations using response surface methodology (RSM) through Box-Behnken design in 2 L bioreactor. The reducing sugar obtained is 16.85 g/L, which appeared at substrate concentration of 5.91%, enzyme concentration of 4.88% and agitation of 233 rpm.

The formation of carbon nanofibers on powdered activated carbon impregnated with nickel.

In the present work, the production and characterization of carbon nanofibers (CNFs) composite is reported. Carbon nanofibers (CNF) were produced on powdered activated carbon PAC—impregnated with nickel—by Chemical Vapor Deposition (CVD) of a hydrocarbon in the presence of hydrogen at ∼780° C. The flow rates of carbon source and hydrogen were fixed. The CNFs were formed directly over the impregnated AC. Variable weight percentage ratios of the catalyst salt (Ni+2) were used for the impregnation (1, 3, 5, 7 and 9%, respectively). The product displays a relatively high surface area, essentially constituted by the external surface, and the absence of the bottled pores encountered with activated carbon. FSEM, TEM and TGA were used for the characterization of the product.

Reuse Potential of Carbon Nanotubes in Removing Cadmium from Water

This study was aimed at determining the optimum condition for desorption of cadmium loaded carbon nanotubes (cCNTs) for re-adsorption of the same metal ion. Two independent parameters (contact time and HCl concentrations) were subjected to statistical optimization by face centered central composite design (FCCCD). Maximum desorption cCNT was achieved under the optimized conditions of pH 1.40 and 130 min contact time. The coefficient of determination (R2) of the developed model was found to be 0.988, indicating the fitness of the experimental and predicted responses. Following the desorption experiments, the efficiency of re-adsorption of Cd2+ by the CNT was 61.08%. The reduced re-adsorption capacity of CNT could be linked to modification of its sorption sites based on acid desorption process.

Factors affecting the immobilization of fungal biomass on CNT as a biosorbent for textile dyes removal

Effluents from dye and textile industries are highly contaminated and toxic to the environment. High concentration of non-biodegradable compounds contributes to increased biochemical oxygen demand (BOD) and chemical oxygen demand (COD) of the wastewater bodies. Dyes found in wastewater from textile industries are carcinogenic, mutagenic or teratogenic. Biological processes involving certain bacteria, fungi and activated carbon have been employed in treating wastewater. These methods are either inefficient or ineffective. These complexities necessitates search for new approaches that will offset all the shortcomings of the present solutions to the challenges faced with textile wastewater management. This study produced a new biosorbent by the immobilization of fungal biomass on carbon nanotubes. The new biosorbent is called “carbon nanotubes immobilized biomass (CNTIB)” which was produced by immobilization technique. A potential fungal strain, Aspergillus niger was selected on the basis of biomass production. It was found out in this studies that fungal biomass were better produced in acidic medium. Aspergillus niger was immobilized on carbon nanotubes. One-factor-at-a time (OFAT) was employed to determine the effect of different factors on the immobilization of fungal biomass on carbon nanotubes and optimum levels at which the three selected parameters (pH, culture time and agitation rate) would perform. Findings from OFAT showed that the optimum conditions for immobilization are a pH of 5, agitation rate of 150rpm and a culture time of 5 days.