Feasibility of Biochar Derived from Sewage Sludge to Promote Sustainable Agriculture and Mitigate GHG Emissions-A Review.

Sewage sludge (SS) has been connected to a variety of global environmental problems. Assessing the risk of various disposal techniques can be quite useful in recommending appropriate management. The preparation of sewage sludge biochar (SSB) and its impacts on soil characteristics, plant health, nutrient leaching, and greenhouse gas emissions (GHGs) are critically reviewed in this study. Comparing the features of SSB obtained at various pyrolysis temperatures revealed changes in its elemental content. Lower hydrogen/carbon ratios in SSB generated at higher pyrolysis temperatures point to the existence of more aromatic carbon molecules. Additionally, the preparation of SSB has an increased ash content, a lower yield, and a higher surface area as a result of the rise in pyrolysis temperature. The worldwide potential of SS output and CO2-equivalent emissions in 2050 were predicted as factors of global population and common disposal management in order to create a futuristic strategy and cope with the quantity of abundant global SS. According to estimations, the worldwide SS output and associated CO2-eq emissions were around 115 million tons dry solid (Mt DS) and 14,139 teragrams (Tg), respectively, in 2020. This quantity will rise to about 138 Mt DS sewage sludge and 16985 Tg CO2-eq emissions in 2050, a 20% increase. In this regard, developing and populous countries may support economic growth by utilizing low-cost methods for producing biochar and employing it in local agriculture. To completely comprehend the benefits and drawbacks of SSB as a soil supplement, further study on long-term field applications of SSB is required.

Recent advances in removal of Congo Red dye by adsorption using an industrial waste.

The Congo Red dye was removed from a simulated textile wastewater solution using fly ash from a local power plant. The characterisation of fly ash was studied in detail by SEM, EDX, XRD, FTIR, BET surface area and TGA techniques. The influence of four parameters (contact time, initial concentration, adsorbent dose, and temperature) was analysed, the results showing that the adsorption capacity depends on these parameters. Thermodynamic and regeneration investigations as well are presented. The fit to pseudo-second-order kinetics models suggests that the removal process is a chemical adsorption. The Langmuir model fitted the experimental data, with a maximum adsorption capacity of 22.12 mg/g. The research is a preliminary case study that highlights that fly ash posed a very good potential as a material for Congo Red dye removal.

Obtaining and Utilizing Cellulose Fibers with in-Situ Loading as an Additive for Printing Paper.

The goal of this study was to analyze the effects of cellulose fibers loading by precipitation in-situ of calcium carbonate over the properties of printing paper obtained from mixtures of the softwood and hardwood fibers. The effects of fibers with in-situ loading were analyzed comparatively with conventional paper loading respectively, by adding precipitated calcium carbonate into fiber stock. The effectiveness of the methods was evaluated by various analyses and investigations: calcium carbonate content, Scanning electron microscope (SEM) images, X-ray diffraction, optical and mechanical properties of the paper sheets. The evaluation of the effects on paper properties led to the conclusion that, at the same filler content, the in-situ loading method gives higher opacity and brightness than conventional methods. The utilization of cellulose fibers with in-situ loading as additive, shown as a modification of the ratio between fibers with in-situ loading and fibers without loading, regardless of whether they are softwood or hardwood fibers, allowed us to optimize printing paper properties, especially regarding the relationship between optical and strength properties.