Arsenic removal from groundwater through iron oxyhydroxide coated waste productsA paper submitted to the Journal of Environmental Engineering and Science.

2009 ◽  
Vol 36 (5) ◽  
pp. 881-888 ◽  
Author(s):  
Elsadig A.M. Abdallah ◽  
Graham A. Gagnon

The goal of this research was to remove arsenic from groundwater supplies via adsorption into media obtained from waste material generated as by-products from glass recycling programs and the seafood industry such as crushed glass and scallop shells. During the course of this research four new adsorbents were developed: ferric hydroxide coated crushed glass (FHCCG); ferric oxide coated crushed glass (FOCCG); ferric hydroxide coated scallop shells (FHCSS); and ferric oxide coated scallop shells (FOCSS). The adsorbents were characterized through evaluation of their structure, surface area, chemical composition, iron content, and coating stability. Efficiency of the adsorbents to remove arsenic from water was examined through batch kinetic and isotherm adsorption experiments. The adsorption capacity of the adsorbents was also evaluated by performing column experiments using real ground waters and a synthetic water. Arsenic removal to a concentration less than 10 μg/L was achieved with the FHCSS and more than 9000 bed volumes of water were treated before the breakthrough point was reached. The research results revealed that scallop shells coated with ferric hydroxideperformed better than crushed glass coated with ferric hydroxide. Both FOCCG and FOCSS had poor arsenic removal compared with FHCSS and granular ferric hydroxide (GFH). Ferric hydroxide coated scallop shells performed similarly to GFH.

Molecules ◽  
2021 ◽  
Vol 26 (13) ◽  
pp. 3917
Author(s):  
Sofia Siciliano ◽  
Elena Cini ◽  
Maurizio Taddei ◽  
Giorgia Vinciarelli

The synthesis of 2-substituted indoles starting from the corresponding unprotected 2-alkynylanilines was made possible in 3% TPGS-750-M water using Pd(OAc)2 alone as the catalyst. The reaction was sensitive to the heating mode respect to the nature of the starting material as, in many cases, convectional heating was better than microwave dielectric heating. The MW (microwave) delivery mode had also an influence in the formation of by-products and, consequently, product yields. A tandem Sonogashira-cyclisation reaction was also accomplished using Pd(OAc)2/Xphos in the nanomicellar water environment.


2007 ◽  
Vol 24 (5) ◽  
pp. 707-715 ◽  
Author(s):  
Ruiping Liu ◽  
Jiuhui Qu ◽  
Shengji Xia ◽  
Gaosheng Zhang ◽  
Guibai Li

2013 ◽  
Vol 2013 ◽  
pp. 1-9 ◽  
Author(s):  
Branislava M. Lekić ◽  
Dana D. Marković ◽  
Vladana N. Rajaković-Ognjanović ◽  
Aleksandar R. Đukić ◽  
Ljubinka V. Rajaković

In this study, removal of arsenic ions using two industrial by-products as adsorbents is represented. Removal of As(III) and As(V) from water was carried out with industrial by-products: residual from the groundwater treatment process, iron-manganese oxide coated sand (IMOCS), and blast furnace slag from steel production (BFS), both inexpensive and locally available. In addition, the BFS was modified in order to minimise its deteriorating impact on the initial water quality. Kinetic and equilibrium studies were carried out using batch and fixed-bed column adsorption techniques under the conditions that are likely to occur in real water treatment systems. To evaluate the application for real groundwater treatment, the capacities of the selected materials were further compared to those exhibited by commercial sorbents, which were examined under the same experimental conditions. IMOCS was found to be a good and inexpensive sorbent for arsenic, while BFS and modified slag showed the highest affinity towards arsenic. All examined waste materials exhibited better sorption performances for As(V). The maximum sorption capacity in the batch reactor was obtained for blast furnace slag, 4040 μgAs(V)/g.


2015 ◽  
Vol 16 (1) ◽  
pp. 115-127 ◽  
Author(s):  
P. Dhanasekaran ◽  
P. M. Satya Sai ◽  
C. Anand Babu ◽  
R. Krishna Prabhu ◽  
K. K. Rajan

Arsenic is a toxic element found naturally in groundwater. Due to its carcinogenicity, risk for heart diseases and diabetes, arsenic needs to be removed from groundwater for potable application. ‘Anjili’ tree sawdust was chemically modified with ferric hydroxide and activated alumina (SFAA) and used as an adsorbent for the removal of arsenic from groundwater. The adsorbent was characterized using scanning electron microscopy (SEM), Fourier transform infrared (FTIR) to study the pore structure and surface functional groups. Effect of contact time, initial concentration, pH, particle size and temperature was studied. Arsenic adsorbed by SFAA followed Freundlich adsorption isotherm. Maximum sorption of arsenic by SFAA adsorbent occurred at pH 6.5. Arsenic sorption kinetics followed a pseudo-second-order model. The maximum sorption capacity at 303 K was found to be 54.32 mg/g for As(III) and 77.60 mg/g for As(V). Interference of other ions on the adsorption was in the order of PO43− > SO42− > HCO3− > NO3−.


2011 ◽  
Vol 64 (5) ◽  
pp. 1046-1055 ◽  
Author(s):  
Dóra Laky ◽  
István Licskó

Jar tests with synthetic water were carried out in order to investigate the effect of phosphate, bicarbonate and silicate on arsenic removal efficiency by in-situ formed ferric hydroxide. Above 12 mg C/L inorganic carbon concentration, the adverse effect of bicarbonate was definite, and resulted in higher remaining arsenic concentration. At all pH values (7.5–7.8) and coagulant dosages (0.84–3.00 mg/L Fe) tested, the negative effect of phosphate on arsenic removal was also evident. In the presence of silicate small ferric-hydroxide colloids were formed, which were able to go through the 0.45 μm pore-size membrane. Compared to silicate-free systems, 2.5–3.5 times higher coagulant dose was needed to achieve the target arsenic concentration in the presence of 14–23 mg/L Si. At higher pH values the adverse effect of silicate was even more significant. All data were merged and multiple linear regression analysis was carried out in order to build up a robust model to predict the residual arsenic concentration if the raw water contains 50–60 μg/L initial arsenic concentration. The estimation was based on the following variables: PO4-P concentration, final pH, Si concentration, Fe(III) dose. The most important influencing factors proved to be the silicate concentration and applied coagulant dosage.


Minerals ◽  
2020 ◽  
Vol 10 (7) ◽  
pp. 583
Author(s):  
Dongdong He ◽  
Yuming Xiong ◽  
Li Wang ◽  
Wei Sun ◽  
Runqing Liu ◽  
...  

Arsenic (As) is considered one of the most serious inorganic pollutants, and the wastewater produced in some smelters contains a high concentration of arsenic. In this paper, we purified the high-concentration arsenic solution with red mud and Fe3+ synergistically. In this system, arsenite anions reacted with Fe(III) ions to form ferric arsenite, which attached on the surface of red mud particles. The generated red mud/Fe1−x(As)x(OH)3 showed a better sedimentation performance than the pure ferric arsenite, which is beneficial to the separation of arsenic from the solution. The red mud not only served as the carrier, but also as the alkaline agent and adsorbent for arsenic treatment. The effects of red mud dosage, dosing order, pH, and molar ratio of Fe/As on arsenic removal were investigated. The efficiency of arsenic removal increased from a pH of 2 to 6 and reached equilibrium at a pH of 7. At the Fe/As molar ratio of 3, the removal efficiency of arsenic ions with an initial concentration of 500 mg/L reached 98%. In addition, the crystal structure, chemical composition, and morphological properties of red mud and arsenic removal residues (red mud/Fe1−x(As)x(OH)3) were characterized by XRD, XPS, X-ray fluorescence (XRF), SEM-EDS, and Raman spectroscopy to study the mechanism of arsenic removal. The results indicated that most of the arsenic was removed from the solution by forming Fe1−x(As)x(OH)3 precipitates on the red mud surface, while the remaining arsenic was adsorbed by the red mud and ferric hydroxide.


1978 ◽  
Vol 18 (93) ◽  
pp. 469
Author(s):  
RJW Gartner

A 3 x 2 x 2 factorial design was used to examine the wheat by-products pollard and bran as a replacement in all-sorghum grain feedlot diets. The by-products replaced either 10, 30 or 50 per cent of the sorghum. Fourteen groups each of five Hereford steers of a mean initial shrunk liveweight of 251.5 � S.E. 0.16 kg and seven groups each of five Santa Gertrudis x Hereford cross bullocks of 391.7 � 0.16 kg were used. They were slaughtered at a mean final shrunk liveweight of 407.0 � 3.54 and 534.5 � 5.04 kg respectively. Production results from cattle receiving 50 per cent by-products were significantly inferior to lower levels of by-product. There were no significant differences between 10 and 30 per cent by-product. Cattle receiving pollard performed significantly better than those receiving bran. The growth rate of the Hereford steers of 1.24 kg day-1 was inferior (P < 0.01 ) to that of 1.41 for the Santa Gertrudis x Hereford bullocks, but the estimated gain in carcase weight of 0.75 kg day-1 was the same. The feed conversion ratio per unit of carcase weight gain favoured the Hereford steers (9.91 vs. 11.95; P < 0.01), but the feed conversion ratio per unit of liveweight gain was not significantly different (6.29 vs. 6.06). The total body fat figures were comparable for steers and bullocks -(mean 20.4 per cent). Both the percentage total yield of saleable meat and the percentage yield from the hindquarter were significantly greater (P < 0.01) in the Santa Gertrudis x Hereford cross bullocks (71.4 vs. 69.5 and 36.8 vs. 35.5 respectively).


2002 ◽  
Vol 2 (2) ◽  
pp. 275-280 ◽  
Author(s):  
W. Driehaus

The reduced German drinking water standard for arsenic of 10 μg/L initiated the development of a new adsorbent, the granular ferric hydroxide. It was introduced into the market in 1997 under the trade name GEH®. 16 drinking water treatment plants for arsenic removal are now using this technique in Germany. The article gives a brief overview over this applications, the design data and the treatment results. This technique requires only small contact times between 3 and 10 minutes, whereas the treatment capacities are up to 250,000 bed volumes. The average treatment costs, including media supply, media exchange service and disposal, are 0.04 EURO per m3 treated water.


2016 ◽  
Vol 11 (4) ◽  
pp. 702-711 ◽  
Author(s):  
Collivignarelli Maria Cristina ◽  
Canato Matteo ◽  
Sorlini Sabrina ◽  
Crotti Barbara Marianna

Many water treatment plants (WTPs) were designed to remove ammonia, iron, and manganese simultaneously using biofilters. In some cases (especially in the Pianura Padana area, in Italy) such plants were designed without a specific treatment stage for arsenic removal because its concentration in the groundwater (i.e. 10 to 20 μg/L) was lower than the previous maximum contaminant level (MCL) of 50 μg-As/L; therefore, specific treatments for arsenic removal must be introduced or upgraded in WTPs. In this work, the results of a 19-month monitoring campaign are reported for a pilot granular ferric oxide (GFO) filter installed in an Italian WTP as a polishing stage. The aim was to investigate the performance of GFO with low arsenic concentrations. The results show that, if the groundwater arsenic concentration is close to the MCL, GFO treatment can be cost effective (approximately 80,000 bed volumes have been treated). It was confirmed that GFO can be effective for the removal of both As(III) and As(V) species.


Sign in / Sign up

Export Citation Format

Share Document