A high-performance liquid chromatographic method (HPLC) with UV detection is described for determination of ceftriaxone sodium (CFX) and cefotaxime sodium (CFM) content in pharmaceutical industrial wastewater. These methods are based on the detection of these antibiotics via the formation of chelate complexes with Cu(II). The developed Liquid Chromatographic method offers symmetric peak shape, good resolution and reasonable retention time for both drugs. The removal percentage reached about 100 and 92.1% at pH 7.2 for CFX and CFM, respectively. In UV detection, the removal of the chelating antibiotics were based on forming of chelate complexes with Cu(II) which detected at λ_{max =} 253 and 244 nm for CFX and CFM, respectively. Linearity, accuracy and precision were found to be acceptable over the concentration range of 5.99–59.86 µg mL⁻¹ for CFX and 14.33–71.63 µg mL⁻¹ for CFM. The proposed method can be used for the quality control of industrial wastewater containing CFX and CFM.

Malachite green accumulation in water causes harmful effects. Biodegradation by microbes was the preferred technique used to remove dyes from wastewater. Thirty yeasts were investigated for their ability to remove 50 mg of dye and belonged to: Deboryomyces, Diutina, Papiliotrema, Rhodotorula, and Saccharomyces. Based on the decolorization index (DI) of the examined yeast on the solid medium, the decolorization activity may be classified as highest, moderate and low decolorization activity with DI 1.66-2.78, 1-1.64, and <1 respectively. Rhodotorula mucilaginosa AUMC13567, R. mucilaginosa AUMC13570, Saccharomyces cerevisiae 11688, R. mucilaginosa KR264902, S. cerevisiae C3, and Diutina rugosa AUMC13571 possess the highest decolorization percentages in broth media: 98.41%, 96.65%, 96.49%, 95.59%, 92.80%, and 92.22%, respectively. The decolorization rate is influenced by time, however, yeast cell optical density has no bearing on this rate. The Fourier Transform Infrared Spectroscopy Analysis (FTIR) results of MG before and after degradation indicate a reduction of peaks along the fingerprint region, which can be attributed to the loss of aromaticity of the metabolites, which also confirm degradation by yeast strains. The effect of malachite green dye and its degradation metabolites by five selected yeasts was studied on wheat (T. aestivum), sorghum (Sorghum bicolor), maize (Zea mays), and radish (Raphanus sativus) seed germination, and results show that the germination index of seeds in untreated malachite green solution was significantly low compared to its degradation metabolites by selected yeasts and yeast …

The predatory efficacy of tilapia Oreochromis niloticus was confirmed against the immature stages of mosquitoes including Culex pipiens. The present study evaluated the detrimental impacts of sublethal concentration of myclobutanil (1000 µg/L) and S-metolachlor (140 µg/L) pesticides for 15 days on the predatory potential of O. niloticus on larvae of Cx. pipiens. Also, effects of both pesticides on acetylcholinesterase (AChE), and certain antioxidant parameters (i.e., total antioxidant capacity [TAC] and superoxide dismutase [SOD]) in the fish were assessed. The exposure of O. niloticus to sublethal concentration of myclobutanil and S-metolachlor caused destructive effects on the predatory behavior of the fish and decreased its predation rates on mosquito larvae compared to the control. Changes in predation capacity of the predatory fish on mosquito larvae may be due to the toxic effect of these pesticides on fish’s antioxidants and AChE activity. The fish pre-exposed to both pesticides presented a significant decrease in the TAC and a significant increase in the SOD activity relative to control group, indicating the advancement of oxidative stress in the treated fish. Fishes pre-exposed to sublethal of both pesticides also showed a significant increase in AChE activity. This study suggests a threat of S-metolachlor and myclobutanil to O. niloticus health and potential as a successful indigenous predatory fish on Cx. pipiens larvae.