Cow Manure Biochar Research Articles

Enhanced removal of tetracycline by vitamin C-modified cow manure biochar in water

Vitamin C (VC), due to its chemical properties, can provide more oxygen-containing functional groups such as hydroxyl groups for biochar (BC), which promotes the adsorption of tetracycline on biochar. Therefore, in this study, cow dung biochar (CDBC) was modified with VC and VC-modified CDBC (CDBC-VC) was synthesized. The modified biochar was characterized and related factors, adsorption kinetics, isotherms and adsorption mechanisms were investigated. Adsorption kinetics indicate a fast rate of adsorption. The adsorption isotherms showed that the maximum adsorption capacity was 31.72 mg/g (CDBC) and 50.90 mg/g (CDBC-VC), respectively, and the adsorption process was inhomogeneous with multiple molecular layers and the adsorbent has a higher affinity. Mechanistic studies showed that hydrogen bonding interactions, π-π electron donor-acceptor interactions, hydrophobic interactions, and electrostatic interactions were the key to the adsorption process. The analysis of adsorbent regeneration showed that CDBC-VC had good adsorption performance. CDBC and CDBC-VC showed the best performance in simulated industrial wastewater with removal rates of 78.81% and 93.69%. The adsorption mechanism was comprehensively analyzed using six machine learning models. The extreme gradient boosting model gave the best fit. Analysis of the weights of the input variables for predicting adsorption efficiency showed that the ratio of initial TC concentration to BC dosage (29.8%), specific surface area (23%), isoelectric point (8.8%), and ash content (7.7%) had a significant effect on the predicted results.

Cow manure biochar for activation of peroxymonosulfate to degrade 17β-estradiol: Performance and mechanism

Estrogens are widely detected in the environment and can strongly disrupt the endocrine systems of humans in extremely minute concentrations. Therefore, it is imperative to address possible 17β-estradiol (17β-E2) pollution and explore resourceful utilization methods from cow manure, which contains estrogen. In this study, cow manure biochar (CBC) was successfully prepared and used for the activation of peroxymonosulfate (PMS), attaining a 17β-E2 degradation rate exceeding 90 % within a mere 10 min. Optimal degradation performance was achieved at 2 mg/L 17β-E2 concentration, 2 mM PMS concentration, and 0.2 g/L CBC concentration. Furthermore, the influence of biochar-activated PMS on estrogen degradation was thoroughly explored under various environmental factors. The key reactive oxygen species were identified as O2– and 1O2 by conducting quenching experiments and delayed experiments. This study elucidated the occurrence of direct electron conduction and the generation of reactive oxygen species to degrade 17β-E2. Furthermore, the phenol group on the benzene ring and the hydroxyl group on the cyclopentane in 17β-E2 as the susceptible reaction sites during the degradation process were predicted using density functional theory (DFT). This study presents promising opportunities for the resourceful utilization of cattle manure and the mitigation of environmental pollution by endocrine disruptors.

Activation of Peroxymonosulfate by P-Doped Cow Manure Biochar for Enhancing Degradation of 17β-Estradiol

Activation of Peroxymonosulfate by P-Doped Cow Manure Biochar for Enhancing Degradation of 17β-Estradiol

Systematic Characterization of Cow Manure Biochar and Its Effect on Salicornia herbacea L. Growth

This study investigated the potential of biochar as a sustainable material for waste utilization and carbon sequestration in soil. Biochar was prepared from cow manure (CM) and applied to the soil. Biochar was processed by subjecting CM to various temperature ranges (400 [CMB400], 550 [CMB550], and 700 °C [CMB700]) under nitrogen gas (allowed to flow to restrict oxygen), with residence time set to 3 h. The characteristics of the biochar produced at each temperature were analyzed. The experiment was conducted for approximately 15 weeks with the laboratory temperature maintained between 24 and 26 °C. The growth rate of plants was obtained by measuring their length weekly, starting 4 weeks after crop establishment. CMB550 exhibited the highest specific surface area (117.57 m2 g−1) and well-distributed pore size; therefore, it was mixed with the soil at a specific ratio and put in pots for the planting of Salicornia herbacea L. (glasswort) in the laboratory. The results demonstrated that adding biochar to soil increased plant growth and that the biochar could store organic carbon. In addition, an investigation of heavy metals demonstrated that samples with biochar had lower heavy metal concentrations in glasswort than those without because of the potential of biochar to adsorb heavy metals. By interacting with heavy metal ions in soil solution, the reactive sites and functional groups on the surface of biochar immobilize them and lessen their potentially detrimental effects on plant growth. Overall, biochar has the potential to be a valuable resource for waste management and environmental improvement.

Mathematical modeling of biochar's role in elevating co-composted poultry carcass temperatures

Previous studies reported that incorporating biochar into composting systems leads to an increase in compost temperatures. Although potential reasons, such as improved microbial activity or increased insulation, were suggested, no study has quantitatively determined the contribution of either aspect. In this study, we developed a heat transfer model for a biochar-amended co-composting system based on the measurements from our two previously published studies conducted to co-compost poultry carcasses with woodchips and wood-based (WBC), distillers grain (DGBC), and cow manure (CMB) biochar. The two composting studies were conducted over three heating cycles, with two turnings separating each cycle. The simulation for the second heating cycle, during which the compost materials began to degrade and were well-mixed, showed an average R2 value of 0.86 and was selected for further analyses. Results from the model suggested that incorporating biochar into the composting mixture increases thermal conductive losses. For example, at a biochar addition rate of 13 % (v/v), the predicted longitudinal conductive resistance of the compost pile was reduced by 24.9 %. However, the total heat unit still increased by 11.2 ± 3.17 % due to the enhancement of microbial activity as supported by elevated oxygen consumption (38.1–61.1 %). When biochar was applied in layers on the surface of the composting bins, its impact on microbial activity was minimal, primarily functioning as an insulator. Under these conditions, the total heat unit was 8.7 % higher than the control. These findings suggest that biochar's primary effect on temperature development was through promoting microbial activity.

Thiamethoxam adsorption by ZnCl2 modified cow manure biochar: Mechanism and quantitative prediction

The overuse of thiamethoxam (THM) has threatened the survival of living organisms and it is necessary to find an environmentally friendly material to remove THM frequently detected in water. Biochar prepared from cow manure modified with ZnCl2 (Zn-CBC) was used to remove THM. Compared to the unmodified cow manure biochar (CBC), the removal ratio of THM by Zn-CBC was enhanced 35 times. In the mechanistic analysis, SEM and BET showed that Zn-CBC had a good pore structure and its specific surface area (166.502 m2 g−1) increased to 17 times that of CBC, indicating that Zn-CBC had good pore adsorption properties. The adsorption kinetic and isotherm implied that the main mechanism was chemisorption including π-π interaction and H-bonding. Furthermore, the stable graphitized structure of Zn-CBC allowed for efficient adsorption and reusability. In addition, this study constructed an intelligent prediction model using batch experiment data, and the high R2 (0.978) and low RMSE (0.057) implied that the model could accurately and quantitatively predict the adsorption efficiency. This paper provides a novel perspective to simultaneously remove the neonicotinoid insecticides and realize the resource utilization of cow manure.

Cadmium Elimination via Magnetic Biochar Derived from Cow Manure: Parameter Optimization and Mechanism Insights

Designing an efficient and recyclable adsorbent for cadmium pollution control is an urgent necessity. In this paper, cow manure, an abundant agricultural/animal husbandry byproduct, was employed as the raw material for the synthesis of magnetic cow manure biochar. The optimal preparation conditions were found using the response surface methodology model: 160 °C for the hydrothermal temperature, 600 °C for the pyrolysis temperature, and Fe-loading with 10 wt%. The optimal reaction conditions were also identified via the response surface methodology model: a dosage of 1 g·L−1, a pH of 7, and an initial concentration of 100 mg·L−1. The pseudo-second-order model and the Langmuir model were used to fit the Cd(II) adsorption, and the adsorption capacity was 612.43 mg·g−1. The adsorption was dominated by chemisorption with the mechanisms of ion-exchange, electrostatic attraction, pore-filling, co-precipitation, and the formation of complexations. Compared to the response surface methodology model, the back-propagation artificial neural network model fit the Cd(II) adsorption better as the error values were less. All these results demonstrate the potential application of CM for Cd(II) removal and its optimization through machine-learning processes.

Activation of peroxymonosulfate by cow manure biochar@1T-MoS2 for enhancing degradation of dimethyl phthalate: Performance and mechanism

Introduction: Dimethyl phthalate (DMP) which has been widely detected in water is neurotoxic to humans and should be effectively eliminated. Persulfate-based advanced oxidation processes are considered to be reliable methods aiming at emerging contaminants degradation, while an efficient catalyst is urgently needed for the activation of the reaction. As a typical 2D material, 1T-MoS2 is expected to be applied to the activation of persulfate owing to its abundant active sites and excellent electrical conductivity. In practical applications, 1T-MoS2 has the phenomenon of reunion which affects the exposure of its catalytic sites.Methods: Therefore, in this study, we used waste cow manure as a raw material to prepare biochar and achieved high exposure of 1T-MoS2 activation sites by loading 1T-MoS2 onto the surface of cow manure biochar through hydrothermal synthesis. The prepared composite catalytic material CMB@1T-MoS2 was used to activate PMS for the degradation of DMP.Results: It was found that CMB@1T-MoS2 has better effect than CMB or 1T-MoS2 alone for the degradation of DMP, reaching 77.65% at pH = 3. Under alkaline conditions, the degradation rate of DMP was reduced due to the inhibition of the catalytic process. Among the different coexisting anions, HCO-3 interfered and inhibited the degradation process the most, leading to the lowest degradation rate of DMP with 42.45%.Discussion: The quenching experiments and EPR analysis showed that SO-4• and •OH were the main ROS in the CMB@1T-MoS2/PMS process. This study promotes the resourceful use of cow manure and is expected to provide a novel persulfate-based advanced oxidation process catalyzed by CMB@1T-MoS2 for the elimination of DMP in an aqueous environment.

Co-composting poultry carcasses with wood-based, distillers’ grain and cow manure biochar to increase core compost temperatures and reduce leachate's COD

Composting has been recognized as a viable method to dispose of animal carcasses. Common concerns related to the composting process include low core temperatures, leachate generation, and ammonia emissions. This study tested co-composting full-size poultry carcasses with commercially available biochars at an aeration rate of 0.8 L∙min−1. Biochars prepared by gasifying wood pallets, distillers’ grains, and cow manure were added to the composting bins at the 13% rate (by volume). Results showed that poultry carcasses with wood-based and cow manure biochar increased temperatures by 2.0 to 3.3 °C. All biochar-amended bins met the time–temperature criteria to eliminate avian influenza (H7N1) viruses, which could not be achieved without biochar addition. Wood-based biochar amendment lowered the cumulative chemical oxygen demand of the leachate samples by 87% (P = 0.02). At the rate studied, the biochar amendment did not significantly affect ammonia emissions (P = 0.56). BET surface area of wood-based biochar was 1.4 and 28 times greater than that of cow manure and distillers’ grain biochar, respectively. Compared to no biochar addition, wood-based biochar resulted in significantly higher compost temperatures (P = 0.02), lower leachate COD values (P = 0.02), and a higher total nitrogen content (P = 0.01) while it did not cause an increase in sodium content (P = 0.94) of the finished compost. In conclusion, amending the poultry carcass composting process with wood-based biochar (13% by volume) is recommended, especially to eliminate disease-causing agents.

Changes in salinity, aggregates and physicomechanical quality induced by biochar application to coastal soil

ABSTRACT Coastal clayey soil has a great potential for food production and safety while poor physico-mechanical properties have impeded its sustainable utilization. A field experiment was conducted to assess the influence of biochar on physicomechanical properties of coastal clayey soil. The biochars were applied to the coastal soil with the rate of 0, 1%, and 3% (w/w), respectively. Compared with control treatment, the application of three biochars (at the rate of 3%) had significantly improved soil fertility, i.e. organic carbon, total nitrogen, available nitrogen and available phosphate, respectively. Biochar treatments significantly increased soil porosity, and aggregates stability, while reduced the soil salinity compared to the control treatment. Meanwhile, biochar application significantly increased the plastic index of coastal clayey soil while decreased soil tensile strength and shrink swell properties compared to the control. Biochar clearly altered soil pore characteristics, consequently rebuilding the new ions leaching channels. Overall, the cow manure biochar (650 °C) at the rate of 3% treatment showed maximum efficiency on soil salinity, fertility, physicomechanical properties, and crop yield. The biochar amendment improved coastal soil by ameliorating soil pore space and structure, improving soil tillage operation and rice yield, decreasing salt stress, and reducing mechanical strength.

Co-ZIF reinforced cow manure biochar (CMB) as an effective peroxymonosulfate activator for degradation of carbamazepine

Excessive emissions of cow manure have put tremendous pressure on environment, the difficulties in disposal methods have presented serious challenges to the livestock industry. Herein, cow manure biochar (CMB) loaded metal-organic framework (ZIF-67) precursors derived Co nanoparticles carbon (Co@NPC) at different temperatures to form biochar-based composites, i.e., Co@NPC-CMB-x. The novel non-homogeneous catalysts activated peroxymonosulfate (PMS) to degrade the carbamazepine (CBZ). The results demonstrated that the pyrolysis temperature directly influenced the intrinsic properties and catalytic ability of products, with the higher pyrolysis temperature favoring the conversion of more graphitic C and graphitic N as active sites. In particular, Co@NPC-CMB-800 showed excellent activation of PMS, degrading 100% CBZ within 30 min. The high specific surface area, highly graphitic structure and the uniform dispersion of cobalt species were the key reasons for the excellent catalytic ability. X-ray photoelectron spectroscopy (XPS) illustrated that the interaction between biochar and transition metal was responsible to generate more reactive oxygen species. Furthermore, electron paramagnetic resonance (EPR) confirmed that non-radical singlet oxygen is the dominant pathway for CBZ degradation by the catalyst. This study provides a new strategy for cow manure application in functional catalysts and offers new prospects for designing efficient biochar-based catalysts for environmental remediation.

Characterization and Utilization of Cow Manure Biochar as Soil Amendment for the Management of Northern Corn Leaf Blight

Characterization and Utilization of Cow Manure Biochar as Soil Amendment for the Management of Northern Corn Leaf Blight

Biochemical phosphorus transformations in a calcareous soil as affected by earthworm, cow manure and its biochar additions

Application of raw or char material may modify the influence of earthworm activity on soil phosphorus (P) transformation. The purpose of this study was to investigate the effect of cow manure or cow manure biochar addition and its interaction with earthworm on organic (Po) and inorganic (Pi) P fractions, alkaline phosphatase activity and P-solubilizing bacteria (PSB) in a calcareous soil of semi-arid region. For this purpose, the soil was amended with cow manure and its biochar in 4 levels (0, 1, 2 and 5%) in the absence and presence of earthworm (Eisenia fetida). The treatments were then incubated for 90 days. The monitoring of earthworms was also carried out after 30 and 90 days incubation. The results showed an increase in weight of earthworms in control and cow manure amended soils at both incubation times. However, application of cow manure biochar resulted in mortality and an initial weight loss of earthworms (36–85%) at 30 days incubation. This negative effect decreased over time, so that the earthworms recovered in 1% biochar amended soil. Amendment additions increased proportion of NaHCO3-Pi and NaOH-Pi but decreased proportion of HCl-Pi, residual-P, NaOH-Po and HCl-Po, making P more available in soil. The impact of cow manure biochar on the NaHCO3-Pi and NaOH-Pi fractions was stronger than that of cow manure. Earthworm decreased the proportion of Pi fractions but increased the proportion of Po fractions, indicating a transformation of P from Pi to Po forms. Alkaline phosphatase activity and PSB number were also increased as affected by earthworm and amendment (especially cow manure) additions. No significant interaction between earthworm and amendment additions was observed (p < 0.05), indicating that the influence of earthworm on P transformations was not dependent on amendment additions. Overall, we concluded that biochar can be useful for the amendment of semi-arid calcareous soil in terms of P availability, but the negative response of earthworms to biochar and its effect on other soil processes should be taken into consideration.

Carbon and Nitrogen Dynamics, and CO2 Efflux in the Calcareous Sandy Loam Soil Treated with Chemically Modified Organic Amendments.

In Saudi Arabia, more than 335,000 tons of cow manure is produced every year from dairy farming. However, the produced cow manure is usually added to the agricultural soils as raw or composted manure; significant nitrogen losses occur during the storage, handling, and application of the raw manure. The recovery of ammonia from cow manure through thermochemical treatments is a promising technique to obtain concentrated nitrogen fertilizer and reducing nitrogen losses from raw manure. However, the byproduct effluents from the recovery process are characterized by different chemical properties from the original raw manure; thus, its impact as soil amendments on the soil carbon and nitrogen dynamics is unknown. Therefore, a 90-day incubation experiment was conducted to study the impact of these effluents on CO2 efflux, organic C, microbial biomass C, available NH4+, and NO3− when added to agricultural soil. In addition to the two types of effluents (produced at pH 9 and pH 12), raw cow manure (CM), composted cow manure (CMC), cow manure biochar (CMB), and control were used for comparison. The application of CM resulted in a considerable increase in soil available nitrogen and CO2 efflux, compared to other treatments. Cow manure biochar showed the lowest CO2 efflux. Cumulative CO2 effluxes of cow manure effluents were lower than CM; this is possibly due to the relatively high C:N ratio of manure effluent. The content of P, Fe, Cu, Zn, and Mn decreased as incubation time increased. Soil microbial biomass C for soil treated with cow manure effluents (pH 12 and 7) was significantly higher than the rest of the soil amendments and control.

Effects of various pyrolysis conditions and feedstock compositions on the physicochemical characteristics of cow manure-derived biochar

Pyrolysis, as a thermal decomposition process and environment-friendly technology, can be used for the safe treatment of cow manure. In this paper, the effects of pyrolysis conditions on the properties of biochar derived from different types of cow manure (i.e., fresh cow manure, flushing cow manure, and anaerobic fermentation residues) were studied using slow pyrolysis methods. The properties of feedstocks, thermal decomposition, and biochar were analyzed using elemental analysis, coarse fiber determination, TG–FTIR, ICP–MS, FTIR, XRD, and SEM–EDS. Results showed that the cow manure-derived feedstocks were rich in total organic C (>37%) and had no heavy metal risk. According to the results of TG–FTIR, pyrolysis produced more residual solids, CO, CH4, and NH3 and less CO2 than combustion. The factors affecting alkalinity, calorific value, adsorption capacity, and surface functional group properties of cow manure-derived biochar in order of effectiveness were as follows: pyrolysis temperature > manure characteristics > heating rate > residence time. In general, increasing the temperature from 300 °C to 700 °C increased the pH (8.05–11.74) and C content (45.75%–49.64%) of fresh cow manure biochar and decreased the yield (62.17%–39.82%), nutrient content (N + P + K = 6.90%–5.64%), iodine adsorption capacity (269–96 mg g−1), aromaticity, and polarity. The biochar derived from flushing cow manure and anaerobic fermentation residues had similar C content (>48%), alkalinity (pH > 10), calorific value (>20000 J g−1), stability, and polarity. Fresh cow manure biochar had higher nutrient recovery (6.6%) and iodine adsorption capacity (215 mg g−1) than others. Compared with flushing cow manure and anaerobic fermentation residues, the pyrolysis of fresh cow manure reduced nutrient loss and treatment energy consumption. This study provides a good basis for the optimization of the pyrolysis process of three typical kinds of cow manures in dairy farms.

Distribution of heavy metal resistant bacterial community succession in cow manure biochar amended sheep manure compost

The aim of this investigation was to study the effects of cow manure biochar (CMB) on the distribution of heavy metal resistant bacterial (HMRB) community succession during sheep manure (SM) composting. The experiments were conducted with six different ratio of CMB (0%(T1), 2.5%(T2), 5%(T3),7.5%(T4),10%(T5) and 12%(T6)onadryweightbasis) and 0% is used as control. The results showed that the most dominant phylum were Proteobacteria (40.89%-5.65%) and Firmicutes (0.16%-93.18%), and 7.5% CMB mixed with sheep manure for best results. Thus, significant correlation was noticed among the analyzed physicochemical factors, gaseous emission and bacterial phylum in used 7.5–10% CMB applied for SM composting. Overall, the application of biochar increased the diversity of the bacterial community and promoted the degradation of organic matter. In addition, 7.5–10% CMB applied treatments showed greater immobilization of HMRB community succession during SM composting.

Characteristics, adsorption behaviors, Cu(II) adsorption mechanisms by cow manure biochar derived at various pyrolysis temperatures

With the aims of exploring the effectiveness of Cu(II) adsorption performed by cow manure biochars (CMBCs) for the treatment and recycling of livestock wastes, the physicochemical characteristics and Cu(II) adsorption behaviors of CMBCs at various pyrolysis temperatures (T) were analyzed. CMBCs displayed surface heterogeneity and the dominant Cu(II) adsorption reactions were chemical adsorption, including mineral co-precipitation and cations exchange, was account for 93.75% − 97.01% of the adsorption contribution. Pearson correlation analysis and quantitative analysis showed that the adsorption capacity of co-precipitation (Qcp) and cations exchange (Qci) were significantly positively correlated with ash content and cations exchange capacity (p < 0.01), respectively. The quantitative relationships between total adsorption capacity (Qt), Qcp or Qci and T are Qt = 54.01 + 0.39exp(0.0051 T), Qcp = 71.80–101.91exp(−0.0024 T), Qci = 12.25 + 311.73exp(−0.0093 T) and Qt = 0.93 Qci + 0.91 Qcp + 7.70.

De-ashed biochar enhances nitrogen retention in manured soil and changes soil microbial dynamics

Enhancing soil N retention is important to mitigate the negative environmental impacts caused by the loss of applied N fertilizers. Therefore, the use of modified biochar in the soil is a novel approach to enhance the sorption of N ions. Biochars derived from bamboo, cow, and pig manures were de-ashed and their properties were characterized. The de-ashed biochars were comparatively assessed with raw biochars on N-retention, and how this process is regulated by microbial activities, diversity, and abundance in a manured soil. De-ashing increased the intensity of biochar functional groups and their surface structure. In manured soils, the application of de-ashed bamboo biochar (PDBB) and de-ashed cow manure biochar (PDCB) led to an increase in NH4+-N retention of 34.5% and 6.8% relative to the amendment with raw biochars. Similarly, increased retention of 20.9%, 14.8%, and 19.1% of NO3−-N, and an increase of 21.1%, 11.1% and 11.5% in total N were observed in PDBB, PDCB and de-ashed pig manure biochar (PDPB) respectively, compared to their raw biochars after 8 weeks. The modified surface properties of de-ashed biochars led to higher bacterial colonization, with an increase in the diversity and relative abundance of bacterial 16S rRNA genes, compared to the raw biochar treatments. This spike in microbial groups stimulated protease activities and hence, an increased abundance of N-cycling organisms. The increased microbial abundance was associated with a reduction in the release of urease by these microbial groups for the hydrolysis of urea, thereby ensuring soil N retention. De-ashing increased the intensity of biochar functional groups and improved its surface properties, which resulted in increased N-sorption, and immobilization by stimulating microbial activities and diversity in soil.

Effects of ZnO Nanoparticles and Biochar of Rice Straw and Cow Manure on Characteristics of Contaminated Soil and Sunflower Productivity, Oil Quality, and Heavy Metals Uptake

Contaminated soils can cause a potential risk into the health of the environment and soil as well as the quality and productivity of plants. The objectives of our study were to investigate the integrative advantageous effects of foliar ZnO nanoparticles (NPs) (60 mg Zn NPs L−1), rice straw biochar (RSB; 8.0 t ha−1), cow-manure biochar (CMB, 8.0 t ha−1), and a combination thereof (50% of each) on sunflowers grown in agricultural land irrigated with polluted wastewater for the long term (≈50 years). The availability of heavy metals (HMs) in soil, HMs accumulation in whole biomass aboveground, growth, productivity, and quality characteristics of the sunflower were investigated. The combination treatment significantly minimized the availability of HMs in soil, and, consequently, substantially lessened the uptake of HMs by the sunflower, compared to treatments of ZnO NPs and control (i.e., untreated soil). The application of the combination treatment reduced the availability of Pb, Cr, Cu, and Cd in the soil by 78.6%, 115.3%, 153.3%, and 178.5% in comparison to untreated plots post-harvest, respectively. Compared to untreated plots, it also reduced the Pb, Cr, Cu, and Cd in plant biomass by 1.13, 5.19, 3.88, and 0.26 mg kg−1 DM, respectively. Furthermore, combination treatment followed by biochar as an individual application caused a significant improvement in sunflower productivity and quality in comparison to untreated soil. For instance, seed yield ha−1, 100-seed weight, and number of seeds per head obtained from the combination treatment was greater than the results obtained from the untreated plots by 42.6%, 47.0%, and 50.4%, respectively. In summary, the combined treatment of NPs and both RSB and CMB is recommended as a result of their positive influence on sunflower oil quality and yield as well as on minimizing the negative influences of HMs.

Comparison of 17β-estradiol adsorption on soil organic components and soil remediation agent-biochar

Steroid estrogen residues (SEs) in the soil have attracted growing attention because of their potential for endocrine disruption. Soil organic matter (SOM) and soil remediation agent-biochar, both have important influences on the fate of SEs in the soil environment. This study compared the adsorption of 17β-estradiol (E2) on wheat straw biochar (W-BC) and cow manure biochar (C-BC) with main SOM components including biomacromolecules (cellulose, collagen and lignin) and humic acids (HA). The impact of pyrolysis temperature (350 °C, 550 °C, and 700 °C) on the adsorption capacity of biochar and different concentrations NaClO oxidation on the adsorption capacity of HA were also investigated. The experimental results showed that the adsorption of E2 by biomolecules conformed to the linear isotherm (R2 > 0.88), and the adsorption of E2 on biochars and HA were well described by the Langmuir and Freundlich isotherm (R2 > 0.94). Meanwhile, the order of the E2 adsorption capacity of sorbents was W-BC > C-BC > HA > lignin > collagen > cellulose. The adsorption capacity of biochar and SOM for E2 increased with the enhancement of aromaticity and hydrophobicity and the reduction of polarity. In addition, the increase of pyrolysis temperature of biochars also promoted the adsorption capacity of E2, while oxidation treatment with NaClO reduced the adsorption capacity of HA to E2. These results deepened the understanding of the adsorption behaviour of E2 on SOM and biochar, and expanded the understanding of the behaviour of SEs in the soil environment.