Heavy Metals Pollution in China
--Challenges and Countermeasures
Dr Prof Li Xiao-ming
Member of Steering group of European Innovation Partnership on
Water (EIP)
College of Environmental Science and Engineering
Hunan University, Email: [email protected];
May 22, 2014
Contents
1 Heavy metals pollution in China
2 Heavy metals pollution in Hunan Province
3 Supporting policies and countermeasures
4 Heavy metals-containing wastewater treatment
5 Prospects and suggestions
Heavy Metals Pollution
Features:
♦ Serious and worldwide problem
♦ Strong enrichment and toxicity
♦ Structure irreversible changes and non-functionalization
of protein
♦ Not easy for treatment and remediation
Main contaminants:
Cadmium (Cd) Mercury (Hg) Copper (Cu)
Chromium (Cr) Arsenic (As) Nickel (Ni)
Lead (Pb)
Zinc (Zn)
Cancer villages in China
 A government study has reaffirmed the existence of
"cancer villages" in China
 China has more than 247 "cancer villages" throughout
the mainland
 Toxic chemicals have caused several environment
emergencies linking to water and air pollution in these
areas.
 Drinking water crises hit many regions while cancer
villages and other severe cases of health and social
problems emerged in some other regions
Cancer village distribution in China
Cancer village distribution in China
This photo shows the distribution of over one hundred cancer villages identified
by social activist Deng Fei several years ago
The main heavy metal pollution accidents in China
Excessive blood lead
in Chenzhou, Hunan,
2010
Chromium
contamination
in Loudi,Hunan,
2009
Arsenic pollution
in Linyi, Shandong,
2009
Recent
five years
Lead contamination
Cadmium, Thalium
in Neijiang,Sichuang,
polluton in Hezhou,
2010
Guangxi, 2013
Cadmium contamination
in Longjiang, Guangxi,
2012
Heavy metals pollution accidents in China
2 Heavy metal pollution in Xiangjiang River, Hunan
It is well known that there are abundant reserves of nonferrous metals in Hunan Province (Nonferrous metal Village),
and most ores for mining, mineral processing, non-ferrous
smelting and precious metals are located in the Xiangjiang
Valley.
The pollution treatment in this area was emphasized in The
Chinese Government’s 12th Five-Year Plan for Xiangjiang
River Water Environmental Pollution Control.
Fig. 1 The geographical location of ten stations in Xiangjiang River.
As
Cd
Ni
Cr
Pb
Cu
Zn
Fig. 2 Spatial variation maps of the heavy metal distributions in the soils from the
midstream and downstream of the Xiangjiang Valley (2012)
Heavy metal pollution accidents in Hunan Province
 2006.1 Cadmium Pollution in Zhuzhou
 2006.9 Arsenic Pollution in Yueyang
 2009.6 Chromium Pollution in Shuangfeng, Loudi
 2009.7 Cadmium Pollution in Liuyang
 2009.8 Lead Pollution in Wugang
 2010.3 Lead Pollution in Jiahe, Chenzhou
 2011.3 Arsenic Pollution in Yiyang
 2014.3 Arsenic Pollution in Shimen, Changde
Cadmium Pollution in Liuyang, Hunan, 2009
More than 1300
children suffered
from Ld poisoning
Pb pollution in Wugang, Hunan, 2009
As Pollution in Shimen, Hunan, 2014. The As concentration
in the exceed the standard 1000 times. Nearly half of the
local village people suffered from As poisoning, 157 persons
die from As poisoning.
3 Supporting policies and safeguard measures
Countermeasures
and
suggestions
Department of
management
authority
Early warning and
emergency
response system
Governance policy
and measures
3.1 Department of management of authority
 Department Responsibility
 Regulatory Content
 The Relative Legal Basis
 Authority Executive Agency
3.2 Early warning and emergency response system
Take preventive measures to
reduce pollution before events
occurs
Participants
Early
warning and
Emergency
response
system
Soft
method
Early warning systems
Suggestions
Hard
method
Emergency response
system
Environmental
Protection
Bureau,
Water Authority,
Government,
etc
Take measures to reduce or stop
pollution when events had occurred
3.3 Governance policy and measures in Xiangjiang
Valley, Hunan
Governance Policy
 Strengthen the monitoring and management of
polluters, control the industry “three wastes” emission
 Eliminate the outdated capacity and be strict with
approval requirements
 Promote enterprise integration and improve industrial
concentration
 Develop the circular economy
3.3 Governance policy and measures in Xiangjiang
Valley, Hunan
Governance Measures
 Ecological comprehensive governance of heavy metal
pollution in the key industrial and mining area
 River regulation of the sediment with heavy metals
pollution
 Economical management of soil which contaminated by
heavy metals
3.4 Case Analysis
— — As Pollution in Shimen, Hunan
Time-to-event: Have been reported in March, 2014.
Causes: Realgar slags over discharged which were used for arsenic
refining in factory at upper reaches from 1956 to 1978 (The factory was
stopped refining arsenic till 1978, but plenty of slags were still piled up in
the open air).
Influences: The region more than 30 square kilometers around of the land
were serious polluted. The water was useless and changed into white and
red. Land with no harvest, crops were severely damaged and difficult to sell,
but the villagers still have to eat because no other food else. Nearly half of
people in the village were arsenic poisoning patients, cancer patients could
be found everywhere.
3.4 Case Analysis
— — As Pollution in Shimen, Hunan
Treatment measures:
The project: Implementation plan for the prevention and control of heavy
metal pollution "12th Five-Year Plan “ in Shimen realgar mining area
• Started in October, 2012, divided into four period, for 5 years
• The 1st and 2nd period for source control: The safe disposal of
nearly 200,000 tons of slags used for Arsenic refining and the
surrounding contaminated soil (basic problems are expected to be
solved in this August)
• 3rd period: local river comprehensive improvement
• 4th period: the remediation of about 5.3 square kilometers
contaminated soil in core pollution area
Suggestions for heavy metal pollution control
 Establish and improve the pollution prevention management
system
 Identify heavy metals pollution risk
 Construct compensation mechanism for environmental
damage
 Strengthen technical guidance and regulation, promote the
industry transformation
 Establish emergency response mechanism of
environmental pollution
4 Heavy metals-containing wastewater treatment
 Chemical Methods
 Physicochemical Methods
 Biological Methods
4 Heavy metals-containing wastewater treatment
4.1 Chemical Methods
Applied Range: high concentration of heavy metal
wastewater treatment
Advantage: relatively simple and inexpensive to operate
Disadvantage: not economical, produce large amount of
sludge to be treated with great difficulties
Type: Chemical Precipitation
Electrolysis
New type of heavy metal capture agent
Tpye
Advantage
Disadvantage
Chemical
Precipitation
simple and convenient,
low cost
secondary pollution,
Disposal of the difficulty
Electrolysis
high heavy metal
concentration wastewater
treatment
energy consumption,
high cost
good selectivity,
high efficiency,
metal capture agent good stability of sediment
New type of heavy
high cost,
disposal of the difficulty
4 Heavy metals-containing wastewater treatment
4.2 Physicochemical Methods
Applied Range: low concentration of heavy metal
wastewater treatment
Advantage: energy-efficient, little or no secondary pollution
Disadvantage: high cost and maintenance
Type:
Ion Exchange
Membrane Filtration
Chemical Adsorbent
Coagulation and Flocculation
Flotation
Type
Advantage
high selectivity,
Ion Exchange removal both anions and
cations
Disadvantage
needs regenerated by chemical
reagents,
expensive,
cannot be used at large scale
Membrane
Filtration
high efficiency
high cost,
process complexity,
the limit of membrane fouling
and low permeate flux
Chemical
Adsorbent
high efficiency
high dosage, high cost,
complicated disposal after
adsorption
Coagulation
and
Flocculation
good sludge settling and
dewatering
chemical consumption,
large sludge production
high selectivity,
high efficiency,
high overflow rates, low
detention periods, low
operating cost
high initial capital cost,
high maintenance and operation
costs
Flotation
4 Heavy metals-containing wastewater treatment
4.3 Biological Methods
Applied Range: heavy metal wastewater
Advantage: high efficiency, high sorption capacity, low cost, no
secondary pollution
Disadvantage: still in the theoretic and experimental phase, the
separation of biosorbents would be difficult after adsorption
Type: Biological Flocculation
Biosorption
Phytoremediation
4 Heavy metals-containing wastewater treatment
4.3 Biological Methods
Biological Flocculation:
• A method for heavy metal removal by utilizing
microorganisms or their metabolic product for
flocculation precipitation.
• Currently, the developed microorganisms with
flocculation involved in 17 species, such as bacteria,
mycete, actinomyces, yeast and algae, etc.
4 Heavy metals-containing wastewater treatment
4.3 Biological Methods
Biosorption:
• Heavy metal ion absorbed by microbial cells after a
series biochemical reactions (complexation,
chelation, Ion exchange, adsorption).
• The mainly bio-adsorbents: algae, bacteria, fungi,
yeast, ect.
4 Heavy metals-containing wastewater treatment
4.3 Biological Methods
Phytoremediation:
• Reduce heavy metal content in contaminated soil
and surface water by plants absorption, precipitation
and enrichment.
• Available plants: algae, herbaceous plants, woody
plants, etc.
• Hyperaccumulator: special plants that could
excessive absorption and accumulation heavy
metals.
4 Heavy metals-containing wastewater treatment
Table 1. Some hyperaccumulator plants with respective metal species
Fig. 3 Influence of soil amendments and plants in the remediation of metal
contaminated soils
Type
Advantage
Disadvantage
Biological
Flocculation
safety, convenient,
non-toxic,
good flocculation
effect
high cost,
difficult to save the living flocculant,
still in the exploring stage
Biosorption
low cost,
rapid adsorption
not suitable for high concentration
system because of the toxicity of
heavy metal
plenty of plants containing heavy
metals would be difficult to disposal
Phytoremediation
good selectivity,
high efficiency,
good stability of
sediment
5 Prospects and Suggestions
• Bioremediation technology, reported to be an effective,
nonintrusive, inexpensive, aesthetically pleasing, and
socially acceptable technology remediate water resource.
• Different environmental protection agencies are
appreciating the role of environmental biotechnology, and
expect to obtain global interests.
• Due to the limited resources, the heavy metals extraction
in wastewater (contaminated soil/surface sediments) and
recycling should considered as a direction in the future.