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Review on Toxicity and Removal of Pharmaceutical Pollutants Using Immobilised Microalgae

Obaid Zahraa Hussein, Salman Jasim Mohammed, Kadhim Nuha F.

Ecological Engineering & Environmental Technology

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2023

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Vol. 24, iss. 6

44--60

EN

In recent years, global pharmaceutical consumption has increased, resulting in the increased release into the environment and endangering the entire ecosystem. These pharmaceuticals have attracted considerable attention due to their persistence, toxicity, and the appearance of resistance genes and development antibiotic-resistance bacteria. Furthermore, conventional wastewater treatment plants are ineffective in treating antibiotic-contaminated wastewater. Thus, algae-based technologies are sustainable, low-cost, and friendly to the environment. In this context, immobilization appears to be of particular interest to many researchers as they develop new, efficient, greener strategies for the elimination of toxic and hazardous pollutants. provide a critical overview of algal immobilization-based technologies, and a biotechnological tool that restricts cell movement by confining it within a polymer matrix or attaching it to a rigid support is a promising, and cost-effective alternative that does not necessitate the use of additional chemicals. This paper presents strategies for the systematic removal of pharmaceuticals based on algae immobilization techniques as an economical, effective, and feasible alternative technology for removing pharmaceuticals and environmental concerns from water bodies and discusses the benefits and drawbacks of these techniques.

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Azo dye wastewater treatment in a novel three-dimensional electrode reactor

Zou Haiming, Sun Zhili, Jiao Zhengtong, Wang Yang

Environment Protection Engineering

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2022

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Vol. 48, nr 2

5--13

EN

A novel three-dimensional electrode reactor (3DER) was designed to treat the dye wastewater. The performance of 3DER was evaluated via methyl orange (MO) removal efficiency. For comparison, the performance of the two-dimensional electrode reactor (2DER) was also assessed. Furthermore, the effects of electrolyte and aeration on treatment performance were preliminarily evaluated to further optimize the operation on 3DER. A repeatable and stable MO treatment efficiency was obtained in the 3DER. The MO removal rate reached 79.5% at the applied voltage of 1.0 V, electrode spacing of 2 cm and initial MO concentration of 60 mg/dm3, significantly higher than that in the 2DER (58.8%), suggesting the obvious improvement of particle electrodes on MO removal. Both adding electrolyte and air sparging into the 3DER contributed to the enhancement of the MO removal rate. These results obtained here suggest that the 3DER may provide an effective alternative for the treatment of azo dye wastewater and/or non-biodegradable industrial wastewaters.

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Uptake of copper ion using protonated dry alginate beads from dilute aqueous solutions

Aracena Alvaro, Álvarez César, Jerez Oscar, Guajardo Nadia

Physicochemical Problems of Mineral Processing

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2019

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Vol. 55, iss. 3

732--744

EN

This research aimed to identify the copper ion removal mechanism when using protonated dry alginate beads. This mechanism was explained through ion exchange between Cu ions and the protons from the functional groups of the alginate beads. Copper removal increased with stirring velocity, reaching values of 97.5 mg g-1 (97.5×10-3 kg/kg of PDAB) of dry alginate at 200 rev min-1, at a solution pH of 6.0 and a run time of 360 min. For the lowest level of copper concentrations, at 10 mg dm-3 (10×10-6 kg dm-3), full removal was attained. The removal kinetics was represented by a pseudo- first order model. A value of 0.0131 min-1 was found for the velocity constant. Under equilibrium conditions, the experiment data was fit to the Langmuir adsorption model, and the highest removal values were 270.3, 222.2 (222.2×10-3 kg/kg of PDAB) and 49 mg g-1 (49×10-3 kg/kg of PDAB) for pH values of 5.0, 3.5 and 2.5, respectively. These are higher than most sorbents used in the literature for copper removal. Increased temperature leads to higher Cu removal. The activation energy was calculated at 9.3 kJ mol-1 for the temperature range of 283 to 343K. Observations using SEM and composition measurements of the alginate cross-section taken by EDS showed a uniform distribution of the copper concentration through the structure of the alginate beads, independent of the solution pH, contact time and temperature.

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Adsorption of malachite green and congo red dyes from water: recent progress and future outlook

Swan Ng Boon, Zaini Muhammad Abbas Ahmad

Ecological Chemistry and Engineering. S

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2019

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Vol. 26, nr 1

119--132

EN

Global concern on dyes-laden effluent has intensified over the years. Dyes are toxic, stable to light, and hardly oxidized and bio-degraded, hence causing severe physiological effects to living organisms. In water, dye hinders the light penetration for photosynthetic activity, consequently oxygen is deficient for respiration by aquatic creatures. Adsorption has been widely recognized as the effective removal strategy to abate dye wastewater. However, the quests to improve the adsorption efficiency are continuously sought through new adsorbents with special characters, while performing the removal process at optimum operating conditions. This short review aims to summarize the recent progress in adsorption studies of two commonly used industrial dyes, namely malachite green and congo red by various adsorbents. From the quoted studies, the oxidized mesoporous carbon yields a higher adsorption capacity of malachite green at 1265 mg/g, while Fe3O4@nSiO2@mSiO2 displays a greater capacity for congo red removal at 1429 mg/g. A superior adsorption relies not only on specific surface area but also the synergistic interactions of pore width and mesoporosity, surface chemistry, and operating conditions. The dyes properties and factors affecting the adsorption are also highlighted and discussed, with recommendations and future outlook.