Reactive dyes account for one of the major sources of dye wastes in textile effluent. In this study, decolorization of the monoazo dye, Acid Orange 7 (AO7) by the Enterococcus faecalis strain ZL that isolated from a palm oil mill effluent treatment plant has been investigated. Decolorization efficiency of azo dye is greatly affected by the types of nutrients and the size of inoculum used. In this work, one-factor-at-a-time (method and response surface methodology (RSM) was applied to optimize these operational factors and also to study the combined interaction between them. Analysis of AO7 decolorization was done using Fourier transform infrared (FTIR) spectroscopy, desorption study, UV–Vis spectral analysis, field emission scanning electron microscopy (FESEM), and high performance liquid chromatography (HPLC). The optimum condition via RSM for the color removal of AO7 was found to be as follows: yeast extract, 0.1 %?w/v, glycerol concentration of 0.1 %?v/v, and inoculum density of 2.5 %?v/v at initial dye concentration of 100 mg/L at 37 °C. Decolorization efficiency of 98 % was achieved in only 5 h. The kinetic of AO7 decolorization was found to be first order with respect to dye concentration with a k value of 0.87/h. FTIR, desorption study, UV–Vis spectral analysis, FESEM, and HPLC findings indicated that the decolorization of AO7 was mainly due to the biosorption as well as biodegradation of the bacterial cells. In addition, HPLC analyses also showed the formation of sulfanilic acid as a possible degradation product of AO7 under facultative anaerobic condition. This study explored the ability of E. faecalis strain ZL in decolorizing AO7 by biosorption as well as biodegradation process. 相似文献
Environmental Science and Pollution Research - Cigarette butt (CB) is a crucial litter in urban communities because it may contain various toxicants. Due to serious limitations on... 相似文献
Cigarette butts are hazardous wastes that are not properly discarded by most smokers. They are one of the most abundant litters in the environment and a threat to various organisms because they leak numerous pollutants. This study aimed to assess the distribution of cigarette butts in a coastal city south of the Caspian Sea in Mazandaran Province, Iran. Observations were performed using the visual survey technique based on standardized protocol. The results showed 11,261 littered cigarette butts in 15 studied urban areas ( an average of 0.306 units per square meter). Also, the average density of littered cigarette butts on the studied beaches was 0.106 per square meter. The littered cigarette butts had significant spatial variation, and the number of counts was 135 to 2090. The land-use has a significant effect on the density of littered cigarette butts due to its population density. The inquiry’s index demonstrated that 33.3% of the studied urban areas are high pollution and severe pollution, while all beaches are high and severe. Therefore, a significant focus must be considered to reduce cigarette butts littering due to the collection problems and challenges of cigarette butt management. Because the pollution on the beaches is higher than in urban areas, improving waste management services and establishing a regular cleaning program are essential.
In this research, the influence of thermo-mechanical degradation of polypropylene (PP) on water absorption and thickness swelling
of beech wood flour–PP composites were studied. For this purpose, a virgin PP was thermo-mechanically degraded by two times
extrusion under controlled conditions. The results showed that the melt flow index, water absorption and thickness swelling
of PP significantly increase by extrusion and re-extrusion. The virgin PP and degraded polypropylene were compounded with
wood flour (at 60% by weight wood flour loading) in a counter-rotating twin-screw extruder in presence or absence of MAPP
to produce wood flour–PP composites. From the results, the composites containing recycled PP exhibited higher water absorption
and thickness swelling. The use of MAPP decreased water absorption and thickness swelling in composites made of virgin or
recycled PP. 相似文献
Strategic health, safety, and environmental management system (HSE-MS) involves systematic and cooperative planning in each
phase of the lifecycle of a project to ensure that interaction among the industry group, client, contractor, stakeholder,
and host community exists with the highest level of health, safety, and environmental standard performances. Therefore, it
seems necessary to assess the HSE-MS performance of contractor(s) by a comparative strategic management model with the aim
of continuous improvement. The present Strategic Management Model (SMM) has been illustrated by a case study and the results
show that the model is a suitable management tool for decision making in a contract environment, especially in oil and gas
fields and based on accepted international standards within the framework of management deming cycle. To develop this model,
a data bank has been created, which includes the statistical data calculated by converting the HSE performance qualitative
data into quantitative values. Based on this fact, the structure of the model has been formed by defining HSE performance
indicators according to the HSE-MS model. Therefore, 178 indicators have been selected which have been grouped into four attributes.
Model output provides quantitative measures of HSE-MS performance as a percentage of an ideal level with maximum possible
score for each attribute. Defining the strengths and weaknesses of the contractor(s) is another capability of this model.
On the other hand, this model provides a ranking that could be used as the basis for decision making at the contractors’ pre-qualification
phase or during the execution of the project. 相似文献
The aim of an ergonomics intervention conducted in the tire manufacturing industry was to improve working conditions. Before the start, a senior manager supported the intervention. Participants were divided into teams and trained. After observing the overall performance of the teams, over 100 improvements were successfully implemented. After the improvements, there were statistically significant differences in annual and weekly prevalence of, and annual disability reported for, the upper back, the lower back, knees and wrists between before and after intervention. The annual prevalence of upper back, lower back, knee and wrist complaints decreased from, respectively, 60.3%, 50.2%, 28.9%, 25.8% before the intervention to 31.3%, 35.9%, 17.1%, 20.7% after the intervention. Significant factors were training and supportive environment based on full commitment of the top management. 相似文献
The basic aim of this work is (1) to review and present practically operational requirements for a sustainability assessment of marine environment, such as describing the monitoring process, research approaches, objectives, guidelines, and indicators and (2) to illustrate how physico-chemical and biological indicators can be practically applied, to assess water and sediment quality in marine and coastal environment. These indicators should meet defined criteria for practical usefulness, e.g. they should be simple to understand and apply to managers and scientists with different educational backgrounds. This review aimed to encapsulate that variability, recognizing that meaningful guidance should be flexible enough to accommodate the widely differing characteristics of marine ecosystems. 相似文献
This study develops and tests a novel optimization method for optimally selecting and sizing stormwater control measures (SCMs) in urban landscapes for selected design storms. The developed methodology yields SCMs that capture and retain stormwater via onsite percolation, remove stormwater pollutants, and minimize stormwater control expenditures. The resulting environmental optimization problem involves integer and real variables imbedded in an objective function that is subjected to multiple constraints. This study's methodology aims at practicality and ease of implementation in the solution of the SCM sizing and selection optimization problem while taking into account the main factors that govern stormwater management in urban landscapes. The near‐optimal global solution of the SCM selection and design problem is obtained with nonlinear programming and verified with the average of multiple solutions calculated with multiple runs of an optimization evolutionary algorithm. The developed methodology is illustrated with one stormwater project in the City of Los Angeles, California. 相似文献