Iranica Journal of Energy & Environment
Volume:3 Issue: 5, Autumn 2012

Nowadays, traditional sources of energy are near exhaustion and alternative sources of energy are considered. One of the newest resources of energy is microbial fuel cell (MFC). MFC is a bioreactor that converts chemical energy in bonds of organic substrate to bioelectricity. The active biocatalysts such as microorganisms or enzymes, in the anode compartment, utilize substrate for growth maintenance; as a result electrons are supplied. Electrons and protons are produced by oxidation of substrate where electrons move from external resistance to the cathode surface while protons move across membrane to the cathode surface as well. Electrons and protons, with solution oxygen, combine to form water. In this study, this process is achieved by a new membrane-less MFC (MLMFC) which is low in cost when compared to other dual chamber MFCs. Maximum power produced by MLMFC was 40.43 mW/m2 while COD removal was 66%. Open circuit voltage of 790 mV has been achieved after 96 h of operation. This study presents a new configuration of MLMFC as an electron generator. The key factor of this configuration is: low cost of design and lack of membrane bio fouling that is common in H-type configuration.

Desired pulp-based product properties can be achieved by addition of filler in the pulp network. In exploring this, fines co-generated upon refining the alkaline peroxide treated oil palm empty fruit bunches (EFB) were collected based on their passage and retention capacities when subjected to varying mesh-sizes stainless-steel square mesh wires. Pulp network incorporating fines produced from the synergy of low alkaline peroxide (AP) and low energy refining effects shows that blending 12% of the 400-mesh fines (P300/R400) with the normal 200-mesh pulp fraction enhanced paper tensile strength by 100% due to their favourable dimensions. This defines the usefulness of fibrillar particles whose cell wall collapsibility increases the web density by increasing bonding ability and thus, strength of pulp-based products. Fines produced from more extreme synergy between alkaline peroxide and degree of refining, exhibit unique submicron fibrils and ‘nano-CGF’ also responsible for further augmentation of EFB alkaline peroxide pulp network. Whether from the simple (low-AP and low energy refining) or the extreme synergy of AP and refining, the co-generated fines are apparently suitable materials for use as natural filler for augmentation of pulp network. Particularly for the simple AP and refining synergy, the introduced recovery and utilization of the cogenerated filler (CGF) was found to reduce 74% turbidity and this improvement will help reduce the complexity of whitewater generation in the pulping system.

Biodegradation of ethyl acetate in batch and continuous cultures was investigated. Pseudomonas putida was selected as a biological agent to biodegrade ethyl acetate. In batch experiment, biodegradation of ethyl acetate was performed in the range of 25-35°C. Walnut shells treated with alkaline solution as natural packing materials provided an appropriate environment for the growth and immobilization of microorganisms. The active biofilm was fully established on the surface of natural packing material. In the early stage, experiments were performed at Empty Bed Resistance Time (EBRT) of 60 s. Maximum removal efficiency of 99% was achieved at inlet concentrations lower than 430 ppm of ethyl acetate. The removal efficiency dropped to 80% with an increase of inlet concentration of ethyl acetate. In order to enhance the removal efficiency, the EBRT was increased from 60 to 75 s. At EBRT of 75 s, the removal efficiency was maintained above 80% even though the inlet concentration increased to 5150 ppm. Michaelis-Menten and Logistic models were perfectly fitted to experimental data. In addition, the kinetic parameters of presented models were defined.

The traditional Malay house is one of the richest components of Malay’s cultural heritage in Malaysia. Generally, the traditional Malay house is a reflection of the Malay community’s way of living. With greater global awareness of the environment and a renewed perspective on contemporary Malaysian architecture, architects and designers are once again looking for tropical solutions in building design. One of the main characteristics of traditional Malay house is that they are designed with a deep understanding and respect for nature, but this designwith- nature approach is no longer found in the modern buildings. The purpose is therefore to study the thermal comfort design elements such as building orientation, interior layout space, natural ventilation and lighting, window designs, and stack effect on the roof design. The investigation was carried out through observations, interviews and some research visits. A comprehensive research was accomplished on the adaptation of Malay house architecture elements with selected the Selangor traditional Malay house as the key study and one modern building which is the Ministry of Energy, Green Technology & Water (MEGTW) building, Putrajaya. This study attempts to have recorded information for those who are interested and for the future generation because the traditional Malayhouse was evolved by the Malays over generations, adapting to their needs, culture and environment. This study is crucial to revive the awareness in the understanding and appreciation of the technique of thermal comfort design elements of traditional Malay house adapted into modern building design.

Conservation of the built environment through reusing historic buildings maximizes the use of existing materials. The research question is how to retain the integrity of historic mosques through using sustainable material? The main purpose of this study is to investigate the impact of materials on conservation of historic mosques in old Mosul city with sustaining the integrity of the mosques. The study applies qualitative method of analysis. The method of collecting data is by making direct observation. The techniques for collecting data are by writing descriptions and making an inventory of the variety and arrangement of the materials used in the historic mosques. The research uses open coding to analyse the data by identification of emerging themes from the raw data. The goal is to create descriptive and multi-dimensional categories and build a conceptual model from the categories, which are grouped. This study highlights the themes of materials used in historic mosques in Mosul old city and show that the integrity of mosques affected by the materials, which were used in these mosques. The research showed that the elements that the damages occurred in as a result of the use of inadequate materials which used in such elements. The research recommends that experience is vital in conversation of the historical buildings and require to performed identification, evaluation, registration and treatment activities. In some cases, additional areas or levels of expertise may be needed, depending on the complexity of the task and the nature of the historic building involved.

Leachate from municipal landfills of the city is often contaminated heavily, especially for parameters such as organic components, heavy metals, microorganisms. However, leachate also contains amounts of valuable nutrients (e.g. N, P, K) which can be used for agriculture as fertilizers. Precipitated of N and P in the form of struvite (MgNH4PO4.6H2O) might be applied as a technique for removal a huge amount of N as well as P in wastewater. This study investigated the recovery ability of N, P in leachate from Nam Son municipal landfill of Hanoi city. Different pH values, anaerobic time and stoichiometric Mg2+: NH4 +: PO4 3- was tested to determine the optimal conditions for precipitating struvite. The effect of pH on the forming of struvite was between pH 9 to 11. The results showed that nutrients in landfill leachate could be recovered with the optimum pH around 9.5 and the optimum Mg2+: NH4 +: PO4 3- molar ratio as 1.15: 1: 1. With the anaerobic interval of 21 days, COD value in landfill leachate was decreased to 60%, the retrieval reached 80.6% for nitrogen and 82.7% for phosphorus. According to estimates, with the application of struvite precipitation technique, the average annual retrieval amount of NH4 + and PO4 3- can reach 263 tons and 25 tons, respectively.

In this study, a series of inorganic-organic composite polymer was prepared. Magnesium hydroxide and polyacrylamide was composed in a composite matrix to prepare Mg(OH)2-PAM (MHPAM) inorganic organic composite polymer. The characteristics of MHPAM inorganic-organic composite polymer was investigated in terms of chemical, physical, physical, thermal and morphological properties through FT-IR, conductivity, intrinsic viscosity, TGA and TEM, respectively. Results showed that the properties of MHPAM composite polymers varied with the compositions in the composite polymers. Different compositions of MHPAM inorganic-organic composite polymers were applied in removing reactive dye from aqueous solution. MHPAM inorganic-organic composite polymer with Mg(OH)2: PAM ratio of 90: 10 gave the best dye removal (%) where it was able to remove 98% of reactive dye at pH 11.00 with a dosage of 500 mg/L. Kinetics study was carried out using different dye concentration and it was found that the experimental data fitted the pseudo-second-order model better compared to pseudo first-order model.

In the supercritical CO2 method of extraction of palm oil, many processes in conventional method, such as degumming, deodorization, refining and bleaching processes, are eliminated. The supercritical method allows palm oil to be extracted and fractionated simultaneously, which not only reduces the cost of processing, but also provides a more environmental-friendly processing alternative. In this research, the high-pressure phase behaviour of the binary system between supercritical carbon dioxide (SC–CO2) and palm oil fatty acid components were investigated. Thephase transition is observed from a camera which is connected to a high-pressure variable-volume view cell. Carbon dioxide has high solvating power, nontoxic, inflammable and low critical points. The determination of phasebehaviour could offer an insight to the right operating condition of palm oil supercritical fluid carbon dioxide extraction process in order to acquire the desired extraction selectivity and an optimum yield. The phase boundaries of some fatty acids components, lauric acid (C12), stearic acid (C18), and oleic acid (C18) in compressed supercritical carbon dioxide were determined at temperatures of 313.15 K, 323.15 K, 333.15 K, 343.15 K and 353.15 K under pressures between 10 MPa and 60 MPa.

This study demonstrates the influence of lysimeter operational condition and tropical seasonal variation of leachate characteristics generated from municipal solid waste (MSW) deposited in landfill lysimeter at KUET campus, Bangladesh. Three different situations of landfill were considered here as well as both the open dump lysimeter-A having a base liner and sanitary landfill lysimeter-B and C at two different types of cap liner were simulated. The leachate characteristics, leachate generation and climatic influence parameter had been continually monitored, from June 2008 to May 2010. This period covers both dry and rainy season. The leachate generation followed the rainfall pattern and the open dump lysimeter-A without top cover was recorded to have the highest leachate generation. Moreover, the open dump lysimeter-A had lower concentration and load of total kjeldahl nitrogen (TKN), ammonia nitrogen (NH4-N) and dissolved organic carbon (DOC), while chemical oxygen demand (COD) and biological oxygen demand (BOD5) concentration were higher compared with sanitary lysimeter-B and C. On the other hand, sanitary lysimeter-B, not only had lowest leachate generation, but also produced reasonably low COD and BOD5 concentration compared with open dump lysimeter-A. Based on evaluated results, it was also concluded that metal concentrations which were comparatively higher in leachate of open dump lysimeter were Ca and K, however,the heavy metal concentrations of Cd, Cu, Zn and Mn, and those apparently lower were metals of Na, Mg and Fe as well as heavy metals of Cr, Pb and Ni. However, significant release of heavy metals under open dump lysimeter was observed compared to sanitary lysimeter. Moreover, meaningful correlation between DOC and leaching of Cu and Pb was observed. Result reveals that lysimeter operational mode had direct effect on leachate quality. Finally, it can be concluded that the knowledge of leachate quality will be useful in planning and providing remedial measures of proper liner system in landfill design and leachate treatment.

Production of biochar from slow pyrolysis of biomass is a promising carbon negative procedure since itremoves the net carbon dioxide in the atmosphere and produce recalcitrant carbon suitable for sequestration in soil. Biochar production can vary significantly with the pyrolysis parameter. This study investigated the impact of temperature and heating rate on the yield and properties of biochar derived from cassava plantations residues which are cassava stem (CS) and cassava rhizome (CR). The pyrolysis temperatures ranged from 400°C to 600°C while the heating rate parameter was varied from 5°C/min to 25°C/min. The experiment was conducted using the lab scale slow pyrolysis system. The increment of temperature and heating rate of slow pyrolysis for both cassava wastes had raised the fixed carbon content of the biochar but decreased the biochar yield. More biochar was produced at lower temperature and lower heating rate. Temperature gave more influence on the biochar yield as compared to the heating rate parameter. The highest biochar yield of more than 35 mf wt. % can be obtained from both CS and CR at 400°C and heating rate of 5°C/min. From the proximate analysis, the results showed that cassava wastes contain high percentage of volatile matter which is more than 80 mf wt. %. Meanwhile, the biochar produced from cassava wastes contain high percentage of fixed carbon which is about 5−8 times higher than their raw samples. This suggested that, it is a good step to convert CS and CR into high carbon biochar via slow pyrolysis process that can substantially yield more biochar, up to 37 mf wt. % in this study. Since the fixed carbon content for both CS and CR biochar produced inany studied parameter were found to be more than 75 mf wt. %, it is suggested that biochar from cassava wastes is suitable for carbon sequestration.

Mining is not only an essential component of social and economic development since prehistoric time, but it also gives a large impact on our civilization. Gold is a noble metal that is highly valued. The extraction of minerals from earth is known as traditional mining. Gold also can be extracted from electronic waste or e-waste, and this new concept is called urban mining. There are many stages in traditional and urban mining process. However, in this study, the focus was on crushing and grinding processes to produce 1 kg of gold. Crushing and grinding are processes in the milling stage. This research evaluates and compares the environmental impacts of crushing and grinding processes, based on electricity consumption. About 50 to 65% of total electricity in milling was used for crushing and grinding processes. Life Cycle Assessment (LCA) methodology was used as a tool to evaluate the environmental burdens of electricity usage in converting ore and electronic waste to gold bars. The Life Cycle Impact Assessment (LCIA) of this process was interpreted by using Eco-indicator 99 assessment methods in SimaPro software. The impact categories included in this study were carcinogens, respiratory organics, respiratory inorganics, radiation, climate change, ozone layer, ecotoxicity, acidification or eutrophication, land use and minerals. The results showed that crushing and grinding from traditional mining gave the largest impact to the environment with single score of 399 Pt compared to the urban mining with only 1.81 Pt score. The highest impact in both types of mining is to human health.

The study was done to investigate the antioxidant, total phenol content and antifungal characteristics of phenolics compounds of extracts from Cinnamomum iners (Reinw. ex Blume-Lauraceae) wood. Radical scavenging activity method of DPPH was used to determine antioxidant activity of the extracts. Four fungus, namely white fungi (Pycnoporus sanguineus, Trametes versicolor, Fomitopsis palustris) and brown fungi (Gleophyllum trabeum) were used to determine the antifungal activity of the Cinnamomum iners extracts. The results showed that ethanol extract had the highest antioxidant activity with EC50 value of 14.96 μg/mL followed by chloroform extract with EC50 >30 μg/mL while water extract did not show any significant antioxidant activity. For total phenolics content, ethanol extract resulted on the highest value of 56.23%, followed by chloroform extract and water extract having total phenolic values of 51.13% and 7% respectively. On the other hand for antifungal assay, ethanol extract produce the widest inhibition zone followed by chloroform extract and water extract respectively.

The main problem of landfill management in Indonesia is the difficulty in getting a location for Final Processing Sites (FPS) due to limited land and high land prices. Besides, about 95% of existing landfills are uncontrolled dumping sites, which could potentially lead to water, soil and air pollution. Based on data from the Ministry of Environment (2010), The Act of the Republic of Indonesia Number 18 Year 2008 Concerning Solid Waste Management, prohibits open dumping at final processing sites and in ratification, the Local Governments have to convert the open dump sites into controlled or sanitary landfill. The Research Institute for Human Settlements has been conducting multi-year researches related to the rehabilitation of dumpsites toward sustainable landfill. The research methods are literature reviews, experiments, laboratory analysis and field observations. A pilot model of dumpsite rehabilitation was carried out in 2010 at the Final Processing Site at Cikundul in Sukabumi City, consisting of (1) mining landfill (2) construction of landfill cells in a former mining area with a semi aerobic landfill and an anaerobic landfill and (3) landfill operations using decomposed material from landfill mining as a soil cover. The purpose of the study is to develop a sustainable approach for landfill management and rehabilitation through landfill mining and implementation of semi aerobic landfill. Findings in the construction of landfill mining indicate that (1) the construction of landfill mining is constrained by leachate that is trapped in a pile of waste, therefore, the leachate needs to be pumped to leachate treatment installations, (2) the volume of waste excavation is expanding due to the high plastic content of about 26% in landfills (3) the potency of decomposed materials from landfill mining is 40– 83% for landfill operations or greening.. The performance of landfill systems shows that leachate quality of semi aerobic landfill tends to be lower than that of anaerobic landfill. Gas composition at semi aerobic landfill in FPS Sukabumi shows about 6–10% CH4 and about 15–16% O2; for an aerobic landfill, the gas composition is about 47– 57% CH4 and about 2–3% O2. In conclusion the concept mining landfill could be developed especially for big cities where it is difficult to find a new site for landfill or to get soil cover for landfill operation. In a sustainable approach, the excavated area can be turned into a new area for landfill cell so that the capacity of existing Final Processing Site can be expanded using the block landfill concept. The landfill should be divided into three blocks: compost block, composting block and active block. Usage of the three blocks are rotated with the intention of using solid waste on the compost block as soil material for the active block through landfill mining.

In general, paper mill wastewater contains complex organic substances which could not be treated completely using conventional treatment processes, e.g. aerobic processes. As a result, anaerobic technology is a promising alternative for paper mill wastewater treatment due to its ability to degrade hard organic compounds. In the present study, treatment of paper mill wastewater using a stage anaerobic reactor was investigated. The more specific objectives of this study were to confirm whether paper mill wastewater can be tolerated by methanogenic sludge and to assess the stability of reactor for measured parameters (e.g. COD removal, and methane composition). Results showed up to 98% CODremoval efficiency in the anaerobic reactor when the reactor was operated at an OLR of 1.560 kg COD/m3.d. Anaerobic digestion can provide high treatment efficiency for recalcitrant substrates, which generates robust microorganism (acidogenesis and methanogenesis), for the degradation of recalcitrant compounds such as in the paper mill wastewater.