Conversion Of Waste Materials Research Articles

Bioenergy Production from Anaerobic Co-Digestion of Sewage Sludge and Abattoir Wastes

Energy is the pillar of human economic development. Several energy sources, renewable and non- renewable, have been exploited to assure and sustain the need for sustainable development. However, depletion of non-renewable energy sources forced researchers to search for alternative cost effective and environmental friendly energy sources. Thus, conversion of waste materials into energy has obtained considerable attention. In line with this, the aim of this study is to investigate the improvement of bio-energy production through anaerobic digestion of mixture of wastes from sewage sludge and abattoir sources. The abattoir waste is functioned as a co-substrate. Laboratory scale batch anaerobic co-digestion of the waste is carried out under mesophilic condition for 20 days. Sewage Sludge (SS) alone, and different mix ratios of SS to Abattoir Waste (AW) were analyzed for bioenergy production. Besides, the nutrient values and reduction in volume of the sewage after digestion were determined. The results show that methane productions of 33.8%, 48.3% and 56.9% were obtained for SS alone and for SS:AW mix ratios of 4:1 and 3:2, respectively. The nutrient values of the slurry increased as mix ratio decreased due to the increase in the amount of AW. The obtained results indicate that bio-energy production can be improved through co-digestion of SS using AW as a co-substrate; thus warranting further investigation for the practical application in the energy production.

폐기저귀 함유 펄프와 혼합 플라스틱의 업사이클링 연구

This study aims to discuss the concept of upcycling as it applies to diaper recycling. Upcycling is the process of converting waste materials into new products of better quality. Through benchmarking of upcycling examples, useless objects can be transformed into valuable materials. However, current upcycling examples determine value creation related to qualitative elements, so that it is difficult to establish any quantitative strategy of upcycled products. Therefore, this study expands a B2B (Business to business) product for improving market availability and establishes a direction using both recovered pulp and mixed plastic at the same time. As a result, the upcycling method for recovered pulp and mixed plastics, is the application of a cellulose insulator. Within the near future, the high quality insulator market will grow more than three times. An upcycling strategy targeting the high quality insulator market needs to be established.

Production of medium chain length polyhydroxyalkanoates from waste oils by recombinant Escherichia coli

Medium chain length polyhydroxyalkanoates (mcl‐PHAs) are attractive “green” alternatives to conventional petroleum‐based plastics, finding application in various fields. However, their sustainable exploitation is still hampered by the high production costs. In this work, an Escherichia coli recombinant system has been designed to allow accumulation of mcl‐type polymers through conversion of waste materials, such as spent cooking oils. The system has been engineered with a newly isolated PHAs biosynthetic operon from Bacillus cereus 6E/2 and tested for PHAs production on different carbon sources. Results have highlighted the peculiar specificity of the designed E. coli system to drive the incorporation of 3‐hydroxyhexanoate monomers (up to 99%) in produced PHAs, whatever is the related C‐source fed to the growth medium: fatty acids with different length, vegetable oils, or complex waste oils. The work also provides first clues about the role played by B. cereus PHA biosynthetic proteins in PHA production process, laying the basis for the development of ad hoc designed cell factories for the synthesis of polymers with defined composition.

Carbon Nanostructures Production from Waste Materials: A Review

Research innovation in finding new carbon sources for carbon nanostructured material production was intensively done lately. In this review, we present the production of carbon nanostructures such as carbon fibers, nanotubes, nanowhiskers, microspheres and porous carbon from several waste materials. The benefit of the use of waste materials such as waste cooking palm oil, chicken fat, waste natural oil, glycerol, printed circuit board, plastic wastes, waste engine oil, scrap tyre, heavy oil residue and deoiled asphalt is not only in the term of their environmentally friendly approach but also the economic value to reduce the high cost of carbon material production using common sources. On the other hand, these materials are easy access sources and can be alternative utilization to convert waste materials into high value nanomaterials.

Carbon Nanostructures Production from Waste Materials: A Review

Research innovation in finding new carbon sources for carbon nanostructures material production was intensively done lately. In this review, we present the production of carbon nanostructures such as carbon fibers, nanotubes, nanowhiskers, microspheres and porous carbon from several waste materials. The benefit of the use of waste materials such as waste cooking palm oil, chicken fat, waste natural oil, glycerol, printed circuit board, plastic wastes, waste engine oil, scrap tyre, heavy oil residue and deoiled asphalt is not only in the term of their environmentally friendly approach but also the economic value to reduce the high cost of carbon material production using common sources. On the other hand, these materials are easy access sources and can be alternative utilization to convert waste materials into high value nanomaterials.

Usage of Sugarcane Bagasse as an Additive in Building Materials

Discovering about sustainability, construction sector should be a part of participant in utilizing waste materials for the benefits of the industry. The idea of converting waste materials into some application can contribute to sustainability and greening the earth. Apart from that, research must be done to promote the waste material into economic and useful construction material. A concept of going green must be adopted rather than just thinking of the rapid construction as the whole project aim. This paper promotes sugarcane bagasse as an additive for construction material in 3 ways which are on concrete strength improver, a concrete retarder and composite brick. The sugarcane bagasse were blended and mixed with 30MPa concrete with certain ratio and tested for compressive, flexural, water absorption and penetration. From the tests, it shows that the sugarcane bagasse gives a positive impact to concrete. Therefore, the usage of sugarcane bagasse can be considered as a concept of utilizing waste material for sustainable approach.

Potential Contribution of Waste-to-Energy to Power Consumption in the Gaza Strip

Sustainable energy supply is one of the main challenges that people will face over the coming decades. Biomass can make a substantial contribution to supplying future energy demand in a sustainable way. Currently it is the largest global contributor of renewable energy, and has significant potential to expand the production of heat, electricity and fuels for transport. Municipal solid waste is an enormous renewable resource that has high energy capacity because it contains a high proportion of biomass materials. This kind of sustainable waste management typically called waste-to-energy is critical for reducing the reliance on fossil fuels and non-renewable materials. Waste-to-energy is a reliable and alternative form of energy that has become the basis for many of the most successful solid waste management systems in many countries. Energy recovery from waste is the conversion of waste materials into useable heat, electricity, or fuel through a variety of processes. This study assesses the potential contribution of waste-to-energy facilities to total Gaza peak power demand up to the year 2040 based on three scenarios: incineration, anaerobic digestion and landfill gas recovery. Three dumping sites are distributed along the Gaza Strip, Johr El-deek, Deir El-balah and Rafah. The analysis shows a potential to produce about 1100 MWh per day based on the anaerobic digestion scenario, about 580 MWh per day based on incineration of municipal solid waste scenario, and about 130 MWh per day based on landfill gas recovery scenario. These values accounts to 275%, 145% and 33% of the year 2014 peak electricity demand of 400 megawatt from the three scenarios, respectively. The forecasted results of the three scenarios can be used to design future waste-to- energy facilities in the main cities of the Gaza Strip. The production cost of energy was 7¢/kWh, 5¢/kWh and 17¢/kWhfor incineration, anaerobic digestion and landfill gas recovery scenarios, respectively.

An extracellular chitinase from Streptomyces sp. CS147 releases N-acetyl-D-glucosamine (GlcNAc) as principal product.

Streptomyces sp. CS147 grown on chitin liquid medium incorporating 0.5 % colloidal chitin as a sole carbon source produced an extracellular chitinase (Ch147). The enzyme (Ch147) was purified using Sepharose CL-6B column chromatography and biochemically characterized. The enzymatic reaction products, analyzed using high-performance liquid chromatography and thin layer chromatography clearly indicates the production of N-acetyl-D-glucosamine (GlcNAc) as principal product which can be further hydrolyzed for the production of alcohol, a second generation biofuel. Ch147 hydrolyzed colloidal chitin to 0.278, 0.817, and 1.058 mg/mL of (GlcNAc) as a major product, at retention time of 4.3, respectively, when incubated for 8, 16, and 24 h at 50 °C. GlcNAc is a monosaccharide that usually polymerize linearly through (1, 4) β linkage. The 41 kDa molecular mass chitinase, as determined by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE), has the amino acid sequences DINGGGATLPQKLYL significantly different from other chitinase. Ch147 had K m and V max values of 2.05 ± 5.3 mg/mL and 467.2 ± 2.4 mmol/min, respectively. Further, the purified enzyme (5 U) inhibits the fungal phytopathogens belonging to the genera Fusarium and Aspergillus. We believe that Ch147 is a potential candidate for the conversion of waste materials into simple sugar for productions of biofuels and also can be used as an alternative option for biological control of plant pathogens being unfriendly to chemicals.

Evaluation of an Energy Production System from Sewage Sludge Using a Pilot-Scale Downdraft Gasifier

Presently, sewage sludge from wastewater treatment systems has become a critical problem in many regions of the world because it can inflict harm on human beings and the environment. Gasification technology is widely held to be a suitable and convenient approach to convert waste materials to energy with minimal greenhouse gas emissions. In a pilot-scale experiment on sewage sludge gasification ultimately aimed at generating electricity, the reactor temperature profile, syngas characteristics, and performance of the syngas in the production of electricity were tied to the equivalence ratio (ER) and syngas flow rate (i.e., 100, 150, or 180 N m3 h–1). An increase of the ER resulted in an increase of the temperature inside the gasifier, causing a variation in syngas characteristics and the level of tar and dust contamination. Calorific values at different syngas flow rates were found to vary from 4.20 to 4.87 MJ N–1 m–3. The syngas obtained at flow rates of 150 and 180 N m3 h–1 could be used in an engine–generator set to generate 21 or 47 kW of electrical power, respectively, whereas at the flow rate of 100 N m3 h–1, the syngas could only run the engine without electrical load. The specific sewage sludge consumption, which is the amount of feedstock required to generate electricity, decreased with an increase in the syngas flow rate. The performance evaluation of the sewage sludge gasification system, i.e., gasification efficiency, engine–generator set efficiency, and electrical efficiency, showed that these were in the range of those obtained from biomass, such as agricultural residues. Overall, sewage sludge can serve as a feedstock for electricity generation using a pilot-scale downdraft gasification system.

Medium-chain-length polyhydroxyalkanoate production by newly isolated Pseudomonas sp. TN301 from a wide range of polyaromatic and monoaromatic hydrocarbons

The aim of this study was to convert numerous polyaromatic and monoaromatic hydrocarbons into biodegradable polymer medium-chain-length polyhydroxyalkanoate (mcl-PHA). Using naphthalene enrichment cultivation method, we have isolated seven bacterial strains from the river sediment exposed to petrochemical industry effluents. In addition to naphthalene, all seven strains could utilize between 12 and 17 different aromatic substrates, including toluene, benzene and biphenyl. Only one isolate that was identified as Pseudomonas sp. TN301 could accumulate mcl-PHA from naphthalene to 23% of cell dry weight. Owing to poor solubility, a method of supplying highly hydrophobic polyaromatic hydrocarbons to a culture medium was developed. The best biomass and mcl-PHA yields were achieved with the addition of synthetic surfactant Tween 80 (0.5 g l(-1)). We have shown that Pseudomonas sp. TN301 can accumulate mcl-PHA from a wide range of polyaromatic and monoaromatic hydrocarbons, and mixtures thereof, while it could also accumulate polyphosphates and was tolerant to the presence of heavy metal (100 mmol l(-1) cadmium and 20 mmol l(-1) nickel). A new Pseudomonas strain was isolated and identified with the ability to accumulate mcl-PHA from a variety of aromatic hydrocarbons. This study is the first report on the ability of a bacterial strain to convert a range of polyaromatic hydrocarbon compounds to the biodegradable polymer (mcl-PHA). Mcl-PHA is gaining importance as a promising biodegradable thermoelastomer, and therefore, isolation of new producing strains is highly significant. Furthermore, this strain has the ability to utilize a range of hydrocarbons, which often occur as mixtures and could potentially be employed in the recently described efforts to convert waste materials to PHA.

Charred and Composted Agriculture-Forestry Organic Wastes as Components of Growing Media for the Production of Anthurium (<i>Anthurium andraeanum</i> Cv. ‘Pink Lady’)

The primary component of soilless rooting media for ornamental plant production is peat. However, quality peat is costly and is a nonrenewable natural resource. The current study compared the suitability of using charred and composted agriculture–forestry organic wastes (AFOW) vs. sphagnum peat as components of the growth medium for the ornamental plant Anthurium (Anthurium andraeanumcv. ‘Pink Lady’). Ten media were prepared from composted corn cobs (C), charred corn cobs (CH), charred garden wastes (CHG), and Pindstrup sphagnum peat moss (P). These media contained (% v/v): CH (100%), C (100%), CHG (100%), C (70%) + CHG (30%), CH (70%) + CHG(30%), C (35%) + CHG (15%) + P (50%), CH (50%) + P (50%), CH (35%) + CHG (15%) + P (50%), C (50%) + P (50%), and P (100%) as the control. After 8 months in the greenhouse, the growth and flowering of transplanted Anthurium were best with P, CH+P, CH+CHG+P. The results indicate that mixing charred AFOW with peat would provide a suitable medium for Anthurium production while reducing the need for peat and converting waste materials into useful products.

A facile green approach for synthesizing monodisperse magnetite nanoparticles

The synthesis of monodisperse magnetite nanoparticles (Fe3O4 NPs) has been widely investigated over the last decade. Among the various synthetic methods, thermal decomposition of iron acetylacetonate, Fe(acac)3, or the premade iron-surfactant complex, was demonstrated to be promising to obtain monodisperse Fe3O4 NPs with controllable size and morphology. However, toxic and expensive precursors or tedious experimental procedures are normally required in these approaches. In this communication, we report a facile chemical top-down method to synthesize monodisperse magnetite NPs by using rust, which is mainly composed of γ-Fe2O3, as the iron source and oleic acid as the capping agent. The particle size, and hence the magnetization, of NPs can be readily controlled by adjusting the rust/oleic acid ratio and reaction temperature. This process is a green chemical approach and is easy to be reproduced and scaled up, which could be developed as an effective way to convert waste materials into high quality nanocrystals.

Monitoring of substrate and product concentrations in acetic fermentation processes for onion vinegar production by NIR spectroscopy: value addition to worthless onions

Wastes and by-products of the onion-processing industry pose an increasing disposal and environmental problem and represent a loss of valuable sources of nutrients. The present study focused on the production of vinegar from worthless onions as a potential valorisation route which could provide a viable solution to multiple disposal and environmental problems, simultaneously offering the possibility of converting waste materials into a useful food-grade product and of exploiting the unique properties and health benefits of onions. This study deals specifically with the second and definitive step of the onion vinegar production process: the efficient production of vinegar from onion waste by transforming onion ethanol, previously produced by alcoholic fermentation, into acetic acid via acetic fermentation. Near-infrared spectroscopy (NIRS), coupled with multivariate calibration methods, has been used to monitor the concentrations of both substrates and products in acetic fermentation. Separate partial least squares (PLS) regression models, correlating NIR spectral data of fermentation samples with each kinetic parameter studied, were developed. Wavelength selection was also performed applying the iterative predictor weighting-PLS (IPW-PLS) method in order to only consider significant spectral features in each model development to improve the quality of the final models constructed. Biomass, substrate (ethanol) and product (acetic acid) concentration were predicted in the acetic fermentation of onion alcohol with high accuracy using IPW-PLS models with a root-mean-square error of the residuals in external prediction (RMSEP) lower than 2.5% for both ethanol and acetic acid, and an RMSEP of 6.1% for total biomass concentration (a very satisfactory result considering the relatively low precision and accuracy associated with the reference method used for determining the latter). Thus, the simple and reliable calibration models proposed in this study suggest that they could be implemented in routine applications to monitor and predict the key species involved in the acetic fermentation of onion alcohol, allowing the onion vinegar production process to be controlled in real time.

The use of the valuable oyster mushroom, Pleurotus sajor-caju, for conversion of waste materials produced from seaweed and brewing industries: preliminary investigations.

The use of the valuable oyster mushroom, Pleurotus sajor-caju, for conversion of waste materials produced from seaweed and brewing industries: preliminary investigations.

The Use of the Valuable Oyster Mushroom, Pleurotus sajor-caju, for Conversion of Waste Materials Produced from Seaweed and Brewing Industries: Preliminary Investigations

The Use of the Valuable Oyster Mushroom, Pleurotus sajor-caju, for Conversion of Waste Materials Produced from Seaweed and Brewing Industries: Preliminary Investigations

Recycling of Hazardous Solid Waste Material Using High-Temperature Solar Process Heat. 1. Thermodynamic Analysis

The thermochemical conversion and recycling of hazardous solid waste materials is investigated using high-temperature solar process heat. Two important sources of wastes contaminated with heavy metal oxides are considered: (1) electric are furnace dust (EAFD) and (2) automobile shredder residue (ASR). The chemical equilibrium composition of these complex materials and the energy required to process them, using carbon, methane, or pyre-coke as reducing agents, are computed for temperatures in the range 300-2000 K. Metals can be extracted from their oxides in reducing atmospheres at above 1300 K for both EAFD and ASR: Zn is obtained in the gas phase, while Fe, Pb, and Cu are obtained in the condensed phase. The thermal energy requirements for converting EAFD at 1500 K are 3008 kJ/ kg and 4143 kJ/kg using C(gr) and CH4 as reducing agents, respectively. For converting ASR at 1500 K, 2455 kJ/kg are required. The solar exergy conversion efficiency, i.e., the efficiency of converting solar energy into the chemical energy of the reaction products (given by the Gibbs free energy change of product oxidation), can be as high as 69% for the EAFD conversion and 87% for the ASR conversion. Major sources of irreversibilities are those associated with the reradiation losses of the solar reactor and the heat rejected during the quenching. The use of concentrated solar energy as the source of process heat avoids emissions of greenhouse gases and other pollutants derived from the combustion of fossil fuels and further offers the possibility of converting waste materials into valuable commodities for processes in closed and sustainable materials cycles.

99/02683 Thermochemical conversion of waste materials to valuable products

99/02683 Thermochemical conversion of waste materials to valuable products

An Overview: Recycling Nutrients from Crop Residues For Space Applications

Without some form of regenerative life support system, long duration space habitation or travel will be limited severely by the prohibitive costs of resupplying air, water, and food from Earth. Components under consideration for inclusion in a regenerative life support system are based on either physicochemical or biological processes. Physicochemical systems would use filtration and elemental phase changes to convert waste materials into usable products, while biological systems would use higher plants and bioreactors to supply crew needs. Neither a purely biological nor strictly a physicochemical approach can supply all crew needs, thus, the best each approach can offer will be combined into a hybrid regenerative life support system. Researchers at Kennedy Space Center (KSC) Advanced Life Support Breadboard Project have taken the lead on bioregenerative aspects of space life support. The major focus has been on utilization of higher plants for production of food, oxygen, and clean water. However, a key to any regenerative life support system is recycling and recovery of resources (wastes). In keeping with the emphasis at KSC on bioregenerative systems and with the focus on plants, this paper focuses on research with biologically-based options for resource recovery from inedible crop residues.

Extraction of leachable metals and recovery of alumina from utility coal ash

The classification of coal ash as a “special waste” by the Environmental Protection Agency (EPA) stimulated questions concerning the environmental impact of the disposal of this voluminous byproduct of coal-fired power plants. Both industry and Government face possible expensive disposal problems because of the large volume of coal ash produced annually. The extraction of metals from coal ash was investigated as part of a Bureau of Mines program to convert waste materials from a disposal problem to potential secondary resources. The objectives of this study were to produce a more environmentally acceptable waste and offset waste disposal costs with recovered metal values. The research was conducted in two steps: determination of parameters affecting extraction of aluminum from coal ash, and development of extraction-recovery procedures. The major parameter affecting the extraction of metals from coal ash was the calcium content of the fly or bottom ash. Other parameters, such as furnace type and operating temperature, had lesser effects on metal extraction. Two procedures were studied for metal extraction: an acid leach for high-calcium ashes and a lime sinter-acid leach for low-calcium ashes. The first procedure removed about 757 of the metals in high-calcium ash, and the second removed about 907 of the metals in low-calcium ash. An alumina product was recovered that, with sufficient washing, meets “Hall Cell” specifications. The leach residues pass the EPA EP toxicity test and are classified as nonhazardous wastes.

WASTE NOT WANT NOT

Novel biological production processes can be utilised to convert waste materials, such as cellulose, crop residues and animal excreta, to products which can be sold or used within agriculture. Some of these biological processes may involve the use of enzymes, bacteria or fungi and may need to be carried out in the controlled conditions of an industrial plant. Unorthodox animals may also be used and with them the degree of control required may be less — or the cost of achieving it less. Costs could be minimised by using very simple methods and cheap equipment.