Microbial Treatment of Domestic Wastewater Treatment Plant Sludge by Liquid State Bioconversion Process

The study of microbial treatment of domestic wastewater treatment plant (DWTP) sludge by liquid state bioconversion (LSB) process was conducted by several approaches. A total of 70 strains of filamentous fungi were isolated from three different sources (wastewater, DWTP sludge and landfill leachate), which belonged to the genera of Penicillium (39 strains), Aspergillus (14 strains), Trichoderma (12 strains), Spicaria (3 strains) and Hyalojlorae (2 strains). In the screening test, the fungal strains WWZPI003 (Penicillium corylophilum), SCahmAI03 (Aspergillus niger), SCahmTI05 (Trichoderma hamianum) and PC-9 (Phanerochaete chrysosporium), among their respective groups of Penicillium, Aspergillus, Trichoderma and Basidiomycete, played potential roles in tenns of separation, biodegradation and filtration of treated DWTP sludge. The results of the compatible mixed culture optimization study showed a compatible growth of the mixed culture for PIA, PIPC and AfPC and the combinations PIT, AfT and T/PC were observed to be incompatible cultures for the bioconversion of the sludge. Among the combinations, the potential compatible mixed culture of PIA was selected for DWTP sludge treatment in LSB process. The results obtained in optimum LSB processes indicated that wheat flour (WF) at a concentration of 1.5- 2% (w/w) was a better co-substrate in sludge containing medium, with optimum initial pH of 4.5-5.5, temperature of 33-350C and inoculum size of 2-3% (v/w). Bioconversion of DWTP sludge was highly influenced by agitation and aeration rate that were 150-200 rpm and 0.5 vvrn, respectively. In a settleability and dewaterability study, 86.45% of TSS was settled in treated sludge while 4.35% in untreated sample after one minute of settling operation. The results for specific resistance to filtration (SRF) showed that the fungal inoculum had significant potentiality to reduce SRF by 99.8% and 98.7% for 1% and 4% of sludge, respectively. Bioconversion efficiency was higher by 0.2-20% in fermenter than in the shake flask in terms of biosolids accumulation and biodegradation of organic matters in sludge. In developed bioconversion processes, 93.75 g/kg of biosolids was enriched with fungal biomass protein and nutrients (NPK), and 98.84% of TSS, 98.22% of TDS, 97.33% of turbidity, 80.24% of soluble protein, 98.81% of reducing sugar and 92.66% of COD in treated sludge supernatant were removed after 8 days of treatment. SRF (1.39xlO12 m/kg) was decreased tremendously by the microbial treatment ofDWTP sludge after 6 days of fermentation. LSB process for microbial treatment of DWTP sludge is a new biotechnological approach that has economic value and is non-hazardous as well as environmental friendly, and therefore may be encouraging to sludge management strategy in future applications

Joint transceiver design and power optimization for wireless sensor networks in underground mines

Avec les grands développements des technologies de communication sans fil, les réseaux de capteurs sans fil (WSN) ont attiré beaucoup d’attention dans le monde entier au cours de la dernière décennie. Les réseaux de capteurs sans fil sont maintenant utilisés pour a surveillance sanitaire, la gestion des catastrophes, la défense, les télécommunications, etc. De tels réseaux sont utilisés dans de nombreuses applications industrielles et commerciales comme la surveillance des processus industriels et de l’environnement, etc. Un réseau WSN est une collection de transducteurs spécialisés connus sous le nom de noeuds de capteurs avec une liaison de communication distribuée de manière aléatoire dans tous les emplacements pour surveiller les paramètres. Chaque noeud de capteur est équipé d’un transducteur, d’un processeur de signal, d’une unité d’alimentation et d’un émetteur-récepteur. Les WSN sont maintenant largement utilisés dans l’industrie minière souterraine pour surveiller certains paramètres environnementaux, comme la quantité de gaz, d’eau, la température, l’humidité, le niveau d’oxygène, de poussière, etc. Dans le cas de la surveillance de l’environnement, un WSN peut être remplacé de manière équivalente par un réseau à relais à entrées et sorties multiples (MIMO). Les réseaux de relais multisauts ont attiré un intérêt de recherche important ces derniers temps grâce à leur capacité à augmenter la portée de la couverture. La liaison de communication réseau d’une source vers une destination est mise en oeuvre en utilisant un schéma d’amplification/transmission (AF) ou de décodage/transfert (DF). Le relais AF reçoit des informations du relais précédent et amplifie simplement le signal reçu, puis il le transmet au relais suivant. D’autre part, le relais DF décode d’abord le signal reçu, puis il le transmet au relais suivant au deuxième étage s’il peut parfaitement décoder le signal entrant. En raison de la simplicité analytique, dans cette thèse, nous considérons le schéma de relais AF et les résultats de ce travail peuvent également être développés pour le relais DF. La conception d’un émetteur/récepteur pour le relais MIMO multisauts est très difficile. Car à l’étape de relais L, il y a 2L canaux possibles. Donc, pour un réseau à grande échelle, il n’est pas économique d’envoyer un signal par tous les liens possibles. Au lieu de cela, nous pouvons trouver le meilleur chemin de la source à la destination qui donne le rapport signal sur bruit (SNR) de bout en bout le plus élevé. Nous pouvons minimiser la fonction objectif d’erreur quadratique moyenne (MSE) ou de taux d’erreur binaire (BER) en envoyant le signal utilisant le chemin sélectionné. L’ensemble de relais dans le chemin reste actif et le reste des relais s’éteint, ce qui permet d’économiser de l’énergie afin d’améliorer la durée de vie du réseau. Le meilleur chemin de transmission de signal a été étudié dans la littérature pour un relais MIMO à deux bonds mais est plus complexe pour un ...With the great developments in wireless communication technologies, Wireless Sensor Networks (WSNs) have gained attention worldwide in the past decade and are now being used in health monitoring, disaster management, defense, telecommunications, etc. Such networks are used in many industrial and consumer applications such as industrial process and environment monitoring, among others. A WSN network is a collection of specialized transducers known as sensor nodes with a communication link distributed randomly in any locations to monitor environmental parameters such as water level, and temperature. Each sensor node is equipped with a transducer, a signal processor, a power unit, and a transceiver. WSNs are now being widely used in the underground mining industry to monitor environmental parameters, including the amount of gas, water, temperature, humidity, oxygen level, dust, etc. The WSN for environment monitoring can be equivalently replaced by a multiple-input multiple-output (MIMO) relay network. Multi-hop relay networks have attracted significant research interest in recent years for their capability in increasing the coverage range. The network communication link from a source to a destination is implemented using the amplify-and-forward (AF) or decode-and-forward (DF) schemes. The AF relay receives information from the previous relay and simply amplifies the received signal and then forwards it to the next relay. On the other hand, the DF relay first decodes the received signal and then forwards it to the next relay in the second stage if it can perfectly decode the incoming signal. For analytical simplicity, in this thesis, we consider the AF relaying scheme and the results of this work can also be developed for the DF relay. The transceiver design for multi-hop MIMO relay is very challenging. This is because at the L-th relay stage, there are 2L possible channels. So, for a large scale network, it is not economical to send the signal through all possible links. Instead, we can find the best path from source-to-destination that gives the highest end-to-end signal-to-noise ratio (SNR). We can minimize the mean square error (MSE) or bit error rate (BER) objective function by sending the signal using the selected path. The set of relay in the path remains active and the rest of the relays are turned off which can save power to enhance network life-time. The best path signal transmission has been carried out in the literature for 2-hop MIMO relay and for multiple relaying it becomes very complex. In the first part of this thesis, we propose an optimal best path finding algorithm at perfect channel state information (CSI). We consider a parallel multi-hop multiple-input multiple-output (MIMO) AF relay system where a linear minimum mean-squared error (MMSE) receiver is used at the destination. We simplify the parallel network into equivalent series multi-hop MIMO relay link using best relaying, where the best relay ..

Upgrading strategies for effective utilization of biogas

Production of biogas is based on anaerobic digestion of different renewable raw materials including human, animal, agricultural, industrial, and municipal wastes. In addition to methane content, biogas contains carbon dioxide along with water vapor, hydrogen sulfide, ammonia, and depending on the raw materials siloxane can be present. Thus, different purification and upgrading strategies are necessary in order to enhance the methane content; this review presents some of the upgrading technologies for practical removal of major contaminants in biogas. Recent development in membrane technology with high selectivity and permeability could serve as a boost in search for the most efficient biogas upgrading process capable of meeting the requirements for its use in vehicle fuel as well as incorporation in the natural gas grid

Biomass energy towards a sustainable circular economy: a potential solution to global problems

Biomass energy refers to bioenergy, is the energy derived from plant-based materials and is considered a potential solution to the global energy problems. Concerning global sustainability, reliance on fossil fuels and greenhouse gas emissions that contribute to global warming are particularly alarming. In order to address the pressing issues and crises, an alternative and potentially viable solution is necessary. Massive amounts of biomass are produced as a result of the industrial and agricultural revolutions of the twenty-first century, making its management a tremendous challenge. Currently, the most prevalent biomass feedstocks for energy conversion are plants, crops, and their wastes, which are potential resources for biofuels, biopower, and a variety of bioproducts. The primary biomass sources in Malaysia are sewage treatment plant (STP) sludge managed by the Indah Water Konsortium (IWK), a national sewerage company, and oil palm industrial (OPI) wastes considered oil palm biomass (OPB) with their treatment and processing facilities. The majority of biomass conversion processes use conventional treatment and management techniques, which are time-consuming, costly, polluting, and limit the possibility of a sustainable future. Current advanced research and development seeks an effective and efficient solution to the biomass by converting waste to bioenergy, which could be a complete and viable solution with the generation of revenue and a circular economy approach at the point of generation for sustainable development. The global focus on this issue necessitates the proposal of an environmentally friendly system that converts abundant and inexpensive renewable resources into valuable bio-products, particularly bioenergy and biofuels. This keynote address will provide an overview of the research on 'Turning waste into useful bio-products,' focusing on biofuels (bioethanol, biodiesel, and biogas) and bioenergy through the lens of green technology. Various biofuels and bioenergy are currently being developed in Malaysia from a variety of domestic and industrial waste sources. Sources and characteristics of various biomass feedstocks in Malaysia are to be discussed. The topic discusses how data from research and development (R&D) could be scaled up to the commercial level for the recovery of renewable energy using green technology. For sustainable development, certain case studies on the bioconversion of food waste, sewage sludge, and oil palm industry waste into biofuels and bioenergy will be shared

How to write and publish a high-impact journal article

The content of the scientific journal writing and publishing in the high-impact journals includes an overview of IIUM publications, writing a scientific article in the international journals, what are major indexed journals, and how to find suitable journals. The keynote covers the steps of the writing of the papers including title, abstract, introduction, methodology and results and discussion, conclusion, and acknowledgment. The topics cover the criteria for acceptance, major reasons for the rejection; ethics in scientific writings, and choosing the right journal for publication. Another important point are shared on the selection of the journal paper writing and publication which are journal database, their impact factor, h-index, g-index, etc. In the end, important journal databases, Scopus, ISI/WoS, Google Scholar, etc. are shared with the proper website, and how to check the status in their database to confirm it

Environmental Biotechnology for Sustainable Development

A huge quantity of domestic and industrial waste is generated annually in Malaysia as the country is moving forward to the industrial development. The major waste streams are mainly household wastewaters managed by the Indah Water Konsortium (IWK) is a national sewerage company and oil palm industrial (OPI) waste at private sector with their own treatment facilities. Most of the treatment plants are based on conventional methods of treatment and management which lead to the high cost, time consuming, environmental pollutions and limiting sustainable future. Current focus of research and development to the efficient waste management is not only the treatment processes but also turning waste into valuable products which could be a complete and potential solution with generation of revenue and zero waste emission at the point source for sustainable development. Therefore the global attention on this issue implicating that an environmental friendly system must be proposed by converting the cheap and abundant renewable resources into valued bio-products. The paper highlights the overview of the recent research on resource recovery from domestic and industrial wastes especially biocatalysts and bioenergies through green technology approach. The topics include the sources and characteristics of selected waste i.e. IWK sludge and OPI waste, and proposed alternative and potential solution for effective management through recovery of bio-products. A case study on pilot scale set up at IIUM for the cellulase production from IWK sludge is also highlighte

Statistical optimization of fermentation conditions for cellulase production from palm oil mill effluent

Palm oil mill effluent discharged by the oil palm industries is considered as the mixed of high polluted effluent which is abundant (about 20 million tonnes year-1) and its effect contributes to the serious environmental problems through the pollution of water bodies. Approach: The aim of this study was to identify the potential of low cost substrate such as Palm Oil Mill Effluent (POME) for the production of cellulase enzyme by liquid state bioconversion. The filamentous fungus Trichoderma harzianum was used for liquid state bioconversion of POME for cellulase production. Statistical optimization was carried out to evaluate the physico-chemical parameters (factors) for maximum cellulase production by 2-level fractional factorial design with six central points. The polynomial regression model was developed using the experimental data including the effects of linear, quadratic and interaction of the factors. The factors involved were substrate (POME) and co-substrate (wheat flour) concentrations, temperature, pH, inoculum and agitation. Results: Statistical analysis showed that the optimum conditions were: Temperature of 30°C, substrate concentration of 2%, wheat flour concentration of 3%, pH of 4, inoculum of 3% and agitation of 200 rpm. Under these conditions, the model predicted the enzyme production to be about 14 FPU mL-1. Analysis Of Variance (ANOVA) of the design showed a high coefficient of determination (R2) value of 0.999, thus ensuring a high satisfactory adjustment of the quadratic model with the experimental data. Conclusion/Recommendations: This study indicates a better solution for waste management through the utilization of POME for cellulase production that could be used in the industrial applications such as bioethanol production

Microbial super strains for high-quality biofertilizer

A pilot project at the International Islamic University Malaysia (IIUM) has produced high-quality biofertilizer by combining microbial super strains with food waste

Kinetic and Thermodynamic Characterization of the Protease from Bacillus licheniformis (ATCC 12759)

Abstract: In this study, the kinetic of a thermo-stable extracellular protease produced by Bacillus licheniformis (ATCC 12759) cultured in skim latex serum fortified media was investigated. The enzyme was stable up to 65 oC after incubation for 60 min at pH 8. The Lineweaver-Burk exhibited vmax (maximum rate) of 37.037 U/mg min-1 and KM (Michaelis-Menten constant) of 8.519 mg/mL. The activation energy (Ea) of casein hydrolysis and temperature quotient (Q10) were found to be 4.098 kJ/mol and 1.038 - 1.034, respectively, at a temperature ranging from 35 oC to 65 oC. The results of the residual activity test allowed estimating activation energy for irreversible inactivation of the protease (denaturation) which was approximately Ea(d) = 62.097 kJ/mol. The thermodynamic parameters for the enzyme irreversible denaturation were as follow enthalpy (59.286 ≤ΔH*d≥ 59.535 kJ/mol), Gibbs free energy (97.375 ≤ ΔG*d≥ 93.774kJ/mol), and entropy (-122.797 ≤ ΔS*d≥ -101.992 kJ/mol). These thermodynamic parameters inferred that the thermo-stable proteases could be potentially important for industrial application, for example, in the detergent industries.Abstrak: Pada penelitian ini, kinetika protease ekstraseluler termo-stabil yang diproduksi oleh Bacillus licheniformis (ATCC 12759), yang dikultur dalam media yang diperkaya serum lateks skim diselidiki. Enzim stabil hingga 65 oC setelah diinkubasi selama 60 menit pada pH 8. Lineweaver-Burk menunjukkan vmax (laju maksimum) adalah 37.037 U/mg min-1 dan KM (konstanta Michaelis-Menten) 8.519 mg/mL. Energi aktivasi (Ea) dari hidrolisis kasein dan suhu quotient (Q10) ditemukan masing-masing sebesar 4.098 kJ/mol dan 1.038 - 1.034, pada suhu yang berkisar dari 35 oC hingga 65 oC. Hasil uji aktivitas residu memungkinkan estimasi energi aktivasi untuk inaktivasi ireversibel dari protease (denaturasi) yang kira-kira Ea (d) = 62.097 kJ/mol. Parameter termodinamika untuk denaturasi enzim ireversibel adalah sebagai berikut entalpi (59.286 ≤ΔH * d≥ 59.535 kJ / mol), energi bebas Gibbs (97.375 ≤ ΔG * d≥ 93.774kJ / mol) dan entropi (-122.797 ≤ ΔS * d≥ -101.992 kJ / mol). Parameter termodinamika pada penelitian ini menyimpulkan bahwa protease termo-stabil dapat berpotensi penting untuk aplikasi industri seperti dalam industri deterjen

Research progress in bioflocculants from bacteria

Although one of the major users of flocculants are water and wastewater treatment industries, flocculants are also used in various food industries. The chemical flocculants are preferred widely in these industries due to low production cost and fast production ability. However, the negative effects of the chemical flocculants should not be neglected to gain the economic benefits only. Therefore, the researchers are working to discover efficient and economical flocculants from biological sources. Several attempts have been made and are still being made to extract or produce bioflocculants from natural sources such as plants, bacteria, fungi, yeast, algae, etc. The review revealed that significant amount of work have been done in the past, in search of bioflocculant. However, commercially viable bioflocculants are yet to be marketed widely. With the advent of new biotechnologies and advances in genetic engineering, the researchers are hopeful to discover or develop commercially viable, safe and environmentfriendly bioflocculant