1. The Biosand Filter
生物慢滤池 – 项目介绍
RISE Tsinghua Association 清华清源协会
Tsinghua University | School of Environment
清华大学 | 环境学院
Presenters 主持人
Andrew
Albert Beardow

2. RISE Tsinghua
Organizational Profile
 Over 50 members
 International and Chinese Student collaboration
 Goal : Apply our knowledge and skills for sustainable development in rural
areas
 Method of knowledge and technology transfer

3. RISE Tsinghua’s Philosophy
 Empower students
 Promote knowledge sharing
 Co-operate with rural communities

4. ONGOING PROJECTS
 Biosand Filter – Shanxi and Ningxia
 Aquaponics
 Bamboo Bicycles
 Solid Waste Management

5. First Project:
Water Safety in China
Did you know that in rural areas of China:
 40% of potable water is considered unhealthy?
 over 300 million rural Chinese residents still don’t
have access to safe drinking water?
There are technologies
available which are SIMPLE and
AFFORDABLE!

6. BIOSAND FILTERS (BSF):
THE ALTERNATIVE
Centre for Affordable Water and Sanitation
Technologies (CAWST) <www.cawst.org
Manz Water Info <www.manzwaterinfo.ca>

7. BIOSAND FILTER THEORY
生物慢滤池理论
说明一下生物慢滤池的理论和如何功能

8. BSF Theory 生物慢滤池理论
Introduction to the BSF?
Four methods of removing contaminants:
Filtration Predation
Starvation Adsorption

9. BSF Theory 生物慢滤池理论
过滤器地介绍
四种除去方法
过滤 生物膜 吸附 饥饿

10. BSF Theory 生物慢滤池理论
Features of the BSF
Application Designed for variable flow rates (avg: 30 L/h)
Easy to use
Can be used intermittently
Can be used in any non-freezing climate
Turbidity of source water must be <50 NTU
User must be educated in maintenance
Construction Simple to construct
Cheap and available source materials
Removal Efficiency Can remove 95% of bacteria and up to 90% of viruses
viruses

11. BSF Theory
Components of the BSF
Sand and Gravel
Removal of contaminants
Container
Hold the sand and gravel
• Must be at least 60 cm tall
Standpipe
Maintains static water level
• Water must always be 5
cm above sand
Lid
Protects the filter
Protects people
Diffuser
Protects the biolayer
when water is added

12. BSF Theory 生物慢滤池理论
过滤器的部分
Sand and Gravel
沙子与碎石
慢滤池主要的滤料组成
Container
滤池的池体
容纳沙子和碎石
• 必须60厘米以上
Standpipe
外置导水管
保证积水面在过滤沙层之上
Lid
盖子
保护过滤器
保护人们
Diffuser
滤层保护器
保护过滤沙层中形成的生
物膜

13. BSF Theory 生物慢滤池理论
A Layered Approach
1) 6 – 12 mm
2) 2 – 6 mm
3) 0.2 – 2 mm
4) <0.2 mm
Filtration Predation Adsorption Starvation
Small
Big
Height of Each LayerSand Size

14. BSF Theory 生物慢滤池理论
四层沙子和碎石
1) 6 – 12 mm
2) 2 – 6 mm
3) 0.2 – 2 mm
4) <0.2 mm
小
大
每层的高度沙子大小
储水区– 15厘米
积水区 – 5厘米
上部过滤沙层– 5厘米
下部过滤沙层
在25-45cm之间调整
分离碎石层 – 3厘米
底部碎石层 – 7厘米

15. BSF Theory 生物慢滤池理论
How does the biolayer develop? 生物膜如何形成

16. BSF Theory 生物慢滤池理论
Allowing the biolayer to develop
Ripening period required to fully develop the biolayer.
A “drop off” occurs during the wet harrowing maintenance technique.

17. BSF Theory 生物慢滤池理论
Arsenic Removal
Add a layer of iron nails in the standing water of the BSF.
Arsenic species adsorb onto ferric hydroxide Fe(OH)3, forming larger
particles which can then be filtered out.

18. BSF Theory 生物慢滤池理论
Removal Efficiency 污染物去除率
Bacteria
细菌
Viruses
病毒
Protozoa
原生动物
Helminths
寄生虫
Turbidity
浊度
Iron
铁
Arsenic
细菌
Laboratory
实验室
>96.5%
70 - 99%
99.9% 100% 95%, <1NTU N/A 93 - 100%
Field
场地
87.9 - 98.5% N/A N/A 100% 85% 90 - 95% 95%
Jenkins, M. et al. (2011) Bacterial, viral and turbidity removal by intermittent
slow sand filtration for household use in developing countries:
Experimental investigation and modeling. Water Research 45 (6227 – 6239).
Significant Factors 显著因素
粒度 接触时间 维护
进水水质 暂停时间
Grain Size Contact Time Maintenance
Influent Turbidity Pause Period

19. BSF Theory 生物慢滤池理论
Discrepancies in the Field
实验室与实践中的差别
All sources stress the soft skills necessary for success of the biosand filter
每个研究说以培训软技能为成功生物慢滤池推广

20. BSF Theory 生物慢滤池理论
Comparison 与其他方法比较
Criteria
指标
BSF
生物慢滤池
Clay Filter
泥土过滤
SODIS
太阳消毒法
Bacteria 细菌的去除 95% 95% 99.99%
Viruses 病毒的去除 80 - 95% Some 一些 99.99%
Parasites寄生虫去除 95% Some 一些 99.99%
Inorganic Contaminants无机污染物去除 Some 一些 Some 一些 None 无
Aesthetic Improvement (turbidity, smell…)
物理性质改善（ 浊度，气味等）
Yes 是 Yes 是 No 否
Typical Flowrate (L/hr)流量 （升/小时） 10 - 30,000 1 2 L / 6 hours
Ease of Construction施工难易 Moderate适度 Difficult 难 Easy 易
Education Level of Users使用者教育水平 Moderate适度 Low 低 High 高
Suitability in Non-Tropic Regions
在非热带地区的适用性
Yes 是 Yes 是 No 否
Suitability in Near Freezing Temperatures
在冰冻温度下的适用性
Yes 是 Yes 是 No 否

21. BSF Theory 生物慢滤池理论
Sources 参考文献
Centre for Affordable Water and Sanitation Technology (CAWST).
<www.cawst.org>
Manz Water Info. <www.manzwaterinfo.ca>
Vanderzwaag, J. et al. (2009) Field evaluation of long-term performance and
use of biosand filters in Posoltega, Nicaragua. Water Qual. Res. J. 44 (2).
Jenkins, M. et al. (2011) Bacterial, viral and turbidity removal by intermittent
slow sand filtration for household use in developing countries:
Experimental investigation and modeling. Water Research 45 (6227 – 6239).

22. HOW TO CONSTRUCT THE
FILTER
生物慢滤池施工
根据生物慢滤池建造手册说明如何建造

23. BSF Construction 生物慢滤池施工
Step 1: Obtain Tools and Materials
 It is important to identify a proper workspace with shelter for your tools and
materials.
 The following tools and materials are needed to construct the filter.
Tools Materials
Sieve Tape measure Container Clean water
Wooden pieces Straight stick Gravel
Shovel Electric drill Sand
Gloves Covers
Face mask PVC pipe
Wheelbarrow PVC angle joints
Basket Screw

24. BSF Construction 生物慢滤池施工
步骤1: 获得工具和材料
定位一个适当的区域，干净，有庇护，能储存工具和材料
必要以下的工具和材料建造慢滤池：
工具 材料
12毫米孔径筛子 木块 大型塑料桶 充足的水源
6毫米孔径筛子 卷尺 碎石
2毫米孔径筛子 手套 沙子
.2毫米孔径筛子 水管胶布
钻子 PVC管
若干个大的盆或
桶用来洗砂子
PVC拐角连接头
记号笔 对丝和弯头

25. BSF Construction 生物慢滤池施工
Step 2: Filter Design
步骤2: 慢滤池容器的设计
Height of the lower filtration sand
layer is based on the height of the
container.
Maximum Flow Rate 最大流量
Maximum Flow Rate = Width × Width ×0.471
最大流量= 宽度 × 宽度 ×0.471
滤层的高度以塑料容器高
度为基础

26. BSF Construction 生物慢滤池施工
Step 3: Construct the Filter
步骤3: 建造生物慢滤池的容器
Consists of 3 Components
包括三个部分
1. Filter Body with Standpipe 容器
和水管
2. Diffuser滤层保护器
3. Lid 盖子

27. BSF Construction 生物慢滤池施工
Step 4: Preparing Sand and Gravel
1. Sieve sand into distinct layers 2. Wash sand and gravel to remove fine
particles
3. Burn sand and gravel to remove
organics

28. BSF Construction 生物慢滤池施工
步骤4: 准备沙子和碎石
1. 筛沙子和随之成为四种不同浆液 2. 以洗沙石为除去细颗粒
3. 为了除去有机物烧沙子和碎石

29. BSF Construction 生物慢滤池施工
Step 5: Installation
1. Find a suitable location for the filter
2. Add each layer of sand and
gravel into the filter,
measuring the height of
each layer.
3. Cut the standpipe so that it is 5 cm
above the top layer of sand.

30. BSF Construction 生物慢滤池施工
步骤5: 安装生物慢滤池
1. 定位合适的位置。
2. 加入每一层的沙石，从最
大石头开始到最细的沙子。
必要把沙石进去水。测量
每一层的高度。
3. 切导水管成为比顶沙层高5厘米

31. BSF Construction 生物慢滤池施工
Testing the Flow rate
Seconds per
500 mL
Litres per
Hour
20 90
30 60
40 45
50 36
60 30
75 24
100 18
Flow rate is too low:
• Filter is OK to use
• Sand has not been washed enough
• Air pockets have formed
• Outlet is too small
Flow rate is too high:
• Filter is NOT OK to use
• Sand has been washed too much
• Filter has not been designed properly

32. BSF Construction 生物慢滤池施工
测试流量
杪 / 500 毫
升 升 / 小时
20 90
30 60
40 45
50 36
60 30
75 24
100 18
流量太少：
• 水质没问题但是流量可能太慢
• 可能沙子还没洗够
• 可能沙石里有空气袋
• 可能水出口太小
流量太多：
• 水质不好
• 可能沙子被洗了太多
• 可能生物慢滤池设计差

33. BSF Maintenance 生物慢滤池维护
Procedure 基本步骤
Swirl and Dump (Wet Harrowing)
• Returns the flow rate to acceptable levels
• On average once every 3 – 6 months
Keep the Filter Clean
清洗滤池
清洗顶层滤料
• 恢复滤池的流量
• 平均每3 至6月

34. Questions? 有问题吗?