A surface amplification powdered carbon material for efficiently removing new pollutants in water and preparation and application thereof

Abstract

This invention relates to the field of water pollution treatment, specifically to a surface-amplified activated carbon material for new pollutants in water, its preparation, and its application. The raw carbon is crushed to 300–500 mesh using an air-classifying crusher to obtain optimal gradation. Regarding process safety, using polyaluminum chloride (PACl) as a coagulant, a linear matching relationship between carbon load and reagent dosage was established for different powdered activated carbon dosages, corresponding to the optimal flocculant dosage. An optimization mode of "medium energy gradient" and "enhanced rapid mixing" was proposed, verifying that there is no risk of filter breakthrough under conventional coagulant dosage, and the effluent turbidity consistently meets standards. In engineering applications, a demonstration was conducted at a 100,000-ton / day water plant in Shanghai, using a containerized on-site preparation equipment. After 16 days of emergency dosing, it was shown that a dosage of 10 mg / L can achieve a broad-spectrum pollutant removal rate of over 70%, and 15 mg / L can achieve 80%–90% deep purification of recalcitrant pollutants.

Description

Technical Field

[0001] This invention belongs to the field of drinking water pollution treatment, specifically relating to a surface-amplified carbon material for efficiently removing new pollutants from water, its preparation, and its application. Background Technology

[0002] Emerging pollutants refer to a class of chemical substances that can be detected in the environment and natural ecosystems. Even at low doses, these substances can pose significant risks and hidden dangers to human health and ecological safety. Currently, emerging pollutants of widespread concern both domestically and internationally mainly include persistent organic pollutants (POPs), endocrine disruptors, antibiotics, and microplastics, which are controlled under international conventions. They are typically characterized by high levels of harm, strong concealment of risks, significant environmental persistence, wide range of sources, and complex remediation processes. On March 5, 2025, the need to formulate a comprehensive solid waste management action plan and strengthen the coordinated management and environmental risk control of emerging pollutants was first proposed; subsequently, on March 5, 2026, it was further emphasized that efforts to control emerging pollutants should be intensified. These policy signals indicate that the control of emerging pollutants has become extremely important.

[0003] The conventional water purification process widely used in water treatment plants currently uses coagulation-sedimentation-filtration-disinfection as its core treatment flow. This process was initially designed to remove suspended particulate matter, colloidal substances, and pathogenic microorganisms from water to meet basic sensory and hygiene requirements for drinking water. However, with the increasing variety of pollutants in the aquatic environment, this type of process is generally ineffective in removing common new pollutants—six odor-causing substances (dimethyl disulfide DMDS, dimethyl trisulfide DMTS, 2-ethyl-3-methoxypyrazine 2-EMD, 2-ethyl-3,5-dimethylpyrazine 2-EDD, 2-methylisoborneol 2-MIB, and geosmin GSM) and five typical new pollutants (bisphenols, antibiotics, stimulants, perfluorinated compounds, and pesticides)—making it difficult to meet the higher demands of current drinking water safety assurance.

[0004] Currently, traditional coagulation-filtration-sedimentation processes are insufficient to meet the water purification requirements for the aforementioned new pollutants. Existing removal methods mainly include chemical oxidation, biodegradation, physical adsorption, and combinations of multiple processes. Among these, activated carbon adsorption technology has advantages such as high removal efficiency and strong adaptability to water quality fluctuations. Furthermore, activated carbon can be regenerated and reused, making it economical. However, activated carbon is also prone to saturation and inactivation, requiring a large dosage, which increases the load on the filter bed and subsequent treatment stages.

[0005] Currently, the main amplification methods for improving activated carbon performance include chemical oxidation, physical grinding, microwave radiation, ultrasonic assistance, and low-temperature plasma modification. Among these, using an air-classifying crusher to crush the raw carbon allows for solvent-free reactions between solids, offering advantages such as a simple and rapid preparation process, low cost, no secondary pollution, and suitability for large-scale production, making it highly suitable for large-scale industrial material preparation. However, it is important to note that excessively fine activated carbon particles may penetrate filter beds, affecting drinking water safety. Furthermore, in practical engineering applications, there are no known cases of using surface-amplified activated carbon to directly treat actual production processes. The application effects of activated carbon for large-scale removal of emerging pollutants in water and the assessment of its process risks are currently still in the research gap stage.

[0006] Therefore, developing a surface-amplified carbon material with superior adsorption efficiency, a green and environmentally friendly production process, and no risk of penetrating the filter bed using an air-classifying crusher is of great significance for promoting the treatment of polluted raw water containing odorous substances. Summary of the Invention

[0007] A surface-amplified carbon material for efficiently removing new pollutants from water, characterized in that the surface-amplified carbon material uses raw carbon as a raw material.

[0008] Furthermore, the feature is that an air-classifying crusher is used to crush the raw charcoal.

[0009] Furthermore, the characteristic feature is that the carbon source of the raw material is selected from any one of coal, wood, and coconut shell.

[0010] Furthermore, the original carbon powder has a mesh size of 1-100 and an iodine value of 400-1200.

[0011] Furthermore, the surface-amplified carbon powder material has a mesh size of 1-600 mesh, of which 300-500 mesh accounts for 50-80%.

[0012] Furthermore, the characteristic feature is that it is added to water to prepare a powdered carbon suspension for dosing.

[0013] The specific preparation method of the surface-amplified carbon powder material for efficiently removing new pollutants from water is as follows: Step 1: Put the raw charcoal into the air-classifying crusher for crushing, run for 1-20 minutes; Step 2: Adjust the outlet diameter difference and collect the powdered carbon blown out of the outlet to obtain surface-amplified powdered carbon.

[0014] The beneficial effects achieved by this invention are as follows: Utilizing high-speed ultrafine pulverization technology with air-separation, and leveraging an integrated pulverization-airflow classification mechanism, powdered carbon with a particle size greater than 300 mesh (over 80%) can be efficiently produced within 5–10 minutes. For the carbon source, activated but unformed raw carbon is used directly, ground and used immediately. This not only avoids pore blockage caused by granulation but also significantly reduces costs. Because pulverization creates new interfaces, it prevents the loss of adsorption capacity after prolonged storage, resulting in a significant improvement in overall adsorption performance compared to commercially available powdered carbon. Based on pollutant characteristics, a differentiated dosing strategy is developed: for highly hydrophobic pollutants (such as carbamazepine), a low dosage of 15–20 mg / L combined with short-term contact is sufficient for efficient removal; while for highly polar and difficult-to-adsorb pollutants (such as sulfonamides), a higher dosage or a coupled "advanced oxidation-powdered carbon adsorption" process is required to overcome the bottleneck of single adsorption.

[0015] To address the safety concerns in the application of surface-amplified powdered activated carbon (PAC), polyaluminum chloride (PAC) was used as a coagulant. The study revealed a linear relationship between carbon loading and reagent dosage (5–6 mg / L PAC was required for every 10 mg / L increase in powdered activated carbon). During the mechanical flocculation stage, sufficient initial high-G-value stirring was crucial for the formation of stable flocs. Furthermore, the effects of humic acid competitive adsorption and calcium ion-assisted coagulation were quantified, and enhanced control strategies for different water quality backgrounds were proposed to ensure that the effluent turbidity was stably controlled below 0.5 NTU, effectively mitigating the risk of carbon powder breakthrough.

[0016] In terms of engineering application verification, the feasibility of the containerized on-site preparation equipment was verified based on a pilot-scale water plant with a capacity of 100,000 tons / day, enabling real-time monitoring of the concentration indicators of hundreds of pollutants throughout the entire process. The experiment established that the adsorption efficiency of surface-amplified charcoal for new pollutants is superior to that of commercially available charcoal, with an economic dosage range of 10–15 mg / L: 10 mg / L can achieve a broad-spectrum pollutant removal rate exceeding 70%, while 15 mg / L can achieve 80%–90% deep purification of recalcitrant pollutants. This fully demonstrates that the prepared surface-amplified charcoal material possesses outstanding advantages such as large adsorption capacity and strong stability, and has broad application prospects and industrialization value.

[0017] Attached image description.

[0018] Figure 1 Scanning electron microscope image of the surface amplification material prepared in Example 1 at low magnification (5000x).

[0019] Figure 2The following are detailed experimental diagrams showing the flocculation effect of polyaluminum chloride on water: (a) shows the effect of the surface amplification material prepared in Example 1 at a dosage of 10 mg / L; (b) shows the effect of the surface amplification material prepared in Example 1 at a dosage of 15 mg / L; (c) shows the effect of the surface amplification material prepared in Example 1 at a dosage of 20 mg / L; and (d) shows the effect of the surface amplification material prepared in Example 1 at a dosage of 30 mg / L.

[0020] Figure 3 The diagram shows the optimal flocculant addition points for the surface amplification material prepared in Example 1 under various initial turbidity conditions, where (a) is the effect at a flocculant dosage of 10 mg / L; (b) is the effect at a flocculant dosage of 20 mg / L; (c) is the effect at a flocculant dosage of 15 mg / L; and (d) is the effect at a flocculant dosage of 30 mg / L.

[0021] Figure 4 The images show the flocculation and sedimentation effects of the surface amplification material prepared in Example 1 over time under different flocculation dosages, where (a) are the flocculation and sedimentation effects of groups A and B; and (b) are the flocculation and sedimentation effects of groups C and D.

[0022] Figure 5 The graph shows the effect of mechanical stirring intensity on the flocculation and precipitation effect of the surface amplification material prepared in Example 1 under different flocculation dosages. (a) Flocculation effect under stirring intensity conditions of group A; (b) Flocculation effect under stirring intensity conditions of group B; (c) Flocculation effect under stirring intensity conditions of group C; (d) Residual turbidity after two hours of precipitation in the three groups.

[0023] Figure 6 The residual turbidity of the surface amplification material prepared in Example 1 after sedimentation for two hours under different calcium ion water conditions.

[0024] Figure 7 The image shows the flocculation effect of the surface amplification material prepared in Example 1 under different turbidity water conditions.

[0025] Figure 8 This is a comparison chart of the adsorption efficiency of the surface amplification material prepared in Example 2 and the powdered carbon prepared in the comparative example.

[0026] Figure 9 The image shows the effect of the surface amplification material prepared in Example 2 on the removal of 6 odor substances at a concentration of 50 ng / L in the raw water.

[0027] Figure 10 The image shows the effect of the surface amplification material prepared in Example 2 on the removal of odor substances from the raw water under an adsorption time of 90 minutes.

[0028] Figure 11The graph shows the overall removal rate of each pollutant in the surface amplification material prepared in Example 2 at a dosage of 5 mg / L.

[0029] Figure 12 The graph shows the overall removal rate of each pollutant in the surface amplification material prepared in Example 2 at a dosage of 10 mg / L.

[0030] Figure 13 The graph shows the overall removal rate of various pollutants in the surface amplification material prepared in Example 2 at a dosage of 15 mg / L. Detailed Implementation

[0031] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the scope of protection of the present invention.

[0032] In the following embodiments, odor substances were determined by purge-trap gas chromatography-mass spectrometry (GC-MS), and other novel pollutants were determined by solid-phase extraction-liquid chromatography-mass spectrometry (LC-MS).

[0033] In the following embodiments, the scanning electron microscope image of the surface-amplified carbon material for efficiently removing new pollutants from water is as follows: Figure 1 Unless otherwise specified, all methods are conventional. Unless otherwise specified, all raw materials used in the following examples are new materials purchased from the market.

[0034] Example 1: This example provides a surface amplification powdered carbon material for efficiently removing new pollutants from water, and its preparation and application. The powdered carbon material comprises the following: 100g of raw carbon.

[0035] The aforementioned surface-amplified carbon material for efficiently removing new pollutants from water uses an air-classifying ultrafine pulverizer (KC-18 Wenzhou Kangyuanxin Co., Ltd.) to crush the raw carbon.

[0036] The carbon source for the raw material is selected from coal.

[0037] The raw material carbon has a mesh size of 8-30 and an iodine value of 850.

[0038] The aforementioned surface-amplified carbon material for efficiently removing new pollutants from water has a mesh size of 50-600 mesh, with 0.2% below 100 mesh, 4.2% between 100 and 200 mesh, 12.3% between 200 and 300 mesh, 43% between 300 and 400 mesh, 32.5% between 400 and 500 mesh, and 7.8% above 500 mesh.

[0039] The aforementioned surface-amplified carbon material for efficiently removing new pollutants from water is added to water to form a carbon suspension for dosing.

[0040] The preparation method of the surface-amplified carbon powder material for efficiently removing new pollutants from water is as follows: Step 1: Put the commercial powder into the air-classifying crusher for crushing and run for 10 minutes; Step 2: Adjust the outlet diameter difference and collect the powdered carbon blown out of the outlet to obtain surface-amplified powdered carbon.

[0041] Example 2: This example provides a surface amplification powdered carbon material for efficiently removing new pollutants from water, and its preparation and application. The powdered carbon material comprises the following: 25 kg of raw carbon.

[0042] The aforementioned surface-amplified carbon material for efficiently removing new pollutants from water uses a carbon surface amplification device to crush the raw carbon.

[0043] The powdered carbon surface amplification equipment is a continuous powdered carbon preparation system integrating crushing, grading, dust removal, and automatic recycling, with a designed processing capacity of 1.0–2.0 tons / day and a total power of 40 kW. Its core consists of a main unit (crushing unit), pulse dust collector, high-pressure induced draft fan, cyclone separator, electrical control system, and supporting container, all integrated into a standard container (dimensions: 6 m × 2.5 m × 2.9 m), enabling modular transportation and rapid on-site deployment.

[0044] The carbon source for the raw material is selected from coal.

[0045] The raw material carbon has a mesh size of 3-80 and an iodine value of 850.

[0046] The aforementioned surface-amplified carbon material for efficiently removing new pollutants from water has a mesh size of 50-600 mesh, with 9% below 100 mesh, 10.1% between 100 and 200 mesh, 25.3% between 200 and 300 mesh, 41.6% between 300 and 400 mesh, 6.7% between 400 and 500 mesh, and 5.7% above 500 mesh.

[0047] The aforementioned surface-amplified carbon material for efficiently removing new pollutants from water is added to water to prepare a 1 g / L carbon suspension for dosing, using polyaluminum chloride (PACl) as a flocculant.

[0048] The preparation method of the surface-amplified carbon powder material for efficiently removing new pollutants from water is as follows: Step 1: Put the raw charcoal into the air-classifying crusher for crushing and run for 10 minutes; Step 2: Adjust the outlet diameter difference and collect the powdered carbon blown out of the outlet to obtain surface-amplified powdered carbon.

[0049] The difference between Example 2 and the comparative example is that the comparative example uses 200-mesh commercial charcoal powder from the same manufacturer and does not involve the preparation process of the material described in this invention.

[0050] The effect of flocculant dosage.

[0051] Using PACl as the flocculant, an optimization experiment was conducted to determine the optimal flocculant dosage under different conditions of powdered carbon addition. The experiment used kaolin-based water to simulate actual raw water, with a fixed initial turbidity of 18 NTU. Four groups of carbon-containing water samples were formed by adding 10, 15, 20, and 30 mg / L of PACl (Example 1) to simulate the conditions of carbon-added water in actual applications. All experiments strictly followed a standard beaker stirring procedure: a 15-minute coagulation phase (rapid mixing, slow flocculation) before 0 minutes, and a settling phase from 0 to 120 minutes. During this period, the turbidity of the supernatant was measured periodically, and the entire dynamic evolution from floc formation to sedimentation was fully recorded. The experimental results are shown in [Figure 1]. Figure 2 .

[0052] Experimental results show that the turbidity-time curves under all operating conditions exhibit a clear three-stage characteristic: the first stage (0–10 min) is the rapid settling period, where large flocs quickly form and settle, and the turbidity drops sharply; the second stage (10–60 min) is the slow settling period, where fine flocs continue to settle, and the turbidity steadily decreases; the third stage (>60 min) is the equilibrium and stabilization period, where settling is basically completed, and the turbidity tends to be constant. Finally, the turbidity at 120 min was used as the core evaluation index to determine the retention efficiency of the pulverized carbon process in Example 1. Data analysis shows that regardless of the pulverized carbon dosage, the treatment effect of PACl exhibits a typical nonlinear response law of "first decreasing and then increasing"—that is, there is a clear optimal dosage point. Below this value, the charge neutralization and entrapment effects are insufficient; above this value, excessive aluminum salts cause colloidal restabilization or floc structure destruction, leading to a turbidity rebound, which is consistent with actual engineering experience.

[0053] See Figure 3When using low-concentration activated carbon (PAC), the PACl dosage is concentrated at low levels. With a PAC dosage of 10 mg / L, wide-sieve experiments showed that PACl was most effective in the 15–25 mg / L range. Further detailed experiments confirmed that 20 mg / L PACl could reduce the turbidity to a minimum of 0.42 NTU within 120 minutes. The sedimentation process was highly efficient and stable: within 0–10 minutes, the turbidity rapidly decreased from approximately 22 NTU (slightly increased due to the addition of activated carbon) to below 2 NTU, and by 30 minutes it was below 0.6 NTU, stabilizing completely after 60 minutes. If PACl was below 15 mg / L, the flocs were loose and sedimentation was incomplete, with the turbidity still above 1.5 NTU after 120 minutes; if it exceeded 25 mg / L, the turbidity showed a slight rebound in the later stages, indicating that the system had entered the excess zone. When the activated carbon dosage increased to 15 mg / L, the required PACl dosage increased accordingly, with 25 mg / L PACl being the optimal value, resulting in a turbidity of 0.51 NTU after 120 minutes. At this point, the sedimentation kinetics slowed down slightly, but still tended to stabilize within 60 minutes; if polyaluminum chloride was insufficient or excessive, the turbidity increased significantly, especially when it was >30 mg / L, a significant restoring phenomenon was observed.

[0054] As the dosage of activated carbon (PCC) was further increased to 20 mg / L and 30 mg / L, the system's demand for coagulant continued to increase. For the 20 mg / L PCC group, 30 mg / L PACl achieved optimal retention, with a turbidity of 0.63 NTU at 120 min; while the 30 mg / L PCC group required 35 mg / L PACl to control the turbidity at 0.78 NTU. It is noteworthy that with higher PCC dosages, not only did the optimal PACl dosage shift to the right, but the sedimentation process also slowed significantly—for example, the 30 mg / L PCC group only decreased to 6 NTU at 0–10 min, remained at 1.2 NTU at 60 min, and only stabilized at 120 min. This indicates that the higher the concentration of activated carbon particles, the greater the resistance to floc formation and the stronger the sensitivity to coagulation conditions. More importantly, the harm of excessive addition is significantly amplified under high carbon load: under 30 mg / L pulverized carbon conditions, when PACl increases from 35 mg / L to 50 mg / L, the turbidity in 120 min soars from 0.78 NTU to 2.3 NTU, an increase of nearly 200%, which is much higher than the fluctuation range of the low carbon group, indicating that the high carbon system has a lower operational error tolerance.

[0055] In summary, the correlation between different powdered activated carbon dosages and the optimal PACl dosage is as follows: 10 mg / L powdered activated carbon corresponds to 10 mg / L PACl, 12.5 mg / L corresponds to 15 mg / L, and 30 mg / L corresponds to 17.5 mg / L. This relationship is approximately linearly positive (slope approximately 1:1–1:1.2), indicating that for every 10 mg / L increase in powdered activated carbon, an additional 5–6 mg / L of PACl is required to maintain efficient retention.

[0056] The effect of mechanical flocculation time.

[0057] In actual water plant operation, mechanical flocculation tanks generally adopt a three-stage gradient decreasing speed stirring process: the first stage is rapid mixing to achieve sufficient collision between the coagulant and particles in the water; the second stage is medium-speed stirring to promote the initial aggregation of small flocs; and the third stage is slow stirring to prevent the breakage of larger flocs that have already formed, allowing them to further grow into dense flocs with good settling properties. According to the "Outdoor Water Supply Design Standard" (GB 50013-2018) and related specifications, the design flocculation time for mechanical flocculation tanks should be 15-20 minutes. In actual water plant commissioning, the three-stage flocculation gradient times are basically the same. By systematically designing four sets of flocculation programs with different time combinations (see Table 1), under the same initial dosage of powdered carbon and the same G value, the influence of the flocculation stage time allocation on the turbidity removal efficiency of carbon-containing water samples was investigated, aiming to guide the optimal retention process parameters for different coagulation processes in Example 1.

[0058] Group Name Three-stage flocculation time / min First segment GT value Second segment GT value Third segment GT value Total value A 4-4-4 22560 6672 840 30072 B 6-6-6 33840 10008 1260 45108 C 5-5-5 28200 8340 1050 37590 D 3-5-7 16920 8340 1470 26730 .

[0059] Experimental data show (see) Figure 4The duration and distribution of flocculation time significantly affect the final effluent turbidity. Overall, all experimental groups exhibited a typical turbidity evolution pattern of "rapid initial decrease followed by slow stabilization": in the initial sedimentation stage (0–15 min), turbidity decreased sharply, indicating that rapid mixing and initial sedimentation were key to removal; in the middle sedimentation stage, turbidity continued to decrease slowly, but the rate slowed significantly, stabilizing at 120 min. Finally, the turbidity of the water at 120 min of sedimentation was used as the core evaluation index, clearly reflecting the advantages and disadvantages of different flocculation time combinations. Comparing groups A (total 12 min), C (total 15 min), and B (total 18 min): Group B showed superior removal efficiency across all PACl dosages. This indicates that appropriately extending the total flocculation time promotes more complete floc growth and maturation, especially providing sufficient time in the slow phase (third stage) to effectively encapsulate fine carbon powder into the large floc structure, thereby improving sedimentation efficiency. Furthermore, the optimal PACl dosage range is around 10 mg / L, which helps save on dosage. Compared to group D, group B showed more stable overall performance under different carbon powder dosages due to the uniform flocculation time across the three stages. Therefore, the recommended optimal time allocation scheme for the three-stage gradient decreasing flocculation is a combination of 6 min-6 min-6 min, which provides sufficient total time, balanced stages, and a moderate GT value, effectively promoting efficient encapsulation and sedimentation in Example 1. Simultaneously, the time allocation strategy is more valuable for regulation than simply extending the total time; priority should be given to extending the slow phase to promote floc maturation, avoiding excessive extension of the rapid mixing phase. If option A is selected, the recommended dosage of pulverized activated carbon is 10 mg / L. If option B is selected, the recommended dosage is 10 mg / L. If option D is selected, the recommended dosage is 10 mg / L or 20 mg / L.

[0060] The effect of concrete strength.

[0061] To guide the dosage of pulverized carbon for different coagulation intensities, three groups of significantly different stirring energy input schemes were designed (see Table 2): Group A (three-stage gradient speed: 120rpm–60rpm–30rpm), Group B (three-stage gradient speed: 150rpm–100rpm–50rpm, total GT value 37600), and Group C (three-stage gradient speed: 180rpm–120rpm–60rpm, total GT value 64972). Each group maintained a three-stage time allocation (5 min–5 min–5 min), and the floc formation kinetics and sedimentation performance were comprehensively evaluated by real-time turbidity monitoring curves and turbidity bar charts at the final sedimentation endpoint. The flocculation GT for each stage is shown in Table 2.

[0062] Group First segment GT Second GT Third segment GT Total value A 14438 1804 225 16468 B 28200 8356 1044 37600 C 48730 14438 1805 64972 .

[0063] Experimental data can be found Figure 5In the low-energy gradient group A, the optimal dosage of powdered carbon under this scheme is 12.5 mg / L. However, due to insufficient initial shear force, the colloidal particles failed to fully collide and destabilize, resulting in a slow decrease in turbidity in the first 5 minutes. It was not until the second stage that significant aggregation began. Although the third stage was conducive to floc growth, due to insufficient nucleation in the early stage, the lowest turbidity at 120 min was still maintained at about 0.9 NTU, which did not reach the ideal clarification level. Therefore, this coagulation scheme is not recommended. In contrast, gradient group B exhibited the best synergistic effect: the first stage of high shear rapidly broke the double-layer stability, causing the turbidity to drop sharply to below 5 NTU within 5 minutes; the second stage of moderate deceleration promoted effective collision and initial formation of micro-flocs; the third stage of low-speed maturation avoided destroying the already formed dense flocs, allowing them to continue to sink during the settling period, and finally the turbidity stabilized in the range of 0.4–0.6 NTU. Moreover, it was superior to the other two groups under all dosage conditions, especially when the optimal powdered carbon dosage (10 mg / L) was most outstanding. This shows that the energy distribution of group B not only ensured sufficient destabilization driving force, but also took into account the mild environment required for floc growth, which is in line with the ideal mode of "rapid mixing + slow flocculation" in classical coagulation theory. Under the C-group scheme with strong flocculation intensity, the optimal powdered activated carbon dosage is 12.5 mg / L. Although the first stage of ultra-high shear can reduce turbidity to below 3 NTU in a very short time, the excessively high energy input in the second and third stages will also break up some of the already formed fragile flocs. This is manifested in the turbidity curve showing a slight rebound or no decrease in turbidity at 20–40 min. This phenomenon is more obvious under low dosage conditions. Finally, at the end of sedimentation, the residual turbidity of the C-group under most operating conditions is actually higher than that of the B-group. It is recommended to ensure that the powdered activated carbon dosage is above 10 mg / L. Figure 5 The horizontal comparison clearly shows that under all dosage gradients, the final turbidity of group B is the lowest, while groups A and C suffer performance degradation due to "insufficient energy" and "excessive energy" respectively. Therefore, the recommended mechanical flocculation stirring frequency scheme is 150rpm-100rpm-50rpm.

[0064] The effect of calcium chloride.

[0065] To guide the coagulation-sedimentation process of calcium chloride as a coagulant aid at different dosages, data are shown below. Figure 6 The experiment included six concentration gradients: 0 mg / L, 10, 20, 50, 100, and 200 mg / L. The regulatory effect of Ca on floc formation kinetics and final sedimentation performance was evaluated using real-time turbidity monitoring curves. The results showed that an appropriate amount of Ca... 2+ The introduction of [a substance] can significantly enhance colloid destabilization and floc compaction, but excessive addition will trigger "restabilization" or structural loosening effect, exhibiting a typical "inverted U-shaped" response characteristic, indicating that there is an optimal coagulant dosage window to maximize effectiveness.

[0066] In the low-dose range (10–20 mg / L), the double-layer compression effect of calcium ions on negatively charged colloidal particles promotes more efficient collision and aggregation of hydrolyzed products of charcoal and suspended solids. Compared with the calcium-free control group, this group showed a faster rate of turbidity decrease during the flocculation stage (0–5 min), especially in the early sedimentation stage (5–20 min). The turbidity of the 10 mg / L and 20 mg / L groups rapidly dropped below the 1 NTU threshold and stabilized in the 0.2–0.3 NTU range after 60 min, which was better than the approximately 0.4 NTU level of the blank group. When the dosage was increased to 50 mg / L, calcium ions not only fully completed the charge neutralization task but also moderately participated in the "netting and sweeping" mechanism, significantly improving the interception capacity and achieving peak coagulation effect. At this time, the turbidity curve dropped below 0.5 NTU within 20 min, and the turbidity at the 120-min endpoint was as low as approximately 0.2 NTU, the lowest among all groups. It is worth noting that the 50 mg / L group maintained a steady downward trend during the mid-sedimentation period (20–60 min) without any rebound or plateau, indicating good floc stability and strong shear resistance, making it suitable for sedimentation tanks with long hydraulic retention times in practical engineering. However, when the calcium chloride dosage was further increased to 100 mg / L and above, the excessively high calcium ion concentration caused a reversal of the surface charge of the colloids, changing from negative to positive, resulting in electrostatic repulsion and hindering further aggregation. The coagulation performance began to decline. Although the 100 mg / L group was still better than the blank control, its endpoint turbidity rose to around 0.5 NTU. The 200 mg / L group performed the worst, with high turbidity throughout, remaining above 1.2 NTU at 120 min, even exceeding the effect of some low-dose powdered activated carbon alone.

[0067] From an engineering application perspective, in conventional surface water treatment, if the raw water has low alkalinity or high organic matter content, adding an appropriate amount of calcium chloride (recommended 20–50 mg / L) can be an economical and effective enhancement method, especially suitable for low-temperature, low-turbidity, or high-color water sources. However, excessive addition must be strictly avoided to prevent adverse effects. In the future, water plants can dynamically adjust the coagulant addition strategy based on online monitoring of the calcium ion concentration and alkalinity ratio of the influent water quality, achieving the dual goals of precise pollution control and cost optimization.

[0068] The effect of turbidity.

[0069] Under different initial turbidity conditions, the removal effect of polyaluminum chloride (PAC) as a flocculant on water turbidity showed significant differences. Experimental data are shown below. Figure 7 .

[0070] The data shows that when the initial turbidity is 10 NTU, the optimal dosage of polyaluminum chloride (PAC) is 15 mg / L. This indicates that for low-turbidity water sources, the dosage can be strictly controlled at around 15 mg / L. In comparison, when the initial turbidity is 18 NTU, the optimal PAC dosage is also at 15 mg / L, at which point the remaining turbidity is only 0.25 NTU. Under the condition that the initial turbidity is as high as 30 NTU, the optimal PAC dosage increases to 20 mg / L.

[0071] The combined data from the three sets show that as the initial turbidity increases, the amount of PAC required to achieve the best treatment effect increases accordingly, and the system's sensitivity to dosage changes gradually decreases. This not only verifies the theoretical expectation that "the higher the turbidity, the stronger the required charge neutralization and adsorption bridging effect," but also provides important guidance for actual water plant operation: a dynamic dosing model based on raw water turbidity should be established. For example, for low-turbidity water, precise dosing is recommended (15±5 mg / L); for medium-turbidity water, the dosage can be appropriately relaxed (15–20 mg / L); and for high-turbidity water, the dosage can be appropriately increased (20–25 mg / L) to ensure stable effluent quality.

[0072] Comparison of adsorption efficiency between the surface amplification material prepared in Example 2 and the comparative example.

[0073] 2-MIB is difficult to treat using conventional processes, and in actual production, it easily exceeds national standards, leading to water plant shutdowns. Using 2-MIB as a typical new pollutant, adsorption efficiency experiments were conducted. Comparative example and Example 2 were added to a 50 ng / L 2-MIB solution (natural water spiked) at a dosage of 10 mg / L. Samples were taken at certain time intervals, and the pollutant response values ​​were measured after passing through a 0.45 μm water filter. Adsorption efficiency was compared based on the C / C ratio. Experimental results are as follows: Figure 8 As shown.

[0074] Depend on Figure 8 It is evident that the adsorption efficiency of odor substances in Example 2 and the comparative example significantly improved with increasing adsorption time. Since Example 2 was freshly ground and used immediately, it had a higher proportion of 300-500 mesh particles. At adsorption times of 30 minutes, 60 minutes, and 90 minutes, the removal rate of 2-MIB in Example 2 was significantly higher than that in the comparative example. The adsorption efficiency of the surface-amplified powdered carbon for pollutants was significantly higher than that of commercially available powdered carbon from the same manufacturer.

[0075] Example 2 demonstrates the effectiveness of the surface amplification material prepared in removing odor substances from raw water used in water treatment plants.

[0076] The effectiveness of the surface-amplified material prepared in Example 2 in removing odor substances from raw water was investigated in a beaker experiment. Figure 9As shown, under the condition of an initial pollutant concentration of 25 ng / L, Example 2 achieved removal rates of 92%, 86%, 85%, 92%, 69%, and 91% for dimethyl disulfide (DMDS), dimethyl trisulfide (DMTS), 2-ethyl-5,5-dimethyl-1,3-dioxane (2-EDD), 2-ethyl-5-methyl-1,3-dioxane (2-EMD), 2-methylisoborneol (2-MIB), and geosin (GSM), respectively.

[0077] Depend on Figure 10 As shown, under the condition of an initial pollutant concentration of 50 ng / L, Example 2 achieved removal rates of 87%, 87%, 88%, 93%, 81%, and 90% for DMDS, DMTS, 2-EDD, 2-EMD, 2-MIB, and GSM, respectively. Under the condition of an initial odorant concentration of 25 ng / L and an adsorption time of 90 minutes, a powdered activated carbon dosage of 17.5 mg / L resulted in odorant concentrations in the water below the limits stipulated by the national drinking water standards; under the condition of an initial odorant concentration of 50 ng / L and an adsorption time of 90 minutes, a powdered activated carbon dosage of 20 mg / L resulted in odorant concentrations in the water below the limits stipulated by the national drinking water standards.

[0078] The surface amplification material prepared in Example 2 at the on-site water plant was used in the practical application of removing new pollutants from the water.

[0079] The surface-amplified material prepared in Example 2 was applied to a modern waterworks with a capacity of 100,000 tons as a pilot plant for a two-week continuous operation test. The test strictly followed the mainstream process flow of "influent-pre-ozone-coagulation-sedimentation-sand filtration-carbon filtration-post-ozone-effluent", and focused on investigating the removal characteristics of surface-amplified powdered activated carbon at different dosages (5 mg / L, 10 mg / L, 15 mg / L) for more than 30 typical new pollutants in the water (including antibiotics, endocrine disruptors, perfluorinated compounds, pesticides and synthetic organic compounds).

[0080] By comparing the pollutant concentration changes at five key nodes—raw water entering the plant, pre-ozonated effluent, sand filter effluent, carbon filter effluent, and clear water tank effluent—multiple radar charts were generated. This systematically revealed the dose-effect relationship between the dosage and removal efficiency, and verified the applicability of the "adsorption kinetics hierarchy" theory derived from the previous laboratory study in complex real-world water quality.

[0081] At a low dose of 5 mg / L ( Figure 11The system exhibits significant selective removal characteristics, primarily relying on the hydrophobicity and molecular structure of the pollutants themselves. Data shows that even at low dosages, high removal rates can be achieved for highly hydrophobic substances in the first tier, such as carbamazepine (CBZ), atrazine, and some sulfonamide antibiotics (e.g., sulfamethoxazole). Specifically, the removal rate of carbamazepine in the effluent of the activated carbon filter is close to 90%, and the final removal rate in the clear water tank exceeds 95%; the removal rate of atrazine is also stable above 80%. This is mainly attributed to the extremely high octanol-water partition coefficient (log Kow > 3.0) and planar aromatic structure of these substances, enabling them to be rapidly captured by the abundant micropores of the surface-amplified powdered activated carbon through hydrophobic interactions and π-π electron donor-acceptor interactions, with minimal impact from competitive adsorption by natural organic matter in the water.

[0082] However, for second- and third-tier substances with strong polarity or large molecular weight, a dosage of 5 mg / L is insufficient. For example, the removal rates of bisphenol A (BPA) and bisphenol F fluctuate only in the range of 40%–50%, while the removal rates of odor-causing substances such as geosmin and 2-methylisocyanate are even lower than 30%. This is even more pronounced with the perfluorinated compounds (PFASs) series, including perfluorooctanoic acid (PFOA), perfluorooctane sulfonic acid (PFOS), and their precursors, whose removal rates throughout the process are generally below 20%. Some short-chain perfluorinated compounds even exhibit negative removal (i.e., increased detection concentration), which may be due to the conversion of long-chain precursors into short-chain products during oxidation or biological processes.

[0083] Furthermore, the removal rates of hydrophilic drug residues such as caffeine and codeine hovered between 30% and 40%, indicating that under low carbon content conditions, the limited adsorption sites of surface-amplified powdered activated carbon are preferentially occupied by high-affinity substances, making it difficult for low-affinity substances to obtain effective adsorption opportunities. The data under this condition strongly demonstrates that although a dosage of 5 mg / L can reduce some high-risk hydrophobic pollutants to a certain extent, it cannot achieve in-depth control of a broad spectrum of new pollutants, making it difficult to meet increasingly stringent drinking water quality standards.

[0084] When the powdered carbon dosage was 10 mg / L, the carbon filter became the core unit for removing new pollutants. Experimental data can be found in [link to experimental data]. Figure 12 .

[0085] Comparing the data from the sand filter effluent and the carbon filter effluent reveals a sharp drop in the concentration of most pollutants at this stage. For example, the removal rate of sulfonamide antibiotics in the sand filter is only 10%–20%, but after passing through the carbon filter, the removal rate surges to 60%–70%. This indicates that the surface amplification material prepared in Example 2 not only plays a physical retention role but also achieves deep chemical adsorption through its huge specific surface area and specific surface chemical properties. Simultaneously, the pre-ozonation unit oxidizes and decomposes some large, recalcitrant organic molecules into smaller, easily adsorbable intermediates, showing a certain reduction in the concentration of some pollutants in the pre-ozonation effluent. However, even at a dosage of 10 mg / L, the removal rate of a small number of highly polar and water-soluble substances (such as certain perfluoroethers and dimethylaminosulfides) remains around 40%. This suggests that for such "hard-to-crack" pollutants, simply increasing the dosage of physical adsorbents may lead to diminishing marginal returns, and it is necessary to consider coupling with advanced oxidation and other enhancement methods.

[0086] Furthermore, the overall removal rate of the vast majority of target pollutants exceeded the 60% threshold, with some substances even reaching over 90%. Specifically, bisphenols, which previously performed poorly at low doses, saw a significant increase in removal rates to 70%–80%; the removal rates of geosmin and 2-methylisocyanate also jumped to 60% and 55%, respectively, demonstrating that Example 2 has good adsorption potential for odor-causing substances, and that sufficient dosage can effectively control odors. Notably, the perfluorinated compound family also showed significant removal effects under these conditions, with the removal rate of long-chain PFASs (such as PFOA and PFOS) increasing to 40%–50%, while short-chain compounds, although still more difficult to remove, reached a level of 20%–30%. This indicates that increasing the amount of carbon can effectively alleviate the competitive adsorption of organic matter, providing more remaining adsorption sites for polar substances.

[0087] Under high-dose conditions of 15 mg / L ( Figure 13 The surface-amplified material prepared in Example 2 achieved a total removal rate of over 80% for most new pollutants, with some dominant substances even approaching 100% complete removal. The overall coverage area of ​​the radar chart was significantly expanded. Specific data showed that the removal rates of substances such as carbamazepine, atrazine, and sulfamethoxazole were close to 100%, while the removal rates of substances such as bisphenol A and geosmin were increased to 90%. For the most difficult-to-remove perfluorinated compounds, the removal rate of long-chain PFASs reached 60%–70% at a dosage of 15 mg / L, and the removal rate of short-chain compounds also increased to 40%–50%.

[0088] Comparing the data curves for 10 mg / L and 15 mg / L reveals that while the overall removal rate of pollutants improves at a dosage of 15 mg / L, the increase is much more gradual compared to the jump from 5 mg / L to 10 mg / L. For example, the removal rate of carbamazepine increases by only 3% from 95% to 98%, indicating that this substance is easily adsorbed. The removal rate of perfluorooctanoic acid (PFOA) increases by 15 percentage points from 50% to 65%. Therefore, 15 mg / L may already be close to the optimal economic dosage point under these water quality conditions. While further increasing the dosage can further reduce trace residues, considering the costs of reagents, sludge disposal, and operating energy, unless facing a sudden high-concentration pollution event or extremely stringent effluent standards, 10–15 mg / L should be the recommended range for routine operation.

[0089] The radar chart data from the three dosage levels show that the pre-ozonation unit directly degraded some easily oxidizable pollutants (such as some antibiotics and phenols), and may have disrupted the structure of large-molecule natural organic matter in the water, reducing their competition for adsorption sites of the surface amplification material prepared in Example 2, thereby indirectly improving the adsorption efficiency of the powdered carbon for the target new pollutants. Secondly, the sand filter mainly removed some pollutants adsorbed on suspended particles through physical interception, reducing the load on the subsequent carbon filter. Finally, the dosing point of the surface amplification material prepared in Example 2 (usually before the carbon filter or in a separately set contact tank) is the decisive factor in the removal efficiency, and its dosage directly determines the safety margin of the final effluent.

[0090] In summary, this 100,000-ton / day pilot-scale test successfully verified the core technological value of surface-amplified powdered activated carbon (SAP) in addressing the challenges of new pollutants. It not only solves the problems of low adsorption capacity and large dosage required by traditional powdered activated carbon, but also achieves a perfect balance between water quality safety and economic operation through precise dosage control, providing strong technical support and empirical data for the upgrading of advanced drinking water treatment processes in my country.

[0091] The present invention and its embodiments have been described above. This description is not restrictive, and the accompanying drawings are only one embodiment of the present invention. The actual application is not limited to this. In conclusion, if those skilled in the art are inspired by this description and design similar methods and embodiments without departing from the spirit of the present invention, they should all fall within the protection scope of the present invention.

Claims

1. A surface-amplified carbon material for efficiently removing new pollutants from water, characterized in that, The surface-amplified carbon material uses raw carbon as a raw material.

2. The surface-amplified carbon material for efficiently removing new pollutants from water according to claim 1, characterized in that, The raw material carbon is crushed using an air-separation crusher.

3. The surface-amplified carbon material for efficiently removing new pollutants from water according to claim 1, characterized in that, The carbon source of the raw material is selected from any one of coal, wood, and coconut shell.

4. The surface-amplified carbon material for efficiently removing new pollutants from water according to claim 1, characterized in that, The raw material carbon has a mesh size of 1-100 and an iodine value of 400-1200.

5. The surface-amplified carbon material for efficiently removing new pollutants from water according to claim 1, characterized in that, The surface-amplified carbon powder materials have a mesh size of 1-600 mesh, of which 300-500 mesh accounts for 50-80%.

6. The surface-amplified carbon material for efficiently removing new pollutants from water according to claim 1, characterized in that, It is added to water to prepare a powdered carbon suspension for dosing.

7. A surface-amplified carbon material for efficiently removing new pollutants from water according to any one of claims 1-6, characterized in that, The specific preparation method is as follows: Step 1: Put the raw charcoal into the air-classifying crusher for crushing, run for 1-20 minutes; Step 2: Adjust the outlet diameter difference and collect the powdered carbon blown out of the outlet to obtain surface-amplified powdered carbon.

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