Mitigation of ammonia and greenhouse gases emissions from urea coated with oil shale residues in a silvopastoral system.

The objective of this work was to investigate the viability of using retorted oil shale as urea coating (U + ROS) in the decrease of N losses by ammonia (NH-N) volatilization. The experiment was carried out in a silvopastoral system with a randomized block design with split-plots. The main treatments consisted of spatial arrangements of the trees, while the subdivision of the plots constituted the surface application of common urea (U) and retorted oil shale-coated urea (U + ROS) for the pasture.

Agricultural use and pH correction of anaerobic sewage sludge with acid pH.

Agricultural use is the main way of recycling sewage sludge. Besides providing nutrients and organic matter to crops and soils, it is an important alternative for recycling this residue. However, problems during the sewage treatment process may generate sludge batches with an acidic pH.

Preconcentration of polar phenolic compounds from water samples and soil extract by liquid-phase microextraction and determination via liquid chromatography with ultraviolet detection.

This work proposes a liquid-phase microextraction (LPME) method to extract the highly polar compounds phenol (Ph), o-cresol (o-Cr), m-cresol (m-Cr), p-cresol (p-Cr), and 2,4-dimethylphenol (2,4-DMP) from aqueous matrices. The first extraction step of the LPME method employed a common volumetric flask and n-octanol, and the second extraction step used NaOH as the acceptor phase. The optimized extraction conditions were 900 μL of n-octanol as the extraction solvent, NaOH at 0.

Transfer of atrazine degradation capability to mineralize aged ¹⁴C-labeled atrazine residues in soils.

The degradation of environmentally long-term aged (22 years) ¹⁴C-labeled atrazine residues in soil stimulated by inoculation with atrazine-adapted soil from Belgium, the United States (U.S.), and Brazil at two different moisture regimes (50% WHCmax/slurried conditions) was evaluated.

Biochar-mediated [14C]atrazine mineralization in atrazine-adapted soils from Belgium and Brazil.

Biochar addition to soil has been reported to reduce the microbial degradation of pesticides due to sorption of the active compound. This study investigated whether the addition of hardwood biochar alters the mineralization of (14)C-labeled atrazine in two atrazine-adapted soils from Belgium and Brazil at different moisture regimens. Biochar addition resulted in an equally high or even in a significantly higher atrazine mineralization compared to the soils without biochar.

Metabolism and persistence of atrazine in several field soils with different atrazine application histories.

To assess the potential occurrence of accelerated herbicide degradation in soils, the mineralization and persistence of (14)C-labeled and nonlabeled atrazine was evaluated over 3 months in two soils from Belgium (BS, atrazine-treated 1973-2008; BC, nontreated) and two soils from Germany (CK, atrazine-treated 1986-1989; CM, nontreated). Prior to the experiment, accelerated solvent extraction of bulk field soils revealed atrazine (8.3 and 15.

Accelerated degradation of (14)C-atrazine in brazilian soils from different regions.

The repeated use of a given pesticide may induce a selection of the soil microbial population, resulting in a rapid degradation of the respective xenobiotic. Patterns of atrazine degradation (mineralization, formation of metabolites and nonextractable residues (NER)) were evaluated in two Brazilian soils with a history of atrazine application. Results were compared with those obtained from soils that had no agricultural use or herbicide application history.