Organic Matter Composition of Digestates Has a Stronger Influence on N2O Emissions than the Supply of Ammoniacal Nitrogen

Manures can be treated by solid–liquid separation and more sophisticated, subsequent approaches. These processes generate fertilizers, which may differ in composition and N2O release potential. The aim of the study was to investigate the influence of processing-related changes in digestate composition on soil-derived N2O emissions after application to soil. For that purpose, N2O emissions within the first 7 weeks after fertilization with two raw and eight processed digestates (derived from solid–liquid separation, drying and pelletizing of separated solid, and vacuum evaporation of separated liquid) were measured in the field in 2015 and 2016. Additionally, an incubation experiment was run for 51 days to further investigate the effect of subsequent solid and liquid processing on soil-derived N2O release. The results showed that, only in 2016, the separation of digestate into solid and liquid fractions led to a decrease in N2O emissions in the following order: raw digestate > separated liquid > separated solid. N removal during subsequent processing of separated solid and liquid did not significantly influence the N2O emissions after fertilization. In contrast, the concentrated application of the final products led to contradictory results. Within the solid processing chain, utilization of pellets considerably increased the N2O emissions by factors of 2.7 (field, 2015), 3.5 (field, 2016), and 7.3 (incubation) compared to separated solid. Fertilization with N-rich ammonium sulfate solution led to the lowest emissions within the liquid processing chain. It can be concluded that the input of less recalcitrant organic C into the soil plays a greater role in N2O release after fertilization than the input of ammoniacal N. Digestate processing did not generally reduce emissions but apparently has the potential to mitigate N2O emissions substantially if managed properly.

An Overview of Nanoparticles: Current Scenario

The simplest type of structures with sizes in the nm range will be nanoparticles. Any atom mean that is associated by intensity with other atoms within a 'limited' distance may be claimed to be a nanoparticle in principle. The creation of novel drug delivery systems using nanoparticles has seen an exponential interest in recent years. In terms of high stability, high precision, high drug carrying capability, managed release potential, the possibility of use in various routes of administration and the ability to deliver both hydrophilic and hydrophobic drug molecules, nanoparticles may offer significant advantages over conventional drug delivery. The emphasis of this study is on classification, types, synthesis, preparation methods, characterization, use, nanoparticle advantages, and health perspectives.

Sedimentary Organic Matter Load Influences the Ecological Effects and Potential Risks of Submerged Macrophyte Restoration Through Rhizosphere Metabolites

Aims Rehabilitation of submerged vegetation is one of the commonly used techniques for the ecological restoration of shallow lakes. The changes of pollution structure in sediments caused by plant recovery and the rhizosphere chemical process under different sediment organic matter (SOM) levels are theoretical basis for the rational application of plant rehabilitation technology in lake management.Methods A circulating extraction system was designed for in situ collection of rhizospheric metabolites especially for the submerged plants. We explored how Vallisneria natans (V. natans) mediate the changes in sediment N and P through rhizospheric metabolites under low (4.94%) and high (17.35%) SOM levels. Results By analysing 63 rhizospheric metabolites from V. natans, glucitol was found to be 146.82% lower in the low SOM than in the high SOM treatment. NH4-N and NO2-N increased by 57% and 68.39%, respectively, in the high SOM treatment, while approximately one-seventh Inorg-P was transferred from Fe/Al-P to Ca-P in the low SOM treatment. The metabolites lactic acid, 3-hydroxybutyric acid, and phosphoric acid mediated NH4-N accumulation. Additionally, 3-hydroxy-decanoic acid and adipic acid mediated the transformation of Fe/Al-P to Ca-P.Conclusions The growth of V. natans significantly changed Inorg-N or Inorg-P fractions. The changes were SOM level-dependent and rhizosphere metabolites related. This study emphasised the benefit of V. natans rehabilitation at low SOM level. When restoring submerged macrophytes from high SOM sediment, care should be taken due to the release potential of labile N and P forms.

Effect of magnetic iron-zirconium modified zeolite on the different phosphorus forms in river sediment under aerobic and anoxic condition

In this study, a magnetic iron-zirconium modified zeolite (FeZrMZ) was synthesized. Through sediment culture experiments, the influence of the addition of modified materials on the migration and transformation of phosphorus in river sediments was investigated. The results show that the modified zeolite can not only effectively reduce the phosphorus concentration in the overlying water, but also significantly reduce the phosphorus concentration in the pore water of sediments. The addition of modified zeolite makes the unstable weakly adsorbed phosphorus (NH4Cl-P) and redox phosphorus (BD-P) transform into the more stable metal oxide bound phosphorus (NaOH-P) and very stable residual phosphorus (Res-P).The four types of bioavailable phosphorus (BAP), including water-soluble phosphorus (WSP), readily desorbable phosphorus (RDP), algae-available phosphorus (AAP), and NaHCO3 extractable phosphorus (Olsen-P). Under anoxic conditions, they were reduced by 53.5%, 14.1%, 23.8%, and 49.9% respectively. Under aerobic conditions, they were reduced by 23.2%, 16.6%, 32.1%, and 50.0%. Obviously, the addition of magnetic iron-zirconium modified zeolite can reduce the release potential of phosphorus in sediment, and it can be recovered through the action of an external magnetic field, so it can be used as an effective sediment modifier to control the sediment the release of phosphorus.

Father Involvement in the First Year After Prison: Considerations for Social Work

Purpose: Paternal incarceration poses significant concerns for fathers and their children. Despite the known negative consequences, little is understood about father involvement after prison. This study aims to further understanding of fatherhood following incarceration to inform future intervention strategies. Method: Using data from the Urban Institute’s Returning Home: Understanding the Challenges of Prisoner Reentry Study ( N = 326), we conduct bivariate and multivariate analyses to examine three dimensions of father involvement and predictors of involvement at two time points after prison. Results: Findings reveal generally high levels of father involvement in the first year following incarceration. Father-child contact during prison and increased work hours after prison showed positive effects on early father involvement, while post-prison engagement and contact following release were associated with later involvement. Conclusions: Promoting father-child contact and positive relationships during incarceration may be important for future father involvement after release. Potential social work and criminal justice practice and research opportunities are discussed.