Occurrence of bisphenol A and microplastics in landfill leachate: lessons from South East Europe.

In order to confirm the landfills as potential sources of microplastics and bisphenol A (BPA), the investigation of microplastics occurrence and concentration levels of BPA in landfill leachate samples from three landfills sites in the South East Europe was conducted. The landfills have been selected depending on the different waste management practice, waste amounts, operating period as well as leachate management practice. Microplastic was detected in different sizes, shapes and colours in all analysed leachate samples. The obtained average concentration values of the microplastics particles in the leachate samples from all three landfills ranged from 0.64 to 2.16 mg L-1. The BPA was detected in leachate samples from all landfill sites in average concentration levels from 0.70 to 2.72 mg L-1 which are related to the content of microplastics.

Decomposition of pharmaceutical micropollutant - diclofenac by photocatalytic nanopowder mixtures in aqueous media: effect of optimization parameters, identification of intermediates and economic considerations.

This study evaluates application of three different nanopowder mixtures for decomposition of diclofenac (DCF), one of frequently detected pharmaceutical in wastewater. Analyzed three photocatalytic mixtures ZnO/SnO2, ZnO/TiO2 and ZnO/In2O3 are for the first time used for diclofenac degradation. A set of experiments were performed in order to investigate influence of catalyst concentration (0.10-0.60 mg mL-1), initial concentration of diclofenac (0.002-0.010 mg mL-1) and pH value (5-9). The increase in the catalyst concentration leads to a decrease in the degradation rate constant, which is the most pronounced in the ZnO/TiO2 and ranges from 0.47 (6) min-1 to 0.25 (3) min-1. The influence of pH on efficacy shows completely different effects: ZnO/In2O3 is most effective in alkaline environments, ZnO/TiO2 in neutral environments, while ZnO/SnO2 efficiency is good in both alkaline and acidic environments. Initial concentrations of diclofenac showed a complex effect on the degradation rate. The four dominant intermediates were detected by LC MS/MS technique. In case of all three nanomaterials, intensive degradation was achieved in first 30 minutes. The economical analysis of photocatalytic treatment was provided where the preparation of nanomaterials does not demand high costs and with the highest diclofenac concentration, total operation costs are the lowest (77.14 US$/kWh).

Sorption of carbendazim and linuron from aqueous solutions with activated carbon produced from spent coffee grounds: Equilibrium, kinetic and thermodynamic approach.

Spent coffee grounds (SCG) have been used for the production of activated carbon (AC) by impregnation with different ratios of phosphoric acid at 600 °C, Xp (H3PO4/coffee): 3:130%, 4:130%, 3:150% and 4:150%. The obtained AC was characterized by BET, FTIR and SEM. BET surface area corresponds to 803.422 m2 g-1. The influences of the main parameters such as contact time, the pesticides initial concentration, adsorbent dose, pH and temperature on the efficiency of separation process were investigated during the batch operational mode. Results were modeled by adsorption isotherms: Langmuir, Freundlich and Temkin isotherms, which gave satisfactory correlation coefficients. The maximum adsorption capacities calculated from the Langmuir isotherms were 11.918 mg g-1 for carbendazim and 5.834 mg g-1 for linuron at room temperature. Adsorption kinetics of carbendazim and linuron have been studied by the pseudo-first-order, the pseudo-second-order and the intraparticle diffusion model. The results of adsorption kinetics have been fitted the best by pseudo-second-order model. The resulted data from FTIR characterization pointed to the presence of many functional groups on the AC surface. SCG adsorbent, as an eco-friendly and low-cost material, showed high potential for the removal of carbendazim and linuron from aqueous solutions.