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Manzar MS, Khan G, dos Santos Lins PV, Zubair M, Khan SU, Selvasembian R, Meili L, Blaisi NI, Nawaz M, Abdul Aziz H, Kayed T. RSM-CCD optimization approach for the adsorptive removal of Eriochrome Black T from aqueous system using steel slag-based adsorbent: Characterization, Isotherm, Kinetic modeling and thermodynamic analysis. J Mol Liq 2021. [DOI: 10.1016/j.molliq.2021.116714] [Citation(s) in RCA: 21] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
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Zubair M, Ferrari R, Alagha O, Mu’azu ND, Blaisi NI, Ateeq IS, Manzar MS. Microwave Foaming of Materials: An Emerging Field. Polymers (Basel) 2020; 12:E2477. [PMID: 33113873 PMCID: PMC7692174 DOI: 10.3390/polym12112477] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2020] [Revised: 10/17/2020] [Accepted: 10/22/2020] [Indexed: 11/28/2022] Open
Abstract
In the last two decades, the application of microwave heating to the processing of materials has to become increasingly widespread. Microwave-assisted foaming processes show promise for industrial commercialization due to the potential advantages that microwaves have shown compared to conventional methods. These include reducing process time, improved energy efficiency, solvent-free foaming, reduced processing steps, and improved product quality. However, the interaction of microwave energy with foaming materials, the effects of critical processing factors on microwave foaming behavior, and the foamed product's final properties are still not well-explored. This article reviews the mechanism and principles of microwave foaming of different materials. The article critically evaluates the impact of influential foaming parameters such as blowing agent, viscosity, precursor properties, microwave conditions, additives, and filler on the interaction of microwave, foaming material, physical (expansion, cellular structure, and density), mechanical, and thermal properties of the resultant foamed product. Finally, the key challenges and opportunities for developing industrial microwave foaming processes are identified, and areas for potential future research works are highlighted.
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Affiliation(s)
- Mukarram Zubair
- Department of Environmental Engineering, College of Engineering, Imam Abdulrahman Bin Faisal University, P.O. Box 1982, Dammam 31451, Saudi Arabia; (M.Z.); (N.D.M.); (N.I.B.); (M.S.M.)
| | - Rebecca Ferrari
- Food, Water, Waste Research Group, Faculty of Engineering, University of Nottingham, University Park, Nottingham NG7 2RD, UK;
| | - Omar Alagha
- Department of Environmental Engineering, College of Engineering, Imam Abdulrahman Bin Faisal University, P.O. Box 1982, Dammam 31451, Saudi Arabia; (M.Z.); (N.D.M.); (N.I.B.); (M.S.M.)
| | - Nuhu Dalhat Mu’azu
- Department of Environmental Engineering, College of Engineering, Imam Abdulrahman Bin Faisal University, P.O. Box 1982, Dammam 31451, Saudi Arabia; (M.Z.); (N.D.M.); (N.I.B.); (M.S.M.)
| | - Nawaf I. Blaisi
- Department of Environmental Engineering, College of Engineering, Imam Abdulrahman Bin Faisal University, P.O. Box 1982, Dammam 31451, Saudi Arabia; (M.Z.); (N.D.M.); (N.I.B.); (M.S.M.)
| | - Ijlal Shahrukh Ateeq
- Department of Biomedical Engineering, College of Engineering, Imam Abdulrahman Bin Faisal University, P.O. Box 1982, Dammam 31451, Saudi Arabia;
| | - Mohammad Saood Manzar
- Department of Environmental Engineering, College of Engineering, Imam Abdulrahman Bin Faisal University, P.O. Box 1982, Dammam 31451, Saudi Arabia; (M.Z.); (N.D.M.); (N.I.B.); (M.S.M.)
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Mu'azu ND, Jarrah N, Zubair M, Manzar MS, Kazeem TS, Qureshi A, Haladu SA, Blaisi NI, Essa MH, Al-Harthi MA. Mechanistic aspects of magnetic MgAlNi barium-ferrite nanocomposites enhanced adsorptive removal of an anionic dye from aqueous phase. Journal of Saudi Chemical Society 2020. [DOI: 10.1016/j.jscs.2020.08.001] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
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Mu'azu ND, Abubakar IR, Blaisi NI. Public acceptability of treated wastewater reuse in Saudi Arabia: Implications for water management policy. Sci Total Environ 2020; 721:137659. [PMID: 32182459 DOI: 10.1016/j.scitotenv.2020.137659] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/31/2019] [Revised: 02/28/2020] [Accepted: 02/29/2020] [Indexed: 06/10/2023]
Abstract
Treated wastewater reuse is increasingly important for sustainable water resource management, especially in water-stressed countries located in the world's arid regions that rely on groundwater and desalination process for meeting their water demands. This study investigates the socio-demographic variables influencing public perceptions of reusing grey and mixed wastewater for non-domestic uses: firefighting, swimming pools, and car washing. Data were collected from 624 households in the Dammam Metropolitan Area, Saudi Arabia using a structured questionnaire and analyzed using descriptive and inferential statistics. The results from logistic regression indicates that the likelihood of a household to accept reusing treated mixed wastewater is influenced by gender with odds ratio (OR) of 2.71-2.18, residential location (OR = 1.32-1.03), age (OR = 1.22-0.18) and educational level (OR = 1.33-0.98), with a tendency for more acceptance of treated grey wastewater than mixed wastewater. These findings showcase the difficulty that the country could face concerning the public acceptance of treated wastewater for non-domestic uses to augment current freshwater sources even among the educated class. This study is significant because sustainably meeting the country's rising water demands requires the stringent implementation of strategic wastewater reuse policy, including bold steps towards wastewater streams segregation, and intensive public awareness campaigns to change negative perceptions on treated sewage effluent. This study concludes that a substantial reduction in the country's reliance on costly desalinated water and fast depleting non-renewable groundwater requires complete reuse and recycling of treated wastewater for wider non-conventional purposes.
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Affiliation(s)
- Nuhu Dalhat Mu'azu
- Department of Environmental Engineering, College of Engineering, Imam Abdulrahman Bin Faisal University, P.O. Box 1982, Dammam 31451, Saudi Arabia.
| | - Ismaila Rimi Abubakar
- College of Architecture and Planning, Imam Abdulrahman Bin Faisal University (formerly, University of Dammam), P.O. Box 1982, Dammam 31441, Saudi Arabia.
| | - Nawaf I Blaisi
- Department of Environmental Engineering, College of Engineering, Imam Abdulrahman Bin Faisal University, P.O. Box 1982, Dammam 31451, Saudi Arabia
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Al-Zoubi H, Zubair M, Manzar MS, Manda AA, Blaisi NI, Qureshi A, Matani A. Comparative Adsorption of Anionic Dyes (Eriochrome Black T and Congo Red) onto Jojoba Residues: Isotherm, Kinetics and Thermodynamic Studies. Arab J Sci Eng 2020. [DOI: 10.1007/s13369-020-04418-5] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
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Yaman C, Anil I, Jaunich MK, Blaisi NI, Alagha O, Yaman AB, Gunday ST. Investigation and modelling of greenhouse gas emissions resulting from waste collection and transport activities. Waste Manag Res 2019; 37:1282-1290. [PMID: 31674292 DOI: 10.1177/0734242x19882482] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Greenhouse gas emissions resulting from municipal solid waste management activities and the associated climate change impacts are getting great attention worldwide. This study investigates greenhouse gas emissions and their distribution during waste collection and transport activities in the Dammam region of Saudi Arabia. Greenhouse gas emissions and associated global warming factors were estimated based on diesel fuel consumption during waste collection and transport activities. Then, waste collection and transport data were used to parameterise a mechanistic collection model that can be used to estimate and predict future fuel consumption and greenhouse gas emissions. For the collection and transport of municipal waste in the study area, the average associated total greenhouse gas emissions were about 24,935 tCO2-eq. Global warming factors for three provinces were estimated as 25.23 kg CO2-eq t-1, 25.04 kg CO2-eq t-1, and 37.15 kg CO2-eq t-1, respectively. Lastly, the American Meteorological Society/Environmental Protection Agency Regulatory Model (AERMOD) modelling system was used to estimate the atmospheric dispersion of greenhouse gas emissions. Model results revealed that the maximum daily greenhouse gas concentrations ranged between 0.174 and 97.3 mg m-3, while annual average greenhouse gas concentrations were found to be between 0.012 and 27.7 mg m-3 within the study domain. The highest greenhouse gas concentrations were observed for the regions involving the municipal solid waste collection routes owing to their higher source emission rates.
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Affiliation(s)
- Cevat Yaman
- Department of Environmental Engineering, Imam Abdulrahman Bin Faisal University, Dammam, Saudi Arabia
| | - Ismail Anil
- Department of Environmental Engineering, Imam Abdulrahman Bin Faisal University, Dammam, Saudi Arabia
| | - Megan K Jaunich
- Civil, Construction and Environmental Engineering Department, North Carolina State University, Raleigh, NC, USA
| | - Nawaf I Blaisi
- Department of Environmental Engineering, Imam Abdulrahman Bin Faisal University, Dammam, Saudi Arabia
| | - Omar Alagha
- Department of Environmental Engineering, Imam Abdulrahman Bin Faisal University, Dammam, Saudi Arabia
| | - Ayse B Yaman
- Department of Environmental Engineering, Imam Abdulrahman Bin Faisal University, Dammam, Saudi Arabia
| | - Seyda T Gunday
- Department of Biophysics, Imam Abdulrahman Bin Faisal University, Dammam, Saudi Arabia
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Blaisi NI, Clavier KA, Roessler JG, Chung J, Townsend TG, Al-Abed SR, Bonzongo JCJ. Material- and Site-Specific Partition Coefficients for Beneficial Use Assessments. Environ Sci Technol 2019; 53:9626-9635. [PMID: 31356749 DOI: 10.1021/acs.est.9b01756] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Partition coefficient (Kd) values available in the literature are often used in fate and transport modeling conducted as part of beneficial use risk assessments for industrial byproducts. Because element partitioning depends on soil properties as well as characteristics of the byproduct leachate, site-specific Kd values may lead to more accurate risk assessment. In this study, contamination risk to groundwater of beneficially reused byproducts was assessed using batch leaching tests on waste to energy bottom ash and coal combustion fly ash. Leachates were equilibrated with eight different soils to obtain the waste-soil-specific Kd,exp values for the metals of interest. The Kd,exp values were used as inputs in the Industrial Waste Management Evaluation Model to demonstrate the degree to which Kd estimates affect risk assessment outcomes. Measured Kd,exp values for the most part fell within the large range of Kd values reported in the literature, but IWEM results using default Kd values for some types of soils resulted in overestimated risk compared to those derived from Kd,exp values. Modeled concentration at the receptor location was much lower for some elements for those soils with high concentrations of iron and aluminum.
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Affiliation(s)
- Nawaf I Blaisi
- Department of Environmental Engineering, College of Engineering , Imam Abdulrahman Bin Faisal University , P.O Box 1982, Dammam , Saudi Arabia
| | - Kyle A Clavier
- Department of Environmental Engineering Sciences , University of Florida , PO Box 116450 Gainesville , Florida 32611-6450 , United States
| | - Justin G Roessler
- Department of Environmental Engineering Sciences , University of Florida , PO Box 116450 Gainesville , Florida 32611-6450 , United States
| | - Jaeshik Chung
- Department of Environmental Engineering Sciences , University of Florida , PO Box 116450 Gainesville , Florida 32611-6450 , United States
- Center for Water Resource Cycle , Korea Institute of Science and Technology , Seoul 136-791 , Republic of Korea
| | - Timothy G Townsend
- Department of Environmental Engineering Sciences , University of Florida , PO Box 116450 Gainesville , Florida 32611-6450 , United States
| | - Souhail R Al-Abed
- National Risk Management Research Laboratory , U.S. Environmental Protection Agency , 26 West Martin Luther King Drive , Cincinnati , Ohio 45268 , United States
| | - Jean-Claude J Bonzongo
- Department of Environmental Engineering Sciences , University of Florida , PO Box 116450 Gainesville , Florida 32611-6450 , United States
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Blaisi NI, Zubair M, Ali S, Kazeem TS, Manzar MS, Al-Kutti W, Al Harthi MA. Date palm ash-MgAl-layered double hydroxide composite: sustainable adsorbent for effective removal of methyl orange and eriochrome black-T from aqueous phase. Environ Sci Pollut Res Int 2018; 25:34319-34331. [PMID: 30298353 DOI: 10.1007/s11356-018-3367-2] [Citation(s) in RCA: 43] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/09/2018] [Accepted: 09/27/2018] [Indexed: 05/09/2023]
Abstract
Date palm ash (DPA) and MgAl-layered double hydroxide (LDH) composites were synthesized by the co-precipitation method and characterized by Fourier transform infrared spectroscopy (FTIR), scanning electron microscope (SEM), X-ray diffraction (XRD), and Brunauer-Emmett-Teller (BET). The DPA-MgAl-LDH (DPA/MgAl) composites were employed for the removal of methyl orange (MO) and eriochrome black-T (EBT) from aqueous phase. Incorporation of 33.33% (w/w) DPA into the layers of MgAl increased the surface area from 44.46 to 140.65 m2/g, which leads to the improved adsorption performance. The maximum adsorption capacity of DPA/MgAl (1:2) at 298 K was 242.98 and 425.16 (mg/g) for MO and EBT, respectively. The adsorption data of dyes were adequately fitted by a pseudo-second-order and Langmuir isotherm model. The composite showed excellent reusability performance up to three cycles. Addition of DPA into MgAl-LDH resulted in an effective low-cost adsorbent for decontamination of dyes from wastewater. Graphical abstract ᅟ.
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Affiliation(s)
- Nawaf I Blaisi
- Department of Environmental Engineering, College of Engineering, Imam Abdulrahman Bin Faisal University, 31982, Dammam, Saudi Arabia
| | - Mukarram Zubair
- Department of Environmental Engineering, College of Engineering, Imam Abdulrahman Bin Faisal University, 31982, Dammam, Saudi Arabia.
| | - Sadaqat Ali
- Department of Mechanical and Energy Engineering, College of Engineering, Imam Abdulrahman Bin Faisal University, 31982, Dammam, Saudi Arabia
| | - Taye Saheed Kazeem
- Department of Chemical Engineering, King Fahd University of Petroleum & Minerals, 31261, Dhahran, Saudi Arabia
| | - Mohammad Saood Manzar
- Department of Environmental Engineering, College of Engineering, Imam Abdulrahman Bin Faisal University, 31982, Dammam, Saudi Arabia
| | - Walid Al-Kutti
- Department of Civil and Construction Engineering, College of Engineering, Imam Abdulrahman Bin Faisal University, 31982, Dammam, Saudi Arabia
| | - Mamdouh A Al Harthi
- Department of Chemical Engineering, King Fahd University of Petroleum & Minerals, 31261, Dhahran, Saudi Arabia
- Center of Research Excellence in Nanotechnology, King Fahd University of Petroleum & Minerals, 31261, Dhahran, Saudi Arabia
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Blaisi NI. Environmental assessment of utilizing date palm ash as partial replacement of cement in mortar. J Hazard Mater 2018; 357:175-179. [PMID: 29886362 DOI: 10.1016/j.jhazmat.2018.06.013] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/30/2017] [Revised: 06/03/2018] [Accepted: 06/04/2018] [Indexed: 06/08/2023]
Abstract
Saudi Arabia's date palm industry generates date palm ash (DPA) from the thermal processing of palm oil fibers and shells. This waste material has potential to be used as partial replacement of cement in structural mortar. However, no studies to date have examined its pollution potential. DPA was used as a cement replacement in Portland cement mortar (PCM) using a 10% and 100% replacement rate and then compared to an ordinary PCM control sample. Total elemental analysis, the toxicity characteristic leaching procedure (TCLP) and monolith leaching tests were conducted. Elemental analysis revealed a standard elemental profile similar to data for the comparably used wood ash. Aluminum (Al) and iron (Fe) were elements with the greatest abundance in DPA but no element exceeded regulatory thresholds. Leachability testing revealed that while concentrations of Al and Fe may appear high in DPA, they experience relatively low mobility when encapsulated in PCM matrices as indicated by their calculated leachability index. The results presented in this paper indicate that DPA poses no environmental risk to human health when used as cement replacement in PCM.
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Affiliation(s)
- Nawaf I Blaisi
- Department of Environmental Engineering, College of Engineering, Imam Abdulrahman Bin Faisal University, PO Box 1982 Dammam, 31451, Saudi Arabia.
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10
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Roessler JG, Olivera FD, Wasman SJ, Townsend TG, McVay MC, Ferraro CC, Blaisi NI. Construction material properties of slag from the high temperature arc gasification of municipal solid waste. Waste Manag 2016; 52:169-179. [PMID: 27020344 DOI: 10.1016/j.wasman.2016.03.031] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/29/2015] [Revised: 03/16/2016] [Accepted: 03/18/2016] [Indexed: 06/05/2023]
Abstract
Slag from the high temperature arc gasification (HTAG) of municipal solid waste (MSW) was tested to evaluate its material properties with respect to use as a construction aggregate. These data were compared to previously compiled values for waste to energy bottom ash, the most commonly produced and beneficially used thermal treatment residue. The slag was tested using gradations representative of a base course and a course aggregate. Los Angeles (LA) abrasion testing demonstrated that the HTAG slag had a high resistance to fracture with a measured LA loss of 24%. Soundness testing indicated a low potential for reactivity and good weathering resistance with a mean soundness loss of 3.14%. The modified Proctor compaction testing found the slag to possess a maximum dry density (24.04kN/m(3)) greater than conventionally used aggregates and WTE BA. The LBR tests demonstrated a substantial bearing capacity (>200). Mineralogical analysis of the HTAG suggested the potential for self cementing character which supports the elevated LBR results. Preliminary material characterization of the HTAG slag establishes potential for beneficial use; larger and longer term studies focusing on the material's possibility for swelling and performance at the field scale level are needed.
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Affiliation(s)
- Justin G Roessler
- Department of Environmental Engineering Sciences, University of Florida, PO Box 116450, Gainesville, FL 32611-6450, USA
| | - Fernando D Olivera
- Department of Environmental Engineering Sciences, University of Florida, PO Box 116450, Gainesville, FL 32611-6450, USA
| | - Scott J Wasman
- Department of Civil Engineering, University of Florida, PO Box 116580, Gainesville, FL 32611-6450, USA
| | - Timothy G Townsend
- Department of Environmental Engineering Sciences, University of Florida, PO Box 116450, Gainesville, FL 32611-6450, USA.
| | - Michael C McVay
- Department of Civil Engineering, University of Florida, PO Box 116580, Gainesville, FL 32611-6450, USA
| | - Christopher C Ferraro
- Department of Civil Engineering, University of Florida, PO Box 116580, Gainesville, FL 32611-6450, USA
| | - Nawaf I Blaisi
- Department of Environmental Engineering Sciences, University of Florida, PO Box 116450, Gainesville, FL 32611-6450, USA
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Blaisi NI, Roessler J, Cheng W, Townsend T, Al-Abed SR. Evaluation of the impact of lime softening waste disposal in natural environments. Waste Manag 2015; 43:524-532. [PMID: 26116006 DOI: 10.1016/j.wasman.2015.06.015] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/16/2015] [Revised: 06/10/2015] [Accepted: 06/11/2015] [Indexed: 06/04/2023]
Abstract
Drinking water treatment residues (WTR), generated from the lime softening processes, are commonly reused or disposed of in a number of applications; these include use as a soil amendment or a subsurface fill. Recently questions were posed by the Florida regulatory community on whether lime WTR that contained a small percentage of other treatment additives could appropriately be characterized as lime WTR, in terms of total element content and leachability. A study was done using a broad range of leaching tests, including a framework of tests recently adopted by the United States-Environmental Protection Agency (EPA) and tests that were modified to account for scenario specific conditions, such as the presence of natural organic matter (NOM). The results of these additional leaching tests demonstrated that certain applications, including disposal in a water body with NOM or in placement anaerobic environment, did result in increased leaching of elements such as Fe, and that a site specific assessment should be conducted prior to using WTR in these types of applications. This study illustrates the importance of leaching test selection when attempting to provide an estimation of release in practice. Although leaching tests are just one component in a beneficial use assessment and other factors including aquifer and soil properties play a significant role in the outcome, leaching tests should be tailored to most appropriately represent the scenario or reuse application being evaluated.
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Affiliation(s)
- Nawaf I Blaisi
- Department of Environmental Engineering Sciences, University of Florida, PO Box 116450, Gainesville, FL 32611-6450, USA
| | - Justin Roessler
- Department of Environmental Engineering Sciences, University of Florida, PO Box 116450, Gainesville, FL 32611-6450, USA
| | - Weizhi Cheng
- Department of Environmental Engineering Sciences, University of Florida, PO Box 116450, Gainesville, FL 32611-6450, USA
| | - Timothy Townsend
- Department of Environmental Engineering Sciences, University of Florida, PO Box 116450, Gainesville, FL 32611-6450, USA.
| | - Souhail R Al-Abed
- National Risk Management Research Laboratory, U.S. Environmental Protection Agency, 26 West Martin Luther King Drive, Cincinnati, OH 45268, USA
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Cheng W, Roessler J, Blaisi NI, Townsend TG. Effect of water treatment additives on lime softening residual trace chemical composition--implications for disposal and reuse. J Environ Manage 2014; 145:240-248. [PMID: 25073099 DOI: 10.1016/j.jenvman.2014.07.004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/28/2014] [Revised: 07/01/2014] [Accepted: 07/03/2014] [Indexed: 06/03/2023]
Abstract
Drinking water treatment residues (WTR) offer potential benefits when recycled through land application. The current guidance in Florida, US allows for unrestricted land application of lime softening WTR; alum and ferric WTR require additional evaluation of total and leachable concentrations of select trace metals prior to land application. In some cases a mixed WTR is produced when lime softening is accompanied by the addition of a coagulant or other treatment chemical; applicability of the current guidance is unclear. The objective of this research was to characterize the total and leachable chemical content of WTR from Florida facilities that utilize multiple treatment chemicals. Lime and mixed lime WTR samples were collected from 18 water treatment facilities in Florida. Total and leachable concentrations of the WTR were measured. To assess the potential for disposal of mixed WTR as clean fill below the water table, leaching tests were conducted at multiple liquid to solid ratios and under reducing conditions. The results were compared to risk-based soil and groundwater contamination thresholds. Total metal concentrations of WTR were found to be below Florida soil contaminant thresholds with Fe found in the highest abundance at a concentration of 3600 mg/kg-dry. Aluminum was the only element that exceeded the Florida groundwater contaminant thresholds using SPLP (95% UCL = 0.23 mg/L; risk threshold = 0.2 mg/L). Tests under reducing conditions showed elevated concentrations of Fe and Mn, ranging from 1 to 3 orders of magnitude higher than SPLP leachates. Mixed lime WTR concentrations (total and leachable) were lower than the ferric and alum WTR concentrations, supporting that mixed WTR are appropriately represented as lime WTR. Testing of WTR under reducing conditions demonstrated the potential for release of certain trace metals (Fe, Al, Mn) above applicable regulatory thresholds; additional evaluation is needed to assess management options where reducing conditions may develop.
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Affiliation(s)
- Weizhi Cheng
- Department of Environmental Engineering Sciences, University of Florida, P.O. Box 116450, Gainesville, FL 32611-6450, USA
| | - Justin Roessler
- Department of Environmental Engineering Sciences, University of Florida, P.O. Box 116450, Gainesville, FL 32611-6450, USA
| | - Nawaf I Blaisi
- Department of Environmental Engineering Sciences, University of Florida, P.O. Box 116450, Gainesville, FL 32611-6450, USA
| | - Timothy G Townsend
- Department of Environmental Engineering Sciences, University of Florida, P.O. Box 116450, Gainesville, FL 32611-6450, USA.
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Roessler JG, Oehmig WN, Blaisi NI, Townsend TG. Chemical characterization of high-temperature arc gasification slag with a focus on element release in the environment. Environ Sci Technol 2014; 48:7781-7788. [PMID: 24912855 DOI: 10.1021/es5007803] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
High-temperature arc gasification (HTAG) has been proposed as a viable technology for the generation of energy and the production of saleable byproducts from municipal solid waste (MSW). Total concentrations of elements in HTAG slag were assessed and indicated a high partitioning of trace elements (Pb, Cd, and As) into the flue gas, an issue of concern when assessing the air pollution control residues (APCR) status as a hazardous waste. Hazardous waste leaching tests [such as the toxicity characteristic leaching procedure (TCLP)] were performed and confirmed that the slag did not meet U.S. criteria for a hazardous waste. Leaching was assessed using batch and column tests; the results revealed that Sb and Al were elevated in respect to risk-based regulatory thresholds. Slag samples were carbonated to simulate weathering effects, and although leachable concentrations of Al did decrease by an order of magnitude, Sb concentrations were found to increase. Low total concentrations of certain trace elements (As, Cd, and Pb), with respect to MSW incineration bottom ashes support the potential for reuse of HTAG slag; however, leaching of elements (Pb, Al, and Sb) in batch and column tests indicate that proper engineering controls would need to be taken to ensure protection of water supplies in a reuse application.
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Affiliation(s)
- Justin G Roessler
- Department of Environmental Engineering Sciences, University of Florida , Post Office Box 116450, Gainesville, Florida 32611-6450, United States
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