Iranica Journal of Energy and Environment (IJEE)

315-324

Authors: K. Ganesh Babu, A. Veeresh Babu , K.Madhu Murthy

The present biggest challenging task in front of the world is to search new energy source. Apart from the all energy sources, biodiesel was the only dominant alternate energy to accomplish the fossil-fuel demand in the transport sector which consist a diesel engine. Biodiesel production from edible, inedible feed stocks causes food versus fuel and greenhouse-gas emissions' problem. It is observed that yields of edible, inedible oils and animal fats are very less compared to third-generation feedstock like Algae: It is one of the fastest growing organisms. It is environmentally friendly because it captures Carbon dioxide (CO 2 ) from the environment to grow. According to the Indian scenario, this is the right time to fix attention on algae biodiesel, to meet the fossil-fuel demand. The higher heating value of biodiesel is slightly lesser than that of diesel, but higher than coal. Biodiesel combusts same like diesel fuel, concerns regulate emissions, and doubtlessly better efficiency than diesel fuel. Algae biodiesel has good physicochemical properties than others. This paper reviews the comparison of yield, fatty acid composition of oil, presently available methods to convert algae into biodiesel and its effect on Direct and Indirect injection diesel engines. Literature reveals that a reduction in exhaust emissions with slight compromise in performances are possible with the usage algae as a biodiesel.

334-339

Authors: A. Dutta and S. M. Ullah

In this research work, the performance parameters , such as fill factor (FF), external quantum efficiency (EQE) , maximum power density and carrier concentration profile of a planar heterojunction poly 3-hexyl thiophene (P3HT) / phenyl-C61-butyric acid methyl ester (PCBM) photovoltaic cell has been simulated for different values of carrier mobility where the simulation has been performed under the consideration of incident solar radiation of 1 kW/m 2 irradiance, air mass of 1.5, ambient temperature of 300K and indium tin oxide (ITO) and aluminium (Al) has been considered as the anode and cathode of the P3HT/PCBM solar cell respectively. The performance parameters has been determined for electron mobility of 5 × 10 -4 , 5 × 10 -3 , 5 × 10 -2 and 5 × 10 -1 (cm 2 /V.s) at the acceptor and hole mobility of 1 × 10-4 , 1 × 10-3 , 1 × 10-2 and 1 × 10-1 (cm2/V.s) at the donor layer. Carrier concentration profile has been studied for 0.4 and 0.5 V junction voltage and for different values of carrier mobility. Finally highest external quantum efficiency of 2.413% and maximum power density of 24.13 W/m2 has been obtained for hole mobility of 1 × 10 -1 (cm2/V.s) and electron mobility of 5 × 10 -1(cm2/V.s).

349-358

Authors: P. Chaithra, K. Hemashree and J. Ishwara Bhat

Activated carbon (AC) was synthesized from raw cocoa pod (RCP) by three activation methods; physical (CPC), chemical (Z CPC, zinc chloride) and microwave activation (MW-CPC). The synthesized AC was characterized using powder X-ray diffraction (XRD), field emission scanning electron microscope (FE-SEM), Fourier transform infrared spectroscopic technique (FT-IR), thermal analysis and differential thermal analysis (TGA-DTA), atomic absorption spectroscopic technique (AAS) and flame photometer instrument. The characterization data reveals that microwave activated carbon having good adsorbent character than physical and chemical activated carbon. Adsorption of malachite green on CPC, Z CPC and MW-CPC were studied at various experimental condition. Freundlich adsorption isotherm model holds good for the adsorption process. The mechanism of adsorption followed the second order kinetics. Thermodynamics of adsorption were studied. The amount of dye adsorbed onto activated carbons varies in the order MW-CPC (29.3632mg/g) > CPC (29.3537mg/g) > Z CPC (27.9905mg/g).

367-374

Authors: M.Anbia, F.Rahimi

The current study adsorption characteristics of platinum(IV) onto the ethylenediamine-modified magnetic cellulose nanoparticles (MCNGE) have been investigated. The prepared adsorbentwere characterized using Fourier transform spectroscopy (FT-IR), X-ray diffraction (XRD), Scanning electron microscopy (SEM) techniques. Optimization the experimental parameters namely Pt(IV) concentration (15-35 mg/l), temperature (34–50 °C), pH of solution (2–5), and particles dose (0.030.06 g) were performed using a means of central composite design (CCD) and response surface methodology (RSM). Analysis of variance (ANOVA) was conducted to evaluation the model, the main of the independent variables and their interactions for adsorption of Pt(IV) from aqueous solution. The results of the quadratic model indicated that the model was highly significant with Fvalue (F model = 55.09) and value of prob> F (<0.0001).The optimum adsorption conditions were determined as initial pH 2.5, temperature 46°C, adsorbent dosage 0.05 g and initial platinum(IV) ion concentration 22mg/l.The maximum capacity of MCNGE for Pt(IV) was found to be 19.45 mg/g. The magnetic cellulose nanoparticle is an environmental friendly product with low energy costs in adsorption of heavy metals from aqueous phase.

382-386

Authors: A. Hedayati, H. Rezaei and F Darabitabar

The aim of study was to investigate the toxicity effect of zinc at low concentration (10% LC50) and high doses (50%LC50) on roach (Rutilus caspicus). Roach with an average weight of 3.3 g and lengths of 4 cm were used in this work. Acclimatized fish were fed daily with a formulated feed.Caspian Roach were exposed to a low concentration of 10% LC50 and high concentration of 50% LC50 ofzinc for a period of control (0), 24, 48 and 96h static toxicity examination, operated within the tank of 400L. In 10% LC50 concentration zinc (96h) immune parameters neutrophil, monocyte and lymphocyte are not shown significant change toward control group (P>0.05) and in 50% LC50 concentration zinc (96h), immune factors lym showed significant decrease toward control but neu factor significantly increase toward control group (P<0.05). Eosino and mono did not showed significant correlation with zinc exposure (P> 0.05). In low and high concentrations of zinc, results showed zinc can cause changes in hematological, biochemical and immunological factors in Caspian roach; therefore, assessment of these indicators, could be useful to detect pollution of aquatic ecosystems.

393-400

Authors: R. J. Jawad, M. H. Shah Ismail and S. I. Siajam

This study was about the investigation of the removal of iron ions from Palm Oil Mill Effluent (POME) by using novel adsorbent which is Alginate–Mangrove Composite Beads Coated by Chitosan (AMCBCC). The adsorbent was characterized by Fourier Transform Infrared Spectroscopy (FTIR) and Scanning Electron Microscope (SEM) with Energy Dispersive X-ray Spectroscopy (EDX) to prove the successful coating by Chitosan and also to provide an evidence of iron ions were adsorbed on the surface of the beads. Batch studies were conducted by using different parameters, such as pH, dosage, contact time, and initial concentration. It was found that at pH value of 3, 300 g/L of AMCBCC concentration, and a contact time of 72 hours the maximum removal of iron ions was 92.7%. The isotherm equilibrium data were followed Freundlich isotherm model and the adsorption kinetic data were well fitted by the pseudo second order.

9

Authors: S. Rai, P. Chand , S. P. Sharma

This paper represented theoretically investigation of energy and exergy performance of an offset finned solar air heater. Parametric study was done to investigate the effect of variation of offset fin parameters i.e. fins spacing (1 to 5cm) and fins height (1.8 to 5.8cm) at different mass flow rates (0.01388 to 0.0833kg/s) on the energy and exergy efficiency. The results indicated that attaching offset finned below the absorber plate at low mass flow rates can lead to noticeable enhancement of exergy efficiency. The results revealed that the trend of variation of the energy and exergy efficiencies are not the same and the exergy efficiency is the chief criterion for performance evaluation. Decreasing the fins height, reducing the fins spacing are effective at low mass flow rates, but at high mass flow rates the inverse trend is observable, such that exergy efficiency reduces sharply. The efficiencies of offset finned solar collector were compared with conventional flat-plate collectors and longitudinal fins collector.

226-232

Authors: H. B. Kulkarni

A Cylindrical parabolic trough (CPT) collector of aperture width 1.03 m and length of 1.82m was designed and fabricated. CPT was covered with glass of thickness of 3 mm to avoid convective heat loss. Reflector coated with polished aluminum sheet having reflectivity 0.87 and receiver tube made of mild steelcoated with black zinc having absorptivity of 0.94 were used for CPT. mass flow rate of working fluid was 4 l/h. Thermal performance of CPT collector was tested according to ASHRAE Standardmethods. Average instantaneous efficiency of closed cylindrical parabolic trough collector system was found to be 66% .The overall efficiency of CPT system is 71% which is best suited for solar thermal applications.

243-246

Authors: J. M Patra, S. S. Panda and N. K. Dhal

Citrus fruits world production is estimated to be over 88 million tons per year, and oranges alone account for about 55% of such amount. Orange peel waste (OPW) is the solid residue of membranes, cores, juice sacs, etc which represents over 50% of the processed fruits. Its disposal is of great concern from the environmental point of view. Due to the large availability and composition rich in the present investigation was focused on the production of ethanol from OPW which will be an economic, environmental friendly and efficient approach. Strains of Aspergillus niger and Saccharamyces cerevisiae was used for hydrolysis and fermentation of pretreated orange waste, respectively. Spectrometry scanning electron microscopy (SEM) and Fourier transformation infrared (FTIR) were used to characterize the sample. Sugar percentage was found to be 3.64 in pretreated sample after 24 hours, which is responsible for the yield of ethanol (6.17 v/v). The results indicated that orange peel can be used as a good low cost alternative feedstock for ethanol production.

255-261

Authors: S. Mohite, S. Kumar and S. Maji

An experimental investigation was carried out to analyze the performance and emission characteristics of a diesel engine fuelled with biodiesel blends (10, 20 and 30%) obtained by mixing karanja and linseed oil and diesel. Brake thermal efficiencies of biodiesel blends were found to be comparable with diesel with a slight reduction. BSEC increased with the proportions of biodiesel in biodiesel blends. B30 was found to cause the lowest HC emissions and the lowest CO emissions and diesel was found to deliver the lowest NOx emissions among the fuels used at all loads. Considerable reduction up to 37.32 % was found in smoke opacity of biodiesel blends. The study revealed that 10% biodiesel blend can be effectively used in an unmodified diesel engine.

268-273

Authors: M. V. kumar, A. V. Babu, P. R. kumar and B. Narendra

In various countries around the world, the emissions of NOX from petrol/gasoline and diesel engine vehicles are restricted by legislation. NOX is produced in the combustion chamber of engines at high temperatures and high pressure. One of the most promising technology for effective control of NOX emissions is Exhaust Gas Recirculation (EGR) and now most modern engines require exhaust gas recirculation to meet emission standards. EGR lowers the presence of oxygen concentration and burn temperature in the combustion chamber and hence controls the NOx. The experimentation was carried out on a 5.2 kW of single cylinder four stroke direct injection diesel engines in computerized mode to investigate the performance, emissions and combustion parameters at different EGR ratios (10, 20 and 30%). From the results, O2, NOX and exhaust temperatures are found to be reduced whereas HC and CO emissions are increased as the EGR concentration increases.

282-293

Authors: A.K. Ojha and Markandeya

The aim of this research work is to isolate bacterial strains with high potential in the degradation and decolorization of lignocellulose compounds of paper mill effluent. Four bacterial strains were isolated from marine sediments and they were screened to their ability to degrade the lignin and decolorize the Century pulp and paper mill effluent. Among four bacterial strains, three bacterial strains Bacillus subtilis, Bacillus endo-phyticus, Bacillus sp. were capable of ligninolytic activity. Consortium made by these bacterial strains enhances the degradation of lignin as well as decolorization. Various nitrogen source, carbon source, pH, temperature and low molecular weight organic acids were used in the optimization process of decolorization and degradation of lignin in paper mill effluent. Maximum decolorization 68.29% was found at pH 7.92, temperature 33°C, in the presence of glucose (as carbon source) 0.99% and yeast extract (as nitrogen source) 0.36% when it was optimized through response surface methodology.

304-307

Authors: V. Garshasbi , M. Jahangiri and M. Anbia

Synthesis of zeolite 13X from modified natural Iranian kaolin at 65˚C for 72 h at various concentration of NaOH solution was investigated. Metakaolinization process was done at 900˚C for 2 h. NaOH solution with different concentrations, 1.0, 1.5, 2.0, 2.5, 3.0, 3.5 and 4 M were separately mixed with metakaolins. A mixture of zeolite 13X, A, quartz and hydroxysodalite (HS) was obtained. The products were characterized by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR) and scanning electron microscopy (SEM). The prepared zeolite 13X has been used to study the adsorption of carbon dioxide, and the results are compared with commercial zeolite 13X.

84-93

Authors: YinMun H’ng and Yusri Yusup

Turbulence intensity measurements of vertical axis wind turbine (VAWT) are essential to detemineitsefficiency and performance. In this study, the eddy covariance (EC) method was used to characterise the flow and directly measure turbulence of a VAWT in a controlled indoor laboratory using an ultrasonic anemometer (at 10 Hz) at specific grid positions of upwind and downwind (in the wake) of the VAWT. In constrast to numerical simulations, this method has the potential to accurately quantify turbulence of wind turbines and thus able to describe the flow patterns around a VAWTexperimentally. Results show that at the upwind position, some of the swept area of the VAWT obstructed the flow due to the counter current flow generated by the VAWT rotors’ rotation while causing some flows to be diverted and concentrated to the concurrent flow area of the VAWT. In the wake of the VAWT, flow velocities and turbulence decreased and dispersed while at the centre line, vertical turbulence decreased towards the bottom (ground) swept area.This downward transfer of turbulence caused generally negative vertical momentum transfer. However, a slight increase of turbulence was observed at the ground surface due to flow deflection.

102-108

Authors: M. A. Ubaidah, S. M. H. Syed Hilmi, M. F. Mohammed Yunus, S. Tahiruddin

Freely emitted biogas at palm oil mills has been regarded as untapped energy source nowadays, despite being recognised as major contributor to the global warming. Up till now, most of palm oil mills are still operating with the conventional anaerobic digestion systems which may not spur biogas industry to life. This study shall explore biogas production between day and night under existing mill operating conditions at KKS Bukit Benut Effluent Treatment Plant (ETP). Biogas produced during day time was 62% as compared to 38% during night time with the total methane emission of 490.3 kg/day. The methane concentration recorded at the digester tank ranged from 58.7 to 68.5%. The correlations between various factors that may influence biogas production were investigated. The finding shows that substrate feeding is the most influencial factor leading to high biogas production during day time.

114-123

Authors: Atieh Ebrahimi and Ghasem D. Najafpour

Microorganisms play an important role in biological treatment processes. Biodegradable organic matter in wastewater would be removed completelyby proper microbial consortia. The mixed culture is either generally present in the wastewater, or is introduced to the target wastewater by mixing it with domestic wastewater or sewage sludge. However, pure cultures bioprocess may be used in certain cases for the removal of specific contaminants. In favorable environmental condition, microorganisms are capable of presenting high efficiency in destruction of pollutants. If environmental conditions such as nutrition, pH, temperature, dissolved oxygen, hydraulic and sludge retention time are suitable and consistent with the nature of process, microorganisms grow and remove organic pollutants through biochemical activities.The aim of this article was to investigate the performance and mechanism of various systems of suspended and attached growth; while the detail of process in different fabricated systems was evaluated. The advantages and disadvantages of NRBC, UASFF, UAPB and normal activated sludge process were discussed. Growth kinetics and COD removal of effluents were also investigated. The result indicated the combination of fluidized and fixed film has created active biogranules which were quite faster and more efficient in treatment of industrial wastewater.

129-136

Authors: R. Alrozi, N. S. Anuar, F. Senusi, M. A. Kamaruddin

In this study, the adsorption behavior of Remazol Brilliant Blue R (RBBR) from aqueous solution by using raw and modified clinoptilolites were investigated. In the experimental work, raw clinoptilolite (R-CL) was treated with Zn(NO3)2 in ethanol and produced zinc-grafted clinoptilolite (Zn-CL).The adsorption experiments were carried out under different conditions of initial concentration (25 -250 mg/L), adsorption time (0-2h), solution pH (2-12), and temperature (300-353 K) to determine optimum conditions for the highest RBBR removal. The influence of these parameters on the adsorption capacity was studied using the batch process. The results indicated that the solution pH was observed to be a key factor of the RBBR adsorption process. The maximum dye adsorption was achieved with Zn-CL adsorbent at pH~6 and the corresponding adsorption capacity was found to be 42.2 mg/g, which was higher than R-CL (12.5 mg/g). Lower adsorption capacity of RBBR was found by Zn-CL between pH 8 and 12 opposite to R-CL which showed a marginal increase in adsorption capacity within the same pH range. The results proved that Zn-CL which is a modified clinoptilolite is an effective adsorbent for the removal of RBBR from aqueous solution.

144-148

Authors: A. Harlina, M. Maheera and I. Norli

This batch study focuses on suitability of laterite soil-pressmud as daily soil cover of landfill. The laterite soil samples were mixed with waste from sugar refinery process, namely pressmud at different percentages of weight ratio (10, 30 and 50%). The batch equilibrium tests were carried out and glaringly showed that the laterite soil-pressmud mixtures have the capability to remove more than 62% of Cr, Cu, Mn, Ni, Pb and Zn concentration in leachate. Meanwhile, the removal efficiency of heavy metals from leachate in the laterite soil alone was lower than 50%. Pressmud alone however showed more than 53% removal. The laterite soil-pressmud mixtures, particularly at 30 and 50 percent of pressmud signify great potential as daily soil cover in reduction of heavy metals migration in landfill leachate.

156-162

Authors: Vivienne Sim Jie Wei*, Chua Han Bing, Agus Saptoroand and Jobrun Nandong

Composting is a biochemical process in a controlled aerobic environment where thermophilic microorganisms stabilize organic waste substrates into valuable humus-like products. Three parameters which are known to affect the composting process including temperature, aeration rate and composting time. This research aims at developing a model to describe the relative influence of different temperatures, aeration rates and reaction time on the composting process and how it affects the final quality of EFB compost produced. EFB samples were mixed with urea as a source of nitrogen and fresh compost as inoculum. The composting process was carried out in a composting test bench for a total of 42 days. The moisture content was found to be significantly affected by temperature and reaction time. Carbon loss was significantly affected by all three factors. Nitrogen content was affected by aeration rate, reaction time as well as interaction between temperature and reaction time. Changes in total ions over time showed a positive correlation with the value of conductivity (Pearson correlation coefficient of 0.853) and the largest reduction in C/N ratio (from 30.2:1 to 17.6:1) was obtained at temperature of 40°C and aeration rate of 0.4 L/min kg. The results of this study could form a basis for palm oil mills to improve the quality of EFB composts produced within a short maturation period and with low C/N ratio.

169-176

Authors: T.Y. Ling, L. Nyanti, M. K. Nurul-Safinaz, S. F. Sim, J. Grinang

New development and expansion of cage culture at Batang Ai Reservoir would require investigation of the water quality. Therefore, the objective of this study was to determine the water quality at three existing aquaculture sites, one abandoned site, and one station without cage culture at three different depths. This study was carried out in October 2013 during the rainy season. Water quality was measured in-situ and water samples were collected and analyzed according to standard methods. Results showed that dissolved oxygen concentrations at the surface is sufficient for healthy aquatic organisms. However, dissolved oxygen at 10 m is not suitable for healthy aquatic organisms. All aquaculture sites showed significantly higher conductivity and ammonia-nitrogen at 20 m depth than the station without aquaculture. The aquaculture site that has been abandoned for nine months still showed higher 20 m chlorophyll-a and surface phosphate. Elevated surface, biochemical oxygen demand, phosphate and nitrate were observed at the largest and oldest aquaculture site. Based on the Chl-a concentration, the stations are classified as mesotrophic. This study showed that cage culture activities at Batang Ai Reservoir has impacted the water quality. Hence, further monitoring of water quality in the reservoir needs to be carried out.

184-192

Authors: Sufia Hena, Nur Fatihah, Huda Awang

In this study a simple and rapid harvesting method using electro conductive polymer coated saw dust has been presented as a new coagulant for separating Chlorella vulgaris from a diluted suspension. Polypyrrole (PPy) coated saw dust as a novel coagulant was prepared via in-situ polymerization of pyrrole (Py) monomer using FeCl3 oxidant in aqueous medium in which saw dust particles were suspended. The zeta potential of coagulant and C. vulgaris and X-ray photoelectron spectroscopic (XPS) analysis of coagulant were characterized. PPy maintain predominantly positive charge over a wide pH range (2-10) with an isoelectric point 10.4 while, C. vulgaris maintained negative surface charge from pH 5 and onward with isoelectric point 3.8. The microalgae showed the highest separation efficiency at pH 10. The maximal recovery efficiency reached more than 90% for microalgae at a stirring speed of 120 rpm within 7 min. The maximal adsorption capacity of C. vulgaris was 28.8 mg dry biomass/mg-saw dust coated PPy. The concentration factor obtained is higher than 32 which save energy and time associated with microalgal harvesting and allows a reduction in the equipment size necessary for biomass dewatering and improves the feasibility of using these microorganisms in biofuel or wastewater processes.

203-211

Authors: A.A. Nurhanim, I. Norli, N. Morad, H.P.S.A. Khalil

Recycling of Construction and Demolition Waste (CDW) aims to minimize the generation of waste and reduce the dependency on natural resources. The aims of the research are to characterize inorganic element and to determine the leaching behavior of CDW (concrete and gypsum) by means of the leaching test. The analyzed results were compared with the European Union (EU) Landfill Directive to assess their acceptance criteria. Both wastes were found to have elements of Ca, Mg, Fe, Zn, Mn, Pb, Cu, Cd, As, Cr, Se, Ni, CI and SO42-. The highest concentration and variety of inorganic element found in waste gypsum (WG) were SO42->Ca>CI>Mg>Zn>Cu>Fe. X-ray diffractometric (XRD) analysis proved that the WCo was dominated by quartz, calcite, ettringite, cordierite, diopside and the WG was only dominated by gypsum. The leaching behavior of WG demonstrated pH dependent particularly for the elements of Ca, Mg, Fe, Zn, Cu and Mn but only the elements of Ca and Cr in WCo were shown to be pH dependent in the leaching test. The element of SO42- from the WG indicated a higher reading than WCo without the influence of pH. Noticeably, the concentration of SO42- within the WG strongly require regulation and control before it can be utilized as part of raw materials in the production of environmental friendly recycled building materials.

1-6

Authors: K.H. Bhujangrao

Today’s India is in need of generating power at higher rate to maintain adequate supply of electricity to users for development and growth of Nation. Non renewable energy sources like coal and petroleum products are the major sources utilized for power production. To reduce the gap between demand and supply of energy and maintain sustainable development, renewable energy sources need to be considered as an alternative source of energy. The solar energy has been identified as one of the promising energy source which can be used directly or indirectly for generation of electricity, hot water and power. A prototype of cylindrical parabolic collector (CPC) is designed and developed to utilize solar energy for hot water generation. Prototype of CPC is tested from 10AM to 4PM in the month of May and thermal performance is evaluated based on solar standards available through literature. Hot water at 600C is produced throughout a day by varying mass flow rate of water. The instantaneous efficiency is calculated after every half an hour and found to be 69% and overall efficiency of system is 71%. This prototype CPC system can deliver hot water at required temperature to meet industrial, domestic demands and saves electricity.

12-17

Authors: Sanjay Mohite, Sudhir Kumar, Sagar Maji, Amit Pal

Karanja and linseed are the potential non-edible oil crops which can be used for the biodiesel production. The main objective of this study is to find out the feasibility of using a mixture of karanja oil and linseed oil to produce biodiesel. Karanja oil has high amount of free fatty acid in it and linseed oil has low amount of free fatty acid content. Karanja biodiesel is produced by two step esterification/transesterification process which is costly, health hazardous & corrosive due to use of concentrated acids. Linseed biodiesel can be produced by alkali-base transesterfication which is much faster and gives higher yield than acid-base transesterification. A production method is developed to produce biodiesel from the mixture of karanja and linseed oil which is faster, safer and non-corrosive. The yields in the range of 68.2 to 78.9% have been achieved with varying different parameters like molar ratio, stirring time, mixture ratio and amount of catalyst. Optimum parameters are also established to achieve maximum biodiesel yield from the transesterification of a mixture of linseed and karanja oils.

31-38

Authors: Claire Xin-Hui Su, Tjoon Tow Teng, Norhashimah Morad and Mohd Rafatullah

A novel inorganic-organic hybrid polymer of magnesium chloride-polyethylene oxide (MgCl2-PEO) was prepared, characterised and applied in the coagulation-flocculation of a reactive dye, Cibacron Blue F3GA (RCB). The hybrid polymers were prepared in various ratios and their conductivity and viscosities were measured. For the application in the coagulation-flocculation of RCB, the hybrid polymer of 90% MgCl2:10% PEO ratio was selected as it showed the highest conductivity and lowest viscosity. The factors that affect coagulation-flocculation of RCB, namely initial dye concentration, initial pH, agitation speed, agitation time and hybrid polymer dosage, were studied using fractional factorial design and response surface methodology (RSM). The process was also optimised, with respect to colour removal and chemical oxygen demand (COD) reduction efficiency. The five factors studied showed significant effects toward the colour removal and COD reduction of RCB. The process was optimum at initial dye concentration of 173 mg/L, pH 11.13, agitation speed of 150 rpm, agitation time of 6 minutes and hybrid polymer dosage of 1020 mg/L. Under these optimum conditions, maximum colour removal of 99.76% and COD reduction of 92.09%, were achieved.

48-51

Authors: Imoisili Patrick Ehi, Jiddah-Kazeem, Bidemi, Yahaya L. E.

The kinetic and characteristics of water absorption of cocoa-pod husk filler reinforced epoxy composite by short-term immersion at room temperature was studied. Composite specimen containing 5, 10, 20 and 30% filler volume fraction were prepared. The percentage of moisture uptake increased as the fibre volume fraction increased due to the high cellulose content of cocoa-pod husk. Results indicate that a D value of 105.8 x 10-7 m2/s at 30% volume fraction was obtained.The process of absorption of water was therefore found to follow the kinetics and mechanism described by Fick's law.

58-63

Authors: L.E Yahaya, A.K Akinlabi

The adsorption of lead (II) ions onto EDTA- modified cocoa pod husk (CPH) in an equilibrium system was investigated. Kinetics, mechanism and thermodynamic parameters were estimated. Adsorption capacity was rapid and time dependent as appreciable level of Pb (II) uptake was achieved at an optimum contact time of 50 minutes. Three kinetic models were used to fit the kinetic data; Pseudo-first order, Pseudo-second order and intraparticle diffusion. Adsorption of the metal ions follows the Pseudo-second order and intraparticle kinetics as these provide a better fit to the experimental data with high R2 values ranging from 0.9776 – 1. Thermodynamic parameters such as change in Gibbs free energy ( ∆Go ) change in enthalpy (∆Ho), and entropy change (∆So ) were calculated. The ∆Go (-5.499kJmol-1), ∆Ho (60.36 kJmol-1) and ∆So (212.44 Jmol-1K-1) of the adsorption process of metal ions onto the modified adsorbent was found to be feasible, endothermic, spontaneous and physiosorption in nature. These results indicate that modified CPH is a promising sorbent for the removal of Pb (II) in industrial effluent and wastewaters containing same.

72-83

Authors: Islam M. Rafizul, Muhammed Alamgir

This study illustrates the leachate treatment efficiency based on leachate pollution index (LPI) of pre-treatment leachate as well as post-treatment leachate with chemical coagulants. Leachate samples were collected at regular intervals of time from the leachate collection chamber of the landfill lysimeter at KUET campus, Bangladesh to compute its pollution potential. The landfill lysimeter consists of one open dump lysimeter-A with leachate detection (A1) and collection system (A2) as well as two sanitary landfill lysimeters B and C having two different types of cap liner. The relevant parameters of leachate sample were measured in the laboratory to evaluate sub-pollution (sub-LPIs) in terms of LPI in organic pollutant (LPIor), inorganic pollutant (LPIin) and heavy metal (LPIhm) as well as the overall LPI. Moreover, the values of LPI in pre-treatment leachate were to be found 19.53, 25.33, 23.48 and 23.74 for the A1 and A2 systems of open lysimeter-A, as well as the collection systems of sanitary lysimeters-B and C, respectively. It reveals significantly the higher values than that of LPI of 5.77, 7.38 and 7.38 for the maximum leachate discharge standards of Bangladesh, India and Hong Kong, respectively. The leachate was then treated with ferric chloride (FeCl3), poly alluminum chloride (PAC), ferrus sulphate (FeSO4) and aluminum sulphate (Al2(SO4)3) in various dosages and pH values. The concentrations in post-treatment leachate by using FeCl3 at optimum dosage were to be found below the limit of maximum leachate discharge standards. Study also reveals the values of LPI of 5.32, 5.69, 5.32 and 5.24 in post-treatment leachate for the A1 and A2 systems of open lysimeter-A, as well as the collection systems of sanitary lysimeters-B and C, respectively below the values of LPI in leachate of maximum discharge standards. Finally, it can be concluded that differences in the level of contaminants of pre-treatment and post-treatment leachate indicated the role of leachate treatment system in minimizing the level of contaminants and lowering the risk of leachate contamination based on LPI.