Ghufran Redzwan

Pleurotus ostreatus spent mushroom compost as green biosorbent for nickel (II) biosorption

The potential of Pleurotus ostreatus spent mushroom compost (PSMC) as a green biosorbent for nickel (II) biosorption was investigated in this study. A novel approach of using the half-saturation concentration of biosorbent to rapidly determine the uptake, kinetics and mechanism of biosorption was employed together with cost per unit uptake analysis to determine the potential of this biosorbent. Fifty per cent nickel (II) biosorption was obtained at a half-saturation constant of 0.7 g biosorbent concentration, initial pH in the range of 4-8, 10 min contact time, 50 mL 50 mg/L nickel (II) initial concentration. The experimental data were well fitted with the Langmuir isotherm model and the maximum nickel (II) biosorption was 3.04 mg/g. The results corresponded well to a second pseudo order kinetic model with the coefficient of determination value of 0.9999. Based on FTIR analysis, the general alkyl, hydroxyl or amino, aliphatic alcohol and carbonyl functional groups of biosorbent were involved in the biosorption process. Therefore, biosorption of nickel (II) must involve several mechanisms simultaneously such as physical adsorption, chemisorption and ion exchange. Cost comparison for PSMC with Amberlite IRC-86 ion exchange resin indicates that the biosorbent has the potential to be developed into a cost effective and environmentally friendly treatment system.

Optimisation of the process variables in production of activated carbon by microwave heating

This study aims to investigate the optimal operating conditions in order to obtain cost effective production of activated carbon (AC) from palm kernel shell (PKS) by microwave heating. Interactions among the independent variables, namely irradiation time (T), microwave power (W), impregnation ratio between impregnating substances and PKS, and the concentration of impregnating substance (sulphuric acid) were considered for optimising the process parameters during the production of AC, aided by Central Composite Design. The optimum conditions for the independent process variables were 11.02 minutes of irradiation time, microwave power of 676 W and impregnation ratio of 0.68. The AC produced in this work had a surface area of 1011 m2 g−1 with high porosity as shown by scanning electron microscopy (SEM). Zinc was used to verify the potential of AC as an adsorbent. Zinc removal at the optimum conditions was found to be 13.72 mg g−1. Such a Zn removal value is comparable with the earlier work of other researchers who used a conventional way of producing the AC. It is believed that microwave technology can be used for the production of AC in a short time with high energy efficiency, e.g., 11 minutes against 2–5 hours of reactivation for conventional methods.

Supplementation of ammonium bicarbonates for the treatment of fruit cordial wastewater by anaerobic digestion process

Lack of nitrogenous substrate and buffering capacity have been identified as causing failure in previous work on the treatment of fruit cordial wastewater using anaerobic continuous stirred tank reactors. In this study, ammonium bicarbonate was proposed to be used as the substrate for nitrogenous and buffering resources. In order to determine the toxicity effect of the ammonium salts on the anaerobic system, a series of concentration from 0 to 40 mg L(-1) was tested. Biogas production was used as the indicator for NH4+ toxicity. The results showed no indication that methanogen was affected by the additional ammonium salt within the dosing regime. Application of the specific mathematical function (G=G(m)(k)(/t)) to describe the kinetic of biogas production, suggested that the optimal concentration of ammonium bicarbonate that can be used is 10 mg L(-1). This study also shows that the dosage regime up to 40 mg L(-1) can be used to supplement the lack of nitrogenous and buffering capacity for the anaerobic digestion process of the fruit cordial wastewater using CSTR.

Copper (II) biosorption characteristic of Pleurotus spent mushroom compost

Pleurotus spent mushroom compost is usually discarded as agricultural waste. This study investigated the biosorption characteristic of copper by Pleurotus spent mushroom compost. Parameters including biosorbent concentration, initial pH, contact time, initial copper (II) concentration and temperatures were examined in batch mode. Half saturation constant of copper (II) biosorption was obtained at 1.4 %(w/v) biosorbent concentration, unadjusted pH of 5.5, 10 minutes contact time and at 50 mg/L copper (II) solution. Copper (II) biosorption process well fitted to Langmuir isotherm and pseudo second order kinetic model. Generally, biosorption was not a spontaneous exothermic reaction. Rapid biosorption process and highly potential in reusability of Pleurotus spent mushroom compost are very useful for pilot or industrial wastewater purification application, which to be favorable for the continuous and reusable operation in a column.

The application of digital elevation model for the interpretation of Klang Valley geological structure

Purpose – The purpose of this paper is to utilise the interactive view capability of the geographical information system (GIS) for the geological interpretation in Klang Valley, Malaysia.Design/methodology/approach – Topographical map scale of 1:10 000 was used to generate digital elevation model (DEM). The geological map was draped over the DEM to create a 3D perspective view. The geological interpretation was undertaken using the 3D capability of the GIS software.Findings – From the study, five lineaments which could possibly be the newly identified faults and one lithological boundary have been delineated.Research limitations/implications – Although these findings need to be rechecked in the field, they show the capability of the DEM application in structural geology interpretation.Practical implications – The results obtained from this study demonstrate the capability of utilising a geological map draped over DEM for structural geological interpretation. Thus the technique may increase the interpretat...

Sensitivity study of Bubble diameter for prediction of flow pattern in homogeneous bubble column regime

Determining the bubble diameter size in a bubble column rector plays an important role to accurately predict flow pattern in a bubble column reactor. This paper employs the Eulerian-Eulerian method to numerically investigate the sensitivity study of bubble diameter size in a cylindrical bubble column reactor. Existing experimental results in the literature are used to validate the implementation of the proposed numerical method. In our simulation various bubble diameter size (i.e., 35.5mm) are used to find an appropriate bubble size inside the bubble column when the regime is homogeneous (superficial gas velocity = 0.005m/s). The result shows that bubble diameter 4mm is a reasonable size for flow pattern prediction inside the column.