矿物法——环境污染治理的第四类方法

New advances in the study of environmental mineralogical materials: Pollution treatment by inorganic minerals—the fourth category of pollution treatment methods.

总结介绍了近10年开展环境矿物材料研究所取得的较为系统的研究成果。新提出环境矿物材料基本性能,包括矿物表面效应、孔道效应、结构效应、离子交换效应、结晶效应、溶解效应、水合效应、氧化还原效应、半导体效应、纳米效应及矿物生物交互效应等。展示环境矿物材料开发应用方面的崭新成就,包括利用天然铁的硫化物矿物强还原性,发明一步法还原Cr(Ⅵ)与沉淀Cr(Ⅲ)废水处理新工艺;利用天然锰的氧化物矿物强氧化性,发明处理高浓度与强污染的印染和酚类废水新方法;利用天然钛的氧化物矿物日光催化性,发明光催化降解卤代有机污染物新方法;利用天然蛭石高温脱水膨胀热效应,发明能大幅度提高型煤固硫率与除尘新方法;利用天然钙基蒙脱石低成本制备出同时防止水体与无机和有机污染物渗漏的自愈性强的填埋场衬层建造用新型防渗材料,发明生活垃圾尤其是危险废物填埋场衬层建造新工艺;发现凝灰岩与花岗岩中长石类矿物发育有良好的孔道结构,核素进入可发生固定化作用,成为有效阻滞核素迁移的天然屏障;利用天然纳米管状纤蛇纹石成功制备二氧化硅纳米管,接枝有机物可由亲水性变为疏水性;利用黄钾铁矾的胶体特征作为多金属矿山废石堆隔离防渗层,防止金属硫化物矿物氧化分解与矿山酸性废水污染等。着重指出今后环境矿物?

A series of case studies related to environmental mineralogical materials, which have mostly been accomplished by our group over the last ten years, are described in the paper. It is new to put forward the basic properties of purification function of environmental mineralogical materials, including surface adsorption, porous filtration, defects of crystal structure, ionic exchange, crystallography, dissolution, hydration, redox, semiconductor effect, nanomineralogy and mineralogical-biological interactions. The prospective investigation and utilization of environmental mineralogical materials have been dealt with in more detail. Cr(VI)-bearing wastewater can be treated by natural iron sulphides which are used as reductant to reduce Cr(VI) and as precipitant to precipitate Cr(III) simultaneously. The cryptomelane may be the real mineral of the active octahedral molecular sieve in nature to degrade phenol sewage and to decolorize dye. Natural rutile TiO_2 shows photocatalysis on degrading trichloroethylene and tetrachloroethylene. Expansion of vermiculite develops loose interior structures inside the briquette, and thus brings enough oxygen for combustion and sulphation reaction. Effective combustion of the original carbon reduces amounts of dust in the fly ash. Batch experiments were conducted using the CTMAB-Montmorillonite as sorbent to adsorb aromatic contaminants that are detected frequently in the leaching water from municipal waste deposits. The CTMAB modification proves very effective in enhancing the sorption capacity of the sorbent. Porous feldspar from tuff and granite can immobilize nuclides and therefore it can be used as natural barrier to prevent nuclide migration in the rocks that are wall rocks of nuclide waste landfill. Acid-eroded derivative of natural chrysotile is non-crystalline silicon dioxide shaped as nano-fibriform. The property of dimethylsilyl derivative of the non-crystalline silicon dioxide changes from hydrophile to hydrophobe. The colloid characteristics of jarosite can be used to insulate metal minerals from air and surface water to prevent contamination of acid mining drainage in metal ore mines. More emphasis is put on the research on the mineralogical photocatalysis in natural self-purification of inorganic minerals. The systematic research is very important to realize redox of organic contaminants, especially the permanent organic contaminants that cannot be degraded by themselves. The new advances are of significance in finding the natural self-purification in inorganic world and show that the mineralogical method (Natural Mineralogical Technology, NMT) for pollution treatment and environmental remediation, can act as the fourth category of pollution treatment methods following the physical, chemical and especially biological methods.