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年度	113	專案性質	實驗性質
專案類別	研究專案	研究主題	整治
申請機構	國立臺灣大學	申請系所	生物環境系統工程學系
專案主持人	潘述元	職等/職稱	副教授
專案中文名稱	生物質衍生水膠材料於永續土壤管理效益評估及可行性分析
中文關鍵字	永續土壤管理,重金屬,生物基水膠循環材料
專案英文名稱	Biomass-Derived Hydrogel Materials for Sustainable Soil Management and Feasibility Study
英文關鍵字	Sustainable Soil Management, Heavy Metal, Biomass-Derived Hydrogel Materials
執行金額
執行期間	2024/11/1 至 2025/11/30
計畫中文摘要	本研究計畫執行期程為一年，開發「本土化生物基水膠循環材料」，利用殼聚醣/海藻酸鹽/生物炭製作成一複合材料，進行土壤中重金屬固定或去除，並將材料磁性修飾以易於從土壤中分離回收複合材料。本研究透過此複合材料之重金屬吸附容量吸附土壤重金屬；此外，磁性化材料能更有利於從土壤中將其分離；再者，水凝膠作為土壤改良劑，可實現土壤營養鹽與水分保持之功能，減少農業非點源污染，並增加作物與土壤健康程度，兼顧綠色永續整治目標。本計畫主要研究目標包括：（一）持續蒐集國際間土壤綠色永續整治材料最新進展，精進本土化生物基水膠循環材料製備程序；（二）進行模擬水田/旱田大盆試驗，建立土壤重金屬流向分析及質量平衡；（三）建立複合材料之反應動力學與等溫吸附模型，評估生物基水膠循環材料之環境穩定性，研提施用頻率及劑量等標準施用流程；（四）進行材料製備成本分析，評估程序碳排放及環境效益（例如：作物安全、土壤保水、土壤健康、氣候變遷土壤韌性提升等面向）。 本計畫已成功製備殼聚醣/海藻酸鈉/生物炭水凝膠球珠（CS/ALG/BC）材料，製備方法透過在殼聚醣溶液中加入氯化鈣，一來是形成晶球狀水凝珠，二來是利用殼聚醣在外層再形成一層保護結構。此保護結構能穩定水凝膠球珠結構，避免其因烘乾後碎裂，且浸泡水中亦能回復到原本體積。隨後，取烘乾後的 CS/ALG/BC 球珠，經與界面活性劑在硫酸鐵溶液混和攪拌1小時使 Fe(II) 吸附於球珠上，接著在通氮氣的厭氧環境下，緩慢滴入NaBH4還原劑將 Fe(II) 還原成 Fe(0)，成功製備負載奈米級零價鐵殼聚醣/海藻酸鈉/生物炭水凝膠球珠（nZVI/CS/ALG/BC）。雖然奈米級零價鐵容易氧化成氧化鐵（Fe2O3），但會在水凝膠外層形成一層氧化球殼，此球殼能保護內部之 Fe(0)。針對 nZVI/CS/ALG/BC 材料進行液相重金屬吸附試驗結果顯示，吸附容量隨著吸附時間的增加而提升，在前 60 分鐘材料吸水後吸附點位增加，吸附速率在60分鐘至2天加快，約2至4天後達到相對穩定之吸附容量（趨於飽和）。當重金屬初始濃度越高時，材料能夠達到的吸附容量也越高。在測試的最高初始濃度下，吸附容量 Qe 以質量計，鉛（Pb）最高達 41.70 mg/g，銅（Cu）達 30.66 mg/g，鉻（Cr）達 16.03 mg/g。吸附動力學模擬結果，偽二階動力學模型的R2值在 0.9924∼0.9982 之間，結果顯示此材料吸附模式以化學吸附為主，作用機制包含沉澱、電子交換或形成共價鍵。Freundlich 等溫吸附模型的R2值極高（0.9943∼0.9999），表示材料吸附形式以多層吸附為主，且材料表面的吸附點位分布不均勻。根據 Freundlich 模型的分析，銅（Cu）和鉻（Cr）的吸附強度大於鉛（Pb）。 關於使用實際受污染土壤（污染型態以鉻、鉛及銅為主）吸附試驗中，吸附速率在 14∼21 天後漸減；當複合材料添加量為 2.0 克/100 克 土壤時，經過 28 天後，重金屬的去除率分別為：鉛約 27%、銅約 25%、鉻約 21%。作物盆栽試驗探討重金屬於土壤系統中之流向與分布，預期水凝膠材料能達到韌性整治之效果。試驗組添加1 g 水凝膠/100 g土壤。在對照組中，因重金屬（鉻）為離子態，約有 93∼95% 之重金屬容易隨著入滲水滲流離開土壤環境。於實驗組中施用水凝膠材料後，關於材料本身吸附輸入鉻之總量，水田盆栽試驗組約為 7.0%，旱田盆栽試驗組約為 12%。綜合以上，此研發材料施用可明顯降低鉻金屬於滲流水中之含量（水田盆栽試驗組減少約 6%；旱田盆栽試驗組減少 11%）、土壤累積量減少（水田盆栽試驗組減少 22%；旱田盆栽試驗組減少 25%），以及作物吸收量也減少（水田盆栽試驗組減少 50%；旱田盆栽試驗組減少 33%）。
計畫英文摘要	This research project is the development of "localized biomass-based hydrogel recycling materials" is planned. A material made from chitosan/alginate/biochar will be created and magnetically modified to fix or remove heavy metals from soil. This study aims to use the heavy metal adsorption capacity of this material to adsorb heavy metals from soil. Additionally, the magnetic modification facilitates easier separation of the material from the soil. Furthermore, hydrogels can serve as soil amendment, achieving nutrient and moisture retention in the soil, reducing non-point source pollution in agriculture, and enhancing crop and soil health, thereby aligning with the goal of green and sustainable remediation. The main research objectives of this project include: (1) continuously collecting the latest international developments in green and sustainable soil remediation materials to improve the preparation process of localized biomass-based hydrogel recycling materials; (2) conducting large-scale pot experiments simulating paddy/upland fields to establish heavy metal flow analysis and mass balance in soil; (3) establishing the reaction kinetics and isothermal adsorption models of the material to evaluate the environmental stability of the biomass-based hydrogel recycling material and proposing standard application procedures, including application frequency and dosage; (4) conducting a cost analysis of material preparation and evaluating carbon emissions and environmental benefits of the process (e.g., crop safety, soil moisture retention, soil health, and enhanced soil resilience to climate change). This project successfully fabricated chitosan/sodium alginate/biochar hydrogel beads (CS/ALG/BC). The preparation method involved adding calcium chloride to a chitosan solution, which not only induced the formation of spherical hydrogel beads but also created an additional protective chitosan layer on the surface. This protective layer stabilized the hydrogel structure, preventing cracking after drying and enabling the beads to re-swell to their original volume upon immersion in water. The dried CS/ALG/BC beads were then mixed with a surfactant in a ferrous sulfate solution and stirred for one hour to allow Fe(II) adsorption onto the beads. Under a nitrogen atmosphere, sodium borohydride (NaBH₄) was slowly added as a reducing agent to convert Fe(II) to Fe(0), yielding nano zero-valent iron–loaded hydrogel beads (nZVI/CS/ALG/BC). Although nano zero-valent iron tends to oxidize into iron oxide (Fe₂O₃), an oxidized shell forms on the outer layer of the hydrogel, protecting the Fe(0) core from further oxidation. Liquid-phase adsorption experiments for heavy metals demonstrated that the adsorption capacity of nZVI/CS/ALG/BC increased with contact time. During the first 60 minutes, water absorption expanded the number of available adsorption sites, accelerating the rate between 60 minutes and 2 days, and reaching a relatively stable capacity (near saturation) after 2–4 days. Higher initial metal concentrations led to greater adsorption capacities. At the highest tested concentrations, the equilibrium adsorption capacities (Qₑ) reached 41.70 mg/g for Pb, 30.66 mg/g for Cu, and 16.03 mg/g for Cr. Kinetic modeling showed that the pseudo-second-order model fitted best, with R² values ranging from 0.9924 to 0.9982, indicating that chemisorption dominated through mechanisms such as precipitation, electron exchange, or covalent bonding. The Freundlich isotherm model also exhibited high R² values (0.9943–0.9999), suggesting multilayer adsorption on heterogeneous surfaces. According to Freundlich analysis, the adsorption intensity followed the order Cu > Cr > Pb. In contaminated soil adsorption tests (mainly containing Cr, Pb, and Cu), adsorption rates declined after 14–21 days. When 2.0 g of composite material was added per 100 g of soil, the removal efficiencies after 28 days were approximately 26.50% for Pb, 24.56% for Cu, and 21.38% for Cr. A pot experiment was conducted to investigate the migration of heavy metals in soil systems and evaluate the hydrogel’s potential for resilient remediation. In the experimental group (1 g hydrogel/100 g soil), 93–94.5% of ionic Cr leached out with percolating water in the control group, whereas in hydrogel-treated soils, the material adsorbed about 7.0% (paddy soil) and 12% (upland soil) of the total Cr input. Application of the hydrogel reduced Cr concentrations in leachate by 5.8% (paddy) and 10.8% (upland), decreased soil accumulation by 22% (paddy) and 25% (upland), and lowered plant uptake by 50% (paddy) and 33% (upland), demonstrating the material’s effectiveness in mitigating heavy metal mobility within soil systems.