Positively charged PVC ultrafiltration membrane via micellar enhanced ultrafiltration for removing trace heavy metal cations

2022 ◽  
Vol 46 ◽  
pp. 102552
Author(s):  
Qian Yang ◽  
Yanxin Xie ◽  
Baoku Zhu ◽  
Yan Zeng ◽  
Hangyue Zhou ◽  
...  
2016 ◽  
Vol 11 (10) ◽  
pp. 3870-3874
Author(s):  
Lassaad Baklouti

The synthesis and the binding properties of novel phthalonitrile derivatives 1-3 towards metal cations have been described in this paper. The complexation and extraction of some transition and heavy metal cations have been followed by UV-visible spectrophotometry absorption in methanol. The conductivity studies have been used in order to confirm complex’s stoichiometries. The treatment of UV spectra by digital program showed the formation of ML (with ML2 in some cases) (M=metal, L=ligand) species. Beyond the discussion of the stability profiles of complexes particular attention is paid to the selectivity towards Cu2+ in the 1st sequence of transition metal cations and towards Hg2+ in the sequence of heavy metal cations.


2019 ◽  
Vol 4 (1) ◽  
pp. 19-22
Author(s):  
Vika Ayu Devianti ◽  
Anisa Rizki Amalia

ABSTRAKVitamin C berperan penting dalam mempertahankan daya tahan tubuh. Vitamin C mudah teroksidasi dan tidakstabil dalam bentuk larutan. Vitamin C banyak ditemukan dalam buah – buahan, diantaranya adalah apel danstroberi. Apel dan stroberi ini sering diolah dalam bentuk minuman sari buah melalui proses ekstraksi osmosis. Tujuan penelitian ini adalah untuk mengetahui pengaruh lama waktu osmosis (30 dan 60 menit) dan penambahan gula 10% terhadap kandungan vitamin C dalam minuman sari buah apel dan stroberi. Penambahan gula 10% mampu memperkecil penurunan kadar vitamin C dalam minuman sari buah. Penurunan kadar vitamin C pada sampel sari buah stroberi tanpa penambahan gula adalah 18,7% pada menit ke-30 dan 37,5% pada menit ke-60, sedangkan penambahan gula 10% mengalami penurunan sebesar 2,7% pada menit ke-30 dan 7,9% pada menit ke-60. Penurunan kadar vitamin C pada sampel sari buah apel tanpa penambahan gula adalah 24,2% pada menitke-30 dan 41,6% pada menit ke-60, sedangkan penambahan gula 10% mengalami penurunan sebesar 10,6% pada menit ke-30 dan 21,4% pada menit ke-60.Kata kunci: Vitamin C, sukrosa, minuman sari buah, apel, strawberry, osmosis ABSTRACTVitamin C plays an important in human body. Vitamin C is easily degraded by heat, light, oxygen, and heavy metal cations. Vitamin C mostly found in fruits, such as strawberry and apple. Generally strawberry and apple are processed into fruit juice by adding sugar using osmosis extraction. The objective of this research is to findout the effect of osmosis time and sugar addition towards the vitamin C level in strawberry and apple juice. The result showed that sugar addition can affect the vitamin C level in strawberry and apple juice. Sugars can decrease the oxygen solubility causing less oxygen availability for oxidation of vitamin C. The diminish of vitamin C content in apple juice with sugar addition were 10,6% and 21,4% for 30 and 60 minutes of osmosis time; while strawberry juice with sugar addition able to lowering vitamin C level until 18,7% and 37,5% for 30 and 60 minutes of osmosis time.Keywords: Vitamin C, sucrose, apple juice, strawberry juice, osmosis,


Water ◽  
2020 ◽  
Vol 12 (8) ◽  
pp. 2150 ◽  
Author(s):  
M.A. Martín-Lara ◽  
M. Calero ◽  
A. Ronda ◽  
I. Iáñez-Rodríguez ◽  
C. Escudero

Bisphenol A (BPA) is an extensively produced and consumed chemical in the world. Due to its widespread use, contamination by this pollutant has increased in recent years, reaching a critical environmental point. This work investigates the feasibility of bisphenol A adsorption from industrial wastewater solutions, testing the reduction of bisphenol A in synthetic solutions by a commercial activated carbon, AC-40, in batch mode. Besides, mixtures of bisphenol A and different heavy metal cations were also studied. So far, no works have reported a complete study about bisphenol A removal by this activated carbon including the use of this material to remove BPA in the presence of metal cations. First, adsorption experiments were performed in batch changing pH, dose of adsorbent, initial bisphenol A concentration and contact time. Results showed greater retention of bisphenol A by increasing the acidity of the medium. Further, the percentage of bisphenol A adsorbed increased with increasing contact time. The selected conditions for the rest of the experiments were pH 5 and a contact time of 48 h. In addition, an increase in retention of bisphenol A when the dose of adsorbent increased was observed. Then, specific experiments were carried out to define the kinetics and the adsorption isotherm. Equilibrium data were adequately fitted to a Langmuir isotherm and the kinetics data fitted well to the pseudo-second-order model. The maximum adsorption capacity provided by Langmuir model was 94.34 mg/g. Finally, the effect of the presence of other heavy metals in water solution on the adsorption of bisphenol A was analyzed. Binary tests revealed competition between the adsorbates and a significant selectivity toward bisphenol A. Finally, the study of the adsorption performance in three consecutive adsorption–desorption cycles showed efficiencies higher than 90% in all cycles, indicating that the activated carbon has good reusability.


2019 ◽  
Vol 43 (46) ◽  
pp. 18079-18091 ◽  
Author(s):  
Leili Esrafili ◽  
Maniya Gharib ◽  
Ali Morsali

In this study, through introducing a new functional group into the structure, the performance and efficiency of MOFs as a sensor for heavy metal cations have been improved.


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