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Aguilera Flores MM, Robles Miranda OE, Ávila Vázquez V, Medellín Castillo NA, Sánchez Mata O, Medina Leaños R, González Fernández LA. Effectiveness of a natural coagulant based on common mallow ( Malva sylvestris) in urban wastewater treatment. ENVIRONMENTAL TECHNOLOGY 2024:1-14. [PMID: 38686920 DOI: 10.1080/09593330.2024.2346861] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/18/2024] [Accepted: 04/17/2024] [Indexed: 05/02/2024]
Abstract
This study evaluated the effectiveness of a natural coagulant based on common mallow (Malva sylvestris) to remove turbidity in urban wastewater. A 22 factorial design was selected to determine the optimal dose and the working pH of the natural coagulant. Its potential was studied in 50.0-450 mg/L and 4.00-10.0 ranges of doses and pH, respectively. A simplex lattice mixture evaluated its effectiveness as a coagulant aid combined with aluminum sulfate (conventional coagulant). Mixture proportions 0.000-1.00 were studied for each component, finding the proportion more effective. Results showed that the coagulation treatment could be feasible since a turbidity removal efficiency of 73.7% can be achieved under optimal conditions (50.0 mg/L and pH of 10.0). Likewise, a turbidity removal of 58.9% is obtained using 250 mg/L and maintaining wastewater pH (7.45). This efficiency can be increased using 31.0% natural coagulant mixed with 69.0% aluminum sulfate at 250 mg/L without modifying the wastewater pH. This improvement was associated with the natural coagulant's high molecular weight and long-chained structure since these properties enhance settling time, floc size and strength, and low sludge production. These results support using common mallow as a natural coagulant, making its use more feasible in alkaline water pH or as a coagulant aid combined with aluminum sulfate for urban wastewater treatment. A cost of USD 370/Kg of natural coagulant was estimated, which is higher than conventional coagulants. However, a cost-effectiveness analysis of its implementation should be performed since process scaling costs could significantly reduce its price.
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Affiliation(s)
| | | | - Verónica Ávila Vázquez
- Interdisciplinary Professional Unit of Engineering Campus Zacatecas, Instituto Politécnico Nacional, Zacatecas, Mexico
| | - Nahum Andrés Medellín Castillo
- Graduate Studies and Research Center, Faculty of Engineering, Autonomous University of San Luis Potosi, San Luis Potosí, Mexico
| | - Omar Sánchez Mata
- Interdisciplinary Professional Unit of Engineering Campus Zacatecas, Instituto Politécnico Nacional, Zacatecas, Mexico
| | - Raudel Medina Leaños
- Interdisciplinary Professional Unit of Engineering Campus Zacatecas, Instituto Politécnico Nacional, Zacatecas, Mexico
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Khaliq MA, Javed MT, Hussain S, Imran M, Mubeen M, Nasim W, Fahad S, Karuppannan S, Al-Taisan WA, Almohamad H, Al Dughairi AA, Al-Mutiry M, Alrasheedi M, Abdo HG. Assessment of heavy metal accumulation and health risks in okra (Abelmoschus Esculentus L.) and spinach (Spinacia Oleracea L.) fertigated with wastwater. INTERNATIONAL JOURNAL OF FOOD CONTAMINATION 2022. [DOI: 10.1186/s40550-022-00097-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
AbstractIn many countries like Pakistan, where crops are irrigated by wastewater, the accumulation of heavy metals is a serious problem, especially when such an irrigation is a widespread practice. The focus of this study was to know the highly toxic metals like cadmium (Cd), chromium (Cr), and lead (Pb) in water, agricultural soil, and crops, besides their probable risk to human health in the area of Vehari district. The physicochemical parameters were determined for the samples, including organic matter, organic carbon, pH, and electrical conductivity. Water used for irrigation, samples of vegetables for Cd, Cr, and Pb concentration, as well as transfer factor from soil to plants (TF) were analyzed for calculating the daily intake of metals (DIM) and their health risk index (HRI). The results show that the wastewater used for irrigation was contaminated with Cr (0.07mg/kg), Cd (0.054mg/kg), and Pb (0.38mg/kg). In the tube well, the concentrations of heavy metals were: Cd (0.053mg/kg), Pb (0.01mg/kg), and Cd (0.03mg/kg). Application of wastewater increased heavy metals concentration in soil and vegetables. Heavy metals concentrations in wastewater irrigated soil before sowing vegetables in mg/kg were: Pb (0.91), Cd (0.12), and Cr (0.48). After the application of wastewater, significant enrichment of wastewater was observed in Pb (1.93mg/kg), Cd (0.07mg/kg), and Cr (0.34mg/kg). Our study showed a high-risk index of food crops polluted with heavy metals and resultantly greater health risk to humans and animals. That is why preventive measures should be adopted to reduce heavy metals pollution to irrigation water and soils to protect both humans and animals in the Vehari district.
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Grafting modification of okra mucilage: Recent findings, applications, and future directions. Carbohydr Polym 2020; 246:116653. [DOI: 10.1016/j.carbpol.2020.116653] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2020] [Revised: 06/08/2020] [Accepted: 06/14/2020] [Indexed: 01/16/2023]
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Salehizadeh H, Yan N, Farnood R. Recent advances in polysaccharide bio-based flocculants. Biotechnol Adv 2017; 36:92-119. [PMID: 28993221 DOI: 10.1016/j.biotechadv.2017.10.002] [Citation(s) in RCA: 100] [Impact Index Per Article: 14.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2017] [Revised: 09/09/2017] [Accepted: 10/05/2017] [Indexed: 01/03/2023]
Abstract
Natural polysaccharides, derived from biomass feedstocks, marine resources, and microorganisms, have been attracting considerable attention as benign and environmentally friendly substitutes for synthetic polymeric products. Besides many other applications, these biopolymers are rapidly emerging as viable alternatives to harmful synthetic flocculating agents for the removal of contaminants from water and wastewater. In recent years, a great deal of effort has been devoted to improve the production and performance of polysaccharide bio-based flocculants. In this review, current trends in preparation and chemical modification of polysaccharide bio-based flocculants and their flocculation performance are discussed. Aspects including mechanisms of flocculation, biosynthesis, classification, purification and characterization, chemical modification, the effect of physicochemical factors on flocculating activity, and recent applications of polysaccharide bio-based flocculants are summarized and presented.
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Affiliation(s)
- Hossein Salehizadeh
- Department of Chemical Engineering and Applied Chemistry, University of Toronto, 200 College St., Toronto, Ontario M5S 3E5, Canada.
| | - Ning Yan
- Department of Chemical Engineering and Applied Chemistry, University of Toronto, 200 College St., Toronto, Ontario M5S 3E5, Canada; Faculty of Forestry, University of Toronto, 33 Willcocks St., Toronto, Ontario M5S 3B3, Canada.
| | - Ramin Farnood
- Department of Chemical Engineering and Applied Chemistry, University of Toronto, 200 College St., Toronto, Ontario M5S 3E5, Canada.
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Bouatay F, Eljebsi N, Dridi-Dhaouadi S, Mhenni F. Valorization of the Vicia faba mucilage on textile wastewater treatment as a bio-flocculant: process development and optimization using response surface methodology (RSM). WATER SCIENCE AND TECHNOLOGY : A JOURNAL OF THE INTERNATIONAL ASSOCIATION ON WATER POLLUTION RESEARCH 2017; 75:629-642. [PMID: 28192357 DOI: 10.2166/wst.2016.480] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
The Vicia faba membranes are an abundant and a low cost product. In the present research paper, the extracted Vicia faba mucilage was tested as an eco-friendly flocculant for textile wastewater treatment. Its performance as flocculant, in decolorization, chemical oxygen demand (COD) removal and the concentration of total suspended solids was checked. The natural extracted product was characterized using infrared spectroscopy. The total sugars were determined in the extracted product. The effect study, followed by an optimization and modeling analysis, of some experimental parameters on the coagulation-flocculation performance, using Vicia faba mucilage (as a flocculant), combined with aluminum sulfate (as a coagulant), showed that the best conditions for the flocculation process were pH of the effluent about 7, flocculant dose about 6.75 mg/L, flocculation mixing time about 3 min and flocculation mixing speed about 30 rpm, leading to a decolorization equal to 92.32%, COD removal of about 97.52% and total suspended solids of about 15.3 mg/L. A comparison study between the flocculation performance of commercial reagents and the bio-agent showed that the natural product presented a good flocculation performance.
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Affiliation(s)
- Feriel Bouatay
- Research Unit of Applied Chemistry and Environment, Faculty of Sciences of Monastir, University of Monastir, Environment Street, Monastir 5000, Tunisia E-mail:
| | - Nesrine Eljebsi
- Research Unit of Applied Chemistry and Environment, Faculty of Sciences of Monastir, University of Monastir, Environment Street, Monastir 5000, Tunisia E-mail:
| | - Sonia Dridi-Dhaouadi
- Research Unit of Applied Chemistry and Environment, Faculty of Sciences of Monastir, University of Monastir, Environment Street, Monastir 5000, Tunisia E-mail:
| | - Farouk Mhenni
- Research Unit of Applied Chemistry and Environment, Faculty of Sciences of Monastir, University of Monastir, Environment Street, Monastir 5000, Tunisia E-mail:
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Jones AN, Bridgeman J. An assessment of the use of native and denatured forms of okra seed proteins as coagulants in drinking water treatment. JOURNAL OF WATER AND HEALTH 2016; 14:768-779. [PMID: 27740543 DOI: 10.2166/wh.2016.015] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
The effects of temperature, storage time and water pH on the coagulation performance of okra seed protein in water treatment were assessed. In a jar test experiment, okra salt extract achieved a notable improvement in treatment efficiency with storage time and showed good performance in quality after thermal treatment at 60, 97 and 140 °C temperatures for 6, 4 and 2 hours, respectively. The performance improvement of more than 8% is considered to be due to the denaturation and subsequent removal of coagulation-hindering proteins in okra seed. Furthermore, the results of a sodium dodecyl sulphate polyacrylamide gel electrophoresis analysis show two distinctive bands of protein responsible for the coagulation process after denaturation. It was further shown that at optimal coagulant dose, the pH of the treated water remained unaffected as a result of the protein's buffering capability during coagulation. Therefore, denatured okra seed exhibited improved performance compared to the native crude extract and offers clear benefits as a water treatment coagulant.
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Affiliation(s)
- Alfred Ndahi Jones
- School of Civil Engineering, University of Birmingham, Edgbaston, Birmingham, B15 2TT, UK E-mail:
| | - John Bridgeman
- School of Civil Engineering, University of Birmingham, Edgbaston, Birmingham, B15 2TT, UK E-mail:
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Balkhair KS, Ashraf MA. Field accumulation risks of heavy metals in soil and vegetable crop irrigated with sewage water in western region of Saudi Arabia. Saudi J Biol Sci 2015; 23:S32-44. [PMID: 26858563 PMCID: PMC4705247 DOI: 10.1016/j.sjbs.2015.09.023] [Citation(s) in RCA: 151] [Impact Index Per Article: 16.8] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2015] [Revised: 09/10/2015] [Accepted: 09/14/2015] [Indexed: 11/04/2022] Open
Abstract
Wastewater irrigated fields can cause potential contamination with heavy metals to soil and groundwater, thus pose a threat to human beings . The current study was designed to investigate the potential human health risks associated with the consumption of okra vegetable crop contaminated with toxic heavy metals. The crop was grown on a soil irrigated with treated wastewater in the western region of Saudi Arabia during 2010 and 2011. The monitored heavy metals included Cd, Cr, Cu, Pb and Zn for their bioaccumulation factors to provide baseline data regarding environmental safety and the suitability of sewage irrigation in the future. The pollution load index (PLI), enrichment factor (EF) and contamination factor (CF) of these metals were calculated. The pollution load index of the studied soils indicated their level of metal contamination. The concentrations of Ni, Pb, Cd and Cr in the edible portions were above the safe limit in 90%, 28%, 83% and 63% of the samples, respectively. The heavy metals in the edible portions were as follows: Cr > Zn > Ni > Cd > Mn > Pb > Cu > Fe. The Health Risk Index (HRI) was >1 indicating a potential health risk. The EF values designated an enhanced bio-contamination compared to other reports from Saudi Arabia and other countries around the world. The results indicated a potential pathway of human exposure to slow poisoning by heavy metals due to the indirect utilization of vegetables grown on heavy metal-contaminated soil that was irrigated by contaminated water sources. The okra tested was not safe for human use, especially for direct consumption by human beings. The irrigation source was identified as the source of the soil pollution in this study.
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Affiliation(s)
- Khaled S Balkhair
- Department of Hydrology and Water Resources Management, King Abdulaziz University, P.O. Box 80200, Jeddah 21589, Saudi Arabia; Center of Excellence in Desalination Technology, King Abdulaziz University, P.O. Box 80200, Jeddah 21589, Saudi Arabia
| | - Muhammad Aqeel Ashraf
- Faculty of Science & Natural Resources, Universiti Malaysia Sabah, 88400 Kota Kinabalu, Sabah, Malaysia; Centre for Research in Biotechnology for Agriculture (CEBAR), University of Malaya, 50603 Kuala Lumpur, Malaysia
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Lee CS, Chong MF, Robinson J, Binner E. Optimisation of extraction and sludge dewatering efficiencies of bio-flocculants extracted from Abelmoschus esculentus (okra). JOURNAL OF ENVIRONMENTAL MANAGEMENT 2015; 157:320-325. [PMID: 25929197 DOI: 10.1016/j.jenvman.2015.04.028] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/13/2014] [Revised: 04/14/2015] [Accepted: 04/16/2015] [Indexed: 06/04/2023]
Abstract
The production of natural biopolymers as flocculants for water treatment is highly desirable due to their inherent low toxicity and low environmental footprint. In this study, bio-flocculants were extracted from Hibiscus/Abelmoschus esculentus (okra) by using a water extraction method, and the extract yield and its performance in sludge dewatering were evaluated. Single factor experimental design was employed to obtain the optimum conditions for extraction temperature (25-90 °C), time (0.25-5 h), solvent loading (0.5-5 w/w) and agitation speed (0-225 rpm). Results showed that extraction yield was affected non-linearly by all experimental variables, whilst the sludge dewatering ability was only influenced by the temperature of the extraction process. The optimum extraction conditions were obtained at 70 °C, 2 h, solvent loading of 2.5 w/w and agitation at 200 rpm. Under the optimal conditions, the extract yield was 2.38%, which is comparable to the extraction of other polysaccharides (0.69-3.66%). The bio-flocculants displayed >98% removal of suspended solids and 68% water recovery during sludge dewatering, and were shown to be comparable with commercial polyacrylamide flocculants. This work shows that bio-flocculants could offer a feasible alternative to synthetic flocculants for water treatment and sludge dewatering applications, and can be extracted using only water as a solvent, minimising the environmental footprint of the extraction process.
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Affiliation(s)
- Chai Siah Lee
- Centre of Excellence for Green Technologies, Department of Chemical and Environmental Engineering, Faculty of Engineering, The University of Nottingham Malaysia Campus, 43500 Semenyih, Selangor, Malaysia; Industrial Microwave Processing, Faculty of Engineering, The University of Nottingham, Nottingham NG7 2RD, UK.
| | - Mei Fong Chong
- Centre of Excellence for Green Technologies, Department of Chemical and Environmental Engineering, Faculty of Engineering, The University of Nottingham Malaysia Campus, 43500 Semenyih, Selangor, Malaysia.
| | - John Robinson
- Industrial Microwave Processing, Faculty of Engineering, The University of Nottingham, Nottingham NG7 2RD, UK.
| | - Eleanor Binner
- Industrial Microwave Processing, Faculty of Engineering, The University of Nottingham, Nottingham NG7 2RD, UK.
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Okolo BI, Nnaji PC, Menkiti MC, Onukwuli OD. A Kinetic Investigation of the Pulverized Okra Pod Induced Coag-Flocculation in Treatment of Paint Wastewater. ACTA ACUST UNITED AC 2015. [DOI: 10.4236/ajac.2015.67059] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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10
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Lee CS, Chong MF, Robinson J, Binner E. A Review on Development and Application of Plant-Based Bioflocculants and Grafted Bioflocculants. Ind Eng Chem Res 2014. [DOI: 10.1021/ie5034045] [Citation(s) in RCA: 68] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Chai Siah Lee
- Department
of Chemical and Environmental
Engineering, Faculty of Engineering, University of Nottingham Malaysia Campus, 43500 Semenyih, Selangor, Malaysia
- Department
of Chemical and Environmental Engineering, University of Nottingham, Nottingham NG7 2RD, U.K
| | - Mei Fong Chong
- Department
of Chemical and Environmental
Engineering, Faculty of Engineering, University of Nottingham Malaysia Campus, 43500 Semenyih, Selangor, Malaysia
| | - John Robinson
- Department
of Chemical and Environmental Engineering, University of Nottingham, Nottingham NG7 2RD, U.K
| | - Eleanor Binner
- Department
of Chemical and Environmental Engineering, University of Nottingham, Nottingham NG7 2RD, U.K
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Mukherjee S, Mukhopadhyay S, Pariatamby A, Ali Hashim M, Sahu JN, Sen Gupta B. A comparative study of biopolymers and alum in the separation and recovery of pulp fibres from paper mill effluent by flocculation. J Environ Sci (China) 2014; 26:1851-1860. [PMID: 25193834 DOI: 10.1016/j.jes.2014.06.029] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2013] [Revised: 01/23/2014] [Accepted: 01/27/2014] [Indexed: 06/03/2023]
Abstract
Recovery of cellulose fibres from paper mill effluent has been studied using common polysaccharides or biopolymers such as Guar gum, Xanthan gum and Locust bean gum as flocculent. Guar gum is commonly used in sizing paper and routinely used in paper making. The results have been compared with the performance of alum, which is a common coagulant and a key ingredient of the paper industry. Guar gum recovered about 3.86mg/L of fibre and was most effective among the biopolymers. Settling velocity distribution curves demonstrated that Guar gum was able to settle the fibres faster than the other biopolymers; however, alum displayed the highest particle removal rate than all the biopolymers at any of the settling velocities. Alum, Guar gum, Xanthan gum and Locust bean gum removed 97.46%, 94.68%, 92.39% and 92.46% turbidity of raw effluent at a settling velocity of 0.5cm/min, respectively. The conditions for obtaining the lowest sludge volume index such as pH, dose and mixing speed were optimised for guar gum which was the most effective among the biopolymers. Response surface methodology was used to design all experiments, and an optimum operational setting was proposed. The test results indicate similar performance of alum and Guar gum in terms of floc settling velocities and sludge volume index. Since Guar gum is a plant derived natural substance, it is environmentally benign and offers a green treatment option to the paper mills for pulp recycling.
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Affiliation(s)
- Sumona Mukherjee
- Institute of Biological Sciences, University of Malaya, 50603 Kuala Lumpur, Malaysia..
| | | | - Agamuthu Pariatamby
- Institute of Biological Sciences, University of Malaya, 50603 Kuala Lumpur, Malaysia
| | - Mohd Ali Hashim
- Department of Chemical Engineering, University of Malaya, 50603 Kuala Lumpur, Malaysia.
| | - Jaya Narayan Sahu
- Department of Chemical Engineering, University of Malaya, 50603 Kuala Lumpur, Malaysia; Department of Petroleum and Chemical Engineering, Faculty of Engineering, Institute Teknologi Brunei, Tungku Gadong, Brunei Darussalam
| | - Bhaskar Sen Gupta
- School of Planning, Architecture and Civil Engineering, Queen's University Belfast, David Keir Building, Belfast BT9 5AG, UK
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Srinivasan R. Natural Polysaccharides as Treatment Agents for Wastewater. GREEN MATERIALS FOR SUSTAINABLE WATER REMEDIATION AND TREATMENT 2013. [DOI: 10.1039/9781849735001-00051] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
This chapter gives an account of recent developments in biopolymers with an emphasis on natural polysaccharides as treatment agents in wastewater remediation. Almost all sources of water around the world are polluted to some degree, owing to a heavy influx of industrial effluents, domestic and agricultural wastes. These discharges vary from simple nutrients to highly toxic hazardous chemicals. Numerous approaches have been studied for the development of cheaper and more effective water remediation agents containing natural polymers. Among these, natural polysaccharides deserve particular attention. These materials have proved to be better treatment alternatives compared to their synthetic counterparts because of their particular structure, physicochemical characteristics, chemical stability, high reactivity and excellent selectivity towards aromatic compounds, metals and other contaminants that cause water pollution.
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Affiliation(s)
- Rajani Srinivasan
- Department of Chemistry Geosciences and Physics, College of Science and Technology, Tarleton State University, Stephenville, TX 76401 USA
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Pendre NK, Nema PK, Sharma HP, Rathore SS, Kushwah SS. Effect of drying temperature and slice size on quality of dried okra (Abelmoschus esculentus (L.) Moench). Journal of Food Science and Technology 2011; 49:378-81. [PMID: 23729860 DOI: 10.1007/s13197-011-0427-8] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Revised: 05/19/2011] [Accepted: 05/25/2011] [Indexed: 12/01/2022]
Abstract
Okra (Abelmoschus esculentus (L) Moench) is an important vegetable crop of India. Dried okra pods have wide use in snacks and are in great demand for domestic as well as export market. Hence, effect of four slice sizes (1, 2, 3 and 4 cm) and four drying temperatures (50, 60, 70 and 80 °C) on quality of hot air dried okra were studied. Okra pods were dried in the form of slices cut across the length at different temperatures. Quality assessment of okra was done on the basis of protein, ascorbic acid and fibre content. Okra slice sizes and drying temperatures affected all the quality parameters significantly (p < 0.05). Maximum retention of protein, ascorbic acid and fibre content were found in 2 cm long slices dried at 60 °C temperature.
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Affiliation(s)
- N K Pendre
- College of Horticulture, RVSKVV, Mandsaur, 458001 Madhya Pradesh India
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Verma S, Prasad B, Mishra IM. Pretreatment of petrochemical wastewater by coagulation and flocculation and the sludge characteristics. JOURNAL OF HAZARDOUS MATERIALS 2010; 178:1055-1064. [PMID: 20303661 DOI: 10.1016/j.jhazmat.2010.02.047] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/12/2009] [Revised: 02/12/2010] [Accepted: 02/14/2010] [Indexed: 05/29/2023]
Abstract
In the present study, coagulation-flocculation was investigated as a pretreatment process for the treatment of purified terephthalic acid (PTA) wastewater. The effect of various inorganic and organic coagulants on the treatment of wastewater collected from flow equalization tank of an effluent treatment plant was studied. The settling and filtration characteristics of the sludge were also studied. The jar tests revealed that the wastewater was best treated when 3000 mg l(-1) of ferric chloride was dosed at pH 5.6. At optimum conditions, COD of the wastewater was reduced by 75.5%. The results of the gravity filtration of the treated wastewater showed that the addition of cationic polyacrylamide (175 mg l(-1)) to ferric chloride coagulation improved the filtration characteristics and reduced the specific cake resistance. Scanning electron microscopy and energy dispersive spectroscopy studies were also conducted to know the sludge structure and composition, respectively. Thermal analysis of the sludge showed that the oxidation of the sludges in the present study is a three step process. However, with the addition of C-PAA to ferric chloride coagulation system, the oxidation was found to be a two step process.
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Affiliation(s)
- Shilpi Verma
- Department of Chemical Engineering, Indian Institute of Technology, Roorkee 247667, India
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Tamarindus indica mucilage and its acrylamide-grafted copolymer as flocculants for removal of dyes. Colloid Polym Sci 2006. [DOI: 10.1007/s00396-006-1539-y] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
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Mishra A, Bajpai M. Removal of sulphate and phosphate from aqueous solutions using a food grade polysaccharide as flocculant. Colloid Polym Sci 2005. [DOI: 10.1007/s00396-005-1399-x] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Mishra A, Bajpai M. Flocculation behaviour of model textile wastewater treated with a food grade polysaccharide. JOURNAL OF HAZARDOUS MATERIALS 2005; 118:213-7. [PMID: 15721546 DOI: 10.1016/j.jhazmat.2004.11.003] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/16/2004] [Revised: 11/11/2004] [Accepted: 11/13/2004] [Indexed: 05/10/2023]
Abstract
In this study, the application of a food grade polysaccharide namely Plantago psyllium mucilage has been assessed for the removal of dyes from model textile wastewater containing golden yellow (C.I. Vat Yellow 4) and reactive black (C.I. Reactive Black 5). A series of contact time experiments were conducted to assess the system variables such as concentrations of mucilage and dyes and pH. This mucilage reduces the dye concentration by flocculation and settling. The optimal flocculant concentration required to affect flocculation is independent of dye concentration within the range examined. The dye removal obtained was influenced by the salts concentrations in the wastewater sample. The flocculation efficiency was sensitive to pH when pure aqueous solutions of dyes were used, but it was relatively unaffected by pH change when salts were added to the dye solutions. The experimental results show that the mucilage is more effective for removal of solubilised vat dye than for reactive black.
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Affiliation(s)
- Anuradha Mishra
- Department of Chemistry, University Institute of Engineering and Technology, CSJM University, Kanpur 208024, India.
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Mishra A, Yadav A, Agarwal M, Bajpai M. Fenugreek mucilage for solid removal from tannery effluent. REACT FUNCT POLYM 2004. [DOI: 10.1016/j.reactfunctpolym.2003.08.008] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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