scholarly journals Removal of arsenic and iron removal from drinking water using coagulation and biological treatment

2015 ◽  
Vol 14 (1) ◽  
pp. 90-96 ◽  
Author(s):  
Biplob Kumar Pramanik ◽  
Sagor Kumar Pramanik ◽  
Fatihah Suja

Effects of biological activated carbon (BAC), biological aerated filter (BAF), alum coagulation and Moringa oleifera coagulation were investigated to remove iron and arsenic contaminants from drinking water. At an initial dose of 5 mg/L, the removal efficiency for arsenic and iron was 63% and 58% respectively using alum, and 47% and 41% respectively using Moringa oleifera. The removal of both contaminants increased with the increase in coagulant dose and decrease in pH. Biological processes were more effective in removing these contaminants than coagulation. Compared to BAF, BAC gave greater removal of both arsenic and iron, removing 85% and 74%, respectively. Longer contact time for both processes could reduce the greater concentration of arsenic and iron contaminants. The addition of coagulation (at 5 mg/L dosage) and a biological process (with 15 or 60 min contact time) could significantly increase removal efficiency, and the maximum removal was observed for the combination of alum and BAC treatment (60 min contact time), with 100% and 98.56% for arsenic and iron respectively. The reduction efficiency of arsenic and iron reduced with the increase in the concentration of dissolved organics in the feedwater due to the adsorption competition between organic molecules and heavy metals.

Author(s):  
Negar Jafari ◽  
Afshin Ebrahimi ◽  
Karim Ebrahimpour ◽  
Ali Abdolahnejad

Introduction: Microcystin-leucine arginine (MC-LR) is a toxin with harmful effects on the liver, kidney, heart, and gastrointestinal tract. So, effective removal of MC-LR from water resources is of great importance. The aim of this study was to remove microcystin-LR (MC-LR) from aqueous solution by Titanium Dioxide (TiO2). Materials and Methods: In the present study, TiO2, as a semiconductor, was used for photodegradation of MC-LR under ultraviolet light (UV). The Response Surface Methodology was applied to investigate the effects of operating variables such as pH (A), contact time (B), and catalyst dose (B) on the removal of MC-LR. The MC-LR concentration was measured by high-performance liquid chromatography (HPLC). Results: The results showed that single variables such as A, B, and C had significant effects on MC-LR removal (pvalue < 0.05). In other words, increase of the contact time and catalyst dose had a positive effect on enhancing the removal efficiency of MC-LR, but the effect of pH was negative. The analysis of variance showed that BC, A2, and C2 variables had a significant effect on the MC-LR removal (pvalue < 0.05). Finally, the maximum removal efficiency of MC-LR was 95.1%, which occurred at pH = 5, contact time = 30 minutes, and catalyst dose = 1 g/l. Conclusion: According to the findings, TiO2, as a photocatalyst, had an appropriate effect on degradation of the MC-LR.


2011 ◽  
Vol 340 ◽  
pp. 487-491
Author(s):  
Xiao Ming Chen ◽  
Jian Feng Ma ◽  
Ding Long Li

Bentonite-supported magnetite particles (MagBt-p) were prepared by co-precipitation. The adsorption capacity of Bentonite-supported magnetic particles on waste water containing OrangeⅡ was tested. Some influence factor such as the dose, the initial concentration of OrangeⅡ, the pH, the contact time and the presence of surfactant were studied. Results showed that cation surfactant (CTAB) greatly enhanced the adsorption of OrangeⅡ. The maximum removal efficiency was 96.6% at 180mg/L (CTAB) and beyond this concentration there was almost no adsorption. Besides, the removal efficiency was affected by pH and contact time, the maximum removal efficiency was found at pH 2.1-3, the adsorption was rapid during the first 120 min and then equilibrium within 180min.


2017 ◽  
Vol 19 (1) ◽  
pp. 122-130 ◽  

<p>Application of nano particle in the treatment of municipal solid waste leachate is of recent interest. In this paper, the effectiveness of silica nano particles synthesized from blast furnace slag and iron nano particle synthesized from chemicals was studied for the removal of organic pollutants and color. The synthesized nano particles were characterized using SEM, TEM, EDX and FTIR analysis. Batch experiments were conducted to remove the BOD, COD and color from Aged landfill leachate (ALL) and leachate from the composting yard (CYL).Influencing parameters like pH, contact time, nano particle dosage and Hydrogen peroxide concentration were studied. The maximum removal was achieved at the pH of 6 for both the nano particle, contact time 90 minutes for silica nano particle and 120 minutes for iron nano particle, silica nano particle dose as 0.4g/50 ml, iron nano particle dose as 0.3g/50ml and hydrogen peroxide concentration was found to be 3M and 4M for silica and iron nano particles respectively. The removal efficiency in CYL and ALL using silica nano particle was obtained as 87.15%, 72.72%, 83.15% and 82.5%, 62.5%, 77.34% for color, BOD and COD respectively. Similarly for iron nano particle, the removal efficiency was found to be 60.3%, 65%, 67.43% and 57.06%, 57.27%, 67% for the removal of color, BOD and COD in CYL and ALL, respectively.</p>


Author(s):  
Faheem Akhter ◽  
Arsalan A. Jokhio ◽  
Javed A. Noonari

Moringa Oleifera is considered to be a natural bio-adsorbent. Unlike chemical coagulants, Moringa Oleifera seeds are environment friendly with various other advantages. The present study investigated the fluoride removal efficiency of Moringa Oleifera from water. Influence of adsorbent dose (1, 2, 4 g/L), contact time (20, 40 and 60 min) and initial fluoride concentration (2 and 5 mg/L) over removal efficiency were determined and optimized. It was found that increased adsorbent dose and contact time enhanced the removal efficiency which is in agreement with the previous studies. The highest removal of 88.1% was achieved when the adsorbent dose and contact time were optimized to 4 g/L and 60 minutes with an initial fluoride concentration of 2 mg/L. The results showed that Moringa Oleifera can be used as an environment friendly, cheap and effective bio-adsorbent for fluoride removal from aqueous solution. All the experimental facilities were provided by Bio-Fuel Lab, Energy & Environment Department, Quaid-e-Awam University of Engineering, Science and Technology, Nawabshah, Pakistan. The samples were analyzed at the Pakistan Council of Research in Water Resources (PCRWR), Tando Jam, Pakistan.


2014 ◽  
Vol 13 (1) ◽  
pp. 73-78 ◽  
Author(s):  
Yong-qing Zhang ◽  
Qing-ping Wu ◽  
Ju-mei Zhang ◽  
Xiu-hua Yang

Granular activated carbon (GAC) was used to remove bromide (Br−) and bromate (BrO3−) from drinking water in both bench- and pilot-scale experiments. The present study aims to minimize BrO3− formation and eliminate BrO3− generated during the ozonation of drinking water, particularly in packaged drinking water. Results show that the Br− and BrO3− levels in GAC-treated water decreased in both bench- and pilot-scale experiments. In the bench-scale experiments, when the empty bed contact time (EBCT) was 5 min, the highest reduction rates of Br− in the mineral and ultrapure water were found to be 74.9% and 91.2%, respectively, and those of BrO3− were 94.4% and 98.8%, respectively. The GAC capacity for Br− and BrO3− removal increased with the increase in EBCT. Reduction efficiency was better in ultrapure water than in mineral water. In the pilot-scale experiments, the minimum reduction rates of Br− and BrO3− were 38.5% and 73.2%, respectively.


Author(s):  
Khadija Qureshi ◽  
Kashif Hussain Mangi ◽  
Zulfiqar Ali Solangi ◽  
Zulfiqar Ali Bhatii ◽  
Mukhtiar Ali ◽  
...  

Arsenic is a carcinogenic element capable to get into water bodies and drinking water supplies from natural deposits and industrial practices. Its presence in drinking underground water is highly toxic to human health. The study is focused on the development of indigenous Iron-Coated Pottery Granules (ICPG) to remove As from groundwater of Hala City. The developed ICPG was agitated with local clay white flour and water. A low-cost adsorbent namely ICPG was synthesized for the expulsion of As from underground water. The ICGP was characterized with SEM and FTIR techniques. Furthermore, the impact of physical parameters including adsorbate concentration, dosage, mixing time, pH, and contact time on As removal efficiency was investigated in batch experiments. The maximum removal efficiency was achieved with an adsorbent dosage of 0.5 grams at pH =7 for a contact time of 90 minutes when agitated at a speed of 150 r/min. The arsenic removal efficiency was found highly dependent on contact time increase and optimum pH (maximum removal achieved at strong adsorption of As at pH 4–7), however, the rise of adsorbate concentration resulted in the decrement in the efficiency after certain range. Batch adsorption study of underground water sample collected from Hala, Sindh, Pakistan was performed with satisfactory results, i.e. 94 arsenic removal from water. All the water samples were analyzed through atomic absorption Spectrophotometer. The investigation has indicated that ICPG is an exceptionally favourable material for As removal from drinking underground water and can be applied to handle the arsenic issue in most of the regions of Sindh province.


Author(s):  
Kefelegn Bayu ◽  
Abraham Geremew ◽  
Wegene Deriba ◽  
Yohannes Mulugeta ◽  
Samuel Wagari ◽  
...  

Abstract Fluoride concentration in drinking water higher than recommended value imposes different health problems and there are advanced and chemical based defluoridation techniques even if they are not feasible for developing countries and have limitations. Due to this, defluoridation by using locally available plants is one of the most efficient and sustainable options. Therefore, the current study was intended to investigate fluoride removal efficiency of Tulsi (Ocimum Sanctum) from water that can be an alternative means to reduce the problem related to its high concentration. A laboratory based experimental study was implemented by using potentiometric determination in Haramaya University. The leaves of Tulsi were collected, washed with tap water, rinsed with distilled water, and then were dried at room temperature, crushed and sieved through 500-μm stain-less steel sieve. The experiments were conducted on artificially fluoridated water by anhydrous fluoride and natural water samples collected from deep well water sources from Adama and Harar town. Data was analyzed using Design of Expert (DOE) and Microsoft excel. Twenty-nine runs for aqueous solution were conducted at different factor combinations and the optimum combinations were applied for natural water samples. The study depicts that plant has an efficiency of removing 68.4% of fluoride from water. The best factor combinations to achieve this efficiency was 0.2 g/100 ml, 22.6 min, 5.7 and 6.6 mg/l, adsorbent dose, contact time, pH and initial concentration respectively. pH and initial concentration have a negative effect and adsorbent dose and contact time have a positive effect on removing fluoride from water. Hence, people living in fluorosis endemic areas can use the processed plant as a de-fluoridating agent to minimize adverse health effects. HIGHLIGHT This research articles paves way to further study to remove contaminants from water, wastewater, which can pose a substantial effect on public health. The study conducted to investigate removal mechanism of fluoride from drinking water with low cost locally available plant and the software technologies were applied to find the optimum conditions at which the adsorbent works best.


2012 ◽  
Vol 499 ◽  
pp. 152-155
Author(s):  
Guang Ming Zhang ◽  
Qian Qing Shen

A novel three-stage catalytic ozonation-BAC process is proposed to treat highly polluted source water. A pilot study of 120 m3/d was performed in south China and lasted 9 months. The results showed that catalysts improved the THMsFP reduction efficiency by around 18% for BAC step and reduced the effluent bromate by 20%-77%; reduced NH4-N to below 1 mg/L; The effluent COD met the national standard under all circumstances.


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