Types Of Biowaste Research Articles

Gasification performance of biowaste-derived hydrochar: The properties of products and the conversion processes

Hydrothermal carbonization (HTC) coupled with gasification is recognized as an effective approach to produce hydrogen-rich syngas from biowastes, but only a few studies concerning the gasification capacity of various biowaste-derived hydrochars have been published yet. In this work, three types of biowaste (i.e., lignocellulosic, non-lignocellulosic and ash-rich types) were selected for the HTC experiments, and the subsequent gasification of hydrochars was carried out to investigate its thermogravimetric curves and the properties of products (i.e., syngas, tar and biochar). The results found that HTC improves the gasification efficiency in terms of the syngas quality and the conversion degree of sample. The concentrations of H2 and CH4 in syngas were increased, while the gasified tar from hydrochars was concurrently reduced to half of its original value from biowastes under similar conditions. Furthermore, as HTC progressed, the gasification period and dynamic kinetics of samples exhibited slightly different, but the variation in the conversion process of gasification was similar; biowaste diversity in components is the reason for the former, while the developed aromatic structures in hydrochars is the explanation for the latter. These findings can not only provide a comprehensive knowledge on the gasification conversion of hydrochar, but also give a referential observation for designing, optimizing as well as scaling up the thermochemical conversion of industrial biowastes.

Nutrient in Leachate of Biowaste Compost and its Availability for Plants

Compost leachate (CL) is a liquid by-product of compost that contains carbon, nitrogen, phosphorus, potassium and trace elements. It can partially replace the commercial liquid fertilisers to promote plant growth. However, CL may contain heavy metals, phytotoxic substances such as ammonia, organic compounds of low molecular weight, high level of salt and oils. Treatment of leachate is required to avoid the damage on the plant. This paper aims to review the nutrient and physical characteristics of the CL from three types of bio-wastes, i.e. municipal solid waste, animal waste and green waste. The effects of plants treated with CL in terms of rate and nutrient absorption were discussed. The nutrient and physical composition of the leachate is highly variable due to the diversity of the sources and age of the leachate. Compost leachate from municipal solid waste contains the highest chemical oxygen demand (COD) (15,188 – 105,300 mg/L) followed by those from animal waste (6,542 – 100,000 mg/L) and green waste (804 – 1,152 mg/L). The difference in COD is due to the difference in organic carbon content in the biowaste. Other physical parameters, such as electrical conductivity and pH, are correlated with the organic carbon content. For nutrient composition, municipal solid waste leachate contains the highest nitrogen content (630 – 2,438 mg/L), green waste has the highest potassium content (500 – 1,000 mg/L), while animal waste has the highest phosphate content (170 – 500 mg/L). The nutrient contents of CL derived from different biowaste reviewed in this study serves as a guideline for users to estimate the dilution rate and further nutrient formulation required for the application of CL on plants.

Olive Pomace-Derived Carbon Materials-Effect of Carbonization Pressure under CO2 Atmosphere.

The valorization of waste and by-products from various industrial activities is a must in our world of depleting natural resources and increasing volume of environmentally negative waste materials. The economic utilization of solid biowaste involves predominantly its use as a carbon-neutral energy resource or a precursor of porous carbon materials, with a potential application range including sorption processes, energy storage, and electric engineering. With the considerable number of lignocellulosic residues tested and applied as the most suitable porous material precursors, such as woods, shells, stones, peels, husks, and stalks of various crop plants, there is still space and need for further developments in the valorization of high amounts of other types of biowaste. Here, the olive pomace was considered because of both the vast volume and the environmentally undesired (when stored) phytotoxic effect of its components. While the literature on chemical (acidic and alkali treatment) and physical activation (temperature, carbon dioxide, and/or steam) of various biowaste precursors is considerable, the effects of pressure in the carbonization step are reported rarely, although the results observed are promising. The same applies to reports on the application of olive pomace for porous materials production, which indicate that olive pomace currently seems to be underestimated as a carbon materials precursor. In the study presented, the combined effects of pressure (0.1–3 MPa), temperature (800 °C), and carbon dioxide atmosphere in the carbonization of olive pomace were assessed on the basis of qualitative and quantitative data on micro- and mesoporosity of the carbon materials produced. The results showed the positive effect of increasing the process pressure on the development of a porous structure, and particularly, on the development of supermicropores and ultramicropores under the carbonization conditions applied. Carbon material with the most developed porous structure and the highest share of micropores was obtained under the maximum pressure tested.

Overview of hygienization pretreatment for pasteurization and methane potential enhancement of biowaste: Challenges, state of the art and alternative technologies

Hygienization reduces the public health risks involved in the application of biowaste to agricultural land. Recent advances in the hygienization of treated biowaste have not been reviewed to date. In many countries, the process involves using low temperature thermal pasteurization. Thermal hygienization accounts for between 6% and 25% of primary energy production in European biogas plants. Hygienization pretreatment can also influence the production of biogas by the treated substrates (from a slight negative effect to a biogas yield surplus of 50% in most cases). Alternative athermal pasteurization technologies (including electro-technology, microwave, pressurization, ultrasound and chemical treatment) have been shown to be capable of considerably reducing the number of bacteria and increasing the methane yield. The performance of these alternatives varies greatly and depends on the type of biowaste, the operational parameters studied, energy input and the method of interpreting the experimental results. Analyses of energy and exergy efficiency, of environmental impacts and of economic feasibility show that thermal hygienization may be the most energy efficient and economical approach when it exploits the wasted heat recovered from other processes. The present study also revealed that the research focus has been confined to the sewage sludge. Studies on the other biowaste, including animal by-products, are needed.

Carbonaceous Anodes Derived from Sugarcane Bagasse for Sodium-Ion Batteries.

To realize the sustainability of Na-ion batteries (NIBs) for large-scale energy storage applications, a resource-abundant and cost-effective anode material is required. In this study, sugarcane bagasse (SB), one of the most abundant types of biowaste, is chosen as the carbon precursor to produce a hard carbon (HC) anode for NIBs. SB has a great balance of cellulose, hemicellulose, and lignin, which prevents full graphitization of the pyrolyzed carbon but ensures a sufficiently ordered carbon structure for Na+ transport. Compared with HC derived from waste apples, which are pectin-rich and have less cellulose than SB, SB-derived HC (SB-HC) has fewer defects and a lower oxygen content. SB-HC thus has a higher first-cycle sodiation/desodiation coulombic efficiency and better cycling stability. In addition, SB-HC has a unique flake-like morphology, which can shorten the Na+ diffusion length, and higher electronic conductivity (owing to more sp2 -hybridized carbon), resulting in superior high-rate charge-discharge performance to apple-derived HC. The effects of pyrolysis temperature on the material characteristics and electrochemical properties, evaluated by using chronopotentiometry, cyclic voltammetry, and electrochemical impedance spectroscopy, are systematically investigated for both kinds of HC.

A Comparative Study of Fe (II) Ion Adsorption onto Chemically Activated Banana Peel and Sawdust Bio-adsorbent

The adsorption capacity of ferrous ions onto bio-sorbents prepared from two different types of bio-waste of banana peel (CABP) and sawdust (CASD) treated with sulfuric acid was studied using Langmuir and Freundlich isotherms. Result shows that the optimum pH value for about 99 % Fe (II) adsorption onto the CABP and CASD was found to be 3 and 4, respectively, after 5 hours or more contact time period. Both the Langmuir and Freundlich adsorption models are fitted to remove the Fe (II) ions from aqueous solution by the bio-adsorbent of CABP and CASD. The maximum adsorption capacities for the CABP and CASD were found to be about 34 and 116 mg/g, respectively. These results showed that the CASD seems to be more effective bio-adsorbent than the CABP to remove the Fe (II) ions from drinking or/and wastewaters.Int. J. Appl. Sci. Biotechnol. Vol 6(2): 137-141

Feasibility and Sustainability of Bioethanol Production from Starchy restaurants’ Bio-wastes by New Yeast Strains

The study treats an important and imperious worldwide problem. It deals with the production of alternative biofuels from starchy restaurants’ bio-waste. The starchy wastes of the restaurants, especially in developing countries, are produced in huge quantities that represent a sustainable substrate for ethanol production. So, we aimed to study the feasibility of the conversion of the starchy wastes to biofuel (bioethanol) using different pretreatments and new yeast strains. Our results approved the feasibility of conversion of the starchy wastes into biofuel. Using of thermo-acidic hydrolysis, we obtained 360 g of free and fermentable sugars from each dry kg of the wasted materials. Pichia barkeri and Candida intermedia were introduced as new species for the field of biofuel production in addition to the classical Saccharomyces cerevisiae. Among them, S. cerevisiae KKUY-0301 produced 11.5 g/L of ethanol from 27 g of sugars. Its transformation rate was 82% of the theoretical yield, i.e. 1 kg of the waste could produce 150 g of ethanol. Optimization of the cultural conditions approved that 4 days of incubation, pH 5, 35 °C and 5% of the yeast inoculum (108 cell/mL) were the most appropriate conditions that could induce the maximum production bioethanol. This study recommends the application of this technology on a commercial scale all over the world to benefit from all types of bio-wastes. In addition, our findings offer a crucial solution for the recycling the restaurant starchy waste materials into ecofriendly product “biofuel” that reduce the overall cost production of the bioenergy and make it a competitive to the oil-based energy.

20 renewable biowastes derived carbon materials as green counter electrodes for dye-sensitized solar cells

Twenty types of biowastes derived carbon materials (BCM) synthesized by a facile one-step pyrolysis were developed as counter electrodes for the configuration of dye-sensitized solar cells (DSSCs). The biowastes selected for the BCM preparation were divided into three groups: (i) eleven woods, including weeping willow, phoenix, camphor, Chinese fir, maple, peach, poplar, cypress, tea-oil camellia, orange, and chinaberry; (ii) seven leaves, including pine needles, camphor, palm, maple, poplar, Chinese fir, and red after-wood; and (iii) two papers, namely filter paper and facial tissue. Each of the BCM based DSSCs shows a higher efficiency than the graphite based counterparts. The efficiencies of the DSSCs employing the BCM prepared from woods and leaves vary in a range 1.23% -1.91% and 1.07%-1.85%, respectively, while that of the devices using the graphite is 0.77%. The peak efficiency in both groups of the wood and leaf based cells is achieved by employing the phoenix wood and the palm leaf as the raw materials, respectively. Compared with the porous BCM obtained from the woods and leaves, the fibrous BCM fabricated from the papers show better efficiencies of around 4.70% for use in the DSSCs. The high efficiency is mainly attributed to the superior catalytic activity and faster electron transportation for tri-iodide (I3−) reduction induced by the unique morphological and structural characteristics of the paper derived BCM, such as hierarchical fibrous carbon skeletons at nanometer and micron scales, abundant exposed microcrystal edges and defects, rough surface at nanoscale with rich burrs and convex microstructures, and oxygen-containing surface functional groups. Furthermore, the efficiency of the DSSCs employing the paper derived BCM is equal to about 88% of that of the devices using the mesoporous carbon synthesized from the phenolic resin mixtures based on polymerization-induced phase separation.

Multifunctional Power Plant

This Multifunctional Power Plant will have unique features. Sea water which is available in abundance in nature is used as a source of energy by utilising solar radiation through the method of photolysis of water. in this multifunctional plant all types of Bio-Waste e.g. agricultural , forest, domestic etc. are also used for production of fertiliser & biofuel Thus we are able to manage our Bio Wastes.As a byproducts pure water & salt are also generated which can be used in our society. In the process of power generation there is no emission of Green House Gasses and hence no Green House Effect.

In Situ Immobilization of Heavy Metals in Severely Weathered Tailings Amended with Food Waste-Based Compost and Zeolite

Biowastes and inorganic additives are acknowledged efficient but site-dependent alternatives for in situ metal immobilization. The present study evaluates food waste-based compost, a particularly abundant type of biowaste in South Korea, and zeolite as amendments for increasing pH and reducing metal leaching potential in weathered tailings from an abandoned mine site. Two types of biowaste were used: food waste compost (60 % food waste and 40 % sawdust) and market compost (50 % food waste, 10 % agricultural waste, 10 % manure, and 30 % lime). Materials were thoroughly characterized. Leaching tests were then performed in reactors filled with various mixtures of organic–inorganic amended tailings, over a 4-week period. The in situ metal immobilization efficiency of compost was evaluated based on collected leachate quality. Results indicated that both organic and inorganic materials were successful for increasing pH (from 3.0 to up to 8.1) and metal immobilization, except for Pb and As, with which leaching potential increased in most amended reactors relative to un-amended tailings (up to 43 and 158 %, respectively). Over the duration of the experiment, the cumulative reduction of metal leaching potential ranked as follows: Zn (44–91 %) > Mn (4–76 %) > Cr (20–53 %) > Fe (34–44 %) > Cd (17–43 %) > Al (0.5–24 %). Among mixtures, combined biowaste and zeolite-amended tailings showed the best performance for increasing pH (7.5–8.1) and for metal immobilization. Chemical and biological processes, such as sorption and precipitation processes, were predominant. Overall, the study provides useful data on the efficient use of food waste compost for acid mine drainage prevention in South Korea.

Influence on Polychlorinated Biphenyls Content Using Three Types of Biowastes As Fertilizers In Agricultural Soils

A 4-year field study was carried out to investigate the effects of three types of biowastes application on PCB accumulation in agricultural soils. This study was based on the experiments designed for four soils in two areas of Palencia province (Spain) (Cerrato and Tierra de Campos) for non irrigated and irrigated land after applying biowaste. The amounts of the three different types of biowastes added were determined according to the fertilization needs of nitrogen for the crop. The concentrations of PCBs in soils were determined before and after biowaste application. The three biowaste treatments raise the concentration of PCBs in the soil, sewage sludge compost (SC) treatment produced the main increase in PCBs concentration, followed by municipal solid waste compost (MC) treatment and the dehydrated sewage sludge (SD) treatment. The values of biowaste treated areas were 3.7-11.5 times higher than the respective values of the non treated areas. Changes observed in the congener distribution also suggest the influence of the biowaste on the soil. The biowaste used had an average PCBs concentration of 63.16 ng g−1 with a range from 34.08 ng g−1 to 118.93 ng g−1, which are values below the EEC recommended limit (800 ng g−1). In the soils without treatment was found an average concentration 0.206 ng g−1 of PCBs, typical of areas with low levels of environmental pollution.

Composition and parameters of household bio-waste in four seasons

Bio-waste makes up almost half portion of municipal solid waste. The characterization of household bio-waste is important in determining the most appropriate treatment method. The differences in composition and parameters of bio-waste derived from urban settlement (U-bio-waste) and family houses (F-bio-waste) during the four climate seasons are described in this paper. Twelve components and 20 parameters for bio-waste were evaluated. The composition of U-bio-waste was almost steady over those seasons, unlike F-bio-waste. U-bio-waste was comprised mainly (58.2%) of fruit and vegetable debris. F-bio-waste was primarily made up of seasonal garden components. The amount of variation among seasons in both type of bio-waste increased in sequence: basic parameters < macro-elements < potentially toxic elements. Spearman’s correlations among proportions of individual components and parameters of bio-waste were found out. Results of this research could be utilized to support another composition and parameters of bio-waste and be suitable for establishing bio-waste processing.

Factors controlling pathogen destruction during anaerobic digestion of biowastes

Anaerobic digestion is the principal method of stabilising biosolids from urban wastewater treatment in the UK, and it also has application for the treatment of other types of biowaste. Increasing awareness of the potential risks to human and animal health from environmental sources of pathogens has focused attention on the efficacy of waste treatment processes at destroying pathogenic microorganisms in biowastes recycled to agricultural land. The degree of disinfection achieved by a particular anaerobic digester is influenced by a variety of interacting operational variables and conditions, which can often deviate from the ideal. Experimental investigations demonstrate that Escherichia coli and Salmonella spp. are not damaged by mesophilic temperatures, whereas rapid inactivation occurs by thermophilic digestion. A hydraulic, biokinetic and thermodynamic model of pathogen inactivation during anaerobic digestion showed that a 2 log 10 reduction in E. coli (the minimum removal required for agricultural use of conventionally treated biosolids) is likely to challenge most conventional mesophilic digesters, unless strict maintenance and management practices are adopted to minimise dead zones and by-pass flow. Efficient mixing and organic matter stabilisation are the main factors controlling the rate of inactivation under mesophilic conditions and not a direct effect of temperature per se on pathogenic organisms.