Efficacy of Ciprofloxacin and Amoxicillin Removal and the Effect on the Biochemical Composition of Chlorella vulgaris

Antibiotics are frequently detected in the aquatic environment due to their excessive usage and low-efficiency removal in wastewater treatment plants. This can provide the origin to the development of antibiotic-resistant genes in the microbial community, with considerable ecotoxicity to the environment. Among the antibiotics, the occurrence of ciprofloxacin (CIP) and amoxicillin (AMX) has been detected in various water matrices at different concentrations around the Earth. They are designated as emerging contaminants (ECs). Microalga Chlorella vulgaris (C. vulgaris) has been extensively employed in phycoremediation studies for its acclimatization property, non-target organisms for antibiotics, and the production of value-added bioproducts utilizing the nutrients from the wastewater. In this study, C. vulgaris medium was spiked with 5 mg/L of CIP and AMX, and investigated for its growth-stimulating effects, antibiotic removal capabilities, and its effects on the biochemical composition of algal cells compared to the control medium for 7 days. The results demonstrated that C. vulgaris adapted the antibiotic spiked medium and removed CIP (37 +/- 2%) and AMX (25 +/- 3%), respectively. The operating mechanisms were bioadsorption, followed by bioaccumulation, and biodegradation, with an increase in cell density up to 46 +/- 3% (CIP) and 36 +/- 4% (AMX), compared to the control medium. Further investigations revealed that, in the CIP stress-induced algal medium, an increase in major photosynthetic pigment chlorophyll-a (30%) and biochemical composition (lipids (50%), carbohydrates (32%), and proteins (65%)) was observed, respectively, compared to the control medium. In the AMX stress-induced algal medium, increases in chlorophyll-a (22%), lipids (46%), carbohydrates (45%), and proteins (49%) production were observed compared to the control medium. Comparing the two different stress conditions and considering that CIP is more toxic than AMX, this study provided insights on the photosynthetic activity and biochemical composition of C. vulgaris during the stress conditions and the response of algae towards the specific antibiotic stress. The current study confirmed the ability of C. vulgaris to adapt, bioadsorb, bioaccumulate, and biodegrade emerging contaminants. Moreover, the results showed that C. vulgaris is not only able to remove CIP and AMX from the medium but also can increase the production of valuable biomass usable in the production of various bioproducts

UV Light-Irradiated Photocatalytic Degradation of Coffee Processing Wastewater Using TiO2 as a Catalyst

The coffee industry generates a significant amount of wastewater that is rich in organic loads and is highly acidic. The present study investigates the potential of the heterogeneous photocatalytic oxidation process to reduce the pollutant load in coffee processing wastewater. The experimental runs were conducted to evaluate the effect of operative parameters such as pH, catalyst dosage, intensity of UV light irradiation, and addition of oxidant on Chemical Oxygen Demand (COD) and colour reduction. Significant results for COD and colour removal, 67%, and 70% respectively, were achieved at a pH of 4 with titanium dioxide (TiO2), and a catalyst dosage of 500 mg/L, using four ultraviolet-C (UV-C) lamps of 16 W each. With the addition of hydrogen peroxide (H2O2) as an oxidant, the removal efficiency increased to 84% and 75% for COD and colour, respectively. Finally, the best results obtained by photocatalytic degradation using UV light were compared to those using solar light. Based on the investigation, it was inferred that the pollutant removal efficiency in coffee pulping wastewater was also considerably high under sunlight. These findings may have relevance in terms of application in countries where coffee processing is carried out and where sunlight irradiance is usually strong: the technique could be exploited to decrease the pollutant content of this wastewater sustainably

Tannery: Environmental impacts and sustainable technologies

The tannery is an old industrial sector well-developed, plays an important role in the global economy, and has been heavily industrialized over the years in all countries. In developed countries, the legislation forces the tannery sector to develop clean and sustainable production. Due to the strict legislation policies, there was a continuous change in the distribution of the processing sites. There are two main reasons for this shift of the distribution, namely: 1) lower labour costs in some countries than in others; 2) fewer environmental restrictions in some countries than in others. The current tanning process is still mainly based on the traditional one, making use of chromium salts and being able to give leather of very high quality, despite its severe environmental drawbacks. Since its industrialization, the tannery has shown its heavy environmental impacts, caused by the operations and the processes done in the productive/supply chain, from the raw hides and skins to the final leather. Especially, this sector consumes a huge amount of water, which generates wastewater with high concentrations of pollutants (mainly, chromium(III), sodium sulfide, ammonium chloride, biocides, aldehydes, dyes, etc.). Emissions to the air and solid waste production are worth of consideration, too. At last, the health effects on the workers can give problems in the short as well as long term. Looking at the current distribution of the processing sites, most are in developing countries, where the legislation is still weak. Little amounts of leather derive from the green tannery, where the use of chromium is limited or completely avoided. The reason is the lower quality of the leather produced by the so-called ‘‘green technologies”. This paper analyzes the impacts deriving from the tannery industry due to the conventional chromium process. The reduced-chrome processes and green technologies are discussed, too, considering the role of nanotechnologies

Production of Biodiesel from Soybean Oil in Less Time and at Low Temperature

The heterogeneous catalyst plays an important role in the production of biodiesel at industrial level. In present work, the utilization of wollastonite as a heterogeneous catalyst is attempted to explore its non-biomedical application. Wollastonite was synthesized by using the auto combustion method and L-alanine was used as a fuel for combustion. The X-ray diffraction pattern reveals the phase purity of wollastonite. The Fourier transform infrared spectra of the calcined precursor show the presence of characteristics functional groups in wollastonite. To evaluate the catalytic ability of the prepared wollastonite, transesterification reaction of soybean oil with methanol was performed. Following the reaction, the biodiesel, glycerol and the catalyst were separated by centrifugation. Optimization of the percentage of catalyst used in biodiesel production was done by using various quantities of catalyst during the transesterification reaction and subjecting the produced biodiesel to gas chromatography. It can be concluded that combined alkali metal oxide and silica in wollastonite has assisted in production of biodiesel (82.6%) in a less time and at a low temperature.This work is financially supported by the European Union’s Horizon 2020 research and innovation program under the grant agreement No. 857287