Waste In Bioreactor Research Articles

Development of Small-scale Integrated Hydroponics—Animal Waste Bioreactor (AWB) for Romaine Lettuce (Lactuca sativa L. var. longofolia) Production

As improper processing and disposal of animal waste cause negative impacts on the environment, the animal industry sector must shift to more sustainable practices to lessen these effects. Recently, the application of the circular economy concept in agriculture, using animal waste as part of nutrient cycling, has emerged as a sustainable approach. The study aims to develop and test the small-scale integrated hydroponics-animal waste bioreactor (AWB) for romaine lettuce production using chicken manure tea (CMT) derived from dried chicken manure as a primary nutrient source. Three integrated hydroponics-AWB systems, with varying concentrations of CMT at 1,000 ppm, 1,200 ppm, and 1,400 ppm total dissolved solids (maintained within an upper and lower bound of 50 ppm), were constructed, tested, and compared to conventional hydroponics that used a nutrient solution maintained at 1,000 ppm TDS. The test result suggests that the ideal concentration of CMT in the system is 1,000 ppm. Within the optimum manure tea concentration, the small-scale integrated hydroponics-AWB produced romaine lettuce with growth parameters comparable to conventional hydroponics. In addition, increasing the CMT concentration to 1,400 ppm negatively impacts the plant growth parameters of romaine lettuce. The developed small-scale integrated hydroponics-AWB system provides a viable approach for growing lettuce using animal waste as the major source of nutrients. The developed production system could help mitigate the negative environmental effects of improper handling and disposal of animal waste and dependence on chemical-based nutrient solutions in hydroponic crop production.

ENHANCED IN-SITU REDUCTION OF LEACHATE PARAMETERS DUE TO AERATION AND LEACHATE RECIRCULATION IN PILOT SCALE MSW BIOREACTOR LANDFILL MODELS IN TROPICAL CLIMATE

The processes for optimizing toxicity removal of leachate from pilot scale Municipal Solid Waste bioreactor landfills were attempted. Landfill models were simulated in Fibre Reinforced Plastic tanks of size 1.5m x 1.0m x 1.0m by applying interventions like aeration and leachate recirculation. It was found that the Chemical Oxygen Demand and Biochemical Oxygen Demand values increased till 46th week after which the values started reducing. On 89th week after closure of landfill, the aerobic landfill model showed the minimum values for COD (10,200 mg/l) and both anaerobic and aerobic models with leachate recirculation had the lowest BOD (4934 mg/l). By 116th week the least concentrations of COD and BOD were in anaerobic landfill model with leachate recirculation (64 and 22 mg/l). Ammonia Nitrogen was the least in aerated model with leachate recirculation by 116th week from closure (281 mg/l). Conductivity was less in the landfill models with leachate recirculation (4.2 and 5 mS/cm for anaerobic and aerobic respectively).

THE USE OF METHANOGENIC PLANTS BASED ON SOLID COMMUNAL WASTE IN LOW-RISE CONSTRUCTION

The authors consider the main aspects of local utilization of waste of low-rise buildings by methane fermentation with the subsequent production of secondary energy resources. Currently, the generation of methane in artificial conditions is an intensively developing industry. Previously, the authors studied the experience of the regions of Russia in the disposal of solid domestic waste. It is revealed that the processing of solid municipal waste in bioreactors can be carried out with the joint fermentation of various wastes. This is also possible by adding existing accelerators for the methane fermentation reaction. The quantitative characteristics of waste generated on the territory of individual residential low-rise buildings have been studied. From the total volume to be disposed of, waste potentially suitable for the formation of the initial substrate was isolated. The main properties of raw materials for the necessary generation of bio methane have been determined. The specific methane yield during its constant generation has been calculated for various combinations of municipal waste of low-rise buildings. The paper presents a general concept of local processing of municipal solid waste and describes the scheme of the methane generating plant. The dimensions and technical characteristics of the installation for obtaining bio methane from waste at the place of their formation in residential buildings have been determined. In addition, the calculation of thermal energy produced on the base on generated methane was carried out. And it was found that the introduction of methane-generating plants in the technical systems of low-rise buildings allows to increase their energy efficiency, reduce the load on existing landfills of solid domestic waste and achieve maximum utilization of waste from residential areas.

Application of different packing media for the biofiltration of gaseous effluents from waste composting

ABSTRACT A pilot-scale experiment was implemented in a waste bioreactor with an inner capacity of 1 m3 in order to simulate a real-scale composting process. The waste underwent composting conditions that are typical of the initial bio-oxidation phase, characterised by a high production of volatile organic compounds (VOCs), hydrogen sulphide (H2S) and odorants. The waste bioreactor was fed with an intermittent airflow rate of 6 Nm3/h. The target of this study was to investigate the air treatment performance of three biofilters with the same size, but filled with different filtering media: (1) wood chips, (2) a two-layer combination of lava rock (50%) and peat (50%), and (3) peat only. The analyses on air samples taken upstream and downstream of the biofilters showed that the combination of lava rock and peat presents the best performance in terms of mean removal efficiency of odour (96%), total VOCs (95%) and H2S (77%) concentrations. Wood chips showed the worst abatement performance, with respective mean removal efficiencies of 90%, 88% and 62%. From the results obtained, it is possible to conclude that the combination of lava rock and peat can be considered as a promising choice for air pollution control in waste composting facilities.

Dethiosulfovibrio faecalis sp. nov., a novel proteolytic, non-sulphur-reducing bacterium isolated from a marine aquaculture solid waste bioreactor.

A new Dethiosulfovibrio strain, designated F2BT, was isolated from an anaerobic digester for treating solid waste from a marine recirculating aquaculture system. The motile, Gram-negative, non-spore-forming curved rods were 2-7 µm long and 1 µm in diameter. Growth occurred at temperatures ranging from 20 to 40 °C with a maximum rate of growth at 30 °C. The pH range for growth was pH 6.0-8.0, with a maximum rate of growth at pH 7.5. This isolate was halotolerant growing in NaCl concentrations ranging from 0 to 1.6 M with a maximum rate of growth at 0.4 M. Similarly to the five described Dethiosulfovibrio species, this obligate anaerobe isolate was fermentative, capable of utilizing peptides, amino acids and some organic acids for growth, but unlike described strains in the genus did not reduce thiosulphate or elemental sulphur to hydrogen sulphide during fermentation of organic substrates. The G+C content of 55 mol% is similar to the described Dethiosulfovibrio species. The average nucleotide identity analysis between whole genome sequences showed less than 93.15% sequence similarity between strain F2BT and the five other described Dethiosulfovibrio species. Differences in the physiological and phylogenetic characteristics between the new strain and other Dethiosulfovibrio specied indicate that F2BT represents a novel species of this genus and the epithet Dethiosulfovibrio faecalis sp. nov. is proposed. The type strain is F2BT (=DSM 112078T=KCTC25378T).

Continuous recovery and enhanced yields of volatile fatty acids from a continually-fed 100 L food waste bioreactor by filtration and electrodialysis

A novel method to recover VFAs from a continually-fed 100 L food waste bioreactor was developed using industrially applicable methods. The in-situ recovery of VFAs increased production rates from 4 to 35 mgvfa gvs−1 day−1 by alleviating end-product inhibition and arresting methanogenesis, and electrodialysis was able to concentrate the recovered VFAs to 4000 mg L−1. There remains considerable scope to increase the production rates and concentrations further, and the VFAs were recovered in a form that made them suitable for use as platform chemicals with minimal refining. This is the first time that continuous VFA recovery from real-world food waste has been reported at this scale with continual feeding, and represents a promising means through which to produce sustainable platform chemicals. Furthermore the production of VFAs arrests methane production in bioreactors, which is a low value product around which there is a growing concern about fugitive emissions contributing to climate change.

Heavy metals speciation study revealing merits of anaerobic co-disposal of municipal solid waste with discrete paper mill sludges: An experimental investigation in simulated landfill bioreactors

Speciation of heavy metals (Cu, Cr, Pb, Ni, Cd and Zn) during anaerobic co-disposal of two distinct paper mill sludges viz. effluent treatment plant sludge and de-inking plant sludge with municipal solid waste in anaerobic landfill bioreactor was investigated. Effects of moisture content, volatile solids and pH on fractionation of heavy metals over the course of landfilling were also analyzed. Study revealed enhancement in bioavailability of Cu, Cr, Ni and Cd on sole disposal municipal solid waste in bioreactor landfill over 300 days. However, co-disposal of effluent treatment plant sludge with municipal solid waste showed reduction in bioavailability of every analyzed heavy metals with maximum increment in stable residual forms of Cu, Cr, Pb, Ni and Zn by 3.70 %, 0.73 %, 3.08 %, 1.17 % and 3.45 % (dry weight), respectively. De-inking sludge co-disposal was also found effective for reducing bioavailability of Cu, Cd and Zn while bioavailability of Cr, Ni and Pb was unaltered. Strong correlations between increase in residual forms of heavy metals and volatile solid reduction obtained for both co-disposed bioreactors.

Effect of Microbial Inoculation on Lipid and Phenols Removal During the Co-composting of Olive Mill Solid Sludge with Green Waste in Bioreactor

In Mediterranean countries, the olive oil industry generates the most important agro-industrial wastewater, which results in the production of a highly toxic sludge following effluent decantation, thus endangering the environment. In this investigation, an optimized composting process via microbial inoculation is suggested as to alleviate the toxicity of olive mill solid sludge (OMS-Sludge) through addressing its high polyphenol and lipid content. The composting assay was carried out in a bioreactor using mixtures of sludge and green wastes, with or without microbial inoculation, namely: E1 (49% sludge + 49% green waste + 2% thermophilic Inoculum), and E2 (50% sludge + 50% green waste). After 4 months of composting the inoculation had affected at significantly (p < 0.05)pH, EC and total organic carbon degradation compared to control. Furthermore, HPLC analysis revealed that OMS-Sludge composting significantly diminished the polyphenol content (95% and 85% for E1 and E2, respectively), and the lipid content (90% and 81% for E1 and E2, respectively). More importantly, microbial inoculation resulted in a significant composting efficiency, which was corroborated by a decomposition rate 65% for E1 compared to 62% for E2. In-planta assays showed that both the lipid and polyphenol contents werestrongly correlated with the sludge phytotoxicity with respect to seed germination, which was demonstrated by a substantial improvement of the germination index of Cabbage (64.44%), Turnip (86.58%) and Cress seeds (120.85%). Overall, enhancing the composting process through microbial inoculation resulted in a significant alleviation of the initial mixture phytotoxicity, and proved to be an efficient strategy for OMS-Sludge valorization.

Energy Efficiency of Pretreatment of Digester Synthetic Substrate in a Vortex Layer Apparatus

Introduction. Processing organic waste to reduce the anthropogenic impact on the environment remains an urgent task, one of the ways to solve which is the use of methods for bioconversion of organic matter of organic waste to produce gaseous energy carrier and high-quality organic fertilizers. One of the most important stages of anaerobic processing of organic waste in bioreactors is the stage of preliminary preparation of waste for fermentation, which can be carried out by a number of methods. However, the technical literature does not pay enough attention to the use of devices with a vortex layer for the preliminary processing of substrates. The aim of the work is to determine the energy efficiency of the organic waste pretreatment process in the vortex layer apparatus before anaerobic digestion. Materials and Methods. An experimental installation was developed to study the process of organic waste pretreatment. A mixture of organic fraction of municipal solid waste and tap water in the ratio of 300 g/l served as a substrate for treatment in the vortex layer apparatus. Results. The calculations confirmed that the condition for energy efficiency of processing substrate pretreatment of methane is met, despite the additional cost of electrical energy during the integration of this stage in the system of anaerobic processing. Discussion and Conclusion. Integration of the process of organic waste pretreatment in the vortex layer apparatus before fermentation in anaerobic bioreactors into the system of anaerobic treatment of organic waste can improve both the energy efficiency of the system and the level of anaerobic decomposition of organic matter of waste. The specific amount of biogas energy produced in the digestion process in an anaerobic bioreactor with pretreatment of the substrate in the apparatus of the vortex layer fully compensates the energy cost of pre-treatment of the substrate in the vortex layer apparatus. The practical significance of the work is confirmed by an increase in the specific yield of commercial energy by 70% compared to anaerobic treatment in traditional methane tanks.

BIOLEACH: A New Decision Support Model for the Real-Time Management of Municipal Solid Waste Bioreactor Landfills.

This paper introduces BIOLEACH, a new decision support model for the real-time management of municipal solid waste bioreactor landfills that allows estimating the leachate and biogas production. Leachate production is estimated using an adaptation of the water balance equation which considers every hydrological component and the water consumed by anaerobic organic matter degradation to create biogas and the leachate recirculation flows pumped from the landfill pond under a bioreactor management scheme. Landfill gas production is estimated considering the leachate formation process as a coupled effect through the production or consumption of water. BIOLEACH uses waste production and climate data at monthly scale and computes leachate production accounting for the actual conditions inside the waste mass. Biogas production is computed simultaneously, considering the available water to adjust the chemical organic matter biodegradation. BIOLEACH is a valuable bioreactor managing tool as it allows calculating the recirculation volume of leachate that ensures optimal moisture conditions inside the waste mass and therefore maximizing biogas production. As an illustrative example of a BIOLEACH application, the model has been applied to a real landfill located in Murcia Region (Spain) showing the economic and environmental benefits derived from leachate superficial recirculation.

Optimization of carotenoids production by Rhodotorula mucilaginosa (MTCC-1403) using agro-industrial waste in bioreactor: A statistical approach

Bio-colorants are preferred over synthetic colors as bio-colorants not only impart characteristic color to the food also contain harmless bio-active antioxidant nutrients. The present study was undertaken to investigate the potential of agro-industrial waste (Onion peels, potato skin, mung bean husk and pea pods) for carotenoid production from Rhodotorula mucilaginosa. After screening of appropriate carbon, nitrogen sources from agro-industrial waste, the fermentation conditions (pH, temperature, agitation) were optimized using Response Surface Methodology and optimum conditions were pH 6.1, temperature 25.8 ᴼC and agitation 119.6 rpm. Further, to evaluate the effect of aeration on carotenoids synthesis, fermentation was carried out in 3 L bio-reactor under optimum conditions with an air input of 1.0 vvm. Aeration causes elevation of more than 100 μg carotenoids per g of dry biomass. LC-MS of extracted pigment confirmed the presence of some other carotenoids along with β-carotene. The major carotenoid compounds were found from the investigation were torularhodin, β-carotene, and torulene.

KARAKTERISTIK PADATAN ANAEROBIK HASIL PENGELOLAAN TERINTEGRASI SAMPAH KOTA SEBAGAI PUPUK ORGANIK

The issue of municipal waste is a serious problem that threatens environmental sustainability. One of the efforts to overcome this problem is integrated city waste management in the bioreactor. Integrated management leaves a problem, namely the presence of waste in the form of anaerobic solids. The study aimed to analyze the waste content of anaerobic solids in municipal waste in bioreactors and the potential use as organic fertilizer. The method used in the study was analyzing anaerobic solid waste samples from 5 bioreactors containing various sizes of municipal wastes. Sampling by opening the control hole in the middle part of the bioreactor were A: slury, B: 1-3 cm, C: 4-6 cm, D: 7-9 cm, E: without treatment. The sampleswere packed using plastics, then analyzed in laboratory. Observations included analysis of the density of anaerobic solids during the 150-day conversion process in the laboratory. Parameters analyzed included pH, C/N ratio, total solid (TS), volatilesolid (VS), moisture content, nitrite (NO2-N), temperature, and ash content. The results showed that the conversion of anaerobic solids in all sizes of municipal waste in bioreactors showed differences and decreased values indicated by C/N ratio, total solid, volatile solid, nitrite (NO2-N), and moisture content, while ash content increasedand temperature of the material fluctuate during the bio-conversion process. All parameters met the standards and were safe to return to the environment as an organic fertilizer. Keywords: anaerobic solids, municipal waste, oganic fertilizer, bioreactor, bio-conversion

An innovative solution for drying municipal waste in the process of producing alternative fuel on the example of the Municipal Waste Management Company in Olsztyn – a case study

This article presents an innovative solution for drying waste in bioreactors on the example of the Municipal Waste Treatment Plant (ZUOK) in Olsztyn. Shredded mixed waste undergoes fermentation in bioreactors and produces heat for waste drying. Waste transported to the plant is divided into sorted waste which is recycled and mixed waste which is processed into different size fractions. Processed waste is used in the production of alternative fuel which can be burned in dedicated systems in cement plants or incineration plants. Around 5-15% of waste cannot be processed and is landfilled.

Performance of Semi-Aerobic Solid Waste Bioreactor in relation to Decomposition Process and Biogas Production

Solid waste which is sent to Jatibarang landfill in Semarang City can reach up to 4000 m3/day. The composition of solid waste consists of 61.95% of organic waste and 38.05% of inorganic waste. The environmental impacts of solid waste can be reduced using bioreactor methods which being able to accelerate the solid waste decomposition. Large amount of solid waste which is sent to Jatibarang landfill certainly has great potential to environment pollution. Therefore, a technology such as landfill bioreactor is needed to speed up the decomposition process of organic solid waste. Landfill bioreactors are characterized using a range of technologies in order to create an suitable environment for degradation processes. In this study four bioreactors simulated landfills that consist of hybrid bioreactors and anaerobic control bioreactors. The result shows that hybrid bioreactor has increases the decomposition process of organic solid waste. The hybrid bioreactor also produce more methane in subsequent anaerobes.

Simulation of municipal solid waste degradation in aerobic and anaerobic bioreactor landfills.

Municipal solid waste generation is huge in growing cities of developing nations such as India, owing to the rapid industrial and population growth. In addition to various methods for treatment and disposal of municipal solid waste (landfills, composting, bio-methanation, incineration and pyrolysis), aerobic/anaerobic bioreactor landfills are gaining popularity for economical and effective disposal of municipal solid waste. However, efficiency of municipal solid waste bioreactor landfills primarily depends on the municipal solid waste decomposition rate, which can be accelerated through monitoring moisture content and temperature by using the frequency domain reflectometry probe and thermocouples, respectively. The present study demonstrates that these landfill physical properties of the heterogeneous municipal solid waste mass can be monitored using these instruments, which facilitates proper scheduling of the leachate recirculation for accelerating the decomposition rate of municipal solid waste.

Effects of exogenous aerobic bacteria on methane production and biodegradation of municipal solid waste in bioreactors

Landfill is the most common and efficient ways of municipal solid waste (MSW) disposal and the landfill biogas, mostly methane, is currently utilized to generate electricity and heat. The aim of this work is to study the effects and the role of exogenous aerobic bacteria mixture (EABM) on methane production and biodegradation of MSW in bioreactors. The results showed that the addition of EABM could effectively enhance hydrolysis and acidogenesis processes of MSW degradation, resulting in 63.95% reduction of volatile solid (VS), the highest methane production rate (89.83Lkg−1 organic matter) ever recorded and a threefold increase in accumulative methane production (362.9L) than the control (127.1L). In addition, it is demonstrated that white-rot fungi (WRF) might further promote the methane production through highly decomposing lignin, but the lower pH value in leachate and longer acidogenesis duration may cause methane production reduced. The data demonstrated that methane production and biodegradation of MSW in bioreactors could be significantly enhanced by EABM via enhanced hydrolysis and acidogenesis processes, and the results are of great economic importance for the future design and management of landfill.

RESEARCH ON ANAEROBICALLY TREATED ORGANIC WASTE SUITABILITY FOR SOIL FERTILISATION/ANAEROBIŠKAI PERDIRBTŲ ORGANINIŲ ATLIEKŲ TINKAMUMO DIRVOŽEMIUI TRĘŠTI TYRIMAI/ИССЛЕДОВАНИЕ ПРИГОДНОСТИ АНАЭРОБНО ПЕРЕРАБОТАННЫХ ОРГАНИЧЕСКИХ ОТХОДОВ ДЛЯ УДОБРЕНИЯ ПОЧВ

One of the most promising methods to convert organic waste into alternative energy and still obtain fertiliser is anaerobic digestion of waste in bioreactors. To evaluate the suitability of biodegraded organic waste for soil fertilisation, an experiment aimed at determining the amount of total nitrogen, total phosphorus and heavy metals contained in this waste and testing of its pH was carried out. The following organic waste was used for the research: sewage sludge from wastewater treatment plants, fruit and vegetable waste, hen manure, piggery slurry and grain. The biggest contents of nitrogen and phosphorus were determined in anaerobically treated swine manure and therefore, it was found the most suitable organic fertiliser to remediate exhausted soils and used‐up areas. Treated swine manure contains 8.27 mg/l of nitrogen and 293.1 mg/l of phosphorus. The biggest contents of heavy metals were determined in anaerobically treated sewage sludge from wastewater plants. The concentration of chromium amounts to 1.53 mg/kg, that of zinc ‐21.28 mg/kg, manganese ‐ 50.03 mg/kg, lead ‐ 10.46 mg/kg, copper ‐ 50.48 mg/kg and nickel ‐ 12.88 mg/kg. In none of the researched cases heavy metal concentrations in treated organic waste exceeded the maximum permissible concentration (MPC). Anaerobically treated swine manure and sewage sludge with the highest pH indicators, 7 and 7.1, respectively, are most suitable for the fertilisation of acid soils. It could be proposed that digested pig manure is best soil fertilizer from all investigated organic wastes when biogenic elements, heavy metals and pH were measured. Santrauka Vienas iš perspektyviausių metodų organines atliekas paversti alternatyvia energija ir dar gauti trąšą – anaerobinis atliekų skaidymas bioreaktoriuose. Biologiškai suskaidytų organinių atliekų tinkamumas panaudoti dirvai tręšti įvertintas atlikus eksperimentą. Jo tikslas buvo ištirti bendrojo azoto, bendrojo fosforo, sunkiųjų metalų kiekius šiose atliekose bei nustatyti jų pH. Tyrimams naudotos organinės atliekos: nuotekų valymo dumblas, vaisių ir daržovių atliekos, vištų mėšlas, kiaulidžių srutos ir žlaugtas. Nustatyta, kad daugiausia azoto ir fosforo turi anaerobiškai perdirbtas kiaulių mėšlas, todėl jis tinkamiausias kaip organinė trąša labiausiai nualintiems dirvožemiams bei išeksploatuotiems plotams rekultivuoti. Azoto perdirbtame kiaulių mėšle yra 8,27 mg/l, fosforo – 293,1 mg/l. Didžiausi sunkiųjų metalų kiekiai nustatyti anaerobiškai perdirbtame nuotekų valyklos dumble. Chromo koncentracija siekia 1,53 mg/kg, cinko – 21,28 mg/kg, mangano – 50,03 mg/kg, švino – 10,46 mg/kg, vario – 50,48 mg/kg, nikelio – 12,88 mg/kg. Nė vienu iš tirtų atvejų sunkiųjų metalų koncentracijos perdirbtose organinėse atliekose neviršijo DLK. Labiausiai rūgštiesiems dirvožemiams tręšti tinka anaerobiškai perdirbtas kiaulių mėšlas ir nuotekų valymo dumblas, kurių pH rodiklis didžiausias – siekia atitinkamai 7 ir 7,1. Įvertinus biogeninių elementų ir sunkiųjų metalų kiekį bei pH, galima teigti, kad dirvai tręšti iš tirtųjų organinių atliekų tinkamiausias yra kiaulių mėšlas. Резюме Одним из наиболее перспективных методов преобразования органических отходов в альтернативную энергию и удобрения является анаэробное сбраживание отходов в биореакторах. Для оценки пригодности внесения в почву биологически переработанных органических отходов в виде удобрений проводился эксперимент с целью определения суммы содержащихся в отходах общего азота, общего фосфора, тяжелых металлов и рН. Для исследований в качестве органических отходов использовался ил сточных вод из очистных сооружений, фруктово-овощные отходы, куриный помет, навоз и навозная жижа. Наибольшее содержание азота и фосфора было определено в анаэробно переработанном свином навозе, поэтому он наиболее приемлем в качестве органического удобрения для восстановления и рекультивации почв. Обработанный свиной навоз содержит 8,27 мг/л азота и 293,1 мг/л фосфора. Наибольшее содержание тяжелых металлов было установлено в анаэробно переработанном иле из сточных вод предприятий. Концентрация хрома в нем составляла 1,53 мг/кг, цинка – 21,28 мг/кг, марганца – 50,03 мг/кг, свинца – 10,46 мг/кг, меди – 50,48 мг/кг, никеля – 12,88 мг/кг. Ни в одном из исследованных случаев концентрации тяжелых металлов в переработанных органических отходах не превышали максимально допустимых концентраций (ПДК). Для удобрения кислых почв наиболее приемлем анаэробно переработанный свиной навоз и ил стоков из очистителей, содержащие высший показатель pH (соответственно 7 и 7,1). На основании полученных величин биогенных элементов, тяжелых металлов и pH можно утверждать, что из всех исследованных органических отходов наиболее пригоден для удобрения почв свиной навоз.

The pathway of in-situ ammonium removal from aerated municipal solid waste bioreactor: nitrification/denitrification or air stripping?

In-situ ammonium removal from municipal solid waste (MSW) landfill is an attractive method due to its economic advantages. In this study, two simulated MSW bioreactors with different degrees of initial bio-stabilization were utilized to investigate the effects of intermittent aeration mode and the addition of activated sludge on the removal of ammonium. The results showed that up to 90% of ammonium could be removed and the amount of NO(x)-N produced was less than 1% of NH4 (+)-N removed in both reactors. The pH values increased rapidly and finally arrived at a high level of 8.5-8.8. The efficiency of ammonium removal was improved by increasing the continuous aeration time, but it was not affected by the addition of activated sludge. A portion of liquid escaped from the reactors in the form of vapour, and as high as 195-258 mg L(-1) of NH(4) ( +)-N was detected in the vapour collector. According to calculation, nitrification was inhibited by the high level of free ammonia in the bioreactors. As a result, air stripping was enhanced and became the primary pathway of ammonium removal. Therefore, controlling free ammonia concentration was essential in ammonium removal from the aerated MSW bioreactor.

Modeling microbiological and chemical processes in municipal solid waste bioreactor, part II: Application of numerical model BIOKEMOD-3P

Biodegradation process modeling of municipal solid waste (MSW) bioreactor landfills requires the knowledge of various process reactions and corresponding kinetic parameters. Mechanistic models available to date are able to simulate biodegradation processes with the help of pre-defined species and reactions. Some of these models consider the effect of critical parameters such as moisture content, pH, and temperature. Biomass concentration is a vital parameter for any biomass growth model and often not compared with field and laboratory results. A more complex biodegradation model includes a large number of chemical and microbiological species. Increasing the number of species and user defined process reactions in the simulation requires a robust numerical tool. A generalized microbiological and chemical model, BIOKEMOD-3P, was developed to simulate biodegradation processes in three-phases (Gawande et al. 2009). This paper presents the application of this model to simulate laboratory-scale MSW bioreactors under anaerobic conditions. BIOKEMOD-3P was able to closely simulate the experimental data. The results from this study may help in application of this model to full-scale landfill operation.

Modeling microbiological and chemical processes in municipal solid waste bioreactor, part I: Development of a three-phase numerical model BIOKEMOD-3P

The numerical computer models that simulate municipal solid waste (MSW) bioreactor landfills have mainly two components--a biodegradation process module and a multi-phase flow module. The biodegradation model describes the chemical and microbiological processes. The models available to date include predefined solid waste biodegradation reactions and participating species. Some of these models allow changing the basic composition of solid waste. In a bioreactor landfill several processes like anaerobic and aerobic solids biodegradation, nitrogen and sulfate related processes, precipitation and dissolution of metals, and adsorption and gasification of various anthropogenic organic compounds occur simultaneously. These processes may involve reactions of several species and the available biochemical models for solid waste biodegradation do not provide users with the flexibility to simulate these processes by choice. This paper presents the development of a generalized biochemical process model BIOKEMOD-3P which can accommodate a large number of species and process reactions. This model is able to simulate bioreactor landfill operation in a completely mixed condition, when coupled with a multi-phase model it will be able to simulate a full-scale bioreactor landfill. This generalized biochemical model can simulate laboratory and pilot-scale operations in order to determine biochemical parameters important for simulation of full-scale operations.