Cystoseira barbata is an edible brown seaweed, traditionally used in the Black Sea area as functional food. Both alginate and brown seaweed biomass are well known for their potential use as adsorbents for heavy metals. Alginate was extracted from C. barbata recovered from the Romanian coast on the Black Sea with a yield of 19 ± 1.5% (w/w). The structural data for the polysaccharide was obtained by HPSEC-MALS, ¹H-NMR. The M/G ratio was determined to be 0.64 with a molecular weight of 126.6 kDa with an intrinsic viscosity of 406.2 mL/g. Alginate beads were used and their adsorption capacity with respect to Pb²⁺ and Cu²⁺ ions was determined. The adsorption kinetics of C. barbata dry biomass was evaluated and it was shown to have an adsorption capacity of 279.2 ± 7.5 mg/g with respect to Pb²⁺, and 69.3 ± 2 with respect to Cu²⁺. Alginate in the form of beads adsorbs a maximum of 454 ± 4.7 mg/g of Pb²⁺ ions and 107.3 ± 1.7 mg/g of Cu²⁺ ions.

The paper aimed at evaluating the effects of biochar (BC) produced by slow pyrolysis of vine pruning residue on soil physicochemical properties and tomato plant growth. A greenhouse experiment was conducted for 66 days, applying different treatments for 3 soil types, i.e., foliar fertilizer, BC (at a volumetric ratio between BC and soil of 20/80), BC + foliar fertilizer, and no treatments. Strongly alkaline BC (pH = 9.89 ± 0.01) had a significant beneficial effect on the growth performance of tomato plants sown in a strongly acidic soil (pH = 5.40 ± 0.02). The mean values of height, number of leaves, and collar diameter of plants grown in BC-amended soil without foliar treatment were up to 50% higher than those of plants grown in soil with the other treatments. This positive effect of BC on plant growth is due to the changes in the soil properties. The addition of BC led to increased values of electrical conductivity, pH, soluble and available nutrient concentration. Moreover, BC reduced soil bulk density by about 50%, resulting in improved plant root development and thus enhanced water and nutrient uptake. Accordingly, BC derived from vine pruning residues can improve soil quality and tomato plant growth, as well as reduce biomass residues.

The agronomic benefits of biochar (BC) prepared by slow pyrolysis of vine pruning residues, which are produced in large quantities in Romania, were evaluated. Three soil types, i.e., slightly alkaline fluvisol (S1), slightly acidic chernozem (S2), and strongly acidic luvisol (S3), with mean values of pH of 7.99, 6.26, and 5.40, were amended with BC at a volumetric ratio between BC and soil of 20/80. A greenhouse experiment was performed for 109 days to assess the effects of BC amendment on bell pepper growth. The following treatments were applied: foliar fertilizer, BC, BC + foliar fertilizer (using two concentrations of foliar fertilizer solution), and a control. Strongly alkaline BC (pH of 9.89 ± 0.01) had a significant positive effect on the growth performance of bell pepper plants sown in the strongly acidic soil S3. The mean values of height, collar diameter, number of leaves, and root volume of plants grown in BC-amended soil S3 without foliar treatment were significantly higher (13–72% and 14–33%, respectively) than those of plants grown in non-amended soil S3 without and with foliar treatment. This beneficial effect of BC on bell pepper plant growth was due to the changes in the soil properties. BC significantly increased (up to eight times) electrical conductivity, pH, soluble phosphorus, potassium, and ammonium nitrogen concentrations of soil S3, and decreased its bulk density by 51%, resulting in improved water/nutrient uptake and plant growth performance. BC had no favourable effect on the growth parameters of bell pepper plants sown in slightly alkaline soil S1, and slightly acidic soil S2.

The paper aimed at studying the slow pyrolysis of vine pruning waste in a fixed bed reactor and characterizing the pyrolysis products. Pyrolysis experiments were conducted for 60 min, using CO₂ as a carrier gas and oxidizing agent. The distribution of biochar and bio-oil was dependent on variations in heat flux (4244–5777 W/m²), CO₂ superficial velocity (0.004–0.008 m/s), and mean size of vegetal material (0.007–0.011 m). Relationships among these factors and process performances in terms of yields of biochar (0.286–0.328) and bio-oil (0.260–0.350), expressed as ratio between the final mass of pyrolysis product and initial mass of vegetal material, and final value of fixed bed temperature (401.1–486.5 °C) were established using a 2³ factorial design. Proximate and ultimate analyses, FT-IR and SEM analyses, measurements of bulk density (0.112 ± 0.001 g/cm³), electrical conductivity (0.55 ± 0.03 dS/m), pH (10.35 ± 0.06), and water holding capacity (58.99 ± 14.51%) were performed for biochar. Water content (33.2 ± 1.27%), density (1.027 ± 0.014 g/cm³), pH (3.34 ± 0.02), refractive index (1.3553 ± 0.0027), and iodine value (87.98 ± 4.38 g I₂/100 g bio-oil) were measured for bio-oil. Moreover, chemical composition of bio-oil was evaluated using GC-MS analysis, with 27 organic compounds being identified.