scholarly journals Adsorption of Chromium(VI) from Aqueous Solutions by Coffee Polyphenol-Formaldehyde/Acetaldehyde Resins

2013 ◽  
Vol 2013 ◽  
pp. 1-11 ◽  
Author(s):  
Khudbudin Mulani ◽  
Siona Daniels ◽  
Kishor Rajdeo ◽  
Sanjeev Tambe ◽  
Nayaku Chavan
Keyword(s):  
Aqueous Solutions ◽  
Solid Phase ◽  
Spectroscopic Method ◽  
Extraction Procedure ◽  
Ion Concentration ◽  
Maximum Adsorption Capacity ◽  
Adsorption Parameters ◽  
Chromium Vi ◽  
Decaffeinated Coffee ◽  
Solid Phase Extraction Procedure

Removal of chromium(VI) from wastewater is essential as it is toxic. Thus, removal of chromium(VI) was performed using coffee polyphenol-formaldehyde/acetaldehyde resins as adsorbents. Adsorbent resins were prepared by condensation of decaffeinated coffee powder with formaldehyde/acetaldehyde and used for the removal of Cr(VI) ions from aqueous solutions. A simple and sensitive solid phase extraction procedure was applied for the determination of chromium at trace levels by spectroscopic method using 1,5-diphenylcarbazide reagent. The adsorption of Cr(VI) on the coffee polyphenol-formaldehyde/acetaldehyde resins was monitored by FTIR and EDX analysis. The metal adsorption parameters such as contact time, pH, Cr(VI) ion concentration, and adsorbent dose were investigated. For Cr(VI), the maximum adsorption capacity of coffee polyphenol-formaldehyde resins was 98% at pH 2. The experimental results showed that Cr(VI) bound strongly with coffee polyphenol-formaldehyde/acetaldehyde resins and utilization of resins could be improved greatly by reuse.

scholarly journals Adsorption Study of Cu2+ Ions from Aqueous Solutions by Bael Flowers (Aegle marmelos)

2020 ◽  
Vol 11 (4) ◽  
pp. 11891-11904
Keyword(s):  
Aqueous Solutions ◽  
Adsorption Capacity ◽  
Metal Ion ◽  
Low Cost ◽  
Sem Analysis ◽  
Ion Concentration ◽  
Maximum Adsorption Capacity ◽  
Aegle Marmelos ◽  
Batch Mode ◽  
Initial Ph

In the present study, batch mode adsorption was carried out to investigate the adsorption capacity of dried bael flowers (Aegle marmelos) for the adsorptive removal of Cu(II) ions from aqueous solutions by varying agitation time, initial metal concentration, the dose of adsorbent, temperature, and initial pH of the Cu(II) ion solution. The percentage removal of 98.7% was observed at 50 ppm initial metal ion concentration, 0.5 g/100.00 cm3 adsorbent dosage, within the contact time of 120 minutes at 30 ºC in the pH range of 4 – 7. The sorption processes of Cu(II) ions was best described by pseudo-second-order kinetics. Langmuir isotherm had a good fit with the experimental data with 0.97 of correlation coefficient (R2), and the maximum adsorption capacity obtained was 23.14 mg g-1 at 30 ºC. The results obtained from sorption thermodynamic studies suggested that the adsorption process is exothermic and spontaneous. SEM analysis showed tubular voids on the adsorbent. FTIR studies indicated the presence of functional groups like hydroxyl, –C-O, –C=O, and amide groups in the adsorbent, which can probably involve in metal ion adsorption. Therefore, dried bael flowers can be considered an effective low-cost adsorbent for treating Cu(II) ions.

scholarly journals Uniform solid-phase extraction procedure for toxicological drug screening in serum and urine by HPLC with photodiode-array detection

1997 ◽  
Vol 43 (2) ◽  
pp. 312-325 ◽  
Author(s):  
Chi-Kong Lai ◽  
Ting Lee ◽  
Kam-Ming Au ◽  
Albert Yan-Wo Chan
Keyword(s):  
Solid Phase Extraction ◽  
Drug Screening ◽  
Solid Phase ◽  
Extraction Procedure ◽  
Phase Extraction ◽  
Urine Metabolites ◽  
Ultraviolet Spectra ◽  
Solid Phase Extraction Procedure ◽  
Array Detection ◽  
Serum And Urine

Abstract In this HPLC–diode-array detection method for toxicological drug screening, a mixed-mode solid-phase extraction procedure is optimized for isolation of a broad range of drugs from serum and urine. Basic, neutral, and weakly acidic drugs are uniformly recovered. The extract from the solid-phase cartridge is readily injected to a reversed-phase HPLC column for separation by gradient elution. Unknown drugs and metabolites in urine and serum samples from acute drug poisoning cases are rapidly identified by matching their retention times and ultraviolet spectra with hundreds of reference compounds in the library. Urine metabolites of common toxicants from various medications and drugs of abuse are recorded, with their changes of retention times and ultraviolet spectra as related to their metabolic transformations. Glucuronide conjugates of common benzodiazepines, tricyclic antidepressants, and beta-blockers are examined directly without chemical or enzymatic hydrolysis. The system is reliable for diverse clinical investigations of drug overdoses, drug-induced psychoses, and substance abuse.

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