含油廢水不斷排放對環境造成威脅，因此迫切需要高效油水分離材料。另外，全球對於水需求大幅增加，目前常用的海水淡化技術存在高能耗、高成本或二次汙染等問題，因此利用太陽能蒸發技術進行水處理引起了極大的關注。本研究使用菱角炭相關材料進行廢水純化與海水淡化之應用。
1.菱角炭粉於油/水乳化液分離之應用
我們發現菱角炭粉具有超親水、水中超疏油特性，因此在水潤濕後可應用於油在水中乳化液之分離。油在水中乳化液最大通量為74700±3800 L h^(-1) m^(-2) bar^(-1)，濾液油含量<10 ppm。此外，我們發現菱角炭亦展現油中超親水特性，可在油中吸附水滴，進而成功分離水在油中乳化液，水在油中乳化液最大通量241000±6770 L h^(-1) m^(-2) bar^(-1)，濾液油純度>99.99%。菱角炭在兩種乳化液皆展現突出的分離效率與良好的重複使用性。菱角炭也展現純化含金屬離子水溶液與含染料廢水溶液的效果。
2.疏水性菱角炭粉應用於太陽能蒸發
經米糠蠟改質後之菱角炭具有疏水性與水面漂浮特性，可應用於製備低成本太陽能蒸發器，蒸發海水以獲得飲用水。疏水性菱角炭在1kW m^(-2)太陽光下可獲得蒸發速率1.1kg m^(-2) h^(-1)，並在不同濃度鹽水水溶液、長時間照明下，仍有穩定的蒸發速率。海水在蒸餾後，蒸餾水中的鈉、鎂、鈣、鉀離子濃度均低於世界衛生組織的飲用水標準。
我們將使用後的菱角炭粉，摻混於土壤進行盆栽實驗，經過七個月的種植後植物仍綠意盎然，說明其具有良好的環境相容性。基於本研究的菱角炭相關材料之特性，相信其在廢水純化與海水淡化領域會有相當良好的應用性。

Herein, we applied carbonized water caltrop grains (CWCGs)-based materials in wastewater purification and solar evaporation. This study includes two subjects and describes as follows, respectively:
1. The application of CWCGs in emulsion separations.
We found that CWCGs possessed superhydrophilicity, underwater superoleophobicity and under oil superhydrophilicity. Those materials can be used for separations of both oil-in-water and water-in-oil emulsions with very high fluxes (up to 74700 and 241000 L h^(-1) m^(-2) bar^(-1) for oil-in-water and water-in-oil emulsions, respectively) and outstanding separation performance. Besides, CWCGs also can be used for treating wastewater containing metal ions or dyes.
2. Preparation of hydrophobic CWCGs (HCWCGs) for solar evaporation and water purification.
We prepared HCWCGs from CWCGs and rice bran wax. HCWCGs possessed self-floating ability and can be used as photothermal converters. Under one sun irradiation, the evaporation rate of water for the HCWCGs is 1.1kg m^(-2) h^(-1). After the desalination of the seawater, the ion concentrations of Na+, Ca2+, K+, and Mg2+ reduced sharply at a level considerably less than the safe-drinking-water values provided by the WHO.
Finally, we perform pot experiments with used CWCGs and HCWCGs. After seven months, plants still grown well indicating good biocompatibility of CWCGs and HCWCGs. The high performance of CWCGs-based materials suggests that they have great potential for practical application.

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