潘金莲被吸乳揉到高潮的视频,久久99久久99精品免观看,在电影院里拨开内裤挺进,护士交换粗吟配乱大交动态图

???? Ceramic grain filters are made of refined pottery clays added with certain modifiers, and processed of grinding, mixing, shaping and high temperature sintering. They do not contain any substances that harmful to people or environment. They are hard and rough in surface, porous inside the structure, and have the advantages of high mechanical strength, large specific surface area and porosity. When used in water treatment, they behave a activated surface property, a great amount of pollutant entrapment, less water head loss in the filter bed, lower consumption of back-flush water, stable in chemical and biologic property, and long service life. Ceramic grain filters is a new and efficient filter material to increase the water yield, upgrade the water quality and save chemicals and energy.??

?Composition	?Content %??
SiO2	50-70％
Al2O3	15-25％
Fe2O3	0.5-10％
CaO	1-5％
MgO	1-5％
KO2+NaO	3-8％
?The balance	≤ 2

?