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In this study, the aerobic and anaerobic biodegradability of the industrial wastewater from the vegetable tanning process were evaluated. Water from a food wastewater treatment system was used as seed inoculum for the aerobic process and mature granular methanogenic sludge from a brewery industrial wastewater plant was used for the anaerobic process. The water from the tanning industry had a biological to chemical oxygen demand ratio of 33% with values of total chemical oxygen demand (COD) in the range of 342000 mg O2/L and total dissolved solids of 506595 mg/L. The assay of the tannery effluent under aerobic conditions resulted in a decrease of COD of 39.2% and a degradation of tannins lower than 12% after 26 days, while the anaerobic degradation showed a COD reduction of 65% with a 39% of degradation of tannins. The production of methane and Volatile Fatty Acids, during the anaerobic treatment, suggests a potential adaptation of biological organisms present in the mature anaerobic granular methanogenic sludge.

Soil pollution was simulated by means of artificial heavy metal enrichment, in the presence of treated wastewater, and its effect on the growth characteristics of Beta vulgaris L. (red beets) i.e. on the dry matter yield, and on beet quality expressed in terms of dry matter heavy metal, nitrogen and crude protein content, was investigated in a greenhouse pot experiment. Twelve treatment combinations of heavy metals mixtures composed of Zn, Mn, Cd, Co, Cu, Cr, Ni, and Pb, with each one metal participating in the mixture at 0, 2, 4, 6, 8, 10, 12, 14, 16, 18, 20, 22 mg.kg-1 were applied, respectively. It was found that the increase of soil DTPA extractable heavy metal concentrations reflecting high soil pollution, decreased statistically significantly the beet dry matter (dm) yield, but increased the metal and the , the nitrogen concentrations, and consequently, contributed statistisically significantly to the increase of beet crude protein yield.

This work analyzes the extraction behavior of transition heavy metal Zinc and other metal ions such as Copper, and Cadmium from hydrochloride aqueous solution in the absence of chelating agents by using a novel class of hydrophobic ionic liquids. Ionic liquid for this study was synthesized based on 1-(n-alkyl)-3-methylimidazolium cations and hexafluorophosphate anions followed by the metathesis route at room temperature were evaluated. The advantages of using these ionic liquids include their simple synthesis and sustainability. Which makes them “Greener and Simpler” compared to other solvents used for metal extraction. The experimental results show that ionic liquid 1-Butyl-3-methylimidazolium hexafluorophosphate, [BMPSM][PF6] entirely removed of Zinc (extraction percentage 94.4%) and other Copper and Cadmium heavy metals from the aqueous solutions. Based on the results, the use of ionic liquids for selected heavy metal ions as a substitute to the traditional extraction agents in liquid/liquid extraction of heavy metal ions shows considerable potential and is quite promising and promoting for further extraction.

Recently, the exploration of new alternatives to common organic solvents in combination with non-conventional energy sources is a subject of intense research and development as tools for green extraction of plant-derived natural products. This paper deals with the use of low frequency ultrasound (100 W, 32 kHz) and pulsed electrical fields (0.86 kV cm-1, 13 Hz) to raise the efficiency of the extraction of selected plant species rich in valuable phenolic compounds.Four types of natural deep eutectic solvents were applied for the ultrasound-assisted extraction of silymarin from milk thistle among which a choline-chloride-based mixture with glycerol was proved to be the most promising one. Additionally, the usage of high ultrasound power significantly increased the concentration of sylimarin as compared to traditional ethanol extraction, generating rapidly for 10 min considerable temperature rise as a side effect under non-cooling conditions. The application of PEF as a pre-treatment for 0.8 s to the extraction allowed reducing the ethanol percentage in the ethanol/water mixtures giving comparable phenolic yields, without any, or very little, increase in temperature. As such, optimized power intensity in conjunction with appropriate solvent system provides a potential to improve the release of thermally unstable bioactive compounds under mild processing conditions.