Evaluation of Soil Contamination with Industrial Waste Effluent in Riyadh, Saudi Arabia

An optimal magnetite immobilized Pseudomonas putida 5-x cell system was developed to remove Cu2+ from industrial waste effluent. Cu2+ adsorption capacity of P. putida 5-x cultured in sulphate-limiting medium (SLM) was minimum in early log growth phase, and reached maximum in late stationary growth phase or early death phase. Pretreated cells by 0.6 N HCl could greatly enhance the adsorption capacity of biomass up to 85.6 mg/g and had no significant effect for the loss of P. putida 5-x cells during the pretreatment. In a semi-continuous biosorption system, the removal efficiency of Cu2+ from wastewater reached 96%, and recovery efficiency of Cu2+ was 95%, and the concentration in the recovery solution was 1.4 g/L using 0.6 N HCl as eluant. The mechanism of Cu2+ adsorption by this type of biomass was studied by using the technique of transmission electron microscopy (TEM). Degradation of a peptidoglycan layer on the cell surface was observed after acidic pretreatment, but no further degradation appeared after the adsorption-desorption cycle. TEM and X-ray analysis also showed that Cu2+ was mainly accumulated on the cell surface, so it was effectively desorpted by acidic treatment in the desorption process. The process of adsorption obeyed the Freundlich isotherm.

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A Validated SPE-UPLC-DAD Method for Quantification of Parabens in Industrial Waste Effluent Water Samples by Using Activated Carbon Nanofiber Modified Filter Paper

Asian Journal of Chemistry ◽

10.14233/ajchem.2021.23012 ◽

2021 ◽

Vol 33 (2) ◽

pp. 350-358

Author(s):

Eegala Bheema Shankar ◽

Challa Gangu Naidu ◽

CH. N.S. Sai Pavan Kumar ◽

Kasturi Rajashekhar

Keyword(s):

Activated Carbon ◽

Filter Paper ◽

Water Samples ◽

Industrial Waste ◽

Carbon Nanofiber ◽

Solid Phase ◽

Array Detector ◽

Effluent Water ◽

Desorption Process ◽

Industrial Waste Effluent

The present work describes a sensitive, simple, cost-effective and fast analytical procedure to detect the parabens in industrial waste effluent water samples using novel activated carbon nanofiber (CNF) modified filter paper based solid phase extraction technique coupled with liquid chromatography with photodiode array detector (UPLC-PDA). The carbon nanofiber coated filter paper was used as an adsorbent and also characterized by field emission scanning electron microscope (FESEM) showed superior porous structure. Various factors effecting the adsorption and desorption process were studied. The optimum parameters which improve the efficiency are paper length 1 cm × 2 cm, adsorption time 15 min, eluent methanol, eluent volume 5 mL, sample pH 7, desorption time 2 min, 2% salt addition and 300 rpm stirring rate respectively. The parabens exhibited superior linearity ranging from 0.1-50 ng mL-1. The regression coefficient (R2) value ranging from 0.9981-0.9989. This method exhibited good sensitivity with the quantification limit (LOQ) between 0.5-0.75 ng mL-1 and detection limit (LOD) over the range of 0.1-0.25 ng mL-1. The precision was expressed from the RSDs values from 0.74-0.97 %. The spiked analytes revealed excellent recoveries in the range of 95.30-116.72 % with RSD less than 5.72 % for all the water samples also applied for real samples.

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