scholarly journals Elimination of Arsenic (III) using Phaseolus Lunatus and Phaseolus Vulgaris as Natural Coagulants

Author(s):  
Vijayarani. A* ◽  

In this analysis, the efficacy of adding coagulants such as Phaseolus lunatus and Phaseolus vulgaris (polymers) to the coagulation process during the treatment of arsenic aqueous solution to extract the arsenic metal was investigated. Experiments were carried out to evaluate the output of Phaseolus lunatus and Phaseolus vulgaris, both individually and in combination with arsenic, using the standard Jar test protocol. P.lunatus and P.vulgaris were given doses ranging from 1 to 3 gm. For P.lunatus and P.vulgaris, the (optimal) removal efficiency for total arsenic in the aqueous solution was obtained at 2gm. With chemical affinity between arsenic and coagulants used in this process, the valence state of arsenic may affect removal efficiency during the chemical coagulation process. pH is discovered to be a significant factor that has a direct or indirect impact on results. By overcoming the isoelectric point, the complex formed by the interaction of the inorganic pollutant and organic coagulant may aid in the removal of arsenic at pH 9 and 8. P.lunatus and P.vulgaris had optimised arsenic initial concentrations of 57.1µg/L and 42.6µg/L, respectively. The coagulation mechanism is more prevalent in water treatment, as shown by the above findings.

Author(s):  
João Vitor Mariano Ribeiro ◽  
Priscila Vega Andrade ◽  
Adriano Gonçalves dos Reis

This study evaluated the use of Moringa oleifera (MO) seed as a natural coagulant for the removal of turbidity and apparent color in the water treatment with low initial turbidity through the in-line filtration technique. The morphology and surface charge were investigated by characterization techniques such as optical microscopy, laser particle size, and zeta potential. The cationic proteins of the MO seed were extracted in aqueous solution. The jar test showed the potability standards for turbidity and apparent color were reached in the pH range from 4.0 to 8.5 and dosages ≥ 5 mg L-1 of MO. The dominant coagulation mechanism is adsorption and charge neutralization. This study showed that treating low-turbidity water with MO seed by the in-line filtration technique is possible.


2012 ◽  
Vol 573-574 ◽  
pp. 594-598
Author(s):  
Ming Yu Li ◽  
Hai Bo Wu ◽  
Pei Pei Ma ◽  
Gang Cao ◽  
Lin Song ◽  
...  

The removal of arsenic in micro-polluted water by enhanced coagulation with Poly Ferric Metasilicate (PFSS) was studied. The effects of dosage of PFSS , the dosage of oxidant and oxidize time on the removal efficiency of arsenic were discussed. Under the conditions of dosage of PFSS 0.065mmol/L, the residual concentration of arsenic in post-treated water was lower than 0.01 mg/L for raw water with initial concentration of arsenic 0.1 mg/L.


Author(s):  
Julia Aoki Domingues ◽  
Nelson Consolin Filho ◽  
Luiz Augusto Gomes de Souza ◽  
Flávia Vieira da Silva Medeiros

The use of natural coagulants is a promising alternative to replace or assist chemical coagulants due to its numerous advantages. This paper evaluates the effectiveness of a natural coagulant in water treatment. The coagulant was extracted from the Zygia cauliflora (Willd.) Killip seed in saline solutions and defatted using 95% ethanol. The tests were conducted using different concentrations of the coagulant (0.1, 0.5, 1.0, 2.0, 3.0, and 4.0 g L-1) and of NaCl (0.0 M, 1.0 M, and 5.0 M). The results showed that the use of 2 g L-1 of coagulant and 1.0 M of the salt achieved an effectiveness of 20% and 70%, respectively, of color and turbidity removal. The analysis showed an effectiveness of 70% and 30%, respectively, when removing the UV254 compound and DOM (dissolved organic matter). The mechanism for turbidity removal by the coagulants prepared with aqueous solution and with saline solution at 1.0 M of NaCl is supposed to be adsorption and charge neutralization, respectively, following the Freundlich and Langmuir models. However, the coagulant prepared with saline solution at 5.0 M of NaCl tends to form a netlike structure followed by turbidity removal through a sweep coagulation mechanism. Future papers should therefore focus on the use of Zygia cauliflora (Willd.) Killip as an alternative for replacement or use as an auxiliary chemical coagulant.


2020 ◽  
Vol 10 (4) ◽  
pp. 252-269
Author(s):  
Sanarya K. Kamal ◽  
Awad E. Mohammed ◽  
Waleed M. Alabdraba ◽  
Hussein H. Hamed ◽  
Kamaran A. Waly

Recently, water pollution considered a major problem that faced the human. Large quantities of water consume in various industrial oil refinery processes, where the wastewater discharged from these processes contains high organic, phosphate, ammonia, nitrite compounds, and toxic substances. Regarding that, making this resource a fresh is a major concern.  Furthermore, a great attention has been given for the removal of these contaminants discharged by Fenton process combined with coagulation process. Combined Fenton/Coagulation process was used and applied in this study as a novel wastewater treatment to remove Chemical Oxygen Demand (COD), Phosphate (PO4), Ammonia (NH3), Nitrite (NO3) compounds, and turbidity (NTU) from industrial wastewater in North Gas Company (NGC), Iraq. The industrial wastewater used in this study was characterized with 114 mg/L COD ,10.28 mg/L PO4, 4.123 mg/L NH3, 95.6 mg/L NO3, 98 NTU Turbidity. The main goal from this work was to evaluate the performance removal efficiency of combined Fenton/Coagulation process and examine the effect of various operational parameters such as Fenton’s dosages (H2O2, Fe2+), the concentration of coagulant (Alum) on the removal efficiency. The results obtained in this work revealed that maximum removal efficiency of COD, PO4, NH3, NO3, turbidity was 89.43%, 72.94 %, 91.065%, 90.96%, 89.85%, respectively was achieved using Fenton combined with coagulation process at 60 mg/L of Alum and 2.5 Fenton’s mole ratio. Overall it can be established that Combined Fenton/Coagulation process plays an important role in obtaining good results and had better removal efficiency. All the experiments were carried out using jar test apparatus at constant temperature (room temperature).


2019 ◽  
Vol 70 (5) ◽  
pp. 1507-1512
Author(s):  
Baker M. Abod ◽  
Ramy Mohamed Jebir Al-Alawy ◽  
Firas Hashim Kamar ◽  
Gheorghe Nechifor

The aim of this study is to use the dry fibers of date palm as low-cost biosorbent for the removal of Cd(II), and Ni(II) ions from aqueous solution by fluidized bed column. The effects of many operating conditions such as superficial velocity, static bed height, and initial concentration on the removal efficiency of metal ions were investigated. FTIR analyses clarified that hydroxyl, amine and carboxyl groups could be very effective for bio-sorption of these heavy metal ions. SEM images showed that dry fibers of date palm have a high porosity and that metal ions can be trapped and sorbed into pores. The results show that a bed height of 6 cm, velocity of 1.1Umf and initial concentration for each heavy metal ions of 50 mg/L are most feasible and give high removal efficiency. The fluidized bed reactor was modeled using ideal plug flow and this model was solved numerically by utilizing the MATLAB software for fitting the measured breakthrough results. The breakthrough curves for metal ions gave the order of bio-sorption capacity as follow: Cd(II)]Ni(II).


2009 ◽  
Vol 9 (4) ◽  
pp. 469-475
Author(s):  
T. Turtiainen

Radon is one of the contaminants that sometimes impair the water quality of wells, especially those drilled in bedrock. Domestic radon removal units based on aeration have been commercially available for more than ten years. In order to determine how effectively these units remove radon a new test protocol applying frequent sampling while letting 100 litres of water flow, was developed. This way, removal efficiencies can be more accurately calculated and possible malfunctions detected. Seven models of domestic aerators designed for removing radon from household water were tested. The aerators were based on diffused bubble aeration, spray aeration or jet aeration. The average removal efficiencies for 100 litres with a medium flow rate were 86–100% except for a unit that circulated the aerated water back to the well that had removal efficiency of 80% at the maximum. By conducting a questionnaire study usual problems related to the aeration units were localized and recommendations on maintenance and installation are given accordingly.


Author(s):  
Haiyan Song ◽  
Wei Liu ◽  
Fansheng Meng ◽  
Qi Yang ◽  
Niandong Guo

Nanoscale zero-valent iron (nZVI) has attracted considerable attention for its potential to sequestrate and immobilize heavy metals such as Cr(VI) from an aqueous solution. However, nZVI can be easily oxidized and agglomerate, which strongly affects the removal efficiency. In this study, graphene-based nZVI (nZVI/rGO) composites coupled with ultrasonic (US) pretreatment were studied to solve the above problems and conduct the experiments of Cr(VI) removal from an aqueous solution. SEM-EDS, BET, XRD, and XPS were performed to analyze the morphology and structures of the composites. The findings showed that the removal efficiency of Cr(VI) in 30 min was increased from 45.84% on nZVI to 78.01% on nZVI/rGO and the removal process performed coupled with ultrasonic pretreatment could greatly shorten the reaction time to 15 min. Influencing factors such as the initial pH, temperature, initial Cr(VI) concentration, and co-existing anions were studied. The results showed that the initial pH was a principal factor. The presence of HPO42−, NO3−, and Cl− had a strong inhibitory effect on this process, while the presence of SO42− promoted the reactivity of nZVI/rGO. Combined with the above results, the process of Cr(VI) removal in US-nZVI/rGO system consisted of two phases: (1) The initial stage is dominated by solution reaction. Cr(VI) was reduced in the solution by Fe2+ caused by ultrasonic cavitation. (2) In the following processes, adsorption, reduction, and coprecipitation coexisted. The addition of rGO enhanced electron transportability weakened the influence of passivation layers and improved the dispersion of nZVI particles. Ultrasonic cavitation caused pores and corrosion at the passivation layers and fresh Fe0 core was exposed, which improved the reactivity of the composites.


2021 ◽  
pp. 116774
Author(s):  
Fataneh Vasheghani Farahani ◽  
Mohammad Hassan Amini ◽  
Seyed Hamid Ahmadi ◽  
Seyed Amirabbas Zakaria

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