Organic Waste Components Research Articles

Optimizing household organic waste management in support of sustainable household waste management in Bekasi City, Indonesia

Household waste that is not properly managed has the potential to pollute the environment and disrupt health. Providing information and knowledge to the public on proper household waste management is one of the efforts to preserve the environment and improve independent household waste control. The daily amount of organic waste generated from households reaches up to 40% of the total waste generated. Hence, household waste control heavily contributes to reducing the amount of waste transported to the Final Processing Site. Such a program can be carried out by identifying and analyzing an appropriate and beneficial household waste control plan at the household level. Data collecting in this study was conducted online, towards 548 respondents in Bekasi City, Indonesia. Laboratory tests were also carried out on the results of fermentation of household waste samples to analyze the content of organic waste components produced from households. The results showed that the community is still not optimal in managing household waste as only 33% of respondents are known to have utilized organic waste generated from households. The results of laboratory analysis showed that organic waste generated from households has components similar to commercial fertilizers. Considering the similar components of organic waste generated from households with commercial fertilizer, show the potential benefit from organic waste utilization. Further research regarding the benefits of fertilizer from household organic waste, and the benefit comparison with commercial fertilizers would be able to increase public trust and awareness to manage their household waste. Proper waste management on the household level would significantly reduce the volume of waste transported to the Final Processing Site.

Substantiation of the main parameters of a hammer crusher for grinding municipal solid waste

The scientific novelty of the research lies in the determination and substantiation of the rational values of the main parameters of a hammer crusher designed for grinding organic components of municipal solid waste. A method has been developed for calculating the speed and effort, as well as the maximum elastic-plastic deformation of the components of the waste due to the collision of the waste against each other, against the wall of the working chamber of the crusher, as well as against knives welded on the walls of the working chamber at different heights at an angle of 120 degrees with each other. The aim of the study is to develop a hammer crusher design with low energy and material consumption with increased technical and operational performance. As a result of the experimental studies, the dependences of the crusher performance on the number of revolutions of the rotor shaft, on the light area of the grates, and on the diameter of the rotor were obtained. The processing of the obtained experimental data made it possible to obtain a mathematical model that adequately describes the process of crushing the organic components of the waste in a hammer crusher. Design and production of hammer crushers with rational parameters will reduce energy and material consumption by approximately 1.5-2.0 times compared to traditional designs.

Identification of waste composition in Shopping Centre X in Central Jakarta City

Waste is an unavoidable by-product of most human activities. Central Jakarta City is one of the administrative cities in the centre of the Special Capital Region of Jakarta, where Shopping Centre X is situated, a place relied on by the local community to serve their needs and to facilitate community activities. Shopping Center X has ±4,478 active shops which occupy all of its 9 floors, built on an area of 47,760 m2 and the waste generated varies. The purpose of this study was to identify sources of waste, before analysing the waste generation and composition in Shopping Centre X. The waste composition is an illustration of each component contained in the waste produced, and it can be used as a basis for determining a proper waste management in Shopping Centre X. Sampling was carried out using the SNI 19-3694-1994 method, where the waste measurement was made using a sampling box for eight consecutive days. The results of field research showed that, the waste composition in Shopping Centre X consists of 77.42% nonorganic and 22.58% organic waste components. The average rate of waste generation in Shopping Centre X is 3.58 kg/shop/day. The primary data collection was done directly, through field surveys and sampling. Waste samples taken were based on store category grouping on all the 9 (nine) floors, representing the number of samples in Shopping Centre X.

Proteins recovery from waste activated sludge by thermal alkaline treatment

Extracellular polymeric substances(EPS) are the major organic component of waste activated sludge (WAS), and proteins are the dominant organic component of EPS. To recover the protein effectively, hydrolysis treatment should be carried out so that the protein in the sludge flocs and microbial cells is ultimately released into the aqueous phase. In this study, a chemical method(thermal alkaline treatment(TAH)) was used to extract proteins from WAS. The factors affecting the extraction of proteins from sludge by TAH method were optimized with the extraction rate of protein as the index. The peak concentration of 549.86 mg/L and extraction rate of 60.72% of sludge protein for TAH, was achieved at pH of 13, temperature of 70 °C, reaction time of 9 h, and sludge concentration of 20 g/L of experimental conditions. Partial macromolecular protein was broken down into low molecular protein and less melanoid was produced. Further analysis of sludge residue by X-ray diffraction(XRD) and X-ray photoelectron spectroscopy(XPS) indicated it might be related to the formation of calcium carbonate(CaCO3) at pH of 13 and temperature of 70 °C. Relative molecular weight of sludge proteins was tested by sodium dodecyl sulfate polyacrylamide gel electrophoresis(SDS-PAGE) with coomassie blue staining. The relative molecular weight of extracted sludge protein was approximately between 6.5 kDa and 16 kDa. All these indicated that macromolecular protein was changed into low molecular protein during the thermal alkaline hydrolysis process and that released carbon dioxide combined with calcium ions to form insoluble calcium carbonate. However, complete purification of the sludge protein still needs further study.

Analysis of waste processing potential in Gunung Putri District, Bogor Regency

The increase in waste generation in Gunung Putri Subdistrict, Bogor Regency, causes an increased burden at the Landfill Site (TPA). One of the efforts to reduce the burden of Landfill Site (TPA) is to maximize the Waste Processing Site (TPS) by applying the circular economy concept. This study aims to analyze the generation, composition, and potential of waste processing to have economic value. The sampling method used is a combination of purposive sampling and stratified random sampling. The results showed that with a population of 304,672 people and a waste generation rate of 0.48 kg/person/day, it is estimated that the waste generation in Gunung Putri District is 147,156.58 kg/day. The waste material in Gunung Putri Subdistrict consists of 52.86% organic waste components and 47.14% non-organic waste. Organic waste is dominated by food waste by 50.38%. From the results of the characteristic test of the waste, it is known that the water content is 63.16%, the ash content is 29%, the C/N ratio is 7.03%, and the calorific value of the waste is 1.924 kcal/kg by considering the amount of generation, composition, and characteristics of waste, which are then used with standards or criteria for waste processing technology from various references. Organic waste in Gunung Putri Subdistrict has good potential to be processed using the Black Soldier Fly (BSF) and organic waste processing with Peuyeumisasi Method (Biodrying) and recycling for non-organic waste.

Reactor for Waste Gasification with Highly Superheated Steam

Using highly superheated steam (HSS) with a temperature of above 2000 K for oxygen-free gasification/detoxification of industrial, municipal, and toxic waste, the organic component of waste can be completely converted to syngas or power gas. It was proposed for the first time to produce such HSS by cyclic detonation of stoichiometric ternary mixtures fuel–oxygen–steam at a near-atmospheric initial pressure and to feed it into a cooled flow-type spherical reactor as supersonic countercurrent two-phase jets together with finely divided waste particles. Three-dimensional gas-dynamic calculations showed that the cyclic feed of supersonic jets into the reactor gives rise to intense vortex zones of high-temperature HSS. Waste particles repeatedly enter into these vortex zones and are gasified or heat-treated, and the shock waves accompanying the feed of the supersonic jets prevent particle agglomeration. In the quasi-stationary operation process, a small overpressure is maintained in the reactor (to prevent the suction of atmospheric air), and the median mean residence time of the particles is sufficient for their complete gasification.

Sparking Anaerobic Digestion: Promoting Direct Interspecies Electron Transfer to Enhance Methane Production.

Anaerobic digestion was one of the first bioenergy strategies developed, yet the interactions of the microbial community that is responsible for the production of methane are still poorly understood. For example, it has only recently been recognized that the bacteria that oxidize organic waste components can forge electrical connections with methane-producing microbes through biologically produced, protein-based, conductive circuits. This direct interspecies electron transfer (DIET) is faster than interspecies electron exchange via diffusive electron carriers, such as H2. DIET is also more resilient to perturbations such as increases in organic load inputs or toxic compounds. However, with current digester practices DIET rarely predominates. Improvements in anaerobic digestion associated with the addition of electrically conductive materials have been attributed to increased DIET, but experimental verification has been lacking. This deficiency may soon be overcome with improved understanding of the diversity of microbes capable of DIET, which is leading to molecular tools for determining the extent of DIET. Here we review the microbiology of DIET, suggest molecular strategies for monitoring DIET in anaerobic digesters, and propose approaches for re-engineering digester design and practices to encourage DIET.

Use of organic wastes to create lightweight green roof substrates with increased plant-available water

Substrate design is important for stormwater retention and plant survival on green roofs. Green roof substrates are mostly inorganic, providing long-term stability, while organic components (<20% v/v) reduce substrate weight and increase water retention, depending on rate and type. Selection of organic components depends on availability and organic waste materials can improve sustainability and reduce costs. We aimed to use organic waste materials to create lightweight substrates with good aeration and increased plant-available water (PAW) to support plant growth on green roofs. We evaluated the effects of five locally available organic waste components (coarse coir, fine coir, composted green waste, almond hull, and pistachio shell) on the physical and chemical properties of a scoria-based substrate when added at 0, 5, 10, 15, and 20% by volume. We also examined their phytotoxic effects on plant growth using lettuce (Lactuca sativa) as bioassay species. Overall, higher rates (15–20 % v/v) of coarse coir, fine coir and composted green waste all reduced substrate weight and improved PAW. Pistachio shells and almond hulls reduced saturated bulk density but adversely affected plant growth, likely due to phenolic compounds. For the other amendments, rates above 10–15 % addition also decreased root and shoot growth in lettuce. This indicates a potential trade-off between water availability and growth in these substrates. Therefore, if a green roof needs to be amended to reduce weight but have improved PAW, coarse coir, fine coir and composted green waste would be the best choices.

Influence of Organic Matters on the Calcium Carbonate Decarbonization Process

Pure calcium carbonate, chalk, and coal wastes are taken as starting materials. The Gibbs energy of calcium carbonate decarbonization reactions is calculated. By the method of thermodynamic analysis, the effect of carbon and its gasification products on the calcium carbonate decarbonization process is investigated. The intensifying effect of organic matter during heat treatment of calcium carbonate is shown. In addition to carbon, the decarbonization reactions are influenced by gases evolved as a result of the gasification of the organic part of the coal waste. It is theoretically proven that the organic component of coal waste contributes to lowering the temperature of the onset and end of the decomposition of calcium carbonate. To confirm the theoretical background, experimental studies of the behavior of mixtures during heating have been carried out. The effect of organic matter on decarbonization of pure calcium carbonate and chalk has been studied. Thermograms have shown that less caloric energy is required for the decarbonization of chalk than for the decarbonization of pure CaCO3. Organic transformations occur in the material layer, which contributes to intensive heat transfer. The products of thermochemical transformations of the organic mass increase the efficiency of the process of decarbonization of calcium carbonate using the waste of coal enrichment in the composition of the raw mix. The organic component of the waste not only reduces the amount of heat energy expended on the endothermic process of calcination, its presence in the raw material mix reduces the temperature of the process of calcination as pure calcium carbonate and chalk.

Composition of a Microbial Community at Different Stages of Composting and the Prospects for Compost Production from Municipal Organic Waste (Review)

This paper summarizes the current understanding of changes in the composition of the microbial community within compost in relation to the temperature at each stage of the process and explores the role of microbial associations in the biodegradation and detoxification of organic waste components. Attention is paid to the process of creating a balance between the active aerobic and anaerobic microorganisms in the compost mass, which allows nitrogen to be preserved in the finished compost and the cost of aeration to be reduced. It has been shown that the addition of natural minerals, in particular, zeolite, has a positive effect on the composting process and improves the quality of the compost, ensures the content of silicon in a bioavailable form in the compost, prevents ammonia emissions, and reduces the concentration of heavy metals. Particular attention is paid to the prospect of composting compacted anaerobically treated sewage sludge with the addition of an organic fraction of municipal solid waste (MSW) and lignocellulosic waste.

Recovery of Sulfur-Alkaline Waste by Processing into Cellular Silicate Material

The formation of cellular silicate glasses from sulfide-alkaline solutions and amorphous silicon oxide has been studied. The mechanism of formation of silicates from sodium hydroxide and amorphous silicon oxide and processes of gasification with the participation of the organic component of waste are considered. Technological solutions for recovery of sulfide-alkaline solutions are proposed. At the same time, the process of recovery consists in mixing sulfuralkaline waste with natural amorphous silicon oxide, tripoli, and further roasting the resulting composition at glass formation temperatures. As a result of heat treatment, sulfur from organosulfur compounds is oxidized to sulfur (IV), and sodium hydroxide, after dehydration, enters in composition of the resulting vitreous silicate cellular material.

Composting parameters and compost quality: a literature review

Economic growth and rising food consumption in the world have led to increased production of organic wastes due to an important intensification of the agricultural production systems. The analysis of macro elements (nitrogen [N], phosphorus [P], and potassium [K]) in organic wastes reveals that the economic loss is significant with the intensification of the agricultural system. The good management of those wastes would be an effective means of organic matter restoration through carbon restitution to the depleted soils through organic amendments. Composting is a type of waste processing that has gained increasing acceptance over the years. As a rule, the process consists of the natural biological decomposition of organic waste components and involves diverse species of microorganisms. Those organic residues could reconstitute soils and be an important fertilization backup. Composts prepared from different organic wastes differ in their quality and stability, which further depends upon the composition of raw material used for the compost production. Compost quality is closely related to its stability and maturity. The wide variety of chemical and biological variations that occur during composting, and the range of methods suggested in literature, has made it difficult to agree on methods for the practical assessment of maturity. A literature review of the main start-up, monitoring and maturity parameters are discussed concerning different raw materials used and different composting methods practiced.

Carbon Trade Project “Biological Waste Treatment” for Gaobeidian (PR China)

AbstractThe Department of Waste Management at the Braunschweig University of Technology is designing a biological treatment plant for municipal solid waste (MSW) for the City of Gaobeidian (Hebei province/PR China). A German‐Chinese joint venture has contracted the project, KfW banking group provides financial assistance. The project aims on the reduction of methane emissions from decay of organic waste components at landfills. Due to biological treatment, organic components are being stabilized, what reduces methane emissions after final disposal significantly. The mechanical biological treatment (MBT) plant is designed for a capacity of 40000 t/year. In the first project phase a feasibility study is being conducted. The residual waste has been analyzed and treated in a pilot plant. Regarding the project financing, additional turnovers shall be achieved by the sale of Certified Emission Reductions (CERs). Emission reductions of approximately 10000 t CO2 equivalents (CO2eq) per year are expected, worth some 80000 to 100000 Euro/year. The official registration of the project at the United Nations Framework Convention on Climate Change (UNFCCC) is being prepared.

Geochemically derived non-gaseous radionuclide source term for the Asse salt mine – assessment for the use of a Mg(OH)2-based backfill material

SummaryThe Asse salt mine was used as a test site for radioactive waste disposal from 1967 to 1978. Low- and intermediate-level waste forms (LLW/ILW) were emplaced, containing a total radionuclide inventory of 3×1015Bq, estimated for reference date January 1, 2005. It is expected that MgCl2-rich brine will enter the emplacement rooms and react with the cemented waste products. Possible microbal degradation of organic waste components in MgCl2-rich brine could produce significant quantities of CO2, resulting in an acidification and consequently in an increase of element solubilities. Application of buffering backfill materials is discussed for closure of the mine. Selection of backfill materials is based on geochemical modeling taking into account the corrosion of the cemented LLW/ILW and degradation of organic waste components. In the present study the evolving geochemical milieu and respective solubilities of Am, Np, Pu, U, Th, Tc, Sr, Cs and I were modeled for each emplacement room. Laboratory experiments were undertaken to selectively verify the modeling predictions.Geochemical modeling leads to the conclusion that Portland cement, a Mg(OH)2-based material and crushed salt can be used in different combinations as backfill materials. According to the predictions Mg(OH)2-based backfill material controls the pH and concentration of dissolved inorganic carbon within ranges that are favorable with respect to actinide solubilities. A source term for radioelements and fission products is derived from a comparison of the respective solubilities and the radionuclide inventories. Calculated solubilities of Th, Pu and U are lower than their inventories. These are controlled by the thermodynamic solubility therefore. Maximum solution concentrations of all other elements are controlled by their inventory.

Alternative MSW treatment options to reduce global greenhouse gases emissions - the Israeli example

In order to comply with the Kyoto Protocol agreements, Israel has to assess all the sources contributing to greenhouse gases (GHG) and analyze the alternative options to reduce these emissions. The waste sector in Israel contributes 13% of total GHG emissions for a time horizon of 100 years (for a time horizon of 20 years, the waste sector contribution equals more than 25% of total GHG emissions). Mitigation options from the waste sector, as well as the costs associated with each alternative, show that the most cost-effective means to treat the degradable organic components of waste is by aerobic composting (investment of less than 10 US$ to reduce emission of 1 t of CO2 equivalent per year). The environmental basis for regulating landfill gas (LFG) flares should be based on the potential damage of GHG emitted from landfills. The economic rational in the additional investment needed to recover energy from the LFG will be partially covered by income from energy sales. The ultimate goal is to minimize the amount of methane by converting it to CO2; this can be done most effectively by incineration. But, compared with other technologies, this is the most expensive option. Steps taken to minimize GHG emission from the waste sector should play a significant role in the short- and medium-term. The considerations used here apply to many other countries worldwide as well. It seems that a proper waste management may be one of the immediate and available means to mitigate GHG in the short- and medium-term.

The migration of uranium through Clashach Sandstone: the role of low molecular weight organics in enhancing radionuclide transport

The migration of uranium through siliceous porous media has been investigated by conducting a series of core flood experiments in conjunction with the development of predictive coupled chemical transport models. Initial investigations made during the programme have demonstrated that under oxidising conditions, at pH≈5–6 with NaCl concentrations ≈0.3 mol dm −3, uranium is strongly retarded by adsorption to a Clashach Sandstone matrix. Sorption has been shown to be largely reversible, dependent on the absolute concentrations involved and on the finite sorptive capacity of the rock. Comparative experimental and modelling studies have also demonstrated the sorptive behaviour of the Clashach Sandstone to be close to that of amorphous silica. Recent work has focused on assessing the role of EDTA and cellulose degradation products in enhancing uranium mobility by complexation/chelation. Laboratory scale migration experiments involving radio-labelled EDTA and saccharic acid have been supported by batch sorption studies to investigate the behaviour of the U–EDTA-silica and U–saccharic acid-silica systems. In order to obtain unequivocal comparisons of the rates of uranium migration in the presence and absence of the organic complexant, parallel column floods have been carried out such that intact cores of Clashach Sandstone have been flooded with waters from the same reservoirs at carefully controlled flow rates. Geochemical modelling techniques have been used to assess the chemical speciation of the waters, to describe the sorption behaviour observed in the batch sorption studies and, where appropriate, derive model specific data to allow predictive coupled chemical transport modelling of the migration experiments. It is shown that, for a pre-equilibrated uranium-organic system, the use of conventional techniques encompassing complexation in the aqueous phase and reversible adsorption of organically-bound species would give a reasonable approximation of the system. Conversely, where uranium is introduced ahead of the organic plume, re-mobilisation is severely constrained by slow desorption kinetics. The results point to the need to consider the sequence of radionuclide interactions with organic waste components in formulating models used in performance assessment.

Coprecipitation of Radionuclides During Cement Degradation: A Preliminary Modeling Study for the Swiss L/ILW Repository

ABSTRACTProduction of carbonate minerals will be a dominant alteration reaction during cement degradation in the near-field of the L/ILW repository planned at Wellenberg (Switzerland). Very large amounts of calcite are predicted to precipitate as a result of (a) the interaction between bicarbonate-rich ground water and cement phases and (b) the in-situ degradation of organic waste components in the repository.A preliminary model was developed to estimate to which extent coprecipitation with calcite could reduce radionuclide concentrations in solution. Since the main objective was only to determine the order of magnitude of this effect, a very simple, closed-system model was considered to be sufficient. The model assumes instantaneous dissolution of the entire radionuclide inventory in the water-saturated pore space of the repository caverns and simultaneous reversible sorption on the cement. Coprecipitation of radionuclides with calcite and residual solution concentrations are calculated assuming in-situ precipitation of a given amount of calcite and using nuclide-specific partition coefficients.The model calculations show that the solution concentration of several radionuclides (tetravalent and trivalent actinides, Sr and Ni) is likely to decrease by orders of magnitude as a consequence of coprecipitation with large amounts of secondary calcite. Further, radionuclide coprecipitation is found to depend on the extent to which the same radionuclide is sorbed on cement phases. The results confirm that coprecipitation with calcite will be an important process in determining concentration limits for dissolved radionuclides in the Wellenberg repository.

Radiation treatment of solid wastes

Solid waste is now generally recognized as both a major problem and an underutilized renewable resource for materials and energy recovery. Current methods for dealing with solid wastes are admittedly inadequate for cost effective utilization of the latest material and energy values, especially of cellulose and other organics. Processes for production of energy from organic wastes including incineration, pyrolysis and biodegradation, are receiving considerable attention even though the heating value of dried organic wastes is substantially less than that of fossil fuels. An attractive alternative approach is conversion into chemical feedstocks for use as fuels, intermediates for plastics, rubbers, fibers etc., and in the preparation of foods. Radiation treatment of solid wastes offers attractive possibilities for upgrading the value of such organic waste components as cellulose and putrescible matter. The latter can be cold sterilized by radiation treatments for the production of animal feed supplements. The wide availability of cellulosic wastes warrants their consideration as an alternate feedstock to petrochemicals for fuels, intermediates and synthesis of single cell protein. The crucial step in this developing technology is optimizing the conversion of cellulose to its monomer glucose which can be accomplished by either acid or enzymatic hydrolysis. A combination pretreatment consisting of radiation of hydropulped cellulosic wastes has shown considerable promise in improving the yields of glucose for acid hydrolysis reactions at substantially lower cost than presently used methods such as grinding. Data are presented to compare the effectiveness of this pretreatment with other techniques which have been investigated.