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Waste management is an increasing global concern due to the rise in urbanization and industrialization. This study examines the co-pyrolysis of date pits (DP) and single-use plastics (polypropylene-PP and Styrofoam-PS) as a way to create value-added products. Single, binary, and ternary mixtures were pyrolyzed at three different heating rates to understand the synergy, kinetics, and thermodynamics. The results showed positive synergy and reduced activation energies during co-pyrolysis, due to varying reaction mechanisms. The positive values of ∆H, ∆G, and negative ΔS indicate endothermic non-spontaneous reactions and disorder in the products instead of the reactants during pyrolysis. Future studies should explore upscaling this process for sustainable energy production. [ABSTRACT FROM AUTHOR]

One of the primary sources of waste in Qatar is animal waste, which includes poultry litter. Annually, Qatar produces approximately 0.83 x 106 t of poultry litter. Consequently, there is a need for a more sustainable waste treatment approach to handle it. Hence, this study's principal objective is to investigate the suitability of poultry litter as a feedstock for pyrolysis, with a specific emphasis on its potential for biochar generation. The physicochemical evaluations of poultry litter were performed. The potential for biochar formation from poultry litter was assessed using empirical equations at two different pyrolysis temperatures, namely 250 °C and 500 °C. Additionally, an economic analysis was conducted in order to ascertain the potential revenue generated by biochar derived from poultry litter. The composition of poultry litter, characterised by a moderate volatile content of 60 % and a fixed carbon content of 16 %, along with a moderate higher heating value (HHV) of 16 MJ/kg, indicates its potential suitability as a highly suitable feedstock material for biochar generation through pyrolysis. According to the findings of the technical analysis, biochar yields of up to 50 % and 31 % can potentially be achieved at 250 °C and 500 °C, respectively. Moreover, the findings of the study indicate that Qatar has the capacity to generate up to 0.35 x 106 t of biochar annually from its poultry litter. Additionally, the economic analysis suggests that the country can generate annual revenue of about 69 x 106 USD from the selling of biochar. [ABSTRACT FROM AUTHOR]

Cucumber waste from the greenhouse is a nutrient and high cellulose-rich biomass that could potentially be used to produce biochar as a valuable resource. Therefore, this study was conducted to produce biochar from cucumber green waste collected from a greenhouse in Qatar. The green waste was cut into small pieces (5 to 10 cm) for oven drying at a temperature of 105 °C for 24 h to remove moisture and was then pyrolysed in a muffle furnace at three temperatures of 300, 350, and 550 °C with a heating rate of 5 °C min-1 and residence time of 30 min. This study focuses on the nutrient analysis of biochar, including yield, pH and electrical conductivity (EC). Additionally, a small-scale pot test with cucumber plants applied 0% (control) and 2% biochar to a coco-peat substrate under a controlled microclimate with an enriched CO2 environment of 1000 ppm in a climate chamber. The pots were irrigated with a nutrient rich solution. Results demonstrate that the biochar produced with a higher pyrolysis temperature has a higher C content of 71%, pH of 10.59 and EC of 12.93 mS cm-1 with more aluminium, copper, and manganese. The lower pyrolysis temperature biochar possessed a higher N content of 3% and improved biochar yield of 48% with maximum potassium and iron concentrations. The application of 2% biochar was found to be linked to a maximum increase of 39% in plant height, 32% in leaf area, 3% in chlorophyll content, and a reduction of 71% in water loss by drainage as compared to the control. Moreover, both low and high temperature biochar applications display good plant growth by reducing water loss, while nutrient loss was more significant in the 2% biochar application at all three temperature conditions than the control. This study demonstrates that a lower fraction of biochar application could be beneficial for sustainable agricultural practices to reduce water drainage and nutrient supply. [ABSTRACT FROM AUTHOR]

Coffee is one of the world's most traded commodities grown in about 80 countries and widely consumed. Accordingly, a high quantity of spent coffee grounds (SCGs) produced from coffee beverage preparation is generated and disposed globally. The high availability and low cost of SCG allow its valorization to obtain a valuable product that could be used as an alternative adsorbent for water treatment applications. This study used dried SCG to produce biochar by pyrolyzing the biomass at three different temperatures: 300, 450, and 600 °C. Pyrolysis was conducted at a slow heating rate of 5 °C.min-1 for 30 min. SCG biomass and biochar were characterized for various properties that would describe the biomass changes during pyrolysis and the effectiveness of biochar for water treatment applications. The SCG biomass was acidic in nature with a pH of 5.54, whereas biochar was mildly alkaline with a pH of 7.5 to 10.6, increasing with pyrolysis temperature. The electrical conductivity of SCG biochar at 600 °C (2,278 µS.cm-1) was higher than that of biomass (550 µS.cm-1). This indicates SCG biochar could have promising ion-exchange capacity. SCG biochar produced at 450 °C has the most negative zeta potential of -57.33 mV, compared to the least negative measure of -30.73 mV for SCG biomass. A negative zeta potential has a strong affinity for positively charged cations and this was confirmed through cation exchange capacity (CEC) measurements. The highest CEC was 29 cmolc.kg-1 for 450 °C SCG biochar, a 58 % increase over that for the SCG biomass. SCG biochar contained 63 % to 88 % of C content for pyrolysis temperatures of 300 to 600 °C, respectively, whereas the SCG biomass had a C content of 43 %. With increasing temperature, the fixed carbon (FC) content of biochar increases and reached 69 % at 600 °C, while in biomass, the FC content was only 13 %. The large change in C content as SCG biomass is pyrolysed indicates large changes in structure and therefore tunability. SCG could be a promising carbonaceous adsorbent to remove organic and inorganic pollutants from polluted water. [ABSTRACT FROM AUTHOR]

The citrus industry is considered one of the main contributors to agricultural waste. Peels are commonly used in the food industry or as feedstock in biorefining. In this study, the potential of waste orange peel biochar for agricultural applications in sandy soil was investigated. This will not only increase the percentage of agricultural waste recycling, but also lead to more sustainable agriculture with environmental benefits such as carbon sequestration. Biochar was produced through slow pyrolysis in the temperature range 300–600°C and at two holding durations (10 min and 60 min). Both factors had a significant impact on the physicochemical characteristics of biochar in the heating region 300–450°C. However, varying the holding time for pyrolysis temperatures beyond 450°C had a diminishing effect on biochar properties compared with the impact of increasing pyrolysis temperature. The study also looked at certain properties that are specific to agricultural application not previously reported for orange peel. Very high cation exchange capacities of 70 cmol kg−1 were achieved at 300°C, whereas water holding capacity was not strongly influenced by pyrolysis conditions. Preliminary planting tests indicate potential for improving agricultural sustainability in sandy soils. The technoeconomic analysis of biochar showed that the pyrolysis process can be profitable with sufficient plant capacity. [ABSTRACT FROM AUTHOR]

This study investigates the production of high-performance activated carbon (AC) from coconut shells (CS) through acid and base activation processes, along with pre- and post-functionalization of the biochar, aiming to effectively remove dyes from aqueous solutions. The resulting AC exhibited outstanding adsorption capabilities, with the Langmuir model providing a good fit to the experimental data. Maximum adsorption capacities were observed at different temperatures: 805 mg g -1 at 298 K, 904 mg g -1 at 318 K, and 1000 mg g -1 at 338 K for NaOH-activated AC, and 252 mg g -1 at 298 K, 295 mg g -1 at 318 K, and 305 mg g -1 at 338 K for H 2 SO 4 -activated AC. The presence of active sites and functional groups on the surface of AC facilitated dye adsorption. The influence of various parameters, including adsorbent dosage, dye concentration, pH, and temperature, on the adsorption process were also examined, identifying the ideal conditions for dye removal. Thermodynamic analysis confirmed the endothermic nature of the adsorption process, with higher temperatures leading to increased adsorption capacities. Overall, the research highlights the potential of various activation routes for the production of high-value AC as a sustainable and effective adsorbent for dye removal from wastewater., Competing Interests: There are no conflicts to declare., (This journal is © The Royal Society of Chemistry.)