Chapter 8 Soil colloidal chemistry and soil surface reaction ■■■ 高子 Nat 交换机制 H Ca++ 土壤胶体带负 电荷,其表面上吸 附着很多阳离子 这些阳离子可 以被土壤溶液中的 其它阳离子替换下 来 a
Chapter 8 Soil colloidal chemistry and soil surface reaction
Section 1 Soil colloidal surface nature 一、 Surface types of the soil colloid (一) Siloxane surface (= Hydrous oxide surface (=)Organic matter surface
一、Surface types of the soil colloid （一）Siloxane surface （二）Hydrous oxide surface （三）Organic matter surface Section 1 Soil colloidal surface nature
0.72nm 6(OH) 卓}铝氧八面体层{4A c轴 4O+2(OH) 硅氧四面体层 4 Si 60 b轴 冫代表OH群 图1-101:1型层状硅酸盐(高岭石)晶体结构示意图
H (铝醇) HO 〔 Lewis酸点位) 硅烷醇 图2-20高岭石的表面羟基
123m·x·x● c=0387nm 图2-22纤铁矿晶体结构示意图 (a)立体图;(b)yz截面图
AOOH上层●OH下层◎HO上层◎HO下层 图2-24氢氧化铝基本结构单元图解5
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二、 The specific surface area and surface area of the soil colloid C Surface area of the soil colloid 表8-1土壤中常见粘土矿物的比表面积(m2:g1) 胶体成分内表面积外表面积总表面积 蒙脱石 700-750 15-150 700-850 蛭石 400-750 1-50 400-800 水云母 0-5 90-150 90-150 高岭石 5-40 5-40 埃洛石 00 10-45 10-45 水化埃洛石 400 25-30 430 水铝英石 130-400 130-400 260-800
二、The specific surface area and surface area of the soil colloid (一) Surface area of the soil colloid 表8－1 土壤中常见粘土矿物的比表面积（m2·g-1） 胶体成分 内表面积 外表面积 总表面积 蒙脱石 蛭 石 水云母 高岭石 埃洛石 水化埃洛石 水铝英石 700-750 400-750 0-5 0 0 400 130-400 15-150 1-50 90-150 5-40 10-45 25-30 130-400 700-850 400-800 90-150 5-40 10-45 430 260-800
The specific surface area of main soils in China Latosol 60-80m2gI R ea so il100-150m2g Yellow brown earth 200-300m2g-l ( Measurement method of the specific surface area 1、 Instrument method 2、 Adsorbed method: nitrogen、 glycerine etC
The specific surface area of main soils in China Latosol 60－80m2 g -1 Red soil 100－150m2 g -1 Yellow brown earth 200－300m2 g -1 (二) Measurement method of the specific surface area 1、Instrument method 2、Adsorbed method: nitrogen 、glycerine etc
三、 Surface charge and potential of soil (-) Cause and categories of the soil charge 1. Permanent charge-The net negative(or positive charge of clay particles inherent in the crystal structure of the particle; not affected by changes in ph or by ion exchange reactions 2, Variable charge-pH dependent charge Zero point of charge(ZPC)-The pH value of a solution in equilibrium with a variable charge material or mixture of materials whose net charge from all sources is zero
三、Surface charge and potential of soil （一）Cause and categories of the soil charge 1、Permanent charge-The net negative (or positive) charge of clay particles inherent in the crystal structure of the particle; not affected by changes in pH or by ionexchange reactions. 2、Variable charge- pH dependent charge Zero point of charge (ZPC) –The pH value of a solution in equilibrium with a variable charge material or mixture of materials whose net charge from all sources is zero