scholarly journals Photo-reduction of heavy metal ions and photo-disinfection of pathogenic bacteria under simulated solar light using photosensitized TiO2 nanofibers

RSC Advances ◽  
2018 ◽  
Vol 8 (36) ◽  
pp. 20354-20362 ◽  
Author(s):  
Samina Ghafoor ◽  
Syed Zajif Hussain ◽  
Sadia Waseem ◽  
Salman Noshear Arshad

Photosensitization of titania nanofibers by low bandgap silver sulfide nanoparticles for treating heavy metal ions and pathogenic bacteria simultaneously under simulated solar light irradiation.

Author(s):  
T. V. Gudzenko ◽  
O. G. Gorshkova ◽  
O. V. Voliuvach ◽  
T. V. Burlaka ◽  
I. P. Metelitsina

Aim. Оssessment of wastewater from a pharmaceutical company according to sanitary-microbiological and chemical indicators to determine the method of treatment and remediation of them from pollutants and pathogens. Methods. In sanitary and bacteriological studies, classical microbiological methods were used to determine the total microbial number of pathogenic bacteria. Determination of the concentration of ammonium, nitrite and nitrate in wastewater samples from a pharmaceutical company was carried out spectrophotometrically using the chemical reaction of ions to Nessler's reagent, Griss reagent, and phenol sulfide acid. The content of heavy metal ions was determined by the method of electrothermal AAS using the device "Saturn-2", by the photometric method using 4-aminoantipyrine – phenol, by the extraction-photometric method – by surfactants, by the method of infrared spectrometry – by petroleum hydrocarbons. Results. It was experimentally confirmed that the total microbial count in wastewater samples from a pharmaceutical company slightly exceeded the standard value. The BGKP index and the E. coli index were within the normal range. The pathogenic bacteria Salmonella moscow and Klebsiella pneumoniae were found in the wastewater of pharmaceutical company. The contamination of pharmaceutical stock can be judged by the 8.5 times excess of the concentration of ammonium ions in them compared to the MPC. The results of chemical analysis of wastewater samples from a pharmaceutical company indicate their multicomponent composition.Of the heavy metal ions, ions of zinc, copper, lead, hexavalent chromium and cadmium were mainly detected. With the exception of cadmium ions, the concentration of heavy metal ions was 1.4–7.2 times higher than the MPC norm. Anionic surfactants predominated in pharmaceutical stocks – their concentration was 8.2 ± 0.7 mg/dm3. The level of phenolic and oil pollution of wastewater was minimal in comparison with the content of anionic surfactants, which could be caused by the activity of aboriginal strains of bacteria-destructors with a high phenolic capacity. Conclusion. The results of sanitary-microbiological and chemical analysis of wastewaters of a pharmaceutical company indicate their multicomponent nature and environmental hazard – they contain pathogenic bacteria Salmonella moscow and Klebsiella pneumoniae and pollutants of various nature: heavy metal ions Cu (II), Cr (VI) and Pb (II) at a concentration of 36.0 ± 14 μg/dm3, 3.0 ± 0.4 μg/dm3 and 14.0 ± 0.7 μg/dm3, respectively, and organic pollutants – phenol, oil products and anionic surfactants at a concentration of 0.003 ± 0.0006 mg/dm3, 0.81 ± 0.05 mg/dm3 and 8.2 ± 0.7 mg/dm3, respectively. Werecommend to carry out a comprehensive purification of wastewater from a pharmaceutical company from phenol, heavy metal ions [Cu (II), Cr (VI), Zn (II)], oil products, anionic surfactants and pathogens.


2017 ◽  
Vol 14 (1) ◽  
pp. 15
Author(s):  
M.B. Nicodemus Ujih ◽  
Mohammad Isa Mohamadin ◽  
Milla-Armila Asli ◽  
Bebe Norlita Mohammed

Heavy metal ions contamination has become more serious which is caused by the releasing of toxic water from industrial area and landfill that are very harmful to all living organism especially human and can even cause death if contaminated in small amount of heavy metal concentration. Currently, peoples are using classic method namely electrochemical treatment, chemical oxidation/reduction, chemical precipitation and reverse osmosis to eliminate the metal ions from toxic water. Unfortunately, these methods are costly and not environmentally friendly as compared to bioadsorption method, where agricultural waste is used as biosorbent to remove heavy metals. Two types of agricultural waste used in this research namely oil palm mesocarp fiber (Elaesis guineensis sp.) (OPMF) and mangrove bark (Rhizophora apiculate sp.) (MB) biomass. Through chemical treatment, the removal efficiency was found to improve. The removal efficiency is examined based on four specification namely dosage, of biosorbent to adsorb four types of metals ion explicitly nickel, lead, copper, and chromium. The research has found that the removal efficiency of MB was lower than OPMF; whereas, the multiple metals ions removal efficiency decreased in the order of Pb2+ > Cu2+ > Ni2+ > Cr2+.


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).


2020 ◽  
Vol 13 ◽  
Author(s):  
Rishabha Malviya ◽  
Pramod Sharma ◽  
Akanksha Sharma

: Manuscript discussed about the role of polysaccharides and their derivatives in the removal of metal ions from industrial waste water. Quick modernization and industrialization increases the amount of various heavy metal ions in the environment. They can possess various disease in humans and also causes drastic environmental hazards. In this review the recent advancement for the adsorption of heavy metal ions from waste water by using different methods has been studied. Various natural polymers and their derivatives are act as effective adsorbents for the removal of heavy metal ions from the waste water released from the industries and the treated water released into the environment can decreases the chances of diseases in humans and environmental hazards. From the literature surveys it was concluded that the removal of heavy metal ions from the industrial waste water was important to decrease the environmental pollution and also diseases caused by the heavy metal ions. Graft copolymers were acts as most efficient adsorbent for the removal of heavy metal ions and most of these followed the pseudo first order and pseudo second order model of kinetics.


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