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2.
Environ Sci Technol ; 56(18): 13085-13095, 2022 09 20.
Artigo em Inglês | MEDLINE | ID: mdl-35973975

RESUMO

Endocrine-disrupting potential was evaluated during the sewage treatment process using in vitro bioassays. Aryl hydrocarbon receptor (AhR)-, androgen receptor (AR)-, glucocorticoid receptor (GR)-, and estrogen receptor (ER)-mediated activities were assessed over five steps of the treatment process. Bioassays of organic extracts showed that AhR, AR, and GR potencies tended to decrease through the sewage treatment process, whereas ER potencies did not significantly decrease. Bioassays on reverse-phase high-performance liquid chromatography fractions showed that F5 (log KOW 2.5-3.0) had great ER potencies. Full-scan screening of these fractions detected two novel ER agonists, arenobufagin and loratadine, which are used pharmaceuticals. These compounds accounted for 3.3-25% of the total ER potencies and 4% of the ER potencies in the final effluent. The well-known ER agonists, estrone and 17ß-estradiol, accounted for 60 and 17% of the ER potencies in F5 of the influent and primary treatment, respectively. Fourier transform ion cyclotron resonance mass spectrometry analysis showed that various molecules were generated during the treatment process, especially CHO and CHOS (C: carbon, H: hydrogen, O: oxygen, and S: sulfur). This study documented that widely used pharmaceuticals are introduced into the aquatic environments without being removed during the sewage treatment process.


Assuntos
Estrogênios/metabolismo , Receptores de Estrogênio/metabolismo , Esgotos/química , Poluentes Químicos da Água/análise , Bioensaio/métodos , Carbono/metabolismo , Estradiol/metabolismo , Estrogênios/genética , Estrona/metabolismo , Hidrogênio/metabolismo , Oxigênio/análise , Preparações Farmacêuticas , Receptores Androgênicos/metabolismo , Receptores de Hidrocarboneto Arílico/metabolismo , Receptores de Glucocorticoides/metabolismo , Enxofre , Instalações de Eliminação de Resíduos/normas , Eliminação de Resíduos Líquidos/métodos , Eliminação de Resíduos Líquidos/normas
3.
Appl Microbiol Biotechnol ; 104(1): 291-302, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31732752

RESUMO

Kinetic parameters affecting effluent water quality including half saturation constant (Ks), maximum specific growth rate (µmax), and specific affinity ([Formula: see text], defined as µmax/Ks) were investigated using three types of anaerobic sludge (raw anaerobic digestion sludge referred to as unacclimated sludge, unacclimated sludge after endogenous decay, and sludge acclimated to low-strength wastewater in an anaerobic membrane bioreactor (AnMBR) for 360 days). Long-term acclimation to low-strength wastewater resulted in sludge with high specific affinity (1.6 × 10-3 L/mg COD/day for acclimated sludge compared to 4.1 × 10-4 L/mg COD/day for unacclimated sludge). The µmax values for unacclimated sludge and acclimated sludge were 0.08 and 0.07 day-1, respectively. The Ks values for unacclimated sludge and acclimated sludge were 194 ± 81 mg COD/L and 45 ± 13 mg COD/L, respectively. Although the Ks of unacclimated sludge after endogenous decay increased to 772 ± 74 mg COD/L, µmax increased to 0.35 day-1 as well, resulting in no statistically significant difference of [Formula: see text] between the two types of unacclimated sludge. Overall, [Formula: see text] is a better indicator than µmax or Ks alone for determining effluent water quality, as effluent substrate concentration is approximately inversely proportional to the specific affinity. 16S rRNA sequencing data analysis indicated a high abundance (85.8% of total archaea) of Methanosaeta in the microbial community after long-term acclimation. High [Formula: see text] associated with the enrichment of Methanosaeta appears to ensure successful anaerobic treatment of low-strength wastewater.


Assuntos
Euryarchaeota/metabolismo , Metano/metabolismo , Microbiota , Esgotos/microbiologia , Águas Residuárias/microbiologia , Anaerobiose , Reatores Biológicos/microbiologia , Euryarchaeota/genética , Cinética , Methanosarcinales/metabolismo , Eliminação de Resíduos Líquidos/métodos , Eliminação de Resíduos Líquidos/normas
4.
Water Sci Technol ; 77(5-6): 1149-1164, 2018 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-29528303

RESUMO

A researcher or practitioner can employ a biofilm model to gain insight into what controls the performance of a biofilm process and for optimizing its performance. While a wide range of biofilm-modeling platforms is available, a good strategy is to choose the simplest model that includes sufficient components and processes to address the modeling goal. In most cases, a one-dimensional biofilm model provides the best balance, and good choices can range from hand-calculation analytical solutions, simple spreadsheets, and numerical-method platforms. What is missing today is clear guidance on how to apply a biofilm model to obtain accurate and meaningful results. Here, we present a five-step framework for good biofilm reactor modeling practice (GBRMP). The first four steps are (1) obtain information on the biofilm reactor system, (2) characterize the influent, (3) choose the plant and biofilm model, and (4) define the conversion processes. Each step demands that the model user understands the important components and processes in the system, one of the main benefits of doing biofilm modeling. The fifth step is to calibrate and validate the model: System-specific model parameters are adjusted within reasonable ranges so that model outputs match actual system performance. Calibration is not a simple 'by the numbers' process, and it requires that the modeler follows a logical hierarchy of steps. Calibration requires that the adjusted parameters remain within realistic ranges and that the calibration process be carried out in an iterative manner. Once each of steps 1 through 5 is completed satisfactorily, the calibrated model can be used for its intended purpose, such as optimizing performance, trouble-shooting poor performance, or gaining deeper understanding of what controls process performance.


Assuntos
Biofilmes/crescimento & desenvolvimento , Reatores Biológicos/normas , Modelos Biológicos , Eliminação de Resíduos Líquidos/métodos , Fenômenos Fisiológicos Bacterianos , Calibragem , Eliminação de Resíduos Líquidos/normas , Águas Residuárias
5.
Artigo em Inglês | MEDLINE | ID: mdl-29764288

RESUMO

Sixteen polycyclic aromatic hydrocarbons (PAHs) and some typical substituted polycyclic aromatic hydrocarbons (SPAHs) were investigated in wastewater treatment plants (WWTPs) and effluent effluent-receiving rivers in order to indentify the elimination of these compounds in WWTPs, as well as the potantial potential risk in the effluent-receiving rivers. The concentrations of ΣPAHs in the total phase (combined dissolved and adsorbed phases) in influent were between 944.1 and 1246.5 ng·L-1, and ΣSPAHs, including methyl PAHs (MPAHs) and oxygenated PAHs (OPAHs), between 684.9 and 844.9 ng·L-1. Regarding the SPAHs, the concentrations of ΣOPAHs (312.3 ng·L-1) were higher than those of ΣMPAHs (271.8 ng·L-1). The total removal efficiencies of PAHs in the biological treatment processes were between 59% and 68%, and those of SPAHs were a little lower (58-65%). The removal efficiency in the adsorbed phase was higher than in the dissolved phase. The concentrations of PAHs and SPAHs in the effluent were a little higher than in the receiving river. According to a PAH risk assessment of the effluent, 7 carcinogenic PAHs accounted for a relatively high proportion. Benzo[a]pyrene (BaP) and Dibenz[a,h]anthracene (DBA) were major contributors to the TEQs in the effluent of WWTPs, which should be taken into consideration.


Assuntos
Monitoramento Ambiental , Hidrocarbonetos Policíclicos Aromáticos/análise , Rios/química , Águas Residuárias/química , Poluentes Químicos da Água/análise , Pequim , China , Monitoramento Ambiental/métodos , Hidrocarbonetos Policíclicos Aromáticos/química , Hidrocarbonetos Policíclicos Aromáticos/isolamento & purificação , Medição de Risco , Eliminação de Resíduos Líquidos/normas
6.
Artigo em Inglês | MEDLINE | ID: mdl-29465297

RESUMO

In this work, the effect of the improvement carried out at a large-scale wastewater treatment plant (WWTP) was evaluated, by means of modelling works, with the aim to determine the influence of the modernization over the process performance. After modernization, the energy consumption due to the aeration decreased about a 20% maintaining the effluent quality. In order to double-check the good effluent quality, modelling works were carried out at the full-scale plant. After calibration, the model was applied to the upgraded full-scale plant obtaining deviations lower than 10%. Then, the performance of the main biochemical processes was evaluated in terms of oxygen uptake rate (OUR), ammonia uptake rate (AUR), and chemical oxygen demand (COD) consumption. The rate of the main processes depending on the aeration, that is OUR and AUR, were about 22 gO2/(kg VSS·h) and 2.9 gN/(kg VSS·h), respectively.


Assuntos
Modelos Teóricos , Melhoria de Qualidade , Eliminação de Resíduos Líquidos , Águas Residuárias , Purificação da Água/normas , Amônia/metabolismo , Análise da Demanda Biológica de Oxigênio , Humanos , Oxigênio/química , Oxigênio/metabolismo , Melhoria de Qualidade/organização & administração , Esgotos/química , Esgotos/microbiologia , Eliminação de Resíduos Líquidos/instrumentação , Eliminação de Resíduos Líquidos/métodos , Eliminação de Resíduos Líquidos/normas , Águas Residuárias/química , Purificação da Água/instrumentação , Purificação da Água/métodos
7.
Environ Res ; 156: 284-290, 2017 07.
Artigo em Inglês | MEDLINE | ID: mdl-28395239

RESUMO

The development of entrepreneurships in the 21st century cannot occur without taking care of the natural environment. The article presents issues related to eco-innovation. Despite the opportunities offered by eco-innovations, implementation of such initiatives remains to lead to various difficulties. They vary across countries and sectors. The insufficient number of enterprises in Poland and other European countries implement adequate level of eco-innovations. The main aim of this paper is to indicate the causes of this status and activities aimed to develop eco-innovativeness. The benefits and risks connected with implementation of innovative products and technologies were also discussed. Furthermore, the advantages of and barriers to their implementation into companies were analysed. The entrepreneurs from the least eco-innovative countries emphasize serious barriers, including uncertain demand from the market, uncertain return on investment or too long a payback period for eco-innovation, lack of funds within the enterprise, insufficient access to existing subsidies and fiscal incentive. They are especially afraid of the financial risks, which raises uncertainty and leads to refraining from innovative initiatives. The possibilities were indicated for the entrepreneurs who face problems with the implementation of innovative solutions. Particular attention was paid to the European Union activities for the development of eco-innovations. Numerous programs supporting their implementation were indicated. The article also presents examples of eco-innovation in water and sewage enterprises. It was emphasized that planning of eco-innovative solutions should be based on comprehensive information about actual benefits and possibility of threats to the environment which can be caused by implementation of eco-innovations. The study presents the example of threats resulting from different methods of sewage sludge management.


Assuntos
Conservação dos Recursos Naturais/métodos , Invenções , Conservação dos Recursos Naturais/economia , Europa (Continente) , União Europeia , Invenções/economia , Esgotos/análise , Eliminação de Resíduos Líquidos/economia , Eliminação de Resíduos Líquidos/normas , Purificação da Água/economia , Purificação da Água/normas , Abastecimento de Água/economia , Abastecimento de Água/normas
8.
Rev Esc Enferm USP ; 51: e03234, 2017 Jun 12.
Artigo em Inglês, Português | MEDLINE | ID: mdl-28614439

RESUMO

OBJECTIVE: Quantifying residual volume contained in vials of antibiotics used in pediatrics. METHOD: This is an experiment involving samples from vials of antibiotics used in a pediatric hospital. Residual volume was identified by calculating the difference in weight measurement before and after the vials were washed. Evaluation of the residual volume difference in the vials was determined by the Wilcoxon non-parametric test for a sample and established at a significance level of 5%. RESULTS: 105 samples of antibiotics were selected. The correct use of the antibiotics oxacillin (88.57%) and ceftriaxone (94.28%) predominated with low residual values. The same did not occur for procaine benzylpenicillin + potassium benzylpenicillin, since a greater residual volume was discarded in 74.28% of the vials. CONCLUSION: We highlight the need for improvements in managing antibiotics in the institution under study, so that the excess volume of the antibiotics in the vials is used within the acceptable stable time. It is also necessary that the disposal of the residual volume be adequately disposed, since it presents a risk to public health and the environment. OBJETIVO: Quantificar o volume residual contido em frascos-ampola de antibióticos utilizados na pediatria. MÉTODO: Trata-se de um experimento com amostras de frascos-ampola de antibióticos utilizados em hospital pediátrico. O volume residual foi identificado calculando-se a diferença da aferição do peso antes e após a lavagem do frasco-ampola. A avaliação da diferença dos volumes residuais nos frascos-ampola foi determinada pelo teste não paramétrico de Wilcoxon para uma amostra e estabelecido o nível de significância de 5%. RESULTADOS: Foram selecionadas 105 amostras de antibióticos. Predominou o correto aproveitamento dos antibióticos oxacilina (88,57%) e ceftriaxona (94,28%), com baixos valores residuais. O mesmo não ocorreu com a benzilpenicilina procaína + potássica, pois em 74,28% dos frascos houve descarte de volume residual superior. CONCLUSÃO: Destaca-se a necessidade de melhorias na gestão dos antibióticos na instituição em estudo, para que o volume excedente do antibiótico em frasco-ampola seja aproveitado até o tempo de estabilidade permitido, assim como é necessário que haja a adequação da forma de descarte do volume residual, que apresenta risco à saúde pública e ao meio ambiente.


Assuntos
Antibacterianos , Eliminação de Resíduos Líquidos , Criança , Estudos Transversais , Humanos , Eliminação de Resíduos Líquidos/normas , Eliminação de Resíduos Líquidos/estatística & dados numéricos
9.
J Water Health ; 14(6): 942-949, 2016 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-27959872

RESUMO

Hospital wastewater has the potential to be a threat to the hospital environment as it can contain pathogenic bacteria that may facilitate the resistant nature of organisms within effluent or water treatment plants. The recycling of hospital wastewater should have good quality. This study was carried out to highlight the incidence of antibiotic resistant bacteria in hospital-generated recycled water. This study was conducted in a tertiary care teaching hospital during June 2013-June 2014. One hundred and forty wastewater samples were aseptically collected at different stages in the recycling plant. The samples were processed within 2 hours following standard procedures for identification of bacteria and the pathogenic bacteria were isolated. The mostly identified pathogens were Staphylococcus aureus (11.42%), Pseudomonas aeruginosa (9.28%), Enterococcus faecalis (10%) and Bacillus subtilis (8.57%) which were removed by treatment, but Escherichia coli (16.42%), Klebsiella pneumonia (8.57%), and Proteus mirabilis (11.42%) survived in the final sedimentation tank (lagoon) from where this water will be used for gardening purposes. An antibiogram study showed these pathogens were resistant to first-line antibiotics. Effluent treatment plants in hospitals should be monitored for the fulfillment of the guidelines and quality control of treated water to stop the emergence of multi-drug resistant bacteria in the hospital environment.


Assuntos
Bactérias/isolamento & purificação , Farmacorresistência Bacteriana , Eliminação de Resíduos Líquidos , Águas Residuárias/microbiologia , Antibacterianos/farmacologia , Bactérias/efeitos dos fármacos , Hospitais , Índia , Eliminação de Resíduos Líquidos/instrumentação , Eliminação de Resíduos Líquidos/normas
10.
J Environ Manage ; 165: 22-30, 2016 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-26406876

RESUMO

The paper presents energy and carbon footprints of sewage treatment plants (STPs) operating at different scales and using different technology options based on primary data from 50 STPs operating in India and the UK. The study used a combination of fundamental mass-balance approach for energy consumption and the methodology defined by IPCC for the carbon emissions. Small-scale institutional STPs consume twelve times the energy consumed by large-scale municipal STPs, the corresponding energy intensities being 4.87 kWh/m(3) and 0.40 kWh/m(3) respectively. Embodied energy from construction material and chemicals accounted for 46% and 33% of the total energy intensity of the municipal and institutional STPs respectively. The average carbon footprint of large-scale STPs is 0.78 kgCO2eq/m(3) and for small-scale STPs it is 3.04 kgCO2eq/m(3). However, fugitive emissions from large-scale STPs constituted 74% of the total carbon emissions whereas the figure was only 0.05% for small-scale STPs. Average electrical energy intensity in STPs in India is much lower (0.14 kWh/m(3)) than that in the UK (0.46 kWh/m(3)). This is due to the reason that STPs in India do not have resource recovery processes and use solar heat for sludge drying. The paper offers information and insights for designing low carbon strategies for urban waste infrastructure.


Assuntos
Pegada de Carbono , Eliminação de Resíduos Líquidos/métodos , Carbono/análise , Pegada de Carbono/estatística & dados numéricos , Eletricidade , Índia , Esgotos , Tecnologia , Reino Unido , Eliminação de Resíduos Líquidos/normas , Eliminação de Resíduos Líquidos/estatística & dados numéricos
11.
Environ Monit Assess ; 188(7): 390, 2016 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-27260530

RESUMO

In this paper, a new systematic approach is designed to maximize the demand coverage and receiving waste load by river-reservoir systems while enhancing water quality criteria. The approach intends to control the reservoir eutrophication while developing a trade-off between the maximum receiving load and shortage on demand coverage. To simulate the system, a hybrid process-based and data-driven model is tailored. Initially, the two-dimensional hydrodynamics and water quality simulation model (CE-QUAL-W2) is linked with an effective single and/or multiple optimization algorithms (PSO) to evaluate the proposed scenarios. To increase the computational efficiencies, the simulation model is substituted with a surrogate model (ANN) in an adaptive-dynamically refined routine. The proposed method is illustrated by a case study in Iran, namely, Karkheh River Reservoir, for 180-monthly periods. The results showed the applicability of the methodology especially to solve high-dimensional multi-period complex water resource optimization problems. Also, the results demonstrated that eutrophication could be reduced under the optimal inflow phosphate control and reservoir operation, regulating the total phosphorous concentration in the reservoir.


Assuntos
Monitoramento Ambiental , Eliminação de Resíduos Líquidos/métodos , Qualidade da Água/normas , Algoritmos , Eutrofização , Hidrodinâmica , Irã (Geográfico) , Modelos Teóricos , Fósforo/análise , Rios/química , Eliminação de Resíduos Líquidos/normas , Eliminação de Resíduos Líquidos/estatística & dados numéricos , Recursos Hídricos , Abastecimento de Água
12.
Rev Esc Enferm USP ; 50(6): 922-928, 2016.
Artigo em Inglês, Português | MEDLINE | ID: mdl-28198956

RESUMO

OBJECTIVE: To verify the disposal of pharmaceutical waste performed in pediatric units. METHOD: A descriptive and observational study conducted in a university hospital. The convenience sample consisted of pharmaceuticals discarded during the study period. Handling and disposal during preparation and administration were observed. Data collection took place at pre-established times and was performed using a pre-validated instrument. RESULTS: 356 drugs disposals were identified (35.1% in the clinic, 31.8% in the intensive care unit, 23.8% in the surgical unit and 9.3% in the infectious diseases unit). The most discarded pharmacological classes were: 22.7% antimicrobials, 14.8% electrolytes, 14.6% analgesics/pain killers, 9.5% diuretics and 6.7% antiulcer agents. The most used means for disposal were: sharps' disposable box with a yellow bag (30.8%), sink drain (28.9%), sharps' box with orange bag (14.3%), and infectious waste/bin with a white bag (10.1%). No disposal was identified after drug administration. CONCLUSION: A discussion of measures that can contribute to reducing (healthcare) waste volume with the intention of engaging reflective team performance and proper disposal is necessary. OBJETIVO: Verificar o descarte dos resíduos de medicamentos realizado em unidades pediátricas. MÉTODO: Estudo descritivo e observacional, realizado em um hospital universitário. A amostra de conveniência foi constituída pelos medicamentos descartados durante o período de estudo. Observaram-se a manipulação e o descarte durante o preparo e a administração. A coleta dos dados ocorreu em horários preestabelecidos e realizada por meio de instrumento pré-validado. RESULTADOS: Identificaram-se 356 descartes de medicamentos (35,1% na clínica, 31,8% na unidade de cuidados intensivos, 23,8% na cirúrgica e 9,3% na infectologia). As classes farmacológicas mais descartadas foram: 22,7% antimicrobianos, 14,8% eletrólitos, 14,6% analgésicos, 9,5% diuréticos e 6,7% antiulcerosos. Vias mais utilizadas: caixa descartável para perfurocortante com saco amarelo (30,8%), ralo da pia (28,9%), caixa de perfurocortante com saco laranja (14,3%) e lixeira infectante com saco branco (10,1%). Não foi identificado descarte após a administração dos fármacos. CONCLUSÃO: Faz-se necessária a discussão de medidas que contribuam para a redução do volume de resíduos, com o intuito de engajar a atuação reflexiva da equipe e o descarte adequado.


Assuntos
Unidades Hospitalares , Pediatria , Preparações Farmacêuticas , Eliminação de Resíduos Líquidos/normas , Hospitais Universitários
13.
Gig Sanit ; 95(12): 1121-4, 2016.
Artigo em Russo | MEDLINE | ID: mdl-29446278

RESUMO

The aim of the study was the hygienic characteristics of the location of sewage pumping stations (SPSs) in the residential area of the city and the assessment of working conditions for the staff. The features of the technological process at the SPSs resulted in the formation of specific working conditions characterized by the presence of a cooling microclimate, noise production, technological vibration, air pollution by microorganisms. The assessment of working conditions has allowed to refer them to the 3 class (harmful working conditions) of the 2 and 3 degree. Preventive measures for SPSs should include the use of equipment for cleaning the air of working zone, having a combined odourremoving and microbicidal action; the automation of the labor process; the installation of additional equipment for filtering air circulating in workplaces and emitting into the atmosphere; provision of sealing equipment with the use of noise insulating materials.


Assuntos
Poluentes Ocupacionais do Ar/análise , Ruído/prevenção & controle , Exposição Ocupacional , Esgotos , Eliminação de Resíduos Líquidos , Humanos , Exposição Ocupacional/análise , Exposição Ocupacional/prevenção & controle , Saúde Ocupacional/normas , Federação Russa , Esgotos/análise , Esgotos/estatística & dados numéricos , Eliminação de Resíduos Líquidos/métodos , Eliminação de Resíduos Líquidos/normas
14.
Gig Sanit ; 95(6): 525-8, 2016.
Artigo em Russo | MEDLINE | ID: mdl-29424218

RESUMO

In the Perm Territory from 2010 to 2014 155 samples offoul andfecal waste waters, 293 samples of surface water, 827 samples of supply net water, and 57 vegetable and fruit water-washes were examined for the RNA enterovirus agent with the use of polymerase chain reaction (PCR) method. In parallel 155 wastewater samples, 20 samples of surface water, and 4 samples of supply net water were examined for non-polio enterovirus agent with the use of virological methods. In the samples of foul waste waters the RNA enterovirus agent was detected in 74.8 ± 3.4%, and nonpolio enterovirus agent - in 65.1 ± 3.8%. In the samples of surface water the RNA enterovirus agent was detected in 2.3 ± 0.8%; in the area offoul and fecal waste waters the non-polio enterovirus agent was detected in 20.0 ± 4.4% in the process of virological investigation of RNA-positive water samples. In supply net water the RNA enterovirus agent was detected in 0.8 ± 0.3 %, on the surface of vegetables, fruits, and grapes - in 10.5 ± 3.9 %.


Assuntos
Infecções por Enterovirus , Enterovirus , Água Doce , Frutas/virologia , Verduras/virologia , Águas Residuárias/virologia , Enterovirus/isolamento & purificação , Enterovirus/patogenicidade , Infecções por Enterovirus/epidemiologia , Infecções por Enterovirus/prevenção & controle , Infecções por Enterovirus/virologia , Monitoramento Ambiental/métodos , Água Doce/análise , Água Doce/virologia , Humanos , Saúde Pública/métodos , Saúde Pública/normas , Saúde Pública/estatística & dados numéricos , Federação Russa/epidemiologia , Eliminação de Resíduos Líquidos/normas , Abastecimento de Água/normas
15.
Water Sci Technol ; 71(1): 1-8, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-25607662

RESUMO

In Africa, different studies have been conducted at different scales to evaluate wastewater treatment efficiency of constructed wetland. This paper aims to review the treatment performance efficiency of constructed wetland used in African countries. In the reviewed papers, the operational parameters, size and type of wetland used and the treatment efficiency are assessed. The results are organized and presented in six tables based on the type of wetland and wastewater used in the study. The results of the review papers indicated that most of the studies were conducted in Tanzania, Egypt and Kenya. In Kenya and Tanzania, different full-scale wetlands are widely used in treating wastewater. Among wetland type, horizontal subsurface flow wetlands were widely studied followed by surface flow and hybrid wetlands. Most of the reported hybrid wetlands were in Kenya. The results of the review papers indicated that wetlands are efficient in removing organic matter (biochemical oxygen demand and chemical oxygen demand) and suspended solids. On the other hand, nutrient removal efficiency appeared to be low.


Assuntos
Eliminação de Resíduos Líquidos/normas , Áreas Alagadas , África , Egito , Quênia , Tanzânia
16.
Water Sci Technol ; 72(4): 510-9, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-26247748

RESUMO

The energy costs usually represent the second largest part of the running costs of a wastewater treatment plant (WWTP). It is therefore crucial to increase the energy efficiency of these infrastructures and to implement energy management systems, where quantitative performance metrics, such as performance indicators (PIs), play a key role. This paper presents energy PIs which cover the unit energy consumption, production, net use from external sources and costs, and the results used to validate them and derive their reference values. The results of a field study with 17 Portuguese WWTPs (5-year period) were consistent with the results obtained through an international literature survey on the two key parcels of the energy balance--consumption and production. The unit energy consumption showed an overall inverse relation with the volume treated, and the reference values reflect this relation for trickling filters and for activated sludge systems (conventional, with coagulation/filtration (C/F) and with nitrification and C/F). The reference values of electrical energy production were derived from the methane generation potential (converted to electrical energy) and literature data, whereas those of energy net use were obtained by the difference between the energy consumption and production.


Assuntos
Biocombustíveis/análise , Eletricidade , Metano/análise , Eliminação de Resíduos Líquidos/métodos , Eliminação de Resíduos Líquidos/normas , Águas Residuárias/análise , Filtração , Portugal , Esgotos/química
17.
Water Sci Technol ; 72(12): 2251-61, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-26676014

RESUMO

Characterization and modelling of primary settlers have been neglected pretty much to date. However, whole plant and resource recovery modelling requires primary settler model development, as current models lack detail in describing the dynamics and the diversity of the removal process for different particulate fractions. This paper focuses on the improved modelling and experimental characterization of primary settlers. First, a new modelling concept based on particle settling velocity distribution is proposed which is then applied for the development of an improved primary settler model as well as for its characterization under addition of chemicals (chemically enhanced primary treatment, CEPT). This model is compared to two existing simple primary settler models (Otterpohl and Freund; Lessard and Beck), showing to be better than the first one and statistically comparable to the second one, but with easier calibration thanks to the ease with which wastewater characteristics can be translated into model parameters. Second, the changes in the activated sludge model (ASM)-based chemical oxygen demand fractionation between inlet and outlet induced by primary settling is investigated, showing that typical wastewater fractions are modified by primary treatment. As they clearly impact the downstream processes, both model improvements demonstrate the need for more detailed primary settler models in view of whole plant modelling.


Assuntos
Modelos Químicos , Material Particulado , Esgotos , Instalações de Eliminação de Resíduos , Eliminação de Resíduos Líquidos/métodos , Análise da Demanda Biológica de Oxigênio , Calibragem , Material Particulado/química , Material Particulado/classificação , Projetos Piloto , Quebeque , Reprodutibilidade dos Testes , Esgotos/química , Instalações de Eliminação de Resíduos/normas , Eliminação de Resíduos Líquidos/normas
18.
Water Sci Technol ; 72(12): 2201-11, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-26676008

RESUMO

The concept of a greywater-fed bioretention system in arid regions was investigated in this study. Bioretention systems are conventionally used as a source control mechanism for urban runoff. Nevertheless, in arid regions, where rain and urban runoff are not an abundant water resource, their application is limited. Greywater (residential wastewater without toilet and kitchen sources) is comparatively less polluted and has the potential for reuse in irrigation and non-potable water uses. However, selection of an appropriate treatment is a challenge. A prototype bioretention system was made and its ability to improve greywater quality was monitored for more than 10 consecutive days. A vegetative and non-vegetative system were monitored separately. After 24 hours of retention in both systems, greywater quality was improved significantly. Both systems performed almost equally well; however, the vegetative system (with canary reed grass, Phalaris arundinacea) was found to be more effective in reducing the sodium and chemical oxygen demand contents. The study revealed that the concept of the greywater-fed bioretention system has the potential to add multi-functional benefits (greywater treatment, water conservation, landscape aesthetic and biodiversity) to the arid regions' urban environment.


Assuntos
Reciclagem/métodos , Eliminação de Resíduos Líquidos/métodos , Águas Residuárias/química , Purificação da Água/métodos , Amônia/análise , Bactérias Aeróbias/crescimento & desenvolvimento , Análise da Demanda Biológica de Oxigênio , Cálcio/análise , Clima Desértico , Condutividade Elétrica , Enterobacteriaceae/crescimento & desenvolvimento , Concentração de Íons de Hidrogênio , Nitratos/análise , Oxirredução , Poaceae/metabolismo , Potássio/análise , Reciclagem/normas , Salinidade , Sódio/análise , Sulfatos/análise , Eliminação de Resíduos Líquidos/normas , Águas Residuárias/microbiologia , Purificação da Água/normas , Qualidade da Água , Abastecimento de Água/normas
19.
Waste Manag Res ; 33(7): 612-29, 2015 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-26060197

RESUMO

Industrial wastes with a high iron or aluminium oxide content are produced in huge quantities as by-products of water treatment (water treatment residuals), bauxite processing (red mud) and hard and brown coal burning in power plants (fly ash). Although they vary in their composition, the wastes have one thing in common--a high content of amorphous iron and/or aluminium oxides with a large specific surface area, whereby this group of wastes shows very good adsorbability towards heavy metals, arsenates, selenates, etc. But their physical form makes their utilisation quite difficult, since it is not easy to separate the spent sorbent from the solution and high bed hydraulic resistances occur in dynamic regime processes. Nevertheless, because of the potential benefits of utilising the wastes in industrial effluent treatment, this issue attracts much attention today. This study describes in detail the waste generation processes, the chemical structure of the wastes, their physicochemical properties, and the mechanisms of fixing heavy metals and semimetals on the surface of iron and aluminium oxides. Typical compositions of wastes generated in selected industrial plants are given. A detailed survey of the literature on the adsorption applications of the wastes, including methods of their thermal and chemical activation, as well as regeneration of the spent sorbents, is presented. The existing and potential ways of modifying the physical form of the discussed group of wastes, making it possible to overcome the basic limitation on their practical use, are discussed.


Assuntos
Óxido de Alumínio/química , Compostos Férricos/química , Resíduos Industriais/análise , Metais Pesados/química , Eliminação de Resíduos/normas , Eliminação de Resíduos Líquidos/normas , Adsorção
20.
Water Environ Res ; 86(12): 2309-16, 2014 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-25654933

RESUMO

The performance of duckweed and algal systems in removing fecal bacteria, organic matter, and nutrients was evaluated in three full-scale ponds operating in series. Trucks collected septage from holding tanks and discharged it into the system, daily. The inflow rates varied between the warm and the cold season. Duckweed and algae naturally colonized the ponds in two successive periods of 10 and 13 months, respectively. Environmental conditions were determined at various pond depths. Without harvesting, the duckweed system was neutral and anoxic. Alkaline and oversaturation conditions were observed in the algal system. The overall removals of 5-day biochemical oxygen demand, total suspended solids, total nitrogen removal, and orthophosphate (ortho-PO4(3-)) ranged from 94 to 97, 62 to 84, 68 to 74, and 0 to 26%, respectively. The E. coli and enterococci reductions varied between 2.2 to 3.0 and 1.1 to 1.4 log units, respectively. The upper values were always associated with the algal system.


Assuntos
Fenômenos Fisiológicos Bacterianos , Esgotos/análise , Eliminação de Resíduos Líquidos/normas , Águas Residuárias/análise , Poluentes Químicos da Água/metabolismo , Araceae/metabolismo , Biodegradação Ambiental , Monitoramento Ambiental , Eucariotos/metabolismo , Fezes/microbiologia , Grécia , Lagoas/análise
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