This study aims to analyze the perception of the users of an Enterprise Resources Planning (ERP) system implemented in a research and development (R&D) institute in Romania regarding the achievement of the objectives proposed by this implementation but also the factors that contributed to the successful implementation of this ERP system. To study the perception, a questionnaire was sent for completion, to which 54 users, employees of the R&D institute, replied. The results obtained show that the users' perception is favorable to the achievement of the implementation objectives and the factors that have contributed the most to the success of the implementation are the support offered by the implementation team in the implementation of the ERP System Microsoft Dynamics NAV and the involvement of the management team in defining and following the objectives.

The removal of metal ions by biosorption on inexpensive materials is still a challenge for environmental engineering research. In this study, marine green algae biomass (Ulva lactuca sp.) and the biochars obtained from this biomass, at 320 ◦C (BC-320) and 550 ◦C (BC-550), were used as biosorbents for the removal of Cu(II) ions from aqueous solution. In addition to comparing the biosorption capacities, the determination of the thermodynamic parameters allows the choice of the most suitable material for the biosorption processes. The experimental results, obtained for Cu(II) ions biosorption on each biosorbent (algae biomass (AB), BC-320 and BC-550), at three different temperatures (10, 30 and 50 ◦C) were analyzed using Langmuir and Freundlich isotherm models, while pseudo-first order, pseudo-second order and intra-particle diffusions models were used to model the kinetic data. The biosorption of Cu(II) ions is best described by the Langmuir model and the pseudo-second kinetic model, regardless of the type of biosorbent. Such behavior is characteristic for the retention of metal ions on low-cost materials and is explained in the literature using the concepts of molecular symmetry. The maximum biosorption capacity (qmax, mg/g) depends on the temperature, but also on the type of biosorbent, and follow the order: BC-320 < AB < BC-550. Using the experimental isotherms, the thermodynamic parameters (DG0, DH0 and DS0) for the biosorption of Cu(II) ions on each biosorbent were calculated. The analysis of the obtained values constitutes the main arguments for choosing BC-550 as the most effective biosorbent for the removal of Cu(II) ions from aqueous media.

Nowadays, heavy metal pollution has become an acute problem. Due to toxic toxicity, persistence, and accumulation tendency, high concentrations of heavy metals are found in the environment, becoming an important factor in the degradation of the ecosystem. More and more cases of accidental pollution of inland or international waters, air, or soil with substances or products containing heavy metals are frequently reported in the media and are also the subject of concern in the scientific world. Algae biomass is widely found and has a wide range of uses, representing a valuable biomass resource due to its properties in solving various environmental problems, such as decontamination of soil and wastewater, etc