The carbon rich material obtained from pyrolysis process, i.e. biochar, has been widely discussed during the last decade due to its utilisation as a soil amendment. Furthermore, there is an unsolved question of biomass disposal from phytoremediation technologies. The idea of contaminated biomass pyrolysis has appeared, but there is lack of information about possible biochar utilisation obtained by this process. The aim of our study was to observe sorption properties of biochar prepared from contaminated biomass and release of contaminants from biochar back into the environment. The biomass of fast growing trees and maize was harvested on a site significantly damaged by risk element contamination (Cd, Pb and Zn). Plant biomass was pyrolysed and then the batch (de)sorption experiments were settled. The results confirmed no significant differences in metal sorption ability between biochars prepared from contaminated and uncontaminated biomass under the same conditions. The trend of maximum sorption capacity of observed matrices followed the order: wood biochar + soil (WB + soil) > wood uncontaminated biochar + soil (WUB + soil) > maize biochar + soil (MB + soil) > soil for cadmium, WB + soil > WUB + soil > soil for lead and MB + soil > WUB + soil > WB + soil > soil for zinc. Despite of increase of Zn desorption from wood biochars, maximum sorption capacity of the final WB + soil system was comparable to the WUB+soil sample. Our laboratory experiments showed high potential of biochar from contaminated plants as a soil amendment with sorption abilities and minimal risk of metal release.

This study investigates the use of sericite beads and microalgae for the removal of heavy metals from acid mine drainage (AMD) and the simultaneous enhancement of biomass productivity. The experiment was conducted over a period of 6 days in a hybrid system containing sericite beads and microalgae Chlorella sp. The results show that the biomass production increased to ~8.04 times its initial concentration of 0.367 g/L as measured by an optical panel photobioreactor (OPPBR) and had a light transmittance of 95 % at a 305-mm depth. Simultaneous percent removal of Fe, Cu, Zn, Mn, As, and Cd from the AMD effluent was found to be 97.78 to 99.26 %. Biomass production was significantly enhanced by removal of heavy metal ions. We thus found that our hybrid system of sericite beads and microalgae was highly effective in removing heavy metal and in enhancing biomass production and could be a useful alternative treatment of AMD.

Urban soil amendment with organic matter can increase the steady state concentration of trace metals in urban soil. Different types of organic matter have different abilities to sorb and retain trace metals. The potential of urban soil amended with compost derived from mixed green and table waste and with maple-wood-derived biochar to retain trace metals (Cu, Zn, Cd, Pb) in the presence of de-icing salt (Na) was studied in a leaching test. Soil amended with compost retained significantly higher concentrations of Zn and Pb, as compared to soil amended with biochar, possibly due to the high cation exchange capacity of compost and its positive effect on soil pH. Indicating high ability for retaining trace metals, compost can bind contaminants originating from urban runoff water percolating through urban soil and provide a healthier medium for street tree growth.

Residual antibiotics in land-applied manure and biosolids present a potential threat to public and ecological health. It remains important to determine antibiotic degradation efficiencies for manure and biosolids waste management practices and to identify conditions that enhance antibiotic degradation. The fates of the antibiotics florfenicol, sulfadimethoxine, sulfamethazine, and tylosin were studied during pilot-scale static pile thermophilic composting, and the effects of temperature and feedstock particles on antibiotic degradation rates were tested. The antibiotics were spiked into dairy manure solids and wastewater biosolids, and treatments included aerated and non-aerated manure and biosolids/wood-product (1:3 v/v) composting. Results showed no significant differences between aerated and non-aerated treatments; on average, ≥85, ≥93, and ≥95 % antibiotic degradation was observed after 7, 14, and 21 days of composting. Greater antibiotic degradation was observed in manure compost compared to biosolids compost for florfenicol (7, 14, 21, 28 days) and tylosin (14, 28 days); however, there was no significant difference for sulfadimethoxine and sulfamethazine. Peak temperatures were 66–73, and ≥55 °C was maintained for 6–7 days in the biosolids compost and 17–20 days in the manure compost. Bench-scale experiments conducted at 25, 55, and 60 °C showed that lower temperature decreased degradation of the sulfonamides and tylosin in both feedstocks and florfenicol in the biosolids. The presence of compost particles increased antibiotic degradation, with time to 50 % degradation ≤2 days in the presence of solids (60 °C) compared to no degradation in their absence. These results indicate that thermophilic composting effectively degrades parent antibiotic compounds in manure and biosolids.

The potential of granular activated carbon (GAC) to remove iopromide and its intermediates from ozone-treated river water was evaluated. Mass spectrum analysis showed that ozone treatment lead to partial removal of iopromide (m/z 791.8) with generation of various intermediates. GAC demonstrated a lower iopromide adsorption (1.60 μg/g) in the presence of natural organic matter (NOM) compared to NOM-free water (12.54 μg/g), indicating the inhibitory effect of NOM on iopromide adsorption. Ozone treatment of the influent reduced the inhibitory effect of NOM by altering its composition and inducing polarity shift. GAC post-treatment resulted in improved removal of residual iopromide and its intermediates from the ozone-treated influent. Application of such combined treatment of ozonation followed by GAC adsorption can be an effective strategy for the removal of iopromide and its intermediates from contaminated water streams.

A series of column experiments was conducted to evaluate the effect of organic carbon fraction on long-term atrazine elution tailing for calcareous soil (foc = 0.97 %) and calcareous soil with 10 % by weight terra rossa amendment (foc = 1.20 %). Effluent atrazine concentrations were monitored for approximately 400 pore volume to understand the influence of controlling sorption–desorption kinetics on long-term tailing behavior. Laboratory studies showed that the sorption of atrazine was described by rate-limited, nonlinear reversible processes for both soils. Atrazine transport exhibited extensive elution tailing for all experiments due to the presence of hard carbon components such as black carbon and kerogen in both soils. This nonlinear sorption and extensive atrazine tailing behavior were more pronounced and extensive for soil with terra rossa amendment due to the addition of approximately 20 % organic carbon including 10 % hard carbon components from terra rossa soil. A mathematical model incorporating nonlinear, rate-limited sorption/desorption described by a continuous distribution function was used to successfully simulate atrazine transport early-time breakthrough and long-term concentration tailing for both porous media.

Microporous–mesoporous activated carbons from five different types of agro-industrial wastes were produced using chemical activation with ZnCl₂ and carbonization at mild conditions of 600 °C, comprehensively characterized and investigated for removal of methylene blue (MB) in aqueous solution, a model large-molecular-size organic pollutant. The external part of the mango pit (mango seed husk) was used for the production of activated carbon (AC) for the first time. Despite that the raw agro-materials exhibited significantly different porosity, all activated carbons produced possessed well-developed microporous–mesoporous structures showing high surface areas and micropore volumes. Further, it was revealed that the pore size distribution of raw agro-material is a more important property in development of microporous–mesoporous structure of produced ACs than their overall porosity. All activated carbons produced adsorbed MB, reaching in most cases 100 % removal from the aqueous phase. Adsorption data were fitted well to a pseudo-second-order kinetic model. For MB adsorption, the mesoporosity and the ratio of micropores accessible for MB were the key factors since there exists the size-selectivity effect on MB adsorption due to MB molecular dimensions. The molecular dimensions of MB were estimated via DFT calculations to 1.66 × 0.82 × 0.54 nm, and this parameter was correlated with determined micropore size distributions of activated carbons.

Because of its long half-life, endosulfan can persist for a long time in the environment, especially in soil. However, little is known about its effect on fungi, which is an important part of microorganisms in soil. In this study, agricultural soil treated with endosulfan (0.1 and 1.0 mg kg⁻¹) in a laboratory experiment was analyzed over 42 days. The effect of endosulfan on bacterial and fungal quantity and community structure were determined by quantitative polymerase chain reaction (qPCR) and denaturing gradient gel electrophoresis (DGGE). The results revealed that endosulfan was removed more than 50 % after 42 days, and its removal fitted single first-order kinetics. The exposure to endosulfan caused a short-lived inhibition on fungal and bacterial quantity, but no effect was observed in both treatments after 42 days. Furthermore, this inhibition was greater in higher endosulfan-treated soil. A significant change in bacterial community structure was found in both treatments after endosulfan application, while the change of fungal community structure was observed only in 1 mg kg⁻¹endosulfan treatment.

Nitrogen- heterocyclic polycyclic aromatic hydrocarbons (N-PAHs) are ubiquitous constituents of contaminated sites in which their high water solubility and lower k ₒw values imply greater mobility and impacts. Biodegradation is a major route of loss for organic contaminants in soil. In this study, microbial degradation was investigated in soil artificially contaminated with N-PAHs and monitored for over 200 days. The results showed that all the aromatic chemicals exhibited loss with increasing incubation time; however, only 0.05 ± 0.04 mg kg day⁻¹ loss was observed for N-PAHs at 10 mg kg⁻¹ amendments over the first 30 days incubation, with the exception of 4,7-phenanthroline which recorded 0.19 ± 0.03 mg kg day⁻¹. The study showed that soil microflora have the potential to degrade N-PAHs since all of the aromatics recorded chemical losses under aerobic condition. However, degradation rates varied between chemicals and this was attributed to N-atom position and/or number of N-substituents. Further, relatively little or no biodegradation was observed in B[h]Q amended soils with increasing concentration; indicating that B[h]Q is more resistance to biodegradation in soil.

Sorption of four ionizable organic amines, n-hexylamine, trimethylamine, 1-naphthylamine, and phenylamine, on a soil sample were measured, and their effects on the sorption of phenanthrene (PHE) to the same adsorbent were studied. The aim of this study was to better clarify sorption mechanisms of chemicals with different polarity and ionization characteristics in a single-solute system and in a polar/nonpolar binary system. In the single system, cationic organic amines exhibited greater sorption than those in a neutral form, and the sorption increased with hydrophobicity for amines with the same form. In the binary system, the sorption of PHE was promoted in the presence of n-hexylamine and the solid-water distribution coefficient (K d) increased with increasing amine concentrations. This may be explained by the elevated amount of hydrophobic organic sites provided by the head-on adsorption of cationic n-hexylamine to the negatively charged sorbent surface, which are probably more favorable for the sorption of PHE compared with natural organic matters. Contrarily, the neutral amine, 1-naphthylamine, might compete with PHE for the mutually available hydrophobic sites and hence inhibited PHE sorption. On the other hand, both trimethylamine and phenylamine had little effects on PHE sorption due to their relatively high solubility and weak hydrophobicity. Therefore, either in single or binary system, both the form and the solubility/hydrophobicity of the compound play important roles in the sorption of ionizable organic amines and their effects on the sorption of nonpolar co-solute.