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1.
J Surg Res ; 257: 597-604, 2021 01.
Artigo em Inglês | MEDLINE | ID: mdl-32932192

RESUMO

BACKGROUND: Standardized prescribing practices are recommended to decrease opioid abuse, however, data regarding the handling and disposal of leftover narcotics are lacking. This quality improvement project and analysis evaluated implementation of standardized prescribing, opioid education, and a narcotic disposal system. METHODS: This initiative was implemented over a 1-y period among patients who underwent breast surgery. The project included the following: 1) implementation of standardized prescribing, 2) voluntary and anonymous survey analysis, and 3) preoperative education regarding risks of opioids, charcoal disposal bag distribution, and follow-up survey to assess use and use of intervention. RESULTS: Preintervention surveys were completed by 53 patients, and 60% (n = 32) underwent lumpectomy. Narcotic prescriptions were filled by 90%; median number of pills taken was 3 (range 0-24), however 93% felt that a non-narcotic was more effective. Eighty three percentage of patients had unused pills, and 58% kept these pills in an unlocked cabinet. Postintervention surveys were completed by 66 patients, and 48% (n = 32) underwent lumpectomy. Narcotic prescriptions were filled by 88%, median number of pills taken was 4 (range 0-40), and 89% of patients had pills leftover. Sixty seven percentage of patients found the education handout useful and charcoal bag use was reported by 37% (n = 17). The median postoperative pain control satisfaction score was 4.5 (5-point Likert scale, 1 = very dissatisfied, 5 = very satisfied) on both preintervention and postintervention surveys. CONCLUSIONS: This study, which included standardized prescribing parameters, opioid education, and implementation of a disposal method, was found to be feasible, beneficial, and did not compromise postoperative pain control.


Assuntos
Analgésicos Opioides , Prescrições de Medicamentos/normas , Transtornos Relacionados ao Uso de Opioides/prevenção & controle , Dor Pós-Operatória/prevenção & controle , Neoplasias da Mama/cirurgia , Estudos de Viabilidade , Feminino , Humanos , Mastectomia Segmentar/efeitos adversos , Pessoa de Meia-Idade , Dor Pós-Operatória/etiologia , Educação de Pacientes como Assunto , Melhoria de Qualidade , Gerenciamento de Resíduos/instrumentação
2.
Artigo em Inglês | MEDLINE | ID: mdl-32475209

RESUMO

Grilling restaurants are a major contributor to airborne particulate matter (PM) in metropolitan areas. In this study, the removal of PM during the grilling of pork belly using an orifice scrubber, which is a form of gas-induced spray scrubber, was assessed. During grilling, the particle mass concentration was the highest for 1.0 < PM ≤ 2.5 µm (55.5% of total PM emissions), followed by 0.5 < PM ≤ 1.0 (27.1%), PM ≤ 0.5 (10.7%), and PM > 2.5 µm (7.0%). The PM removal efficiency of the orifice scrubber at a gas flow of 4.5 m3 min-1 was > 99.7% for PM ≥ 2.5 µm, 89.4% for 1.0 < PM ≤ 2.5 µm, 62.1% for 0.5 < PM ≤ 1.0, and 36.5% for PM ≤ 0.5 µm. Although further research is necessary to optimize its use, the orifice scrubber offers a user-friendly technology for the control of PM in small grilling restaurants because of its simple design, uncomplicated operation, and satisfactory PM removal performance.


Assuntos
Poluentes Atmosféricos/isolamento & purificação , Poluição do Ar/prevenção & controle , Material Particulado/isolamento & purificação , Restaurantes , Gerenciamento de Resíduos/instrumentação , Animais , Culinária , Tamanho da Partícula , Carne Vermelha , República da Coreia , Suínos
3.
Appl Microbiol Biotechnol ; 102(13): 5625-5634, 2018 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-29717342

RESUMO

A novel gas-scrubbing bioreactor based on a downflow hanging sponge (DHS) reactor was developed as a new volatile organic compound (VOC) treatment system. In this study, the effects of varying the space velocity and gas/liquid ratio were investigated to assess the effectiveness of using toluene gas as a model VOC. Under optimal conditions, the toluene removal rate was greater than 80%, and the maximum elimination capacity was observed at approximately 13 g-C m-3 h-1. The DHS reactor demonstrated slight pressure loss (20 Pa) and a high concentration of suspended solids (up to 30,000 mg/L-sponge). Cloning analysis of the 16S rRNA and functional genes of toluene degradation pathways (tmoA, todC, tbmD, xylA, and bssA) revealed that the clones belonging to the toluene-degrading bacterium Pseudomonas putida constituted the predominant species detected at the bottom of the DHS reactor. The toluene-degrading bacteria Pseudoxanthomonas spadix and Pseudomonas sp. were also detected by tmoA- and todC-targeted cloning analyses, respectively. These results demonstrate the potential for the industrial application of this novel DHS reactor for toluene gas treatment.


Assuntos
Reatores Biológicos , Tolueno/metabolismo , Compostos Orgânicos Voláteis/metabolismo , Gerenciamento de Resíduos/instrumentação , Gerenciamento de Resíduos/métodos , Bactérias/genética , Bactérias/metabolismo , Biodegradação Ambiental , RNA Ribossômico 16S , Compostos Orgânicos Voláteis/química
4.
J Environ Sci Health B ; 53(2): 145-151, 2018 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-29131711

RESUMO

Aerobic treatment of swine manure was coupled with anaerobic digestion and microalgal cultivation. A 14-day aerobic treatment reduced the total solid content of swine manure by >15%. Ammonia and carbon dioxide were stripped by the air supplied, and this off-gas was further used to aerate the culture of Chlorella vulgaris. The microalgal growth rates in Bristol medium and the wastewater with the off-gas increased from 0.08 to 0.22 g/L/d and from 0.15 to 0.24 g/L/d, respectively. Meanwhile, the aerobically treated swine manure showed a higher methane yield during anaerobic digestion. The experimental results were used to establish a demonstration unit consisting of a 100 L composter, a 200 L anaerobic digester, a 60 L tubular photobioreactor, and a 300 L micro-open raceway pond.


Assuntos
Chlorella vulgaris/crescimento & desenvolvimento , Esterco , Metano/biossíntese , Microalgas/crescimento & desenvolvimento , Gerenciamento de Resíduos/métodos , Aerobiose , Amônia/metabolismo , Animais , Dióxido de Carbono/metabolismo , Compostagem , Fotobiorreatores , Suínos , Gerenciamento de Resíduos/instrumentação , Águas Residuárias
5.
Water Sci Technol ; 75(7-8): 1659-1666, 2017 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-28402307

RESUMO

This paper aims to present perspectives for energy (thermal and electric) and nutrient (N and S) recovery in domestic sewage treatment systems comprised of upflow anaerobic sludge blanket (UASB) reactors followed by sponge-bed trickling filters (SBTF) in developing countries. The resource recovery potential was characterized, taking into account 114 countries and a corresponding population of 968.9 million inhabitants living in the tropical world, which were grouped into three desired ranges in terms of cities' size. For each of these clusters, a technological arrangement flow-sheet was proposed, depending on their technical and economic viability from our best experience. Considering the population living in cities over 100, 000 inhabitants, the potential of energy and nutrient recovery via the sewage treatment scheme would be sufficient to generate electricity for approximately 3.2 million residents, as well as thermal energy for drying purposes that could result in a 24% volume reduction of sludge to be transported and disposed of in landfills. The results show that UASB/SBTF systems can play a very important role in the sanitation and environmental sector towards more sustainable sewage treatment plants.


Assuntos
Esgotos/química , Gerenciamento de Resíduos/métodos , Anaerobiose , Reatores Biológicos , Países em Desenvolvimento , Temperatura Alta , Instalações de Eliminação de Resíduos , Gerenciamento de Resíduos/instrumentação
6.
Waste Manag Res ; 35(3): 301-312, 2017 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-27928062

RESUMO

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.


Assuntos
Reatores Biológicos , Resíduos Sólidos/análise , Instalações de Eliminação de Resíduos , Gerenciamento de Resíduos/métodos , Aerobiose , Anaerobiose , Projetos Piloto , Eliminação de Resíduos/instrumentação , Gerenciamento de Resíduos/instrumentação
7.
Waste Manag Res ; 35(1): 101-109, 2017 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-27899717

RESUMO

In-vessel composting of agricultural waste is a well-described approach for stabilization of compost within a short time period. Although composting studies have shown the different combinations of waste materials for producing good quality compost, studies of the particular ratio of the waste materials in the mix are still limited. In the present study, composting was conducted with a combination of vegetable waste, cow dung, sawdust and dry leaves using a 550 L rotary drum composter. Application of a radial basis functional neural network was used to simulate the composting process. The model utilizes physico-chemical parameters with different waste materials as input variables and three output variables: volatile solids, soluble biochemical oxygen demand and carbon dioxide evolution. For the selected model, the coefficient of determination reached the high value of 0.997. The complicated interaction of agricultural waste components during composting makes it a nonlinear problem so it is difficult to find the optimal waste combinations for producing quality compost. Optimization of a trained radial basis functional model has yielded the optimal proportion as 62 kg, 17 kg and 9 kg for vegetable waste, cow dung and sawdust, respectively. The results showed that the predictive radial basis functional model described for drum composting of agricultural waste was well suited for organic matter degradation and can be successfully applied.


Assuntos
Agricultura/métodos , Solo , Gerenciamento de Resíduos/instrumentação , Gerenciamento de Resíduos/métodos , Animais , Análise da Demanda Biológica de Oxigênio , Bovinos , Desenho de Equipamento , Índia , Resíduos Industriais , Esterco , Modelos Teóricos , Folhas de Planta
8.
Environ Sci Technol ; 50(5): 2546-55, 2016 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-26883809

RESUMO

Recovering palladium (Pd) from waste streams opens up the possibility of augmenting the supply of this important catalyst. We evaluated Pd reduction and recovery as a novel application of a H2-based membrane biofilm reactor (MBfR). At steady states, over 99% of the input soluble Pd(II) was reduced through concomitant enzymatic and autocatalytic processes at acidic or near neutral pHs. Nanoparticulate Pd(0), at an average crystallite size of 10 nm, was recovered with minimal leaching and heterogeneously associated with microbial cells and extracellular polymeric substances in the biofilm. The dominant phylotypes potentially responsible for Pd(II) reduction at circumneutral pH were denitrifying ß-proteobacteria mainly consisting of the family Rhodocyclaceae. Though greatly shifted by acidic pH, the biofilm microbial community largely bounced back when the pH was returned to 7 within 2 weeks. These discoveries infer that the biofilm was capable of rapid adaptive evolution to stressed environmental change, and facilitated Pd recovery in versatile ways. This study demonstrates the promise of effective microbially driven Pd recovery in a single MBfR system that could be applied for the treatment of the waste streams, and it documents the role of biofilms in this reduction and recovery process.


Assuntos
Reatores Biológicos/microbiologia , Nanopartículas/química , Paládio/isolamento & purificação , Gerenciamento de Resíduos/métodos , Betaproteobacteria/metabolismo , Biofilmes , Desnitrificação , Desenho de Equipamento , Concentração de Íons de Hidrogênio , Consórcios Microbianos/fisiologia , Oxirredução , Paládio/química , Rhodocyclaceae/metabolismo , Gerenciamento de Resíduos/instrumentação
9.
J Environ Manage ; 166: 294-308, 2016 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-26517278

RESUMO

Hydraulic, sanitary, and sulfide control conditions of inverted siphons, particularly in large wastewater systems, can be substantially improved by continuous air injection in the base of the inclined rising branch. This paper presents a simplified approach that was developed for the two-phase flow of the rising branch using the energy equation for a steady pipe flow, based on the average fluid fraction, observed slippage between phases, and isothermal assumption. As in a conventional siphon design, open channel steady uniform flow is assumed in inlet and outlet chambers, corresponding to the wastewater hydraulic characteristics in the upstream and downstream sewers, and the descending branch operates in steady uniform single-phase pipe flow. The proposed approach is tested and compared with data obtained in an experimental siphon setup with two plastic barrels of different diameters operating separately as in a single-barrel siphon. Although the formulations developed are very simple, the results show a good adjustment for the set of the parameters used and conditions tested and are promising mainly for sanitary siphons with relatively moderate heights of the ascending branch.


Assuntos
Gerenciamento de Resíduos/métodos , Hidrodinâmica , Modelos Teóricos , Esgotos , Sulfetos , Gerenciamento de Resíduos/instrumentação , Águas Residuárias/química
10.
J Environ Manage ; 184(Pt 2): 353-362, 2016 Dec 15.
Artigo em Inglês | MEDLINE | ID: mdl-27745768

RESUMO

There has been sustained interest from both environmental regulators and livestock associations to expand the use of anaerobic digester (AD) technology to mitigate greenhouse gas emissions. However, the generally profitable practice of codigesting off-farm organic waste could increase nitrogen and phosphorus content to the farm and exacerbate nutrient over-application concerns near large animal operations. We examine the economic feasibility of a broad set of dairy waste management systems composed of two technology groups that mitigate air and water pollution: an AD system that includes either animal waste input or combination animal/off-farm organic waste codigestion input and either compressed natural gas (CNG) or combined heat and power (CHP) output; and a filtration system that includes fiber separation, nutrient separation, and/or water recovery. We conclude that AD setups without codigestion are only economically feasible under limited conditions, but scenarios which use codigestion have the potential to contribute to nutrient over-application without nutrient separation technology. Trends for CNG and CHP match closely. Net present value (NPV) is greatest for AD with CNG scenarios. Estimated NPV for AD with CNG and environmental credits is $1.8 million and $39.7 million for dairies with 1600 and 15,000 wet cow equivalents, respectively. For these firm sizes, the addition of codigestion contributes $4.8 million and $47.3 million, respectively, to estimated NPV. Nutrient separation and water recovery both lead to decreases in scenario NPV with codigestion, but with the right policies, dairy owners may be willing to adopt AD with nutrient separation.


Assuntos
Esterco , Gerenciamento de Resíduos/economia , Gerenciamento de Resíduos/métodos , Anaerobiose , Animais , Biocombustíveis , Bovinos , Indústria de Laticínios , Poluição Ambiental/prevenção & controle , Feminino , Filtração/instrumentação , Filtração/métodos , Efeito Estufa/prevenção & controle , Metano/metabolismo , Nitrogênio , Fósforo , Gerenciamento de Resíduos/instrumentação , Água
11.
J Environ Manage ; 184(Pt 2): 371-379, 2016 Dec 15.
Artigo em Inglês | MEDLINE | ID: mdl-27742154

RESUMO

The purpose of this study was to implement and evaluate a pilot-scale and closed-loop system that synergistically combines solar thermal collector, anaerobic digester, and constructed treatment wetland to simultaneously treat and utilize organic wastes. The system utilizes 863 kg of mixed animal and food wastes to generate 263 MJ renewable energy, produced 28 kg nitrogen and phosphorus fertilizer, and reclaimed 550 kg water per day. The net revenue considering electricity and fertilizer was $2436 annually. The payback period for the system is estimated to be 17.8 years for a relatively dilute waste stream (i.e., 2% total solids). The implemented system has successfully demonstrated a self-efficient and flexible waste utilization and treatment system. It creates a win-win solution to satisfy the energy needs of the community and address environmental concerns of organic wastes disposal in the region.


Assuntos
Energia Solar , Gerenciamento de Resíduos/métodos , Áreas Alagadas , Anaerobiose , Animais , Reatores Biológicos , América Central , Costa Rica , Fertilizantes , Alimentos , Esterco , Nitrogênio , Fósforo , Projetos Piloto , Energia Renovável , Energia Solar/economia , Gerenciamento de Resíduos/economia , Gerenciamento de Resíduos/instrumentação , Purificação da Água/métodos
12.
Water Sci Technol ; 74(2): 431-7, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-27438248

RESUMO

In this study the mesophilic two-stage anaerobic digestion (AD) of corn bioethanol distillery wastewater is investigated in laboratory-scale reactors. Two-stage AD technology separates the different sub-processes of the AD in two distinct reactors, enabling the use of optimal conditions for the different microbial consortia involved in the different process phases, and thus allowing for higher applicable organic loading rates (OLRs), shorter hydraulic retention times (HRTs) and better conversion rates of the organic matter, as well as higher methane content of the produced biogas. In our experiments the reactors have been operated in semi-continuous phase-separated mode. A specific methane production of 1,092 mL/(L·d) has been reached at an OLR of 6.5 g TCOD/(L·d) (TCOD: total chemical oxygen demand) and a total HRT of 21 days (5.7 days in the first-stage, and 15.3 days in the second-stage reactor). Nonetheless the methane concentration in the second-stage reactor was very high (78.9%); the two-stage AD outperformed the reference single-stage AD (conducted at the same reactor loading rate and retention time) by only a small margin in terms of volumetric methane production rate. This makes questionable whether the higher methane content of the biogas counterbalances the added complexity of the two-stage digestion.


Assuntos
Biocombustíveis/análise , Etanol/química , Metano/análise , Gerenciamento de Resíduos/métodos , Anaerobiose , Reatores Biológicos , Destilação , Resíduos Industriais/análise , Gerenciamento de Resíduos/instrumentação , Águas Residuárias/análise , Zea mays/química
13.
Waste Manag Res ; 34(9): 923-32, 2016 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-27357561

RESUMO

This paper outlines the approach that can assist decision makers to have first preliminary insights regarding costs of complying with requested European Union municipal waste management goals in transition and developing countries. Serbia, as a joining member of European Union, must confront itself with the challenges resulting from European Union waste management directives. Implementation of waste separation units and the construction of sanitary landfills is already in place in Serbia. However, new waste management practice will need additional transformation and will require implementation of waste treatment technologies for additional management of generated waste. Implementation of analyzed best available technology/techniques for waste treatment can support the country's effort in reaching the policy goals. However, the question here is how much will the implementation of additional waste treatments influence the overall waste management costs? Results of the scenario's financial viability show that composting and sanitary landfill are the most viable solutions regarding the costs, even under increasing discount rates. Although different discount rates influence the overall gate fees and net present values, the level of affordability for different scenarios remains the same.


Assuntos
Instalações de Eliminação de Resíduos , Gerenciamento de Resíduos/economia , Gerenciamento de Resíduos/métodos , União Europeia , Objetivos , Eliminação de Resíduos/economia , Eliminação de Resíduos/instrumentação , Sérvia , Gerenciamento de Resíduos/instrumentação
14.
Waste Manag Res ; 34(6): 542-52, 2016 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-27053376

RESUMO

Coal is the main fuel for the direct reduced iron (DRI) plants of India, which are one of the major sources of fly ash generation. The generation of fly ash and its disposal has raised concern because of the environmental impacts. In the present study, two different fly ash samples were investigated to explore the scope of recovery of combustibles. One did not show any recovery potential. The second sample indicated that about 40% of material could be recovered, with 35% fixed carbon and 10,841 kJ kg(-1) gross calorific value. This can be used as a fuel blend in standard fluidised bed combustion boilers efficiently burning inferior coal. A process flowsheet has been suggested for the recovery purpose. It was estimated that for a small 0.2 million tonnes per year (Mtpy) capacity DRI plant, approximately 3.4 ha of land could thus annually be saved from dumping of the generated fly ash, while recovering 1.83 MW of electrical energy.


Assuntos
Cinza de Carvão/química , Carvão Mineral , Centrais Elétricas , Carbono/análise , Cinza de Carvão/análise , Desenho de Equipamento , Índia , Gerenciamento de Resíduos/instrumentação , Gerenciamento de Resíduos/métodos
15.
Waste Manag Res ; 34(6): 564-71, 2016 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-27118736

RESUMO

Small scale biomass gasification is a sector with growth and increasing applications owing to the environmental goals of the European Union and the incentivised policies of most European countries. This study addresses two aspects, which are at the centre of attention concerning the operation and development of small scale gasifiers; reuse of waste and increase of energy efficiency. Several authors have denoted that the low electrical efficiency of these systems is the main barrier for further commercial development. In addition, gasification has several by-products that have no further use and are discarded as waste. In the framework of this manuscript, a secondary reactor is introduced and modelled. The main operating principle is the utilisation of char and flue gases for further energy production. These by-products are reformed into secondary producer gas by means of a secondary reactor. In addition, a set of heat exchangers capture the waste heat and optimise the process. This case study is modelled in a MATLAB-Cantera environment. The model is non-stoichiometric and applies the Gibbs minimisation principle. The simulations show that some of the thermal energy is depleted during the process owing to the preheating of flue gases. Nonetheless, the addition of a secondary reactor results in an increase of the electrical power production efficiency and the combined heat and power (CHP) efficiency.


Assuntos
Biocombustíveis , Gerenciamento de Resíduos/instrumentação , Gerenciamento de Resíduos/métodos , Biomassa , Dióxido de Carbono/análise , Monóxido de Carbono/análise , Carvão Vegetal , Desenho de Equipamento , Gases/química , Hidrogênio/análise , Metano/análise , Modelos Teóricos , Temperatura , Resíduos
16.
Waste Manag Res ; 34(6): 584-92, 2016 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-27126983

RESUMO

Owing to the lack in structural strength while composting certain kinds of organic wastes, 11 co-substrates were tested that are generally locally available in rural areas of northern Tamil Nadu, India. In addition to the classical composting parameters such as carbon/nitrogen ratio, moisture content, dry matter and organic dry matter, a compression test was conducted to evaluate the structural strength and the suitability as bulking agent for composting processes. Additionally, with respect to the climatic conditions in India, the water holding capacity was also evaluated.


Assuntos
Solo/química , Gerenciamento de Resíduos/métodos , Resíduos , Agricultura , Ar , Biodegradação Ambiental , Carbono/análise , Desenho de Equipamento , Índia , Nitrogênio/análise , Gerenciamento de Resíduos/instrumentação , Água/análise
17.
Waste Manag Res ; 34(5): 409-16, 2016 May.
Artigo em Inglês | MEDLINE | ID: mdl-26951339

RESUMO

The addition of various amounts of biochar to anaerobic digestion of food wastes at different ratios of inoculum to substrate (ISR) was investigated to evaluate the effect of biochar as a functional additive and to optimize the additive dosage of biochar. The biochar treatments at ISR 2, 1, and 0.8 shortened the lag phase of digestion by -20.0%-10.9%, 43.3%-54.4%, and 36.3%-54.0%, and raised the maximum methane production rate by 100%-275%, 100%-133.3%, and 33.3%-100%, respectively, compared to control without biochar. Biochar also enhanced the degradation rate of dissolved organics and volatile fatty acids. Furthermore, the amount of biochar with best effectiveness at ISR = 2, 1, and 0.8 was 2.5, 0.625, and 0.5 g g(-1)-waste, respectively. Therefore, the effectiveness of biochar depended on the additive amount of biochar and at the same time the inoculum amount, implying a complementary role of abiotic biochar to biotic inoculum.


Assuntos
Carvão Vegetal , Alimentos , Gerenciamento de Resíduos/métodos , Anaerobiose , Biocombustíveis , Carbono/metabolismo , Ácidos Graxos Voláteis/metabolismo , Concentração de Íons de Hidrogênio , Metano/metabolismo , Nitrogênio/metabolismo , Gerenciamento de Resíduos/instrumentação
18.
Water Environ Res ; 87(4): 347-57, 2015 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-26462079

RESUMO

In this study, FLUENT software was used to simulate the flow regime of an integrated sludge thickening and digestion reactor. To optimize the flow regime, the combinational effect of key parameters of the reactor structure was investigated with an L16 (4(5)) orthogonal test. The reactor was then redesigned based on the optimization results, and a series of experiments was conducted to study the treatment effect with sludge dosage rates of 12, 18, 24, and 30%. The operation results showed that the reactor obtained the best treatment efficiency when the sludge dosage rate was 24%. At this dosage, the water content of the sludge decreased from 99.1% to 91.8%, with organic matter content (volatile solids [VS]/total solids) decreasing to 21.2% and average gas production (CH4 62.66%, CO2 11.56%, N2 23.91%, O2 1.59%) reaching 231.3 L/kg VS. Therefore, the results implied that the optimized reactor has good effects on sludge thickening and digestion.


Assuntos
Esgotos/química , Gerenciamento de Resíduos/instrumentação , Simulação por Computador , Desenho de Equipamento , Ácidos Graxos Voláteis/análise , Hidrodinâmica , Software
19.
Water Environ Res ; 87(4): 369-77, 2015 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-26462081

RESUMO

This paper deals with the effect of a bioaugmentation batch enhanced (BABE) reactor implementation in a biological nutrient removal pilot plant on the populations of ammonia-oxidizing bacteria (AOB) and nitrite-oxidizing bacteria (NOB). The results of fluorescence in situ hybridization (FISH) technique showed that AOB and NOB populations were significantly enhanced, from 4 to 8% and from 2 to 9%, respectively, as a result of the BABE reactor implementation. Regarding AOB, the percentage of Nitrosomonas oligotropha was mainly increased (3 to 6%). Regarding NOB, Nitrospirae spp was greatly enhanced (1 to 7%). Both species are considered K-strategist (high affinity to the substrate, low maximum growth rates) and they usually predominate in reactors with low ammonium and nitrite concentrations, respectively.


Assuntos
Amônia/metabolismo , Bactérias/metabolismo , Reatores Biológicos/microbiologia , Nitritos/metabolismo , Esgotos/química , Gerenciamento de Resíduos/instrumentação , Aerobiose , Amônia/isolamento & purificação , Nitritos/isolamento & purificação , Oxirredução , Projetos Piloto
20.
J Environ Manage ; 159: 209-217, 2015 Aug 15.
Artigo em Inglês | MEDLINE | ID: mdl-26093343

RESUMO

This study investigates the potential of incorporating inorganic amendments such as coal and bagasse ashes in different composting mixes. 10 different composting mixes were assessed as follows: A-20% bagasse ash (BA) with unsorted municipal solid wastes (UMSW); B-40% BA with UMSW; C-UMSW; D-20% BA with sorted municipal solid wastes (SMSW); E-40% BA with SMSW; F-SMSW; G-20% coal ash (CA) with UMSW; H-40% CA with UMSW; I-20% CA with SMSW and J-40% CA with SMSW. The composting processes were carried out in rotary drum composters. Composting mixes D, F, G and I achieved a temperature above 55 °C for at least 3 days, with the following peak temperatures: D-62 °C, F-57 °C, G-62 °C and I-58 °C. D resulted in the highest average net Volatile solids (VS) degradation of 68.6% and yielded the highest average volume reduction of 66.0%. The final compost from D, G, I, C and F were within range for electrical conductivities (EC) (794-1770 µS/cm) and pH (6.69-7.12). The ashes also helped in maintaining high average water holding capacities within the range of 183-217%. The C/N ratio of sorted wastes was improved by the addition of 20% coal ash and bagasse ash. Higher germination indices, above 0.8 were obtained for the ash-amended compost (D, G, I), indicating the feasibility and enhancement of using bagasse and coal ash as inorganic amendment in the composting process. Regarding heavy metals content, the chromium concentration for the composting mix G was found to be the highest whereas mixes D and I showed compliance with the MS (Mauritian Standards) 164 standards.


Assuntos
Celulose , Cinza de Carvão , Solo , Resíduos Sólidos , Gerenciamento de Resíduos/métodos , Carbono/análise , Cromo/análise , Cidades , Desenho de Equipamento , Metais Pesados/análise , Nitrogênio/análise , Temperatura , Gerenciamento de Resíduos/instrumentação , Água
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