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161. 题目: Influence of Soil Organic Carbon, Water Holding Capacity, and Moisture Content on Heavy Metals in Rice Paddy Soils of Western Ghats of India Analysis of soil samples collected from 16 rice paddy fields located in the Western Ghats region was performed to quantify the concentration of Cu, Zn, Mn, Fe, Ni, Cr, Cd, and Pb using atomic absorption spectroscopy. High concentrations of these heavy metals were found in rice paddy fields regularly cultivated using agrochemicals. We compared this concentration with soils of rice paddy field that was not under cultivation. Cu, Zn, Mn, Fe, Cr, Ni, Pb, and Cd showed increases of 1.2, 1.3, 2.3, 2.2, 1.8, 2.8, 1.8, and 8.5 times, respectively, in the rice paddy fields cultivated with synthetic fertilizers such as NPK, urea, potash, diammonium phosphate, etc., and several categories of pesticides belonging to the class organophosphates, carbamates, and acetanilide herbicide. In contaminated sites, the heavy metals exhibited maximum correlation with soil moisture content (SMC) (Zn, Fe, Cr, Ni, and Cd), soil organic content (SOC) (Fe, Cr, Ni, and Cd), and water holding capacity (WHC) (Cu, Pb, and Cd) than those observed for the reference site. The principal component analysis (PCA) revealed a total of 77.944% variance of heavy metals contributed from WHC (40.259%), SMC (20.854%), and SOC (16.832%). This indicates the build-up of heavy metals in rice paddy soils under the strong influence of moisture content, water holding capacity, and organic carbon content of the soil. | |||||
162. 题目: Emerging trends in role and significance of biochar in gaseous biofuels production Transition from fossil fuels to non-conventional sources is needed to tackle the global energy crisis and environment related issues. Thus, the use of organic waste generated from various industrial sectors can help to produce gaseous fuels through anaerobic digestion, photo and dark fermentation, and other biochemical strategies. Current biogas and biohydrogen production practices are less efficient and require additional interventions for biofuel yield improvement. In this regard, adding biochar has shown to enhancing gaseous fuel yield by about 5%–400%, adsorbing inhibitors such as ammonia, pathogens, hydrogen sulfide, and activating gas-producing mesophilic and thermophilic microorganisms. This review provides recent updates and future perspectives associated with the effect of biochar on gaseous biofuel production and its underlying mechanism. Further, there is a need for establishing a circular bioeconomy approach for biochar production and utilization through a ‘waste-chain’, for which a techno-economic analysis and life-cycle assessment are required. | |||||
163. 题目: Molecular diversity and the fate of biochemical fractions of eucalypt tissues in soil The molecular diversity of the source substrate has been regarded as a significant controller of the proportion of plant material that is either mineralized or incorporated into soil organic matter (SOM). However, quantitative parameters to express substrate molecular diversity remain elusive. In this research, we fractionated leaves, twigs, bark, and root tissues of 13C-enriched eucalypt seedlings into hot water extractables (HWE), total solvent (acetone) extractables (TSE), a cellulosic fraction (CF), and the acid unhydrolyzable residue (AUR). We used 13C NMR spectroscopy to obtain a molecular diversity index (MDI) based on the relative abundance of carbohydrate, protein, lignin, lipid, and carbonyl functional groups within the biochemical fractions. Subsequently, we obtained artificial plant organs containing fixed proportions (25%) of their respective biochemical fractions to be incubated with soil material obtained from a Haplic Ferralsol for 200-days, under controlled temperature (25 ± 1 °C) and moisture adjusted to 70–80% of the soil water holding capacity. Our experimental design was a randomized complete block design, arranged according to a factorial scheme including 4 plant organs, 4 biochemical fractions, and 3 blocks as replicates. During the incubation, we assessed the evolution of CO2 from the microcosms after 1, 2, 3, 4, 7, 10, 13, 21, 28, 38, 45, 70, 80, 92, 112, 148, 178 and 200 days from the start of the incubation. After the incubation, soil subsamples were submitted to a density fractionation to separate the light fraction of SOM (LFOM) i.e., with density <1.8 g cm−3. The heavy fraction remaining was submitted to wet-sieving yielding the sand-sized SOM (SSOM) and the mineral-associated SOM (MAOM), with particle-size greater and smaller than 53 µm, respectively. We found that HWE and AUR exhibited comparatively higher MDIs than the TSE and CF. During the incubation, HWE and CF were the primary sources of 13C-CO2 from all plant organs and after 92 days, the respiration of the TSE of bark and roots increased. Otherwise, the AUR contributed the least for the release of 13C-CO2. There were no significant relationships between the MDI and the amount of 13C transferred into the LFOM or SSOM. Otherwise, the transfer of 13C into the MAOM increased as a linear-quadratic function of MDI, which in turn was negatively correlated with the total 13C-CO2 loss. Overall, the MDI exerted a stronger control on the 13C-labeled MAOM than on 13C-CO2 emissions, highlighting the need to improve our ability to distinguish and quantify direct plant inputs from those of microbial origin entering soil C pools. | |||||
164. 题目: Porous MgO-modified biochar adsorbents fabricated by the activation of Mg(NO3)2 for phosphate removal: Synergistic enhancement of porosity and active sites Engineering magnesium oxide (MgO)-modified biochar (MgO-biochar) with high porosity and active MgO load is a feasible pathway to enhance phosphate adsorption capacity. However, the blockage to pores caused by MgO particles is ubiquitous during the preparation, which seriously impaired the enhancement in adsorption performance. In this research, with the intent to enhance phosphate adsorption, an in-situ activation method based on Mg(NO3)2-activated pyrolysis technology was developed to fabricate MgO-biochar adsorbents with abundant fine pores and active sites simultaneously. The SEM image revealed that the tailor-made adsorbent has well-developed porous structure and abundant fluffy MgO active sites. Its maximum phosphate adsorption capacity was coming up to 1809 mg/g. The phosphate adsorption isotherms are in accordance well with the Langmuir model. The kinetic data, which agreed with the pseudo-second-order model, indicated that chemical interaction is existing between phosphate and MgO active sites. This work verified that the phosphate adsorption mechanism on MgO-biochar was composed of protonation, electrostatic attraction, monodentate complexation and bidentate complexation. In general, the facile in-situ activation method using Mg(NO3)2 pyrolysis illuminated biochar activation with fine pores and highly efficient adsorption sites for efficient wastewater treatment. | |||||
165. 题目: Dacryodes edulis leaf derived biochar for methylene blue biosorption Carbonized Dacryodes edulis leaf (CDEL) which was obtained at 250 oC, was used for the biosorption of methylene blue (MB) dye from aqueous solutions. The biosorbent was characterised using Boehm titration, pH of zero point charge (pHzpc), FTIR, SEM, XRD and ED-XRF. Mineral compositions of CDEL revealed good amounts of Fe, Ca and K which are of nutritional importance. The pH at zero point of charge (pHzpc) and specific surface area (SSA) of CDEL were found to be 7.5 and 0.983 m2/g respectively. Freundlich isotherm gave good fit to equilibrium biosorption data. Elovich kinetic model gave the best fit to kinetic data which is consistent with chemisorption. Scanning electron microscopy (SEM) and infrared spectroscopy (FTIR) revealed effective biosorption processes. Calculated thermodynamic parameters revealed spontaneous and exothermic biosorption of MB onto CDEL. Highest amount of MB was removed at pH 4 and the percentage removal was about 93%; hence, CDEL is a good biosorbent for MB from aqueous solutions. Generally, CDEL exhibited > 70% MB removal after three adsorption-desorption cycles, showing that it is re-usable and a promising biosorbent for the treatment of MB dye contaminated water. | |||||
166. 题目: Effects of pH and phosphate on cadmium adsorption onto goethite and a paddy soil: experiments and NOM-CD model PurposePhosphate is one of the most frequently used fertilizers to promote the crop growth, whereas the impact of phosphate on the adsorption behaviors of cadmium (Cd) is complex. The objectives of this study were to reveal effects of pH, phosphate, and organic molecules on Cd adsorption onto soil (hydr)oxides, and to validate the reliability of the NOM-CD model in depicting effect of pH and phosphate on Cd solubility in soil systems. Materials and methodsIn this study, effects of phosphate on Cd adsorption onto goethite and a paddy soil at pH 3–8 were studied by combing batch adsorption experiments with an advanced surface complexation model, i.e., natural organic matter-charge distribution (NOM-CD) model. In the NOM-CD model, the adsorption of ions onto oxides in the absence of NOM is calculated with the charge distribution and multi-site complexation (CD-MUSIC) model. Results and discussionAdsorption of Cd onto goethite is dramatically increased with the addition of phosphate at pH 5–8, whereas effects of citric acid on Cd adsorption are weaker. The synergic co-adsorption of Cd and phosphate onto goethite, according to CD-MUSIC model, is mainly due to electrostatic attractions of these two ions instead of formation ternary surface complex. The NOM-CD model can basically predict variations of Cd solubility in the soil system, and it is observed only a slight increase of Cd solubility with phosphate addition under acidic conditions. It might be caused by competitive adsorption between NOM and phosphate to soil (hydr)oxides, which leads to a higher amount of Cd binding by dissolved organic matters in soil solution, thus inhibiting Cd adsorption. ConclusionsElectrostatic attraction dominates the co-adsorption of Cd and phosphate onto goethite, whereas the interactions between Cd-P-oxide-NOM result in negligible effects of phosphate on Cd solubility in the soil. Overall, this study revealed that the NOM-CD model could make predictions on the distribution of Cd at soil–water interface, and the outcome of this study can provide a more in-depth understanding of the factors controlling Cd solubility and mobility in contaminated soil and sediment environment. Graphical | |||||
167. 题目: Ciprofloxacin degradation performances and mechanisms by the heterogeneous electro-Fenton with flocculated fermentation biochar Antibiotic fermentation residue flocculated by polymeric ferric sulfate (PFS) has been classified as a “hazardous waste” in China. In this study, it was recycled into antibiotic fermentation residue biochar (AFRB) by pyrolysis and used as a heterogeneous electro-Fenton (EF) catalyst for ciprofloxacin (CIP) degradation. The results show that PFS was reduced to Fe0 and FeS during pyrolysis, which was beneficial for the EF process. The AFRB with mesoporous structures exhibited soft magnetic features, which were convenient for separation. CIP was completely degraded within 10 min by the AFRB-EF process at an initial concentration of 20 mg/L. Increasing the working current and catalyst dosage within a certain range could improve the degradation rate. ·OH and O2·- were the dominant reactive oxygen species that played critical roles for CIP degradation. The antibacterial groups of CIP have been destroyed by the heterogeneous electro-Fenton process and its toxicity was negligible. The AFRB showed satisfactory performance, even though it was recycled five times. This study provide new insights into the resourceful treatment of antibiotic fermentation residues. | |||||
168. 题目: Substantial uncertainties in global soil organic carbon simulated by multiple terrestrial carbon cycle models | |||||
169. 题目: Elevated methylmercury production in mercury-contaminated paddy soil resulted from the favorable dissolved organic matter variation created by algal decomposition Algae-derived organic matter (AOM) may considerably regulate methylmercury (MeHg) production and accumulation in the paddy fields by changing the soil-dissolved OM (SDOM) properties. In this study, a 25-day microcosm experiment was performed to compare the responding mechanisms of MeHg production in the Hg-contaminated paddy soil-water system to the input of algae-, rice-, and rape-derived OMs. Results showed that algal decomposition could release much more cysteine and sulfate than crop straws. Compared with crop straw-derived OMs, AOM input greatly increased the dissolved organic carbon concentrations in soil but resulted in a greater decrease in tryptophan-like fractions while accelerated the formation of high-molecular-weight fractions in soil DOM. Moreover, AOM input significantly increased MeHg concentrations in the pore water by 19.43%–3427.66% and 52.81%–5846.57% compared to rape- and rice-derived OMs, respectively (P < 0.05). And, a similar MeHg changing pattern was also observed in the overlying water (10–25 d) and the soil solid-phase particles (15–25 d) (P < 0.05). Correlation analysis revealed that MeHg concentrations in the AOM-added soil-water system had significantly negative and positive relationships with the tryptophan-like C4 fraction and molecular weight (E2/E3 ratio) of soil DOM, respectively (P < 0.01). These findings suggest that AOM has a higher capacity than crop straw-derived OMs to promote MeHg production and accumulation in the Hg-contaminated paddy soils by creating a favorable soil DOM variation and providing more microbial electron donors and receptors. | |||||
170. 题目: Hydrological Controls on Dissolved Organic Matter Composition throughout the Aquatic Continuum of the Watershed of Selin Co, the Largest Lake on the Tibetan Plateau | |||||
171. 题目: Adsorption of Pb(II) from wastewater using a red mud modified rice-straw biochar: Influencing factors and reusability Efficient environmental remediation of toxic chemicals using effective sorbents has received considerable attention recently. For the present study, the synthesis of a red mud/biochar (RM/BC) composite was performed from rice straw with the aim of achieving Pb(II) removal from wastewater. Characterization was performed by using X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), energy dispersive spectroscopy (EDS), Zeta potential analysis, elemental mapping, scanning electron microscopy (SEM), and transmission electron microscopy (TEM). Results showed that RM/BC had higher specific surface area (SBET = 75.37 m2 g−1) than raw biochar (SBET = 35.38 m2 g−1). The Pb(II) removal capacity (qe) of RM/BC was 426.84 mg g−1 at pH 5.0, and the adsorption data well fitted pseudo second order kinetics (R2 = 0.93 and R2 = 0.98), as well as the Langmuir isotherm model (R2 = 0.97 and R2 = 0.98) for both BC and RM/BC. Pb(II) removal was slightly hindered with the increasing strength of co-existing cations (Na+, Cu2+, Fe3+, Ni2+, Cd2+). The increase in temperatures (298 K, 308 K, 318 K) favored Pb(II) removal by RM/BC. Thermodynamic study indicated that Pb(II) adsorption onto BC and RM/BC was spontaneous and primarily governed by chemisorption and surface complexation. A regeneration study revealed the high reusability (>90%) and acceptable stability of RM/BC even after five successive cycles. These findings indicate that RM/BC evidenced special combined characteristics of red mud and biochar, hence its use for Pb removal from wastewater offers a green and environmentally sustainable approach fitting the “waste treating waste” concept. | |||||
172. 题目: Microbial necromass carbon in estuarine tidal wetlands of China: Influencing factors and environmental implication Microbial necromass is an important component of the stable soil organic carbon (SOC) pool. However, little is known about the spatial and seasonal patterns of soil microbial necromass and their influencing environmental factors in estuarine tidal wetlands. In the present study, amino sugars (ASs) as biomarkers of microbial necromass were investigated along the estuarine tidal wetlands of China. Microbial necromass carbon (C) contents were in the range of 1.2–6.7 mg g−1 (3.6 ± 2.2 mg g−1, n = 41) and 0.5–4.4 mg g−1 (2.3 ± 1.5 mg g−1, n = 41), which accounted for 17.3–66.5 % (44.8 % ± 16.8 %) and 8.9–45.0 % (31.0 % ± 13.7 %) of the SOC pool in the dry (March to April) and wet (August to September) seasons, respectively. At all sampling sites, fungal necromass C predominated over bacterial necromass C as a component of microbial necromass C. Compared to bacterial necromass C, fungal necromass C showed a stronger connection with ferrous oxides (Fe2+) and total Fe concentrations. Both fungal and bacterial necromass C contents revealed large spatial heterogeneity and declined in the estuarine tidal wetlands with the increase in latitude. Statistical analyses showed that the increases in salinity and pH in the estuarine tidal wetlands suppressed the accumulation of soil microbial necromass C. | |||||
173. 题目: Fluorescence of solvent-extractable organics in sub-micrometer forest aerosols in Hokkaido, Japan Excitation–emission matrix (EEM) fluorescence spectroscopy is an analytical method for obtaining the properties, components, and sources of chromophores of atmospheric organic aerosols (OA). Most studies have been limited to water-soluble OA; the chemical structures of OA associated with chromophores and the sources of chromophores are still not well understood. In this study, the fluorescence properties of solvent-extractable organic components, fractionated based on their polarity in sub-micrometer forest aerosols in Hokkaido, Japan, were characterized on the basis of their EEMs in combination with chemical structural characterization from offline aerosol mass spectrometry. The fluorescence volume normalized by the mass concentration (NFV) and the fluorescence volume (FV) corresponding to the atmospheric abundance for water-insoluble organic matter (WISOM) were higher than those of other OA fractions and highest in the winter. Correlation analyses between the NFVs and the relative intensities of ion groups from the mass spectra from a high-resolution aerosol mass spectrometer suggest that organic compounds containing O and N contributed to the fluorescence of the OA fractions. Although the fluorescence indices used to characterize aquatic dissolved organic matter exhibited comparable values for water-soluble organic matter (WSOM) in this study and in previous studies, they are not applicable in explaining the types or sources of other OA fractions. A parallel factor (PARAFAC) analysis for EEM profiles identified five components. Four components had fluorescence characteristics similar to those associated with humic-like substances (HULIS), and one had fluorescence characteristics associated with protein-like compounds (PLOM). The chromophores commonly associated with HULIS with oxygenated structures contributed significantly to respective OA fractions; this implies that for fluorescence measurements, such as the detection of primary biological aerosol particles (PBAP), contributions from oxygenated organics should be considered in the forest region. | |||||
174. 题目: Electron exchange capacity of pyrogenic dissolved organic matter (pyDOM): complementarity of square-wave voltammetry in DMSO and mediated chronoamperometry in water | |||||
175. 题目: Exploring impacts of water-extractable organic matter on pre-ozonation followed by nanofiltration process: Insights from pH variations on DBPs formation This study investigated the influence of pH (4–10) on the treatment of water-extractable organic matter (WEOM), and the associated disinfection by-products (DBPs) formation potential (FP), during the pre-ozonation/nanofiltration treatment process. At alkaline pH (9–10), a rapid decline in water flux (> 50 %) and higher membrane rejection was observed, as a consequence of the increased electrostatic repulsion forces between the membrane surface and organic species. Parallel factor analysis (PARAFAC) modeling and size exclusion chromatography (SEC) provides detailed insights into the WEOM compositional behavior at different pH levels. Ozonation at higher pH significantly reduced the apparent molecular weight (MW) of WEOM in the 4000–7000 Da range by transforming the large MW (humic-like) substances into small hydrophilic fractions. Fluorescence components C1 (humic-like) and C2 (fulvic-like) exhibited a predominant increase/decrease in concentration for all pH conditions during pre-ozonation and nanofiltration treatment process, however, the C3 (protein-like) component was found highly associated with the reversible and irreversible membrane foulants. The ratio C1/C2 provided a strong correlation with the formation of total trihalomethanes (THMs) (R2 = 0.9277) and total haloacetic acids (HAAs) (R2 = 0.5796). The formation potential of THMs increased, and HAAs decreased, with the increase of feed water pH. Ozonation markedly reduced the formation of THMs by up to 40 % at higher pH levels, but increased the formation of brominated-HAAs by shifting the formation potential of DBPs towards brominated precursors. | |||||
176. 题目: CCN activation of ultrafine biogenic-WSOC under restricted anthropogenic emissions: A study over eastern Himalaya in India The present study was conducted to investigate the potential of water soluble organic carbon (WSOC) in CCN activation under restricted anthropogenic emissions over a high altitude station, Darjeeling (27.01° N and 88.15° E,~2200 amsl and covered with huge coniferous forests) in the eastern parts of Himalaya in India. We measured CN, CCN, and ultrafine WSOC (WSOC0.1) during April–May 2020 (COVID-19 lockdown) and compared with the normal period (April–May 2019) to investigate the relative dominance of biogenic over anthropogenic emissions to the aerosol-CCN activation. Though an expected significant decline (53%) in CN concentration was observed, CCN exhibited ~17% increase during the lockdown period.The activation ratio (AR: CCN/CN) jumped from 0.30 during normal to 0.72 during the lockdown period. The aerosol solubility was also found to be increased during the lockdown period (~27% decrease in the k- parameter (k)). Lockdown-WSOC was higher (1.62 μg m−3) than the normal-WSOC (1.13 μg m−3) and exhibited better regression with CCN in absence of anthropogenic emissions (Lockdown: R2 = 0.83, p < 0.05; normal: R2 = 0.40, p < 0.05). Here we hypothesize that under restricted fossil fuel emissions during lockdown (57% decline in NOx), surface ozone was increased by 31%, that in turn favored the photochemical oxidation of biogenic VOCs emitted only from coniferous forest cover to produce huge amount of SOC. The ultrafine “biogenic-only” WSOC (under restricted anthropogenic WSOC during lockdown) participated in CCN activation actively and with higher proficiency compared to the normal period. The study bears immense importance of the role of biogenic emissions in cloud droplet formation over this part of the Himalaya under restricted anthropogenic emissions. The present hypothesis could open a new route of aerosol formation and their CCN activation under high deficiency of anthropogenic emissions. | |||||
177. 题目: Kinetic Study of the Influence of Humic Acids on the Oxidation of As(III) by Acid Birnessite | |||||
178. 题目: Effects of physical aging processes on the bioavailability of heavy metals in contaminated site soil amended with chicken manure and wheat straw biochars The physicochemical properties of biochars undergo slow changes in soils due to the natural aging processes, which influences their interaction with heavy metals. The effects of aging on immobilization of co-existing heavy metals in contaminated soils amended with fecal and plant biochars possessing contrasting properties remain unclear. This study investigated the effects of wet–dry and freeze–thaw aging on the bioavailability (extractable by 0.01 M CaCl2) and chemical fractionation of Cd and Pb in a contaminated site soil amended with 2.5% (w/w) chicken manure (CM) biochar and wheat straw (WS) biochar. Compared to that in the unamended soil, the contents of bioavailable Cd and Pb in CM biochar-amended soil decreased by 18.0% and 30.8%, respectively, after 60 rounds of wet–dry cycle, and by 16.9% and 52.5%, respectively, after 60 rounds of freeze–thaw cycle. CM biochar, which contained significant levels of phosphates and carbonates, effectively reduced the bioavailability of Cd and Pb and transformed them from the labile chemical fractions to the more stable ones in the soil during the accelerated aging process, mainly through precipitation and complexation. In contrast, WS biochar failed to immobilize Cd in the co-contaminated soil in both aging regimes, and was only effective at immobilizing Pb under freeze–thaw aging. The changes in the immobilization of co-existing Cd and Pb in the contaminated soil resulted from aging-induced increase in oxygenated functional groups on biochar surface, destruction of the biochar's porous structure, and release of dissolved organic carbon from the aged biochar and soil. These findings could help guide the selection of suitable biochars for simultaneous immobilization of multiple heavy metals in co-contaminated soil under changing environmental conditions (e.g., rainfall, and freezing and thawing of soils). | |||||
179. 题目: Influence of grain size, organic carbon and organic matter residue content on the sorption of per- and polyfluoroalkyl substances in aqueous film forming foam contaminated soils - Implications for remediation using soil washing A soil that was historically contaminated with Aqueous Film Forming Foam (AFFF) was dry sieved into size fractions representative of those produced during soil washing. Batch sorption tests were then conducted to investigate the effect of soil parameters on in situ per- and polyfluoroalkyl substances (PFAS) sorption of these different size fractions: <0.063 mm, 0.063 to 0.5 mm, 0.5 to 2 mm, 2 to 4 mm, 4 to 8 mm, and soil organic matter residue (SOMR). PFOS (513 ng/g), 6:2 FTS (132 ng/g) and PFHxS (58 ng/g) were the most dominant PFAS in the AFFF contaminated soil. Non-spiked, in situ Kd values for 19 PFAS ranged from 0.2 to 138 L/Kg (log Kd − 0.8 to 2.14) for the bulk soil and were dependant on the head group and perfluorinated chain length (spanning C4 to C13). The Kd values increased with decreasing grain size and increasing organic carbon content (OC), the two parameters which were correlated to each other. For example, the PFOS Kd value for silt and clay (<0.063 mm, 17.1 L/Kg, log Kd 1.23) were approximately 30 times higher compared to the gravel fraction (4–8 mm, 0.6 L/Kg, log Kd − 0.25). The highest PFOS Kd value (116.6 L/Kg, log Kd 2.07) was found for the SOMR fraction, which had the highest OC content. Koc values for PFOS ranged from 6.9 L/Kg (log Koc 0.84) for the gravel fraction to 1906 L/Kg (log Koc 3.28) for the silt and clay, indicating that mineral composition at the different size fractions also influenced sorption. The results here emphasize the need to separate coarse-grained fractions and fine-grained fractions, and in particular the SOMR, to optimize the soil washing process. Higher Kd values for the smaller size fractions indicate that coarser soils are better suited for soil washing. | |||||
180. 题目: Meat and bone meal biochar can effectively reduce chemical fertilizer requirements for crop production and impart competitive advantages to soil Safe and effective circulation of nutrient-rich meat and bone meal (MBM) could become a carbon-based alternative to limited chemical fertilizers (CFs). Therefore, MBM biochars (MBMCs) were produced at 500, 800, and 1000 °C to evaluate their effects on plant growth, nutrient uptake, and soil characteristics. The results revealed that MBMC produced at 500 °C (MBMC500) contained the maximum amount of C, N, and phytoavailable P. All additional MBMC doses with recommended CF increased sorghum shoot yield (6.7–16%) and significantly improved P uptake. Additional experiments were conducted with decreasing doses of CF (100–0%) with or without MBMC500 (7 t/ha) to quantify its actual fertilizing value. MBMC500 showed the capability to reduce CF requirement by 20% without compromising the optimum yield (by 100% CF) while increasing pH, CEC, total-N, available-P, Mg, and microbial population of post-harvest soil. Although a δ15N analysis confirmed MBMC500 as a source of plant N, a reduction in N uptake by MBMC500 + 80% CF treatment compared to 100% CF might have limited further sorghum growth. Thus, future studies should concentrate on producing MBMC with better N utilization capability and achieving maximum CF reduction without negative environmental impacts. | |||||