Coconut Shell Biochar Research Articles

Investigating coconut shell biochar as a sustainable solution for removing iron residues in recycled concrete aggregates

Investigating coconut shell biochar as a sustainable solution for removing iron residues in recycled concrete aggregates

Enhanced removal of fluoride ions using lanthanum-doped coconut shell biochar in PVDF ultrafiltration membranes

Fluoride contamination in surface and ground water poses significant health risks, necessitating a low-energy, cost-effective removal method. Herein, an ultrafiltration (UF) adsorptive membrane doped with lanthanum (La)-based coconut shell biochar was synthesized to effectively remove fluoride ions. Based on the results of adsorption and membrane separation performance, it was found that La-based biochar showed a significantly higher adsorption capacity (126.7 mg F/g) compared to bare biochar (27.41 mg F/g), due to the oxygen-containing functional groups from La2O2CO3 that enhance binding sites and electrostatic attraction for fluoride ions. Furthermore, the addition of La-modified adsorbent to the polyvinylidene fluoride (PVDF) UF membrane markedly altered its structure and surface properties, changing the pore structure to porous, narrowing pore size, increasing active adsorption sites, and improving hydrophilicity. These changes boosted fluoride ion rejection from 9.53 % to 62.07 % with tiny effect on membrane permeability. More important, this UF adsorptive membrane exhibited excellent antifouling ability with the lowest flux decline (J/J0 =0.450) compared to pristine PVDF membrane (J/J0 =0.142), which was owing to the better improved surface properties. In all, this study provides a novel strategy for efficient, economic and selective separation of fluoride ions and further extends the application of UF to the field of ion removal.

A multifunctional coconut shell biochar modified by titanium dioxide for heavy metal removal in water/soil and tetracycline degradation

Heavy metals and tetracycline pollute the environment and endanger human health. This work prepared a multifunctional coconut shell biochar (Ti-XBC) through NaHCO3 activation and TiO2 modification. The modified coconut shell biochar was characterized by various methods. Ti-4BC exhibited excellent removal performance for heavy metals. The maximum adsorption capacity of Ti-4BC on Cd2+, Pb2+, Cr3+, and Cr6+ reached 104.2, 136.8, 101.2, 112.4 mg/g in water. The adsorption of Ti-4BC for four metal ions had a competitive effect in the binary metal system. It also reduced the mobility of four heavy metal ions in soil. Density functional theory (DFT) calculations were employed to explain the mechanism of heavy metal removal. Additionally, the degradation performance and mechanism of Ti-4BC towards tetracycline were investigated. The results indicated that the maximum degradation rate was 99.4%. Overall, this work developed a multifunctional material capable of both removing heavy metals and degrading antibiotics, addressing the issue of single-function in biochar. This provided a novel approach for tackling complex and diverse environmental pollution scenarios.

Preparation of a slow-release fertilizer from MgO-modified biochar and struvite and its capacity for cadmium passivation

This study investigates the development of a slow-release coated fertilizer using magnesium oxide-modified coconut shell biochar (MgO-BC), struvite, and urea. The performance of this coated fertilizer in terms nitrogen and phosphorus release and cadmium (Cd) passivation in Cd-contaminated soil was evaluated through soil column leaching tests and pot experiments. The coated fertilizer, prepared with a mass 6: 2: 1 ratio of MgO-BC: urea: struvite, achieved a compressive strength of 38.6 N/grain. The nitrogen and phosphorus release rates from Cd-contaminated soil treated with the coated fertilizer were 887.391 μg/d and 2.884 μg/d, respectively, representing decreases of 5.0 % and 32.8 % compared to soil treated with struvite and urea. The coated fertilizer demonstrated a good Cd fixation effect in Cd-contaminated soil. The coated fertilizer effectively reduced Cd mobility, with the total accumulated Cd leached from the soil decreasing by 73.2 % after ten leaching cycles. Furthermore, the coated fertilizer significantly inhibited Cd uptake by peas (Pisum sativum L.), with Cd content in the above-ground and under-ground parts of the plants decreasing by 82.78 % and 68.04 %, respectively, compared to the control. The transport coefficient (TFS/R) of Cd for peas decreased by 46.12 %. The Cd passivation efficiency of the coated fertilizer was 37.76 %, attributed to the transformation of acid extractable/exchangeable Cd to residual Cd. These results demonstrate that the coated fertilizer, prepared from MgO-modified biochar and struvite, effectively combines slow releasing nutrient properties with Cd passivation capabilities.

Coconut Shell Biochar for the Removal of Acetaminophen and Ciprofloxacin in Low Concentrations: Single and Competitive Adsorption Studies

Coconut Shell Biochar for the Removal of Acetaminophen and Ciprofloxacin in Low Concentrations: Single and Competitive Adsorption Studies

Enhancing the Growth of Chili Plants and Soil Health: Synergistic Effects of Coconut Shell Biochar and Bacillus Sp. Strain Ya-1 on Rhizosphere Microecology and Plant Metabolism

To mitigate soil degradation and decrease dependency on chemical inputs in agriculture, this study examined the joint effects of coconut shell biochar and Bacillus strain Ya-1 on soil fertility, rhizosphere bacterial communities, and the growth of chili (Capsicum annuum L.). A controlled pot experiment with four treatments was conducted: control (CK), biochar only (C), Bacillus strain Ya-1 only (B), and a combination of both (BC). The BC treatment significantly enhanced the soil carbon and available phosphorus contents by approximately 20% and the soil nitrogen content and pH by 18% and 0.3 units, respectively, compared to the control. It also increased microbial biomass carbon and nitrogen by 25% and 30%, respectively, indicating improved soil microbial diversity as shown by the highest Pielou evenness index and Shannon index values. The combined application of biochar and the Ya-1 strain resulted in a 15% increase in chili plant height and a 40% improvement in root dehydrogenase activity, suggesting enhanced nutrient uptake and metabolism. Metabolic profiling showed shifts in stress response and nutrient assimilation under different treatments. Collectively, these results indicate the potential of biochar and microbial inoculants to significantly promote soil and plant health, providing a sustainable strategy to improve agricultural productivity and reduce reliance on chemical inputs.

Effect of biochar on soil chemical properties of tidal wetland in Jambi, Indonesia, and growth and yield of various rice varieties

The study aimed to determine the effect of biochar on the growth and yield of several rice varieties in a tidal wetland agroecosystem. This research used a split-plot design with the main plot was biochar application, consisting of three levels (no biochar, rice husk biochar, and coconut shell biochar), and the subplot was rice variety consisting of ten varieties (Inpara, Inpari 30, Kuning, Karya Rendah, Bujang Pelawah, Pandan Wangi, Bujang Berinai, Kwatek Tinggi, Candu, and Serai). Plant parameters observed were plant height, number of tillers, productive tillers, panicle length, number of grains per panicle, number of empty grains per panicle, milled rice weight, and weight of 1,000 grains. Results of this study showed that the application of biochar improved soil fertility by increasing organic carbon, available phosphorus and potassium, cation exchange capacity, and reducing the soluble iron in the soil. However, the application of biochar did not significantly affect the height of rice plants. The application of coconut shell biochar yielded the best results in increasing the number of productive tillers, the number of grains per panicle, grain dry weight, and reducing the number of empty grains per panicle.

Effectiveness of Biochar application on the growth of red chili plants during the vegetative stage under waterlogging

The riparian wetland offers potential for horticultural crop cultivation, such as chili peppers. It is important to consider cultivation techniques and the use of organic matter to improve soil properties, particularly to combat waterlogging during the rainy season. This study aimed to assess the impact of biochar application on the growth of chili peppers (Capsicum annuum L.) during the vegetative stage under waterlogging conditions. This research was conducted at the experimental land of the Agrotechnology Department, Faculty of Plant and Animal Sciences, Universitas Bina Insan from December 2022 to February 2023. This research employed a complete randomized design (RAL) factorial with two factors. The first factor involved waterlogging stress, including control (C) and waterlogging stress (W). The second factor (N) encompassed the application of biochar, namely without biochar (N0), rice husk biochar (N1) and coconut shell biochar (N2) at a dose of 200 g plant-1. The results showed that waterlogging conditions (W) and biochar application (N) showed significantly different results in shoot length, root length, number of leaves, and total dry weight of chili plants, while the interaction (WxN) showed significantly different in shoot length and root length of plants. Treatment without biochar (N0) in waterlogging conditions actually showed shoot length, root length, number of leaves and total dry weight of plants that were significantly higher than treatment coconut shell biochar (N1) and rice husk applications (N2).

Remediation of multi-metal(loid) contaminated soils using Mn-modified biochar: Mechanistic insights and influencing factors

Mn-modified biochar could impact soil quality and metal(loid) migration in contaminated soils. However, the remediation efficiency, mechanism, and influencing factors of Mn-modified biochar on multi-metal(loid) contaminated soils were largely unknown. In this study, three Mn-modified biochar were prepared by using MnCl2-impregnated rubber, tobacco rod, and coconut shell biochar, respectively. The remediation efficiency of Mn-modified biochar on Pb, As, Cd, Cu, and Zn contaminated soil was also compared. Our data revealed that the addition of Mn-modified biochar increased the effective cation exchange capacity (ECEC), organic matter (OM), alkaline hydrolyzed nitrogen (AHN), and the mobility of the nutrient Zn in the soil. Furthermore, Mn-modified rubber biochar and Mn-modified coconut shell biochar reduced acid extractable or Diethylenetriamine Pentaacetic Acid (DTPA) leached Pb, As, Cd, and Cu However, Mn-modified tobacco rod biochar increased the acid extractable or DTPA leached Pb, Cd, and Cu. The study showed that three Mn-modified biochars could effectively improve soil physicochemical properties and significantly increase soil nutrient activity. Mn-modified rubber and coconut shell biochar can effectively immobilize metal(loid)s and reduce their damage to soil. However, the Mn-modified tobacco rod biochar instead increased the mobility of metal(loid)s. The results indicate that feedstock is an important factor influencing the application of Mn-modified biochar and should be considered in the production.

Corncob Hydrolysis Using Graphene Oxide Activated Coconut Shell Biochar Catalyst

Corncob Hydrolysis Using Graphene Oxide Activated Coconut Shell Biochar Catalyst

Degradation mechanism and ecotoxicity analysis of levofloxacin by palladium-modified nano zero-valent iron doped coconut shell biochar

The palladium-modified nano zero-valent iron (nZVI) doped coconut shell biochar (Pd-nZVI/BC) was successfully obtained through bimetallic modification and liquid-phase reduction. The synthesized Pd-nZVI/BC was further enhanced by the addition of an H2O2 co-catalyst for the removal of antibiotic levofloxacin (LVF). Results demonstrated that removal of LVF by Pd-nZVI/BC accomplished 94.6 % under proper conditions. Adsorption and degradation processes were involved in the LVF removal, and the predominant free radicals were •OH and •O2-. Adsorption relied mainly on electrostatic interactions, π-π interactions, and hydrogen bonding. While demethylation, deamidation, quinolone ring aldolization, depiperazinylation, deacetylation, decarboxylation, dehydroxylation, and oxidative breakage of the piperazine ring occurred during the degradation processes. Based on the degradation pathways, the ecotoxicity of LVF and its degradation intermediates were compared and assessed. Results implied that majority of the antibiotic LVF pollutant was eliminated or mineralized, and the toxicity potential of LVF was reduced in the Pd-nZVI/BC system. Simultaneous biochar utilization and pollutants removal could be achieved.

Unraveling the mechanisms of biochar and steel slag in alleviating lithium stress in tomato (Solanum lycopersicum L.) plants via modulation of antioxidant defense and methylglyoxal detoxification pathways

With progress in technology, soaring demand for lithium (Li) has led to its release into the environment. This study demonstrated the mitigation of the adverse effects of Li stress on tomato (Solanum lycopersicum L.) by the application of waste materials, namely coconut shell biochar (CBC) and steel slag (SS). To explore the impact of Li treatment on tomato plants different morphological, biochemical parameters and plant defense system were analyzed. Tomato plants exposed to Li had shorter roots and shoots, lower biomass and relative water contents, and showed decreases in physiological variables, as well as increases in electrolyte leakage and lipid peroxidation. However, the application of CBC and SS as passivators, either singly or in combination, increased growth variables of tomato and relieved Li-induced oxidative stress responses. The combined CBC and SS amendments reduced Li accumulation 82 and 90% in tomato roots and shoots, respectively, thereby minimizing the negative impacts of Li. Antioxidant enzymes SOD, CAT, APX and GR reflected 4, 5, 30, and 52% and glyoxalase enzymes I and II 7 and 250% enhancement in presence of both CBC and SS in Li treated soil, with a concurrent decrease in methylglyoxal content. Lithium treatment triggered oxidative stress, increased enzymatic and non-enzymatic antioxidant levels, and induced the synthesis of thiols and phytochelatins in roots and shoots. Hence, co-amendment with CBC and SS protected tomato plants from Li-induced oxidative damage by increasing antioxidant defenses and glyoxalase system activity. Both CBC, generated from agricultural waste, and SS, an industrial waste, are environmentally benign, safe, economical, and non-hazardous materials that can be easily applied on a large scale for crop production in Li-polluted soils. The present findings highlight the novel reutilization of waste materials as renewable assets to overcome soil Li problems and emphasize the conversion of waste into wealth and its potential for practical applications.

Effect of biochar composition and paclobutrazol concentration on growth and yield of G1 Medians cultivar potato seeds in Jatinangor medium plain

Potato seed production in the medium plain is necessary to avoid environmental damage and the limited area of potato seed production in the high plain. The effort to increase the production of G1 potato seeds on the medium plain is the evaluation of the biochar composition and concentration of paclobutrazol that can increase the production G1 potato seeds cv Medians in the medium plain of Jatinangor. The research was conducted from August to December 2022 at the Ciparanje Experimental Field. Jatinangor. Faculty of Agriculture. Universitas Padjadjaran. The experiment used a Factorial Randomized Block Design (RBD). The first factor was the biochar composition: m1 (100% compost), m2 (80% compost + 20% rice husk biochar), m3 (80% compost + 20% coconut shell biochar), and m4 (80% compost + 10% biochar husk rice + 10% coconut shell biochar). The second factor was the paclobutrazol concentration: p1 (without paclobutrazol), p2 (100 ppm paclobutrazol), and p3 (150 ppm paclobutrazol). The experimental results showed that there was no reaction effect of biochar compositions and paclobutrazol concentrations on the growth and yield of G1 potato seeds. The application of 80% compost + 20 % rice husk biochar gave significantly higher yields than treatment without biochar. The number of tubers was 6.29 knol per plant and the tuber weight was 66.80 g per plant. Application of 100 ppm paclobutrazol resulted in lower plant height, gave the number of tubers was 6.39 knol per plant, tuber weight per plant was 63.34 g higher than without paclobutrazol and produced more seed tubers with S class.

Synthesis of eco-friendly bio-based coconut shell magnetic biochar for efficient bisphenol S sequestration in aqueous environment: green technology breakthrough

Water pollution has emerged as a critical global challenge, particularly the contamination of water bodies with persistent organic pollutants such as Bisphenol S (BPS), a known endocrine disruptor. This study presents the synthesis and application of eco-friendly bio-based coconut shell magnetic biochar (CSMB) for efficient sequestration of BPS from aqueous environments. Utilizing pyrolysis and co-precipitation techniques, the magnetic biochar was characterized through various methods including surface chemistry (pHpzc), electron dispersive X-ray analysis (EDX), Brunauer-Emmett-Teller (BET) N2 adsorption-desorption, scanning electron microscopy (SEM), vibrating sample magnetometer (VSM), and Fourier transform infrared spectroscopy (FTIR). SEM revealed a porous structure with a high surface area, while FTIR confirmed the presence of functional groups essential for adsorption. X-ray diffraction (XRD) and VSM successfully incorporated magnetic nanoparticles, enhancing the separation process post-adsorption. The CSMB demonstrated a significant surface area of 373 m2 g−1, outperforming regular coconut shell biochar (CSB), with a BPS adsorption capacity of 43.5 mg/g compared to 26.7 mg/g for CSB. Batch adsorption tests assessed the impact of operational factors such as initial BPS concentration (8–150 ppm), contact time (30–150 min), temperature (298.15, 318.15, and 338.15 K), pH (3–11), and CSMB dosage (0.1–0.9 g). The results indicated optimal adsorption at pH 6 with a maximum capacity of 52.3 mg/g. Kinetic studies revealed that the pseudo-second-order model best described the adsorption process, while the Langmuir isotherm model provided an excellent fit for the adsorption data. The reusability of CSMB was validated over five cycles, with adsorption capacity decreasing slightly from 43.5 mg/g to approximately 41 mg/g, making it a sustainable and effective adsorbent for water treatment.

Suitability of coconut bran and biochar as a composite substrate for lettuce cultivation in aquaponic systems

Growth substrates are essential for aquaponic systems and play an important role in vegetable growth and water quality. In this study, we explored an innovative combination of coconut bran and coconut shell biochar (CSB) as a composite growth substrate for lettuce cultivation in aquaponic systems. The study included the control (100 % coconut bran as the growth substrate) and treatment groups (T1–T5; containing 10 %, 20 %, 30 %, 40 %, and 50 % CSB as the growth substrate, respectively). The substrate properties; lettuce growth performance; and soil enzyme activity, nitrogen content, and abundance of microbial communities in the substrate were analyzed to determine the optimal substrate. Our findings indicated that CSB incorporation significantly altered the properties of the substrate, resulting in increased dry and bulk densities, pH, and water-holding capacity, and decreased electrical conductivity, water-absorption capacity, and porosity. Furthermore, the fresh weight of lettuce was notably increased in the treatment groups. The activities of fluorescein diacetate hydrolase, urease, nitrate reductase, and hydroxylamine reductase initially increased and further decreased, reaching the maximum in the T3 group. Conversely, the activity of nitrite reductase and contents of available nitrogen, nitrate-nitrogen, and ammonium-nitrogen in the substrates initially decreased and further increased, with the minimum values observed in the T3 group. The microbial sequencing results indicated that CSB incorporation significantly increased the microbial diversity and relative abundance of microorganisms associated with nitrogen transformation. Moreover, 30 % CSB incorporation exhibited the greatest effect on lettuce growth, with a 34.5 % and 31.6 % increase in fresh weight compared to the control during the growth and harvest periods, respectively. This study indicated the enormous potential of biochar in the research and development of green technologies for substrate amendment in aquaponic systems.

Effects and Mechanisms of Different Types of Biochar on Heavy Metal Passivation during Sludge Composting.

The effects and mechanisms of the different types of biochar on heavy metal passivation are still not fully understood. This study compared the effects of three types of biochar on heavy metal passivation during sludge composting. Compared with composting without biochar, rice husk biochar was most effective for the passivation of Zn and Pb, with increased passivation rates of 1.90% and 20.43%, respectively. In contrast, sludge biochar was the most effective for the passivation of Cr and Hg, with increased passivation rates of 28.30% and 3.09%, respectively. Coconut shell biochar showed the best performance for the passivation of Cu, Ni, As, and Cd, and was enriched with micropore structures, which possibly led to the adsorption and reaction of heavy metals, organic matter, and microorganisms. The improved passivation effect of the rice husk and sludge biochar on heavy metals can be attributed to the improved humification of organic matter. This study suggests that specific types of biochar should be considered for the passivation of different types of heavy metals for practical applications.

Investigating the efficacy of biochar produced from agro-waste for basic fuchsin dye removal: Kinetics, isotherm, and thermodynamic studies

The present article investigates the efficacy of biochar (BC) derived from agricultural waste for treating cationic dyes. Various biomass, including sycamore leaf (SL), cotton waste (CW), groundnut shell (GS), rice husk (RH), coconut shell (CS), banana pith (BP), and coconut husk (CH) were used to prepare biochar at 400, 600, and 800 °C. The highest removal of basic fuchsin (BF) dye was observed onto the BC prepared at 800 °C, with the removal efficiency as follows: cotton waste biochar (CWB) 88.12 %, groundnut shell biochar (GSB) 88.73 %, rice husk biochar (RHB) 89.37 %, coconut shell biochar (CSB) 90.4 %, coconut husk biochar (CHB) 91.24 %, banana pith biochar (BPB) 96.7 %, and sycamore leaf biochar (SLB) 100 %, respectively. The dye concentration, BC dose, reaction time, temperature, and pH were optimized. Optimal conditions for higher BF dye sorption (174.5 mg g−1) were found at the dye concentration of 3500 mg L−1, SLB dose of 0.2 g, time 45 min, temperature 40 ± 2 °C, and pH 9 ± 0.2. The sorption kinetic data best fit a pseudo-second-order model, while isotherm data followed the Freundlich model, suggesting chemisorption with a multilayer sorption process. Thermodynamic data implied that the sorption process was endothermic and spontaneous. The present research revealed the hidden potential of widely and easily available waste biomass to competently remove the cationic dye.

Eco‐friendly approach to thermal energy storage: Assessing the thermal and chemical properties of coconut biochar‐enhanced phase change material

AbstractPhase change materials (PCMs) can absorb, store, and release substantial latent heat within a specific temperature range during phase transition and have gained huge attention due to environmental concerns and energy crises. However, PCMs have a significant downside in energy storage due to their relatively lower thermal conductivity, leading to inadequate heat transfer (HT) performance. The foremost aim of the research is to synthesize an eco‐friendly coconut shell biochar (CSB) dispersed with organic A46 PCM in the temperature range of 44°C to 46°C to form a green nanocomposite. A two‐step approach is adopted to formulate the nanocomposites with different weight concentrations (0.2% and 0.8%) of green CSB particles. The developed nanocomposite's thermal conductivity and chemical stability were examined using a thermal properties analyzer and a Fourier transforms infrared spectrometer. The developed biochar composites have excellent thermal conductivity (0.39 W/m K) compared with base PCM (0.22 W/m K). Also, the developed nanocomposites were physically mixed together; there were no additional functional groups formed compared to pristine PCM, and the prepared materials were composite. Furthermore, a numerical analysis was performed using two‐dimensional energy modeling software to ascertain the HT rate of A46 composites. These thermally energized green nanocomposites show great promise for thermal energy storage and thermal management applications like battery thermal management, photovoltaic thermal systems, desalination systems, electronic cooling, building applications, and textiles.

Mechanism of enhanced degradation of antibiotic wastewater by three-dimensional electrocatalytic oxidation system: Coconut shell biochar as particle electrode

A porous particle electrode, coconut shell biochar (CBC), was prepared using coconut shell as raw material and applied to the treatment of tetracycline (TC) wastewater. Exploring the three-dimensional electrocatalytic oxidation system using a series of key factors such as pH (2−10), current density (20–60 mA/cm2), CBC particle size (0.88–2.36 mm), CBC dosage (3–13 g/L), electrolyte concentration (5000–10,000 mg/L), and electrode spacing (3–5 cm). The optimal conditions for these parameters were 10, 50 mA/cm2, 1.4–1.7 mm, 7 g/L, 8000 mg/L, and 4 cm. Under these conditions, the degradation of TC conformed to pseudo-first-order kinetics. The chemical oxygen demand (COD) and TC removal rates reached 84.01 % and 99.18 % within 45 min, while the two-dimensional system only achieved 29.27 % and 39.83 %, respectively. The degradation mechanism of TC was determined based on the production of H2O2 and •OH. The adsorbed saturated CBC might be regenerated through electrochemical reactions, inducing further adsorption, and forming numerous micro electrolysis cells to promote the production of free radicals, thereby boosting TC mineralization. Finally, the high-performance liquid chromatography-mass spectrometer was applied to identify the transformation products and degradation pathways of TC. Additionally, the CBC still showed excellent catalytic degradation effect after being reused for 4 times. Therefore, this study makes it possible to prepare an efficient and low-cost electrocatalyst for the treatment of antibiotic wastewater, as well as for further understanding the electrocatalytic mechanism, conversion products, and degradation pathways of TC in wastewater.

Performance and mechanism of sulfadiazine and norfloxacin adsorption from aqueous solution by magnetic coconut shell biochar.

In this study, magnetic coconut shell biochar loaded with spherical Fe3O4 and γ-Fe2O3 particles was successfully synthesized using a chemical coprecipitation method. The magnetic biochar exhibited a good magnetic separability and environmental security. The maximum sulfadiazine (SDZ) and norfloxacin (NOR) removal efficiencies were 94.8% and 92.3% at pH 4 and 25°C with adsorbent dosage of 2.5g/L, respectively. When antibiotic concentrations ranged from 5 to 50mg/L, the theoretical maximum adsorption capacities of SDZ and NOR were 16.7mg/g and 25.8mg/g, respectively. The Langmuir isotherm and pseudo-second-order kinetic models could better describe the adsorption process of both antibiotics, implying the monolayer chemical adsorption. The thermodynamic analysis indicated that the adsorption process was spontaneous and endothermic. The ionic strength had no significant effect on the adsorption behavior of either antibiotic. Combined with BET, FTIR, and XPS results, the dominant mechanisms for SDZ and NOR adsorption were pore filling, π-π electron-donor-acceptor interaction, hydrogen bonds and surface complexation. Moreover, Lewis acid-base interaction also contributed to SDZ adsorption.