A low cost technique of arsenic removal from drinking water by coagulation using ferric chloride salt and alum

2002 ◽  
Vol 2 (2) ◽  
pp. 281-288 ◽  
Author(s):  
M.M.T. Khan ◽  
K. Yamamoto ◽  
M.F. Ahmed
Keyword(s):  
Removal Efficiency ◽  
Ferric Chloride ◽  
Arsenic Removal ◽  
Low Cost ◽  
Chloride Salt ◽  
Oxidizing Agent ◽  
Bleaching Powder ◽  
Treatment Processes ◽  
Intensive Investigation ◽  
Removal Of Arsenic

A variety of treatment processes have been used for arsenic removal from water. In a laboratory study using natural (tubewell) water, ferric chloride salt and alum were used, which are the most studied and widely used flocculents in water treatment due to their low price, comfortable availability and low risk usability. The solubility of arsenate(III) is much more than arsenite(V). Arsenate(III) was converted into arsenite(V) by proper oxidation using bleaching powder as an oxidizing agent before coagulation. The concentrations of ferric chloride salt and alum dose were varied from 10 mg/l to 200 mg/l, and pH was varied from 4 to 9. After intensive investigation, it was found that at pH 7 and for 100 mg/l to 125 mg/l dose of alum, the removal efficiency of arsenic and iron were around 82 to 86% and 92 to 95% respectively. Again, the optimum removal of arsenic and iron were around 90 to 93% and 97 to 100% respectively at pH 7 for 200 mg/l of ferric chloride salt. This research was carried out not only to observe the removal efficiency of arsenic, but also iron. Because most of the tubewells in Bangladesh, sometimes, contain higher amount of iron.

A contribution to solve the arsenic problem in groundwater of Ganges Delta by in-situ treatment

2008 ◽  
Vol 58 (10) ◽  
pp. 2009-2015 ◽  
Author(s):  
U. Rott ◽  
H. Kauffmann
Keyword(s):  
Arsenic Removal ◽  
Low Cost ◽  
Treatment Plant ◽  
Cost Effective ◽  
Treatment Technology ◽  
Manganese Removal ◽  
Arsenic In Groundwater ◽  
Cost Effective Treatment ◽  
Removal Of Arsenic

Arsenic in groundwater is a huge problem in numerous regions of the world. Many people are exposed to high arsenic concentrations and consequently risk getting ill or even die as a result of arsenic poisoning. There are several efficient technologies for the removal of arsenic but often these methods have disadvantages, e.g. high costs for installation and/or operation, the need for chemicals or the production of arsenic contaminated filter sludge. These disadvantages can make the application difficult, especially in poor regions. Under suitable ancillary conditions the subterranean (in-situ) treatment, which is often used for iron and manganese removal from groundwater, can also be applied for the removal of arsenic and can be a cost-effective treatment technology. A field trial was carried out with a low-cost in-situ treatment plant in West Bengal/India which is described in this paper, in order to investigate whether this treatment technology is also applicable under the boundary conditions there. As for the in-situ treatment technology besides oxygen no additives are required and no arsenic contaminated filter sludge is produced this technology could be a suitable method for arsenic removal especially in poor regions.

scholarly journals Enhancing arsenic removal from groundwater at household level with naturally occurring iron

2016 ◽  
Vol 11 (3) ◽  
pp. 486 ◽  
Author(s):  
Anitha Kumari Sharma ◽  
Sabrina Sorlini ◽  
Barbara Marianna Crotti ◽  
Maria Cristina Collivignarelli ◽  
Jens Christian Tjell ◽  
...  
Keyword(s):  
Small Volume ◽  
Arsenic Removal ◽  
Low Cost ◽  
Buffering Capacity ◽  
Basic Solution ◽  
Oxidizing Agent ◽  
Household Level ◽  
Naturally Occurring ◽  
Pale Pink ◽  
High Concentrations

A supply of drinking water low in Arsenic (As) prevents arsenic poisoning. The presence of high concentrations of iron (Fe) in groundwater under the alluvial plains of the large rivers in Southeast Asia is a prerequisite for the simple removal of As. This study investigated the mechanisms and possibilities for enhancing As removal with naturally occurring Fe in a reliable, low cost and sustainable way. The results of the study show that As removal with Fe is greatly enhanced by the addition of an oxidizing agent (preferably KMnO4) immediately after the pumping of groundwater. Further enhancement of As removal in the presence of Fe can be achieved by adding a small volume of a concentrated basic solution of MnO4- and AlO2-, which has a combined oxidation, coagulation and buffering capacity. Best results were obtained when this solution was mixed with the groundwater immediately after its pumping until a pale pink color appeared. Maximum required reaction time was 10 minutes and subsequent filtration of the water was able to reduce the As concentration to near zero. Concentrations of MnO4- and AlO2- can be varied in the solution to achieve sufficient As removal to suit different Fe/As ratios and the presence of interfering co-occurring anions.

Removal of Arsenic from Landfill Leachate by Selected Low-Cost Sorbents: An Experimental Study at the Zixiaguan Landfill of Wuhan City, Central China

2011 ◽  
Vol 356-360 ◽  
pp. 1427-1432
Author(s):  
Zhi Yan Lu ◽  
Qing Hai Guo
Keyword(s):  
Arsenic Removal ◽  
Removal Rate ◽  
Low Cost ◽  
Arsenic Concentration ◽  
Silty Sand ◽  
Central China ◽  
Wuhan City ◽  
Sorption Model ◽  
Silty Soil ◽  
Removal Of Arsenic

The leachate from the Zixiaguan landfill of Wuhan City contains a lot of undesirable or toxic chemicals, among which arsenic may have the most serious threat to environment and human health. Lowering the arsenic concentration in the leachate is therefore of extreme importance. In this study, natural sediments obtained from Wuhan City, including clay, silty soil and silty sand, were used as low-cost sorbents to remove arsenic from solution. The results of the batch sorption experiments indicate that the sorption processes of clay and silty sand match well with linear isothermal sorption model, while that of silty soil is in good accordance with Langmuir isothermal sorption model. Among the three sorbents, clay has the best ability for arsenic removal from solution. Further experiments were carried out to determine the optimum sorption conditions for clay sorbent, the results showing that as the ratio of sorbent dosage to solution volume is 25.0 g/L, the reaction time is 120 min, and the pH of solution equals 7.0, the removal rate of arsenic from the leachate by clay sorbent reaches the highest value of 99.3 %.

scholarly journals Energy Efficient Rapid Removal of Arsenic in an Electrocoagulation Reactor with Hybrid Fe/Al Electrodes: Process Optimization Using CCD and Kinetic Modeling

Water ◽  
2020 ◽  
Vol 12 (10) ◽  
pp. 2876 ◽  
Author(s):  
Saif Ullah Khan ◽  
Izharul Haq Farooqi ◽  
Muhammad Usman ◽  
Farrukh Basheer
Keyword(s):  
Energy Consumption ◽  
Arsenic Removal ◽  
Low Cost ◽  
Minimum Energy ◽  
Ferric Hydroxide ◽  
Cost Effective ◽  
Complete Removal ◽  
Coefficient Of Determination ◽  
Time Duration ◽  
Removal Of Arsenic

Threats due to insufficient, inadequate and costlier methods of treating contaminants such as arsenic have emphasized the significance of optimizing and managing the processes adopted. This study was aimed at the complete elimination of arsenic from an aqueous medium with minimum energy consumption using the electrocoagulation process. Arsenic removal around 95% was rapidly attained for optimized conditions having a pH of 7, 0.46 A current intensity, 10 mg/L initial concentration and only 2 min of applied time duration using the energy of 3.1 watt-hour per gram of arsenic removed. Low values of applied current for longer durations resulted in the complete removal of arsenic with low energy consumption. Various hydroxide complexes including ferrous hydroxide and ferric hydroxide assisted in the removal of arsenic by adsorption along with co-precipitation. Surface models obtained were checked and found with a reasonably good fit having high values of coefficient of determination of 0.933 and 0.980 for removal efficiency and energy consumption, respectively. Adsorption was found to follow pseudo-first-order kinetics. Multivariate optimization proved it as a low-cost effective technology having an operational cost of 0.0974 Indian rupees (equivalent to USD 0.0013) per gram removal of arsenic. Overall, the process was well optimized using CCD based on response surface methodology.

Research Progress on Biological Removal of Arsenic Technology

2012 ◽  
Vol 253-255 ◽  
pp. 1040-1043
Author(s):  
Xing Sheng Kang ◽  
Qiang Su ◽  
Jun Shen ◽  
Yi Li
Keyword(s):  
High Efficiency ◽  
Arsenic Removal ◽  
Environmental Concern ◽  
Low Cost ◽  
Research Progress ◽  
Polluted Water ◽  
Biological Removal ◽  
Global Environmental ◽  
Removal Technology ◽  
Removal Of Arsenic

Arsenic is a toxic element, which is harmful to environment and human health. How to treat arsenic polluted water has become a global environmental concern. Current biological arsenic removal technology was researched base on plants, microorganisms and so on. Biological removal of arsenic technology has high efficiency, low cost, and low secondary pollution, which will be the most promising technology.

Arsenic Removal by Precipitation with Calcium Phosphate Hydroxyapatite

2012 ◽  
Vol 506 ◽  
pp. 413-416 ◽  
Author(s):  
W. Dungkaew ◽  
K.J. Haller ◽  
A.E. Flood ◽  
J.F. Scamehorn
Keyword(s):  
Calcium Phosphate ◽  
Water Sample ◽  
Removal Efficiency ◽  
Arsenic Removal ◽  
Arsenic Speciation ◽  
Arsenic Concentration ◽  
Contaminated Water ◽  
Low Levels ◽  
Removal Of Arsenic ◽  
Key Parameter

The removal of arsenic from synthetic arsenic contaminated water sample by precipitating arsenic (in the form of arsenate oxyanion) with calcium phosphate hydroxyapatite, HAp, was studied under conditions that induce arsenate incorporated calcium phosphate hydroxyapatite, Ca (P/As)HAp, to form. Arsenate is able to substitute for a fraction of the phosphate in HAp host material as it forms. Consequently, arsenic is successfully removed from the contaminated water achieving up to 99% arsenic removal from 25 ppm initial arsenic concentration. The Ca:(P+As) and P:As mole ratios were found to play an important role in arsenic removal efficiency. Higher Ca:(P+As) and P:As mole ratios give higher arsenic removal efficiency. Surprisingly, the pH of the initial anion solution, a key parameter in arsenic speciation, was found to not have a significant effect on arsenic removal by this process. The advantage of this process is that the precipitation can occur rapidly at relatively low levels of arsenic contamination, implying an easy and inexpensive process for arsenic removal can be developed based on this approach.

Study on Arsenic Removal Efficiency and Mechanism of Titanium Modified Manganese Ore

2011 ◽  
Vol 356-360 ◽  
pp. 1061-1065
Author(s):  
Yong Bing Huang ◽  
Xiu Ying Liu ◽  
Li Li Wang ◽  
Xiao Juan Li ◽  
Shu Xin Tu
Keyword(s):  
Adsorption Isotherm ◽  
Removal Efficiency ◽  
Arsenic Removal ◽  
Low Cost ◽  
Manganese Ore ◽  
Langmuir Adsorption ◽  
Freundlich Adsorption Isotherm ◽  
Adsorption Quantity ◽  
Modification Condition ◽  
Dipping Time

Natural manganese ore is a kind of arsenic removal mineral. It is low-cost and widely available. In order to enhance its removal efficiency and adsorption quantity of arsenic, this paper adopted TiCl4 to modify natural manganese ore and optimized the conditions of modification. The results showed that the best modification condition was: TiCl4 at a concentration of 10 mg•L-1, dipping time of 18h, pH 3.05, reaction time of 60 min; under these conditions, the removal rates of As (Ⅲ) and As (Ⅴ) respectively reached 94.87% and 99.31%, much higher compared with natural manganese ore (82.95% and 77.93%). The saturated adsorption quantity of As (Ⅲ) and As (Ⅴ) reached 3.48 mg•g-1 and 3.27 mg•g-1, each increasing 1.25 mg•g-1 and 1.21 mg•g-1. The adsorption of As (Ⅲ) by modified manganese ore fits the Freundlich adsorption isotherm, while As (Ⅴ) fits the Langmuir adsorption isotherm best.

scholarly journals Fabrication and Preliminary Assessment of Fixed Adsorption Column for Arsenic (As) Removal Using Local Rice Husk

2020 ◽  
Vol 18 (02) ◽  
pp. 21-82
Author(s):  
Abdul Qudoos ◽  
Sikandar ALMANI ◽  
Kashif Hussain Mangi ◽  
Memoona Hafeez ◽  
Syed Farman Ali Shah
Keyword(s):  
Removal Efficiency ◽  
Residence Time ◽  
Rice Husk ◽  
Low Cost ◽  
Arsenic Concentration ◽  
Environmental Parameters ◽  
Poor Countries ◽  
Adsorption Column ◽  
Before And After ◽  
Removal Of Arsenic

Arsenic (As) being a carcinogenic element present in drinking water in the less developed areas in the deprived countries contributes to many infectious diseases. The removal of arsenic traces from water needs to have an easy and efficient way for poor countries. Concerning this, a low-cost bio-adsorbent from Rice husk is prepared to remove arsenic from groundwater. Preparation of the absorbent is performed by crushing, sieving, washing and drying the rice husk. The Arsenic present in groundwater samples before and after treatment were tested by Arsenic kit. Batch experiments were carried out with ten contaminated samples of groundwater from Indus river origin area (Nasarpur) to investigate the influence of operating parameters such as adsorbent bed height (ABH) and initial arsenic concentration and residence time(TR) on As removal efficiency using locally fabricated adsorption column. Environmental parameters such as pH, temperature, TDS, and EC were also determined. It was observed that the highest optimized removal efficiency of 90% was achieved at ABH 30 cm: residence time, 60 minutes for feed arsenic concentration of 80 ppb samples. These results suggest that this bio-adsorbent can provide an easy, efficient, and economical method for removing As ions from effluents and water resources.

Arsenic removal by MF membrane with chemical sludge adsorption and NF membrane equipped with vibratory shear enhanced process

2003 ◽  
Vol 3 (5-6) ◽  
pp. 303-310 ◽  
Author(s):  
S.-H. Yi ◽  
S. Ahmed ◽  
Y. Watanabe ◽  
K. Watari
Keyword(s):  
Arsenic Removal ◽  
Membrane Surface ◽  
Membrane Process ◽  
Low Concentrations ◽  
Strong Shear ◽  
Low Levels ◽  
Removal Processes ◽  
Removal Of Arsenic ◽  
Concentration Polarization Layer ◽  
Chemical Sludge

Conventional arsenic removal processes have difficulty removing low concentrations of arsenic ion from water. Therefore, it is very hard to comply with stringent low levels of arsenic, such as below 10 μg/L. So, we have developed two arsenic removal processes which are able to comply with more stringent arsenic regulations. They are the MF membrane process combined with chemical sludge adsorption and NF membrane process equipped with the vibratory shear enhanced process (VSEP). In this paper, we examine the performance of these new processes for the removal of arsenic ion of a low concentration from water. We found that chemical sludge produced in the conventional rapid sand filtration plants can effectively remove As (V) ions of H2AsO4- and HAsO42- through anion exchange reaction. The removal efficiency of MF membrane process combined with chemical sludge adsorption increased to about 36%, compared to MF membrane alone. The strong shear force on the NF membrane surface produced by vibration on the VSEP causes the concentration polarization layer to thin through increased back transport velocity of particles. So, it can remove even dissolved constituents effectively. Therefore, As (V) ions such as H2AsO4- and HAsO42- can be removed. The concentration of As (V) ions decreased from 50 μg/L to below 10 μg/L and condensation factor in recirculating water increased up to 7 times by using NF membrane equipped with VSEP.

Removal of sulphite-reducing clostridia spores by full-scale water treatment processes as a surrogate for protozoan (oo)cysts removal

2000 ◽  
Vol 41 (7) ◽  
pp. 165-171 ◽  
Author(s):  
W. A. Hijnen ◽  
J. Willemsen-Zwaagstra ◽  
P. Hiemstra ◽  
G. J. Medema ◽  
D. van der Kooij
Keyword(s):  
Water Treatment ◽  
Removal Efficiency ◽  
Water Quality Monitoring ◽  
Full Scale ◽  
Process Conditions ◽  
Safe Drinking Water ◽  
Unit Process ◽  
Treatment Processes ◽  
Scale Unit ◽  
Micro Organisms

At eight full-scale water treatment plants in the Netherlands the removal of spores of sulphite-reducing clostridia (SSRC) was determined. By sampling and processing large volumes of water (1 up to 500 litres) SSRC were detected after each stage of the treatment. This enabled the assessment of the removal efficiency of the full-scale unit processes for persistent micro-organisms. A comparison with literature data on the removal of Cryptosporidium and Giardia by the same type of processes revealed that SSRC can be considered as a potential surrogate. The average Decimal Elimination Capacity (DEC) of the overall treatment plants ranged from 1.3–4.3 log. The observed actual log removal of SSRC by the unit processes and the overall treatment at one of the studied locations showed that the level of variation in removal efficiency was approximately 2 log. Moreover, from the actual log removal values it was observed that a low SSRC removal by one unit process is partly compensated by a higher removal by subsequent unit processes at this location. SSRC can be used for identification of the process conditions that cause variation in micro-organism removal which may lead to process optimization. Further research is necessary to determine the optimal use of SSRC in water quality monitoring for the production of microbiologically safe drinking water.

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