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Resultados 1 - 20 de 641
1.

The Sustainable Development Goal for Urban Sanitation: Africa's Statistical Tragedy Continues?

J Urban Health; 2018 Jun 01.
Artículo en Inglés | MEDLINE | ID: mdl-29858977

RESUMEN

Sanitation delivery in the urban areas of sub-Saharan African countries has been a chronic issue, particularly difficult to tackle. Under the Millennium Development Goals, the sanitation target in urban sub-Saharan Africa was missed by a wide margin and witnessed almost no improvement. After 2 years of review, the WHO/UNICEF Joint Monitoring Programme published a new measure of access to sanitation as a baseline for the Sustainable Development Goals. There are a number of improvements in the new measure. However, despite the improvements, the new measure continues to be characterized by an important flaw: it continues to disregard how shared toilet facilities contribute towards the SDG sanitation target. As a result, the new measure does not indicate whether progress is being made in low-income urban areas where a large number of households rely on shared sanitation; nor does it provide a goal that can be achieved in cities of the poorest countries over the measurement period. But, its most egregious failing is that it directs resources towards investments which will often fail cost/benefit tests. In sum, it is not a surprise that a Working Group recommended that the measure should be changed to include some shared facilities. Following the Working Group's recommendation would have avoided the adverse consequences of continued reliance on a key component of the methodology used for monitoring sanitation improvements under the Millennium Development Goals. The paper discusses the limitations of this methodology in the context of urban sub-Saharan Africa, where current sanitation conditions are seriously lacking, and the significant future urban population growth will add more pressure for the delivery of vital sanitation services.
2.

Water, Sanitation, and Hygiene Services in Public Health-Care Facilities in Indonesia: Adoption of World Health Organization/United Nations Children's Fund Service Ladders to National Data Sets for a Sustainable Development Goal Baseline Assessment.

Am J Trop Med Hyg; 2018 Jun 25.
Artículo en Inglés | MEDLINE | ID: mdl-29943724

RESUMEN

Provision of basic water, sanitation, and hygiene (WASH) services in health-care facilities is gaining increased attention, given growing acceptance of its importance to the maternal and newborn quality of care agenda and the universal health coverage framework. Adopting and contextualizing an emerging World Health Organization/United Nations Children's Fund Joint Program Monitoring service ladder approach to national data collected in 2010/2011, we estimated the national coverage of primary health centers (PHCs) ( = 8,831), auxiliary PHCs ( = 22,853), village health posts ( = 28,692), and village maternity clinics ( = 14,396) with basic WASH services in Indonesia as part of a Sustainable Development Goal baseline assessment. One quarter of PHCs did not have access to a combination of basic water and sanitation (WatSan) services (23.6%) with significant regional variation (10.6-59.8%), whereas more than two-third of PHCs (72%) lacked handwashing facility with soap in all three locations (general consulting room, immunization room, and delivery room). More than a half of the three lower health service level facility types lacked basic WatSan services. National health facility monitoring systems need to be urgently strengthened for tracking the progress and addressing gaps in basic WASH services in health facilities in Indonesia.
3.

Evaluation of metal removal efficiency and its influence in the physicochemical parameters at two sewage treatment plants.

Environ Monit Assess; 190(5): 263, 2018 Apr 03.
Artículo en Inglés | MEDLINE | ID: mdl-29616342

RESUMEN

In sewage treatment plants, physicochemical parameters are highly controlled since treated sewage can be returned to water bodies or reused. In addition, pollutants such as heavy metals also deserve attention due to their potential toxicity. In general, these characteristics of sewage and treated water are evaluated independently, with the support of Brazilian legislation that does not require a routine for the analysis of metals as frequent as for the physicochemical parameters. In this work, 66 samples of raw sewage, treated sewage, and effluents from two treatment plants in the city of Bauru, São Paulo, Brazil, were evaluated to assess the efficiency of the treatment plants in the removal of metals. In addition, the influence of these pollutants on the quantification of physicochemical parameters was evaluated. The quantification of metals was performed using inductively coupled plasma optical spectroscopy (ICP-OES), and Spearman's test was applied to evaluate correlation between physicochemical parameters and metal content. The main metals found in the samples were Ba, Mn, Zn, Cu, Se, Fe, and Al. The results indicate that concentrations of metals in the aquatic environment can significantly affect the physicochemical parameters, since high concentrations of metals can interfere mainly in the pH, chemical oxygen demand, and dissolved oxygen.
4.

Phthalates removal efficiency in different wastewater treatment technology in the Eastern Cape, South Africa.

Environ Monit Assess; 190(5): 299, 2018 Apr 20.
Artículo en Inglés | MEDLINE | ID: mdl-29679156

RESUMEN

The removal capacity of different wastewater treatment plant (WWTP) technologies adopted in rural areas for phthalate was investigated in the Eastern Cape, South Africa. Wastewater samples collected from three selected WWTPs which use activated sludge (AS), trickling filter (TF), and oxidation pond (OP) technology were extracted using the solid-phase extraction method followed by gas chromatography-mass spectrometry (GC-MS) analysis. The six selected phthalate esters (PAEs) dimethyl phthalate (DMP), diethyl phthalate (DEP), di-n-butyl phthalate (DBP), benzyl butyl phthalate (BBP), di(2-ethyl hexyl) phthalate (DEHP), and di-n-octyl phthalate (DOP) were detected in all the samples collected from the WWTPs. DBP was the most abundant compound in the influent, effluent, and sludge samples with a maximum detection of 2497 µgL , 24.2 µgL , and 1249 µg/g dW, respectively, followed by DEHP and BBP. There was a relatively high removal capacity achieved by AS in Alice, TF in Berlin, and OP in Bedford with a removal efficiency that varied between 77 and 99%, 76 and 98%, and 61 and 98%, respectively. A high significant correlation of PAE removal with total suspended solids (TSS) and turbidity suggests that the removal performance proceeded more through adsorption on settling particles and sludge than on biodegradation. However, the concentrations of PAEs detected in the final effluent and sludge samples exceeded acceptable levels allowed internationally for a safe aquatic environment. AS may have exhibited a more stable and better performance across the different seasons; however, pollution source control still deserves a special attention to prevent the risk posed by these micropollutants.
5.

Biological minimization of excess sludge in a membrane bioreactor: Effect of plant configuration on sludge production, nutrient removal efficiency and membrane fouling tendency.

Bioresour Technol; 259: 146-155, 2018 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-29550667

RESUMEN

Excess sludge minimization was studied in a MBR with pre-denitrification scheme. Sludge minimization, nitrogen removal performance and membrane fouling tendency were investigated in two configurations, characterized by a different position of the sludge retention reactor (SRR). In particular, the SRR was placed: i) in the return activated sludge line (Anaerobic Side-Stream Reactor - ASSR configuration) and ii) in the mainstream between the anoxic and aerobic reactor (Anaerobic Main-Stream Reactor - AMSR configuration). The achieved results demonstrated that the ASSR enabled a higher excess sludge reduction (74% vs 32%), while achieving lower biological nitrogen removal (BNR) (TN = 63% vs 78%) and membrane fouling tendency (FR = 2.1 ·â€¯10 m d vs 4.0 ·â€¯10 m d ) than the AMSR. It was found that metabolism uncoupling, destruction of EPS and endogenous decay simultaneously occurred in the ASSR. Conversely, selective enrichment of bacteria population with low biomass yield was found the main mechanism affecting sludge minimization in the AMSR.
6.

The role of community participation for sustainable integrated neglected tropical diseases and water, sanitation and hygiene intervention programs: A pilot project in Tanzania.

Soc Sci Med; 202: 28-37, 2018 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-29501716

RESUMEN

Strategies aimed at reducing the prevalence of neglected tropical diseases (NTDs) in Tanzania including those attributed to water, sanitation and hygiene (WASH) problems have been largely top-down in nature. They have focused on strengthening the governance of NTD-WASH programs by integrating different vertical disease programs and improving the efficiency of report-generation. In this paper, we argue for community participation as an effective strategy for developing sustainable village health governance. We present the results of a pilot undertaken between November 2015 and April 2016 in which we adopted a mixed methods case study approach to implement an Enhanced Development Governance (EDG) model using existing village governance structures. Our results show that the EDG model was associated with a statistically significant reduction in the prevalence of schistosomiasis and diarrhoea, and has led to an increase in awareness of WASH interventions for sustaining gains in NTD control. We identify five key social processes enacted by the EDG model that have led to improved health benefits related to frequency of meetings and attendance, promotion of health and sanitation awareness, income-generating activities, self-organising capabilities, and interaction between village bodies. These findings hold important implications for conceptualising the role of community participation in sustaining NTD-WASH intervention programs and for sensitising institutional and policy reform.
7.

How immediate and significant is the outcome of training on diversified diets, hygiene and food safety? An effort to mitigate child undernutrition in rural Malawi.

Public Health Nutr; 21(6): 1156-1166, 2018 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-29338801

RESUMEN

OBJECTIVE: The present study examined the impacts of training on nutrition, hygiene and food safety designed by the Nutrition Working Group, Child Survival Collaborations and Resources Group (CORE). DESIGN: Adapted from the 21d Positive Deviance/Hearth model, mothers were trained on the subjects of appropriate complementary feeding, water, sanitation and hygiene (WASH) practices, and aflatoxin contamination in food. To assess the impacts on child undernutrition, a randomised controlled trial was implemented on a sample of 179 mothers and their children (<2 years old) in two districts of Malawi, namely Mzimba and Balaka. Settings A 21d intensive learning-by-doing process using the positive deviance approach. SUBJECTS: Malawian children and mothers. RESULTS: Difference-in-difference panel regression analysis revealed that the impacts of the comprehensive training were positive and statistically significant on the Z-scores for wasting and underweight, where the effects increased constantly over time within the 21d time frame. As for stunting, the coefficients were not statistically significant during the 21d programme, although the level of significance started increasing in 2 weeks, indicating that stunting should also be alleviated in a slightly longer time horizon. CONCLUSIONS: The study clearly suggests that comprehensive training immediately guides mothers into improved dietary and hygiene practices, and that improved practices take immediate and progressive effects in ameliorating children's undernutrition.
8.

Enhancing nitrogen removal efficiency in a dyestuff wastewater treatment plant with the IFFAS process: the pilot-scale and full-scale studies.

Water Sci Technol; 77(1-2): 70-78, 2018 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-29339605

RESUMEN

The activated sludge (AS) process is widely applied in dyestuff wastewater treatment plants (WWTPs); however, the nitrogen removal efficiency is relatively low and the effluent does not meet the indirect discharge standards before being discharged into the industrial park's WWTP. Hence it is necessary to upgrade the WWTP with more advanced technologies. Moving bed biofilm processes with suspended carriers in an aerobic tank are promising methods due to enhanced nitrification and denitrification. Herein, a pilot-scale integrated free-floating biofilm and activated sludge (IFFAS) process was employed to investigate the feasibility of enhancing nitrogen removal efficiency at different hydraulic retention times (HRTs). The results showed that the effluent chemical oxygen demand (COD), ammonium nitrate (NH -N) and total nitrogen (TN) concentrations of the IFFAS process were significantly lower than those of the AS process, and could meet the indirect discharge standards. PCR-DGGE and FISH results indicated that more nitrifiers and denitrifiers co-existed in the IFFAS system, promoting simultaneous nitrification and denitrification. Based on the pilot results, the IFFAS process was used to upgrade the full-scale AS process, and the effluent COD, NH -N and TN of the IFFAS process were 91-291 mg/L, 10.6-28.7 mg/L and 18.9-48.6 mg/L, stably meeting the indirect discharge standards and demonstrating the advantages of IFFAS in dyestuff wastewater treatment.
9.

Industrial wastewater treatment with a bioelectrochemical process: assessment of depuration efficiency and energy production.

Water Sci Technol; 77(1-2): 134-144, 2018 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-29339612

RESUMEN

Development of renewable energy sources, efficient industrial processes, energy/chemicals recovery from wastes are research issues that are quite contemporary. Bioelectrochemical processes represent an eco-innovative technology for energy and resources recovery from both domestic and industrial wastewaters. The current study was conducted to: (i) assess bioelectrochemical treatability of industrial (dairy) wastewater by microbial fuel cells (MFCs); (ii) determine the effects of the applied organic loading rate (OLR) on MFC performance; (iii) identify factors responsible for reactor energy recovery losses (i.e. overpotentials). For this purpose, an MFC was built and continuously operated for 72 days, during which the anodic chamber was fed with dairy wastewater and the cathodic chamber with an aerated mineral solution. The study demonstrated that industrial effluents from agrifood facilities can be treated by bioelectrochemical systems (BESs) with >85% (average) organic matter removal, recovering power at an observed maximum density of 27 W m . Outcomes were better than in previous (shorter) analogous experiences, and demonstrate that this type of process could be successfully used for dairy wastewater with several advantages.
10.

Determination of Appropriate Service Delivery Level for Quantitative Attributes of Household Toilets in Rural Settlements of India from Users' Perspective.

Environ Manage; 61(4): 637-649, 2018 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-29330609

RESUMEN

Improvement of quality of sanitation services in rural settlements is an important development goal in developing countries including India and accordingly several strategies are adopted which promote the demand and use of household toilets through creating awareness and providing subsidies to poor people for construction of household toilets with service-level standards specified from experts' perspective. In many cases, users are unsatisfied with the quality of toilets constructed using subsidies and the same remain unused. Users' satisfaction depends on their perceptions of service quality of individual attributes and overall service quality of the household toilets, which is an important determinant of sustainability and sustained use of toilets. This study aims to assess and benchmark the appropriate service delivery level for quantitative attributes of rural household toilets based on user perception. The service quality is determined with the help of level of service (LOS) scales developed using successive interval scaling technique, the zone of tolerance (ZOT), and users satisfaction level (USL) which relates service delivery levels with user satisfaction directly. The study finds that the service quality of most of the attributes of household toilets constructed using subsidies is perceived as poor. The results also suggest that most of the users expect to have a toilet with the service level of attributes ranging between LOS A and LOS B.
11.

Culturally appropriate organization of water and sewerage projects built through public private partnerships.

PLoS One; 12(12): e0188905, 2017.
Artículo en Inglés | MEDLINE | ID: mdl-29200432

RESUMEN

This paper contributes to the pursuit of socially sustainable water and sanitation infrastructure for all people by discovering statistically robust relationships between Hofstede's dimensions of cross-cultural comparison and the choice of contract award types, project type, and primary revenue sources. This analysis, which represents 973 projects distributed across 24 low- and middle-income nations, uses a World Bank dataset describing high capital cost water and sewerage projects funded through private investment. The results show that cultural dimensions explain variation in the choice of contract award types, project type, and primary revenue sources. These results provide empirical evidence that strategies for water and sewerage project organization are not culturally neutral. The data show, for example, that highly individualistic contexts are more likely to select competitive contract award types and to depend on user fees to provide the primary project revenue stream post-construction. By selecting more locally appropriate ways to organize projects, project stakeholders will be better able to pursue the construction of socially sustainable water and sewerage infrastructure.
12.

Optimizing household survey methods to monitor the Sustainable Development Goals targets 6.1 and 6.2 on drinking water, sanitation and hygiene: A mixed-methods field-test in Belize.

PLoS One; 12(12): e0189089, 2017.
Artículo en Inglés | MEDLINE | ID: mdl-29216244

RESUMEN

BACKGROUND: The Sustainable Development Goals (SDGs) require household survey programmes such as the UNICEF-supported Multiple Indicator Cluster Surveys (MICS) to enhance data collection to cover new indicators. This study aims to evaluated methods for assessing water quality, water availability, emptying of sanitation facilities, menstrual hygiene management and the acceptability of water quality testing in households which are key to monitoring SDG targets 6.1 and 6.2 on drinking Water, Sanitation and Hygiene (WASH) and emerging issues. METHODS: As part of a MICS field test, we interviewed 429 households and 267 women age 15-49 in Stann Creek, Belize in a split-sample experiment. In a concurrent qualitative component, we conducted focus groups with interviewers and cognitive interviews with respondents during and immediately following questionnaire administration in the field to explore their question comprehension and response processes. FINDINGS: About 88% of respondents agreed to water quality testing but also desired test results, given the potential implications for their own health. Escherichia coli was present in 36% of drinking water collected at the source, and in 47% of samples consumed in the household. Both questions on water availability necessitated probing by interviewers. About one quarter of households reported emptying of pit latrines and septic tanks, though one-quarter could not provide an answer to the question. Asking questions on menstrual hygiene was acceptable to respondents, but required some clarification and probing. CONCLUSIONS: In the context of Belize, this study confirmed the feasibility of collecting information on the availability and quality of drinking water, emptying of sanitation facilities and menstrual hygiene in a multi-purpose household survey, indicating specific areas to improve question formulation and field protocols. Improvements have been incorporated into the latest round of MICS surveys which will be a major source of national data for monitoring of SDG targets for drinking water, sanitation and hygiene and emerging issues for WASH sector programming.
13.

Evaluating the efficiency of carbon utilisation via bioenergetics between biological aerobic and denitrifying phosphorus removal systems.

PLoS One; 12(10): e0187007, 2017.
Artículo en Inglés | MEDLINE | ID: mdl-29065157

RESUMEN

There are two biological systems available for removing phosphorus from waste water, conventional phosphorus removal (CPR) and denitrifying phosphorus removal (DPR) systems, and each is characterized by the type of sludge used in the process. In this study, we compared the characteristics associated with the efficiency of carbon utilization between CPR and DPR sludge using acetate as a carbon source. For DPR sludge, the heat emitted during the phosphorus release and phosphorus uptake processes were 45.79 kJ/mol e- and 84.09 kJ/mol e-, respectively. These values were about 2 fold higher than the corresponding values obtained for CPR sludge, suggesting that much of the energy obtained from the carbon source was emitted as heat. Further study revealed a smaller microbial mass within the DPR sludge compared to CPR sludge, as shown by a lower sludge yield coefficient (0.05 gVSS/g COD versus 0.36 gVSS/g COD), a result that was due to the lower energy capturing efficiency of DPR sludge according to bioenergetic analysis. Although the efficiency of anoxic phosphorus removal was only 39% the efficiency of aerobic phosphorus removal, the consumption of carbon by DPR sludge was reduced by 27.8% compared to CPR sludge through the coupling of denitrification with dephosphatation.
14.

Projeto piloto de uma caixa de descarga eficiente, econômica e à prova de vazamentos / Pilot design of an efficient, leak-proof and economical flush system

Eng. sanit. ambient; 22(5): 953-959, set.-out. 2017. tab, graf
Artículo en Portugués | LILACS-Express | ID: biblio-891583

RESUMEN

RESUMO Nas últimas décadas, houve redução de consumo per capita de água. Mesmo assim, diversos países buscam uma redução adicional no consumo por meio da melhoria dos processos de funcionamento de equipamentos. Este artigo descreve um novo design para caixa de descarga econômica, no qual não existe obturador nem juntas que possam ressecar e acarretar vazamento. Foram construídos e testados protótipos; o uso prolongado por 12 meses em uma residência habitada por quatro moradores demonstrou que o novo modelo de caixa de descarga funciona bem e consome menos água do que os demais. Esse projeto dispensa o uso de borrachas de vedação, trabalha com duas células (caixa interna e caixa externa), apresenta boa capacidade de arraste e demonstra boa eficiência tanto para descarga de 3 L como para descarga de 6 L.
ABSTRACT In the last decades, water consumption per capita has been reduced. Nevertheless, several countries look for additional reduction in water consumption through better process of equipment functions. This paper describes a new design for an economical flush system in which there is neither flapper nor gasket that could leak. Prototypes with new design have been made and tested; after a 12 months' test with one of them, by a family of 4 people, the project had good performance, with reduction in water consumption. This new design does not use gasket, works with two boxes (internal box and external box), presents good drag ability and demonstrates good water efficiency both for 3 L and 6 L flushes.
Biblioteca responsable: BR559.1
15.

Constructed wetlands and solar-driven disinfection technologies for sustainable wastewater treatment and reclamation in rural India: SWINGS project.

Water Sci Technol; 76(6): 1474-1489, 2017 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-28953474

RESUMEN

SWINGS was a cooperation project between the European Union and India, aiming at implementing state of the art low-cost technologies for the treatment and reuse of domestic wastewater in rural areas of India. The largest wastewater treatment plant consists of a high-rate anaerobic system, followed by vertical and horizontal subsurface flow constructed wetlands with a treatment area of around 1,900 m and a final step consisting of solar-driven anodic oxidation (AO) and ultraviolet (UV) disinfection units allowing direct reuse of the treated water. The implementation and operation of two pilot plants in north (Aligarh Muslim University, AMU) and central India (Indira Gandhi National Tribal University, IGNTU) are shown in this study. The overall performance of AMU pilot plant during the first 7 months of operation showed organic matter removal efficiencies of 87% total suspended solids, 95% 5-day biological oxygen demand (BOD ) and 90% chemical oxygen demand, while Kjeldahl nitrogen removal reached 89%. The UV disinfection unit produces water for irrigation and toilet flushing with pathogenic indicator bacteria well below WHO guidelines. On the other hand, the AO disinfection unit implemented at IGNTU and operated for almost a year has been shown to produce an effluent of sufficient quality to be reused by the local population for agriculture and irrigation.
16.

Greenlandic water and sanitation-a context oriented analysis of system challenges towards local sustainable development.

Artículo en Inglés | MEDLINE | ID: mdl-28849342

RESUMEN

Today, as Greenland focuses on more economic and cultural autonomy, the continued development of societal infrastructure systems is vital. At the same time, pressure is put on the systems by a lack of financial resources and locally based professional competences as well as new market-based forms of organization. Against this background, the article discusses the challenges facing Greenland's self-rule in relation to further develop the existing water and wastewater systems so that they can contribute to the sustainable development of Greenland. The article reviews the historical development of the water supply and wastewater system. This leads to an analysis of the sectorisation, which in recent decades has reorganized the Greenlandic infrastructures, and of how this process is influencing local sustainable development. The article discusses the socio-economic and human impacts and points to the need for developing the water and sanitation system to support not only hygiene and health, but also local sustainable development.
17.

Estimation of the removal efficiency of heavy metals and nutrients from ecological drainage ditches treating town sewage during dry and wet seasons.

Environ Monit Assess; 189(9): 434, 2017 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-28779427

RESUMEN

Vegetated drainage ditches (ecological drainage ditches, EDD) are commonly used for the treatment of nutrients, suspended solids, and pesticides, from agricultural lands and aquaculture effluent. However, their effectiveness to remove heavy metals/metalloids (HM/Ms) and fate remains largely unexplored. In addition, there exists some uncertainty concerning the performance of the EDD in treating HM/Ms. This study presents a thorough assessment on the removal efficiencies of HM/Ms and identifies the parameters affecting the HM/Ms removal process in the EDD receiving primary domestic sewage for 13 years. The mean concentrations of the studied HM/Ms in sediments were lower than those reported in the aquatic ecosystems affected by coal-mine drainage and industrial wastewaters. The results also showed that the concentrations of the selected HM/Ms in ditch sediment were generally far higher than the soil background values of Sichuan basin. Concentrations of all the studied HM/Ms and nutrients in water entering the EDD were significantly higher than the effluent. The annual mean removal efficiencies of Ni, Cu, Cr, Zn, Cd, Pb, As, Fe, Al, Mn, N, and P in the ecological drainage ditch were 50.6, 56.1, 63.3, 79.3, 67.5, 80.1, 60.3, 52.6, 19.8, 24.3, 72.0, and 59.7%, respectively. The study also displayed that dissolved oxygen levels at the outlet were significantly (p < 0.001) higher after passing into the EDD system. The pH was kept at neutral or alkaline. Removal of HM/Ms and nutrients was seasonal, generally peaking in the growing season. Sedimentation was the major mechanism removing HM/Ms within the EDD system. EDD was found to possess a favorable influence at mitigating HM/Ms and nutrients in situ and can be successfully utilized to resolve this type of environmental pollution.
18.

Effect of reflux ratio on nitrogen removal in a novel upflow microaerobic sludge reactor treating piggery wastewater with high ammonium and low COD/TN ratio: Efficiency and quantitative molecular mechanism.

Bioresour Technol; 243: 922-931, 2017 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-28738547

RESUMEN

A novel upflow microaerobic sludge reactor (UMSR) was constructed to treat manure-free piggery wastewater with high NH -N and low COD/TN ratio. In the light of the potential effect of effluent reflux ratio (RR) on nitrogen removal, performance of the UMSR was evaluated at 35°C and hydraulic retention time 8h with RR decreased from 45 to 25 by stages. A COD, NH -N and TN removal of above 77.1%, 80.0% and 86.6%, respectively, was kept with a RR over 35. To get an effluent of TN not more than 80mg/L with a TN load removal above 0.88kg/(m ·d), the RR should be at least 34. Real-time quantitative polymerase chain reaction of functional bacteria revealed that the RR of less than 34 stimulated ammonium oxidation but badly inhibited anammox, the dominant nitrogen removal pathway, resulting in the remarkable decrease of nitrogen removal in the reactor.
19.

Sustainable pyrolytic sludge-char preparation on improvement of closed-loop sewage sludge treatment: Characterization and combined in-situ application.

Chemosphere; 184: 1043-1053, 2017 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-28662548

RESUMEN

Aiming at closed-loop sustainable sewage sludge treatment, an optimal and economical pyrolytic temperature was found at 400-450 °C considering its pyrolysis efficiency of 65%, fast cracking of hydrocarbons, proteins and lipids and development of aromatized porous structure. Fourier-transform infrared (FTIR) and X-ray diffraction (XRD) tests demonstrated the development of adsorptive functional groups and crystallographic phases of adsorptive minerals. The optimal sludge-char, with a medium specific surface area of 39.6 m g and an iodine number of 327 mgI g , performed low heavy metals lixiviation. The application of sludge-char in raw sewage could remove 30% of soluble chemical oxygen demand (SCOD), along with an acetic acid adsorption capacity of 18.0 mg g . The developed mesopore and/or macropore structures, containing rich acidic and basic functional groups, led to good biofilm matrices for enhanced microbial activities and improved autotrophic nitrification in anoxic stage of an A/O reactor through adsorbed extra carbon source, and hence achieved the total nitrogen (TN) removal up to 50.3%. It is demonstrated that the closed-loop sewage sludge treatment that incorporates pyrolytic sludge-char into in-situ biological sewage treatment can be a promising sustainable strategy by further optimization.
20.

Consumer Perceptions of the Safety of Ready-to-Eat Foods in Retail Food Store Settings.

J Food Prot; 80(8): 1364-1377, 2017 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-28722484

RESUMEN

To better understand how consumers perceive food safety risks in retail food store settings, a survey was administered to 1,041 nationally representative participants who evaluated possible food safety risks depicted in selected photographs and self-reported their perceptions, attitudes, and behaviors. Participants were shown 12 photographs taken at retail stores portraying either commonly perceived or actual food safety contributing factors, such as cross-contamination, product and equipment temperatures, worker hygiene, and/or store sanitation practices. Participants were then asked to specifically identify what they saw, comment as to whether what they saw was safe or unsafe, and articulate what actions they would take in response to these situations. In addition to the survey, focus groups were employed to supplement survey findings with qualitative data. Survey respondents identified risk factors for six of nine actual contributing factor photographs >50% of the time: poor produce storage sanitation (86%, n = 899), cross-contamination during meat slicing (72%, n = 750), bare-hand contact of ready-to-eat food in the deli area (67%, n = 698), separation of raw and ready-to-eat food in the seafood case (63%, n = 660), cross-contamination from serving utensils in the deli case (62%, n = 644), and incorrect product storage temperature (51%, n = 528). On a scale of 1 to 5, where 1 was very unsafe and 5 was very safe, a significant difference was found between average risk perception scores for photographs of actual contributing factors (score of ca. 2.5) and scores for photographs of perceived contributing factors (score of ca. 2.0). Themes from the focus groups supported the results of the survey and provided additional insight into consumer food safety risk perceptions. The results of this study inform communication interventions for consumers and retail food safety professionals aimed at improving hazard identification.
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