Search Results (9)

The excessive levels of neonicotinoid insecticides, particularly thiacloprid (THI), in the environment have become a significant threat to ecosystems. This study investigates the catalytic degradation of THI using pinewood biochar (PBC), zero-valent iron (ZVI), and ZVI/PBC composite, with a particular focus on the reaction activity modulation mediated by organic acids (humic acid: HA and oxalic acid: OA). Reductive dechlorination dominated THI degradation as observed by Cl⁻ release kinetics. Compared to HA (39.73%), the OA (73.44%) addition markedly increased the THI removal efficiency by ZVI/PBC, which alone has a lower removal efficacy, i.e., 37.29%. The increase in the THI removal rate was attributed to its enhanced electron transfer capacity. As confirmed by electrochemical characterization, the addition of organic acids promotes electron transfer between THI and catalysts (ZVI, PBC, or ZVI/PBC), thereby improving the removal efficiency of THI. XRD/XPS analyses elucidated that OA preferentially converted passivating Fe₂O₃/Fe₃O₄ on ZVI/PBC to reactive FeOOH and formed electron-conductive Fe–COO bonds, thereby suppressing oxide layer formation. PBC amplified these effects through ZVI dispersion and electron shuttling, reducing aggregation-induced activity loss. These findings provide a mechanistic framework for optimizing ligand-engineered iron composites, offering practical strategies to enhance pesticide remediation efficiency in organic acid-rich environmental systems. Full article

This study aims to improve water quality and reduce eutrophication downstream when receiving water from aquaculture facilities that can support the aquaculture industry and increase fish production capacity. The primary objective is to investigate a novel approach, using magnesium (Mg)-modified biochar water treatment systems from pinewood, to remove the main eutrophication agents (i.e., phosphorous and nitrogen) from the effluents of aquaculture facilities in Magic Valley, Idaho. The downstream water contains approximately 0.14 mg/L of phosphorous and 2.25 mg/L of nitrogen. The results show that the initial P₂O₅ concentration between Mg-modified and non-modified biochar is comparable. After exposure to aquaculture production water, the modified biochar is shown to have a significant increase in phosphorous and nitrogen adsorption. Non-modified biochar started with noticeably higher concentration levels of nitrogen than modified biochar. Over time in the treatment water, the modified biochar showed a significant increase in nitrogen concentration. Mg bonded to the modified biochar is shown to decrease drastically after exposure to the effluent. This could be due to the insufficient bonding of the magnesium to biomass feedstocks during pre-processing and biochar production. The amount of biochar near the end of experimentation is almost comparable to the non-modified char. We concluded that the proposed approach, using a Mg-modified biochar water treatment system, could sequester more nitrogen and phosphorous over time. Full article

Actions for improving water quality are critical and include the remediation of polluted groundwater. The effectiveness of the remediation strategy to remove contamination by chlorinated solvents may be increased by combining physicochemical treatments (i.e., adsorption) and biological degradation (i.e., biological reductive dechlorination (BRD)). Recent studies have shown the potentialities of bio-based materials for bioremediation purposes, including polyhydroxybutyrate (PHB), a biodegradable microbial polyester tested as a fermentable source of slow-release electron donors. Further, a low-cost biochar derived from the pyrolysis of pinewood waste (PWB), used as sorbent material, has recently been proposed to accelerate reductive microbial dehalogenation. Here, we propose a coupled adsorption and biodegradation (CAB) process for trichloroethylene (TCE) removal in a mini pilot-scale reactor composed of two reactive zones, the first one filled with PHB and the second one with PWB. This work aimed to evaluate the performance of the CAB process with particular regard to the effectiveness of the PWB in sustaining the biofilm, mostly enriched by Dehalococcoides mccartyi. The main results showed the CAB system treated around 1300 L of contaminated water, removing 102 mg TCE per day. Combining PHB and PWB had a positive effect on the growth of the dechlorinating community with a high abundance of Dhc cells. Full article

Biochar, which contains abundant nutrients like phosphorus (P), is considered a potential source of nutrients for plant use after its application in soil. However, the localized distribution of P in the vicinity of biochar (that is, the charosphere) is poorly understood. In this study, the biochars derived from pinewood (PWB), maize straw (MSB), and chicken manure (CMB) were granulated and investigated for their short-term charosphere effect, using an integrated imaging technique in situ. The results showed that biochars significantly elevated the soil pH and P concentration around their granules, leading to the development of a charosphere over several days. Both pH and P were distributed in a gradient in the charosphere: the values were highest where the biochars were located and declined with increasing distance from the biochar. A highly positive correlation (p < 0.01) was found between the pH, electric conductivity (EC), ash content of the biochar, and the scope of the pH gradient in the charosphere. Moreover, the scope of the P gradient was positively related to the pH and EC values of the biochar as well (p < 0.05). The charosphere effect was prominent around the CMB and MSB granules because of their high ash content, an especially soluble component. The P diffusion in the charosphere was inferred to be influenced by the soil pH as well as the endogenous P species in the biochars. These findings provide new insight into the localized effect of biochars in soil, which is conducive to understanding the nutrient availability to plants after biochar application. Full article

Medicines are pharmaceutical substances used to treat, prevent, or relieve symptoms of different diseases in animals and humans. However, their large-scale production and use worldwide cause their release to the environment. Pharmaceutical molecules are currently considered emerging pollutants that enter water bodies due to inadequate management, affecting water quality and generating adverse effects on aquatic organisms. Hence, different alternatives for pharmaceuticals removal from water have been sought; among them, the use of agro-industrial wastes has been proposed, mainly because of its high availability and low cost. This review highlights the adverse ecotoxicological effects related to the presence of different pharmaceuticals on aquatic environments and analyzes 94 investigations, from 2012 to 2024, on the removal of 17 antibiotics, highlighting sulfamethoxazole as the most reported, as well as 6 non-steroidal anti-inflammatory drugs (NSAIDs) such as diclofenac and ibuprofen, and 27 pharmaceutical drugs with different pharmacological activities. The removal of these drugs was evaluated using agro-industrial wastes such as wheat straw, mung bean husk, bagasse, bamboo, olive stones, rice straw, pinewood, rice husk, among others. On average, 60% of the agro-industrial wastes were transformed into biochar to be used as a biosorbents for pharmaceuticals removal. The diversity in experimental conditions among the removal studies makes it difficult to stablish which agro-industrial waste has the greatest removal capacity; therefore, in this review, the drug mass removal rate (DMRR) was calculated, a parameter used with comparative purposes. Almond shell-activated biochar showed the highest removal rate for antibiotics (1940 mg/g·h), while cork powder (CP) (10,420 mg/g·h) showed the highest for NSAIDs. Therefore, scientific evidence demonstrates that agro-industrial waste is a promising alternative for the removal of emerging pollutants such as pharmaceuticals substances. Full article

PFASs are a variety of ecologically persistent compounds of anthropogenic origin loosely included in many industrial products. In these, the carbon chain can be fully (perfluoroalkyl substances) or partially (polyfluoroalkyl substances) fluorinated. Their ubiquitous presence in many environmental compartments over the years and their long-lasting nature have given rise to concerns about the possible adverse effects of PFASs on ecosystems and human health. Among a number of remediation technologies, adsorption has been demonstrated to be a manageable and cost-effective method for the removal of PFASs in aqueous media. This study tested two novel and eco-friendly adsorbents (pinewood and date seeds biochar) on six different PFASs (PFOS, GenX, PFHxA, PFOA, PFDA, and PFTeDA). Batch sorption tests (24 h) were carried out to evaluate the removal efficiency of each PFAS substance in relation to the two biochars. All samples of liquid phase were analyzed by a developed and then a well-established method: (i) pre-treatment (centrifugation and filtration) and (ii) determination by high-performance liquid chromatography coupled with mass spectrometry (HPLC-MS/MS). The results evidenced a comparable adsorption capacity in both materials but greater in the long-chain PFASs. Such findings may lead to a promising path towards the use of waste-origin materials in the PFAS remediation field. Full article

Pinewood biomass in Portugal can be considered a major source of biochar for soil physical, chemical, and biological edaphic amendment. This work intended to evaluate the aptitude of lab produced biochar for upgrading soil moisture dynamics’ relationships considering mixtures of biochar with silica-based sand. The methodology used focused on the carbonization of pine biomass with inert atmosphere at 300 °C, 400 °C, 500 °C and 600 °C, followed by a chemical proximate and thermogravimetric analysis, scanning electron microscopy, Fourier Transform Infrared analysis, numerical modeling, and characterization of biochar porosity by gas adsorption (Brunauer–Emmett–Teller) and mercury porosimetry. The results showed the increased amounts of soil water retention and plant available water, evaluated through pF curves, due to biochar application. The thermogravimetric analysis mass loss patterns and FTIR transmittance, reflected major structural modifications in carbonized products by comparison with raw biomass. Mercury porosimetry showed that biochar pores between 392 and 250 μm and 32 μm and 6 μm gave the highest pore volume for water retention with a major increase from carbonization, by comparison with physical activation. The used methodologies allowed us to conclude that the carbonaceous feedstock can potentiate the improvement of soil water relations aiming at agricultural land use. Full article

Biochar application is reported as a method for improving physical and chemical soil properties, with a still questionable impact on the crop yields and quality. Plant productivity can be affected by biochar properties and soil conditions. High efficiency of biochar application was reported many times for plant cultivation in tropical and arid climates; however, the knowledge of how the biochar affects soils in temperate climate zones exhibiting different properties is still limited. Therefore, a three-year-long field experiment was conducted on a loamy Haplic Luvisol, a common arable soil in Central Europe, to extend the laboratory-scale experiments on biochar effectiveness. A low-temperature pinewood biochar was applied at the rate of 50 t h⁻¹, and maize was selected as a tested crop. Biochar application did not significantly impact the chemical soil properties and fertility of tested soil. However, biochar improved soil physical properties and water retention, reducing plant water stress during hot dry summers, and thus resulting in better maize growth and higher yields. Limited influence of the low-temperature biochar on soil properties suggests the crucial importance of biochar-production technology and biochar properties on the effectiveness and validity of its application in agriculture. Full article

Biochar is a carbon-rich organic material, obtained by the thermochemical conversion of biomass in an oxygen-limited environment, used as a soil amendment to stimulate soil fertility and improve soil quality. There is a clear need in developing countries for access to low cost, low technology options for biochar production, for example, top-lit updraft (TLUD) stoves, which are popular and spread worldwide. However, TLUD biochars are inevitably very variable in their properties for a variety of reasons. We present laboratory triplicate tests carried out on TLUD biochars obtained from waste pinewood and a Guadua bamboo. Analyzed properties include specific surface area (A-BET), porosity, skeletal density, hydrophobicity, proximal and elemental composition, cation exchange capacity (CEC), relative liming capacity and pH. SEM images of the bamboo and wood biochars are compared. The biochars were mixed with composted human excreta at 5% and 10% biochar content, and available water content (AWC) was analyzed. Operating temperatures in the TLUD were recorded, showing different behaviors among the feedstocks during the process. Differences in operating temperatures during charring of the bamboo samples seem to have led to differences in A-BET, hydrophobicity and CEC, following unprecedented trends. For the mixtures of the biochars with compost, at 5% biochar no significant differences were observed for AWC. However, in the 10% biochar mixtures, bamboo biochar showed an unexpectedly high AWC. Overall, variations of chemical and physical properties between bamboo biochars were greater, while pinewood biochars showed similar properties, consistent with more homogeneous charring temperatures. Full article