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Tetracycline Remove from Synthetic Wastewater by Using Several Methods

Al-Kindi Ghayda Yaseen, Alnasrawy Shaimaa Taleb

Journal of Ecological Engineering

2022

Vol. 23, nr 5

137--148

Tetracycline (TC), a commonly utilized drug for human and animal therapy, is one of the most widespread antibiotic residues existing in the environment. The lack of sophisticated techniques for the removal of residual tetracycline from wastewater indicates an actual environmental risk. In this study, three methods for tetracycline removal from synthetic wastewater were utilized. Pillared clay was used as adsorbent (alone) and with coagulant (alum) in a hybrid technique. Coagulation and flocculation technique was the first method. The best operation conditions were alum dose of 2.5 mg/L, pH 7 and tetracycline concentration of 10 mg/L. The second method was the adsorption on Al-Fe pillared clay, the optimum operating conditions were found to be pH 4.5, time 120 minutes, tetracycline dose 90 mg/L, and the amount of Al-Fe pillared clay adsorbent 400 mg/L. In the third method (hybrid method), the optimum conditions for the above methods were used. The highest removal efficiency of tetracycline by using coagulation and flocculation only as a coagulant reached 60%. In turn, by using Al-Fe pillared clay it was 90% and in the case of the hybrid method, it was 94%. Thus, the hybrid technique improves the removal of tetracycline from synthesized wastewater.

Evaluation the Solidification/Stabilization of Heavy Metals by Portland Cement

Al-Kindi Ghayda Yaseen

Journal of Ecological Engineering

2019

Vol. 20, nr 3

91--100

Numerous solutions are used in the site to treat pollution, including remediation of heavy metals and hazardous wastes by solidification/stabilization (S/S) with cement as a binder. S/S is one of the most commonly methods used for treating inorganic wastes. The objective of this research was using unconfined compressive strength test, and EPA Toxicity Leaching Procedure TCLP method 1313, to test the effectiveness performance, and efficiency of the solidification/stabilization method for treatment of some heavy metals (Fe, Zn, Mn, Cr) contaminated sands using ordinary locally produced Portland Cement type A. In this study, three loads of pollution in three mix designs by contaminated sands were used. As a result of the unconfined compression test, it was observed that the value 1–15 MPa with OPC cement content 25% in the solidification/stabilization process was good enough to comply with the limited value set by the (US EPA). In addition, the concentration of zinc ions was 500 kg/mg, 1500 kg/mg, and 3000 kg/mg, which caused an increase in compressive strength in the early period of age, and a decrease at a later age. An increase in the iron ion concentration caused an increase in the compressive strength at a later age, the effective retention percentages were (97, 93.5, 96 and 92) for iron, zinc, manganese and chromium ions, respectively, which exceeded 3000 mg/kg initially. The high effectiveness in holding and retaining metals within the matrix of solidification/stabilization at the particle size above 9.5 mm was found as well. The samples (Mn and Cr) with the low amount of cement in the mix treatment were not able to retain the required TCLP regulatory limits value, and the initial extraction pH 4.9. However, the final pH 9.5 is alkanet and stabilization effects of the cement matrix.