Sorption behaviors of heavy metals in SAT (soil aquifer treatment) system

2004 ◽  
Vol 50 (2) ◽  
pp. 263-268 ◽  
Author(s):  
So Young Lee ◽  
Jong-Un Lee ◽  
Heechul Choi ◽  
Kyoung-Woong Kim
Keyword(s):  
Heavy Metals ◽  
Organic Contaminants ◽  
Water Reuse ◽  
Column Experiment ◽  
Factorial Analysis ◽  
Fractional Factorial ◽  
Soil Aquifer Treatment ◽  
Acidic Water ◽  
Water Ph ◽  
Main Effects

Degradation or detoxification of pollutants by SAT system was generally focused on organic contaminants although the regulation of water reuse has provisions of heavy metals. This study is to evaluate the feasibility of SAT for metals such as Cd, Cr and Pb with the pilot scaled column experiment. The desorption possibility of sorbed metals was also examined in the condition of continuous water and even acidic water (pH 4.3) injection. Fractional factorial analysis is a tool frequently used to identify factors or variables that have an effect on a certain response. A two-level fractional factorial analysis was planned to study the effect of four factors on Pb sorption from the experiments; soil particle size, TOC in solution, Pb concentration in solution and flow rate. The main effects among the factors were obtained by ANOVA based MINITAB software. The effects of four factors were also converted into coefficients; those values may build an empirical model to predict the metal sorption of soils.

Study on the Competitive Adsorption of Dimethoate with Multiple Pesticides and Heavy Metals Based on Fractional Factorial Design

2013 ◽  
Vol 864-867 ◽  
pp. 229-233
Author(s):  
Bing Chuan Cheng ◽  
Lin Liu ◽  
Xiao Yu Cai ◽  
Meng Wang ◽  
Yu Li
Keyword(s):  
Heavy Metals ◽  
Linear Regression ◽  
Multiple Linear Regression ◽  
Factorial Design ◽  
Competitive Adsorption ◽  
Fractional Factorial Design ◽  
Second Order ◽  
Fractional Factorial ◽  
Surficial Sediments ◽  
Main Effects

In order to reveal the composite contaminations characteristic of dimethoate adsorption onto the surficial sediments, the competitive adsorption of dimethoate in pesticide (dimethoate, metalaxyl, atrazine, malathion, and prometryn)/heavy metals (copper, zinc, lead, cadmium and nickel) system is investigated. A 210-5 fractional factorial design method at resolution IV and a multiple linear regression adsorption model are used to identify the main effects and interactions of above ten pollutions. The adsorption amount of dimethoate surficial sediments is set as the dependent variable, and the main effects and second-order interactions of ten pollutions are set as independent variables. Thus, a multiple linear regression model of dimethoate adsorption is screened and established. The results of model show that the main effects of Cd, malathion and prometryn performed a significant antagonistic effect (α=0.05) on the adsorption of dimethoate onto the sediment (competitive adsorption effects), and the order is: prometryn (-0.0925) > Cd (-0.0878) > malathion (-0.0827); while heavy metal Zn performed a significant synergy effect on the adsorption of dimethoate. The second-order interaction effects of Zn*prometryne, Pb*atrazine and Pb*atrazine has a significant antagonistic impact on the adsorption of dimethoate in sediments, which is in a sequence of Zn*prometryne (-0.0967) > Pb*atrazine (-0.0945) > Cd*atrazine (-0.0922). Moreover, according to the rate of contributions of main effects and second-order interaction effects in composite contaminations system, we can also estimate and definite the pollution levels of target pollutant.

Are More Profiles Better Than Fewer?: Searching for Parsimony and Relevance in Stated Choice Experiments

2000 ◽  
Vol 1719 (1) ◽  
pp. 165-174 ◽  
Author(s):  
Peter R. Stopher ◽  
David A. Hensher
Keyword(s):  
New Zealand ◽  
Degrees Of Freedom ◽  
Choice Model ◽  
Fractional Factorial ◽  
Sources Of Information ◽  
Stated Choice ◽  
Complex Design ◽  
Data Collection Instrument ◽  
Main Effects ◽  
Better Than

Transportation planners increasingly include a stated choice (SC) experiment as part of the armory of empirical sources of information on how individuals respond to current and potential travel contexts. The accumulated experience with SC data has been heavily conditioned on analyst prejudices about the acceptable complexity of the data collection instrument, especially the number of profiles (or treatments) given to each sampled individual (and the number of attributes and alternatives to be processed). It is not uncommon for transport demand modelers to impose stringent limitations on the complexity of an SC experiment. A review of the marketing and transport literature suggests that little is known about the basis for rejecting complex designs or accepting simple designs. Although more complex designs provide the analyst with increasing degrees of freedom in the estimation of models, facilitating nonlinearity in main effects and independent two-way interactions, it is not clear what the overall behavioral gains are in increasing the number of treatments. A complex design is developed as the basis for a stated choice study, producing a fractional factorial of 32 rows. The fraction is then truncated by administering 4, 8, 16, 24, and 32 profiles to a sample of 166 individuals (producing 1, 016 treatments) in Australia and New Zealand faced with the decision to fly (or not to fly) between Australia and New Zealand by either Qantas or Ansett under alternative fare regimes. Statistical comparisons of elasticities (an appropriate behavioral basis for comparisons) suggest that the empirical gains within the context of a linear specification of the utility expression associated with each alternative in a discrete choice model may be quite marginal.

scholarly journals Characterization of a Shallow Coastal Aquifer in the Framework of a Subsurface Storage and Soil Aquifer Treatment Project Using Electrical Resistivity Tomography (Port de la Selva, Spain)

2021 ◽  
Vol 11 (6) ◽  
pp. 2448
Author(s):  
Alex Sendrós ◽  
Aritz Urruela ◽  
Mahjoub Himi ◽  
Carlos Alonso ◽  
Raúl Lovera ◽  
...  
Keyword(s):  
Electrical Resistivity ◽  
Water Reuse ◽  
Electrical Resistivity Tomography ◽  
Groundwater Modeling ◽  
Geophysical Methods ◽  
Soil Aquifer Treatment ◽  
Modeling Tools ◽  
Resistivity Tomography ◽  
Implicit Modeling ◽  
The Difference

Water percolation through infiltration ponds is creating significant synergies for the broad adoption of water reuse as an additional non-conventional water supply. Despite the apparent simplicity of the soil aquifer treatment (SAT) approaches, the complexity of site-specific hydrogeological conditions and the processes occurring at various scales require an exhaustive understanding of the system’s response. The non-saturated zone and underlying aquifers cannot be considered as a black box, nor accept its characterization from few boreholes not well distributed over the area to be investigated. Electrical resistivity tomography (ERT) is a non-invasive technology, highly responsive to geological heterogeneities that has demonstrated useful to provide the detailed subsurface information required for groundwater modeling. The relationships between the electrical resistivity of the alluvial sediments and the bedrock and the difference in salinity of groundwater highlight the potential of geophysical methods over other more costly subsurface exploration techniques. The results of our research show that ERT coupled with implicit modeling tools provides information that can significantly help to identify aquifer geometry and characterize the saltwater intrusion of shallow alluvial aquifers. The proposed approaches could improve the reliability of groundwater models and the commitment of stakeholders to the benefits of SAT procedures.

Exploring the Role of Interaction Effects in Visual Conjoint Analysis

2015 ◽  
Vol 137 (9) ◽  
Author(s):  
Brian Sylcott ◽  
Jeremy J. Michalek ◽  
Jonathan Cagan
Keyword(s):  
Conjoint Analysis ◽  
Consumer Preferences ◽  
Consumer Preference ◽  
Interaction Effects ◽  
Fractional Factorial ◽  
Main Effects ◽  
Full Factorial ◽  
Biased Estimates ◽  
Data Requirements

In conjoint analysis, interaction effects characterize how preference for the level of one product attribute is dependent on the level of another attribute. When interaction effects are negligible, a main effects fractional factorial experimental design can be used to reduce data requirements and survey cost. This is particularly important when the presence of many parameters or levels makes full factorial designs intractable. However, if interaction effects are relevant, main effects design can create biased estimates and lead to erroneous conclusions. This work investigates consumer preference interactions in the nontraditional context of visual choice-based conjoint analysis, where the conjoint attributes are parameters that define a product's shape. Although many conjoint studies assume interaction effects to be negligible, they may play a larger role for shape parameters. The role of interaction effects is explored in two visual conjoint case studies. The results suggest that interactions can be either negligible or dominant in visual conjoint, depending on consumer preferences. Generally, we suggest using randomized designs to avoid any bias resulting from the presence of interaction effects.

Impact of metals bioleaching on the nutrient value of biological nutrient removal biosolids

1999 ◽  
Vol 39 (6) ◽  
pp. 175-181 ◽  
Author(s):  
Abdallah Shanableh ◽  
Pushpa Ginige
Keyword(s):  
Heavy Metals ◽  
Nutrient Removal ◽  
Organic Contaminants ◽  
Agricultural Land ◽  
Land Application ◽  
Biological Nutrient Removal ◽  
Environment Protection ◽  
Toxic Heavy Metals ◽  
Beneficial Use ◽  
Nutrient Value

The biosolids industry in Australia is evolving around the beneficial use of biosolids as a resource. Phosphorus rich biosolids from biological nutrient removal (BNR) facilities are highly desirable for land application. However, the accumulation of toxic heavy metals and industrial organic contaminants may render the biosolids unsuitable for land application. The presence of toxic heavy metals has been identified by Local Authorities in Australia as a major constraint limiting the beneficial use of biosolids. The potential of off-site contamination due to the migration of nutrients is also a major concern especially when applying biosolids to acidic agricultural land. Accordingly, the relevant environment protection and conservation agencies are involved in either developing or finalising guidelines to control the beneficial use of biosolids products. Metals bioleaching is a process achieved through bio-acidification. Bio-acidification of biosolids prior to land application can be used to dissolve and remove a significant fraction of the heavy metals content of the product. However, the process also reduces the nutrients content of the resource. Bio-acidification of Loganholme (Queensland) BNR biosolids dissolved 76% of the total phosphorus and 38% of the TKN. The heavy metals solubilisation results reached 50% for Cr, 79% for Ni, 45% for Zn, 24% for Cu, 30% for Cd, and 82% for Pb.

scholarly journals Factors influencing the imposition of a charge on the entrance to the interpretive trails in the large protected areas

2013 ◽  
Vol 61 (4) ◽  
pp. 1041-1049
Author(s):  
Josef Navrátil ◽  
Kamil Pícha
Keyword(s):  
Discrete Choice ◽  
Choice Experiment ◽  
Fractional Factorial Design ◽  
Multinomial Logit Model ◽  
Fractional Factorial ◽  
Large Protected Areas ◽  
A Charge ◽  
Main Effects ◽  
The Impact ◽  
The Way

The aim of this paper is to assess the relation between the character of the interpretive trail and the imposition of a charge on the entrance. This was done using the discrete choice experiment that involves eight attributes, seven of which are with three levels: the overall character of the trail, the way that the route signs are used in the terrain, the ways of providing information, the length of the trail, the way of the routing, the focus of the trail, and the price of the entrance. There is also one with two levels that involves the existence of the places for rest. The fractional factorial design was used (the orthogonal main effects plan) and the Multinomial Logit Model was used in analyzing the data. The 2,830 choices were done by random sampled visitors from eight tourist locations in the Tourist Regions of the Šumava Mts. and South Bohemia during the summer season 2012. The impact of the character of the trail was especially detected in the model. Except for that, the equipment of the trail and its length have had the fundamental impact on the choice of the trail as well. Those longer and worse equipped trails have a significantly lower degree of utility for the respondents. What is quite surprising is that the respondents refused the ecotourism elements of the interpretive trails, such as the possibility of going through the trail on horseback or the accompaniment of an expert who would provide some comments, as it is common to do this at historical attractions within those sightseeing paths.

scholarly journals Simultaneous Adsorption of Heavy Metals from Roadway Stormwater Runoff Using Different Filter Media in Column Studies

Water ◽  
2018 ◽  
Vol 10 (9) ◽  
pp. 1160 ◽  
Author(s):  
Tadele Haile ◽  
Maria Fuerhacker
Keyword(s):  
Heavy Metals ◽  
Sandy Soil ◽  
Quartz Sand ◽  
Stormwater Runoff ◽  
Column Experiment ◽  
Poor Performance ◽  
Filter Media ◽  
Column Studies ◽  
Natural Quartz ◽  
Removal Efficiencies

Stormwater runoff from roadways often contains a variety of contaminants such as heavy metals, which can adversely impact receiving waters. The filter media in stormwater filtration/infiltration systems play a significant role in the simultaneous removal of multiple pollutants. In this study, the capacity of five filter media—natural quartz sand (QS), sandy soil (SS) and three mineral-based technical filter media (TF-I, TF-II and TF-III)—to adsorb heavy metals (Cu, Pb and Zn) frequently detected in stormwater, as well as remobilization due to de-icing salt (NaCl), were evaluated in column experiments. The column breakthrough data were used to predict lifespan of the filter media. Column experiment operated under high hydraulic load showed that all technical filters and sandy soil achieved >97%, 94% and >80% of Pb, Cu and Zn load removals, respectively, while natural quartz sand (QS) showed very poor performance. Furthermore, treatment of synthetic stormwater by the soil and technical filter media met the requirements of the Austrian regulation regarding maximum effluent concentrations and minimum removal efficiencies for groundwater protection. The results showed that application of NaCl had only a minor impact on the remobilization of heavy metals from the soil and technical filter media, while the largest release of metals was observed from the QS column. Breakthrough analysis indicated that load removal efficiencies at column exhaustion (SS, TF-I, TF-II and TF-III) were >95% for Cu and Pb and 80–97% for Zn. Based on the adsorption capacities, filtration systems could be sized to 0.4 to 1% (TF-I, TF-II and TF-III) and 3.5% (SS) of their impervious catchment area and predicated lifespan of each filter media was at least 35, 36, 41 and 29 years for SS, TF-I, TF-II and TF-III, respectively. The findings of this study demonstrate that soil—based and technical filter media are effective in removing heavy metals and can be utilized in full-stormwater filtration systems.

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