MARINE ENVIRONMENTAL
CHEMISTRY
Cai-Minggang
Contents
Introduction
Part One Mechanisms in marine pollution
Part two Topics in marine pollution
Part three Measurement of biological
response toxicity and water quality
assessments
……
Part two Topics in marine
pollution
Chap.2 Marine oxygen-demanded organic pollution
Chap.3 Eutrophication and Red tide
Chap.4 Oil pollution of the sea
Chap.5 Marine synthetic organic pollution
Chap.6 Heavy metal contamination in the sea
Chap.7 Marine radioactivity pollution
Chap.8 Marine heat pollution
Chap.9 Other topics of marine polltion
Chap.3 Eutrophication and Red tide
3.1 What is Eutrophication? (definition)
3.2 Why Should We Be Concerned?
(harmful effect)
3.3 The nutrient in the coastal seawater
3.4 Eutrophication in the coastal seawater
3.5 HABs and Red tide
Eutrophication
Eutrophication is the natural process by which waters
(lakes,rivers etc) become excessively enriched with
nutrients,typically nitrogen and phosphorus,It is one of
the ways in which a water body (lake,rivers,and seas)
transforms from a state where nutrients are scarce
(oligotrophic),through a slightly richer phase
(mesotrophic) to an enriched state (eutrophic),
Human activities often enhance the rate of change due to
activities such as farming,forestry,road-building,industry
and waste treatment that cause nutrients to enter
watercourses,This nutrient enrichment often results in a
population explosion of algae and other aquatic plants.
Eutrophication
BOD and Eutrophication - rapid succession in a body of
water because of an increase in biological productivity,
(Oligotrophic lakes and rivers have clear water and low
biological productivity).
Chap.3 Eutrophication and Red tide
3.1 What is Eutrophication? (definition)
3.2 Why Should We Be Concerned?
(harmful effect)
3.3 The nutrient in the coastal seawater
3.4 Eutrophication in the coastal seawater
3.5 HABs and Red tide
3.3 The nutrient in the coastal seawater
A,Sources
B,nitrogen in the seawater
C,phosphate in the seawater
The main addition of N and P compounds to the
marine environment are considered to be sewage
wastes,either directly discharged to the sea or via
rivers into which treated waste are discharged.
Other sources are agricultural runoff and wastes
from food processing industries,but these are
normally considered to be small compared to the
input of sewage.
3.3 The nutrient in the coastal seawater
Oxygen depletion often leads to complete
deoxygenation or anoxia in the deep layers of the
lake or reservoirs also because oxygen poorly
dissolves in water,
In shallow lakes and
where plant production is
high,deoxygenation of
the sediment and water
occur frequently too
(black sediment,Photo 3).
Such conditions kill fish and invertebrates (Photo 4).
Moreover,ammonia and hydrogen sulfide
originated from bacterial activity can be
released from sediments under conditions
of anoxia,and their concentrations can rise
to levels which adversely affect plants and
animals as they act as poisonous gases
Some particular type of algae,which grow in highly
nutrient enriched lakes and reservoirs,release in
the water very powerful toxins which are
poisonous at very low concentrations,
Photos 5 & 6,Macro- and micro-scopic viwes
of Microcystis aeruginosa.
Photos 7 & 8,Macro- and microscopic views
of Uroglena americana,a culprit of red tide.
Some of the toxins produce negative effects on
the liver of life stock at minimal concentrations but
they can lead to the death of cattle and other
animals even to humans when ingested in
drinking water at higher concentrations,
Although one way to treat and disinfect surface
waters where these algae grow and/or to prevent
high concentration of organic matter is to use
chlorine,unfortunately this leads to the formation
of compounds which may produce or induce
cancer -a serious threat to the safety of drinking
water supplies.
2,Nitrogen in the seawater
The decomposition of DON:
The decomposition equation of DON
under different conditions
有 氧:
(CH2O)106(NH3)16H3PO4+ 138O2— → 106CO2 + 122H2O
+ 16HNO3+H3PO4
缺 氧,脱氧菌
(CH2O)106(NH3)16H3PO4+ 84.8HNO3 — →
106CO2 + 42.4N2 + 148.4H2O + 6NH3 + H3PO4
缺 氧 (NO3-,NO2-已耗尽 ):
还原菌
(CH2O)106(NH3)16H3PO4 + 53SO42- —— → 106CO2 +
53H2S + 106H2O + H3PO4
不同氧化 — 还原条件下的有机氮降解方程式
3.4 Eutrophication
A,The definition of Eutrophication
B,The effect of Eutrophication
C,Environmental Quality Standard(EQS)
of Eutrophication
B,The effect of Eutrophication
Positive effect
Negative effect
C.Environmental Quality
Standard(EQS) of Eutrophication
singal chemical index
Integrated index
Tab 1,Relationship between N,P content and
Eutrophication of seawater
Extent of nutrient TP(mg/m3) TN (mg/m3)
oligotrophic
(nutrient-poor)
8.0(7.3~ 8.7) 312(228~ 392)
mesotrophic 17.6(11.0~ 26.6) 470(342~ 618)
Eutrophic
(nutrient-rich)
84.4(45.8~ 144) 1170(420~ 2370)
特征 腐水域 过营养域 富营养域 贫营养域深域 浅域
Water color 3m以下带臭 呈黄色赤褐色 3m<黄绿色 3~ 10m短时间局部着色 > 10m不着色
COD(mg/L) > 10 3~ 10 1~ 3 < 1
BOD(mg/L) > 10 3~ 10 1~ 3 < 1
DIN(mgat·N/L) > 100 10~ 100 2~ 10 < 2
DO 直至近表层 0~ 30% 0~ 30% 直至中层为饱和状态数米以下为
30~ 80%
直至底层为饱和状态
H2S 接近表层可测 出 底层可检测出 检不出 检不出
PP
(mgC/m2·h)
10~ 200 1~ 10 < 1
sediment 黑色、表层无褐色的氧化层 黑色无氧化层 略带臭味有氧 化层 有时有带黑色的 氧化层 无臭味有氧化层
S2- 1.0< 0.3~ 3.0 0.03~ 0.3 0.3
COD(mg/g)? < 30 5~ 30 < 5
Tab2,The characters of nutrition level of inland seawater
P is limited factor of eutrophication.
Standard of Eutrophication,
DIN:0.2~ 0.3ppm,
DRP:0.01~ 0.02ppm
Eutrophication is also connected with the
capability of nutrients and their ratio.
The UK defines 10 mg chl m-3 as a Environmental
Quality Standard (EQS) for coastal waters,If chlorophyll
frequently exceeds this level in summer,a water body
should be labelled 'eutrophic'.
This label is 'objective' and does not necessarily imply
that 'undesirable disturbances' will result.
Some coastal seas are naturally eutrophic - for example,
those in upwelling regions.
C.Environmental Quality
Standard(EQS) of Eutrophication
1,Eutrophication index(E):
E = COD× DIN× DRP × 106 / 1500
E>1,Eutrophication
2,Nutrient Qquality Index(NQI):
NQI = CCOD /CCOD′+ CTN /CTN ′+
CTP/CTP′+CChla/CChla′
营养质量指数法评价
营养质量指数式:
NQI=ΣAi=ΣCi/Cis
NQI:营养质量指数 ;
Ai,单项营养质量指数 ;
Ci,指标监测的平均值 (mg/l);
Cis,指标评价标准 (mg/l)。
评价指标,COD,DIN,DRP和 Chla。
C.Environmental Quality
Standard(EQS) of Eutrophication
1,Eutrophication index(E):
E = COD× DIN× DRP × 106 / 1500
E>1,Eutrophication
2,Nutrient Qquality Index(NQI):
NQI = CCOD /CCOD′+ CTN /CTN ′+
CTP/CTP′+CChla/CChla′
表 3 营养水平分级
NQI值 营 养 等 级 营 养 水 平
< 2 I 级 贫营养水平
2~ 3 II 级 中下营养水平
3~ 4 III级 中上营养水平
>4 Ⅳ 级 富营养水平厦门同安湾海域营养状态评价
1,研究区域概述
2,样品的采集和分析
3,结果与讨论
4,结语案例分析
1,研究区域概述
地理特征
功能用途
主要环境问题
1,研究区域概述
同安湾海域位于厦门岛的东北部,海湾海域面积约为 91km2,为半封闭海湾,西部和北部水浅,多为滩涂,南部及东部湾口水域较深 。
同安湾海域主要以水产养殖和盐业为主,水产养殖面积 40 km2,是厦门重要养殖区 。 由于海堤的建设和滩涂的围垦,减少了纳潮量,降低了潮流冲刷能力,加剧海域的淤积,影响海域生态环境 。
周边经济的发展,生活污水和工业废水排放量的增加,及水产养殖规规模的扩大,给同安湾环境造成潜在的危险 。
2,样品的采集与分析
2.1 调查站位
2.2 调查时间,
1999年 1月 ( 枯水期 ) 和 1999年 5月 ( 丰水期 )
2.3 监测项目:
T,S,SS,pH,DO,COD,BOD5,DIN、
DRP,Chla和油类 。
2.4 水质评价标准:
二类水质标准 。
2,Results and discussion
2.1 Results
2.2 Evaluation of water quality by Eutro-
phication index(E)
2.3 Evaluation of water quality by Nutrient
Qquality Index(NQI)
2.1 水质监测结果表 1 同安湾海域水质调查统计结果项目
1999,1
(枯水期)
1999,5
(丰水期)
1999
范围 平均值 范围 平均值范围 平均值
pH 8.09~ 8.05 8.07 8.11~ 7.84 7.99 8.11~ 7.84 8.01
DO 8.64~ 8.07 8.32 8.34~ 6.09 6.45 8.64~ 6.09 7.04
COD 1.49~ 0.89 1.17 2.14~ 0.82 1.23 2.14~ 0.82 1.21
BOD5 1.18~ 0.30 0.72 0.70~ 0.04 0.23 1.18~ 0.04 0.38
DIN 0.444~ 0.268 0.372 1.26~ 0.089 0.286 1.26~ 0.089 0.313
DRP 0.022~ 0.012 0.016 0.037~ 0.002 0.017 0.037~ 0.002 0.017
Chla 6.83~ 0.85 2.60 9.60~ 1.38 3.48 9.60~ 0.85 3.20
油类 0.058~ 0.003 0.032 0.041~ 0.003 0.027 0.058~ 0.003 0.027
NH4-N
18%
NO3-N
77%
NO2-N
5%
同安湾营养质量指数站 号 COD DIN DRP Chla NQI 营养等级
Ai
1 0,70 2,85 1,67 1,14 6,63 Ⅳ 级
2 0,63 1,76 1,40 0,62 4,40 Ⅳ 级
3 0,62 1,45 1,00 0,75 3,82 III级
4 0,61 1,30 1,07 0,37 3,34 III级
5 0,51 1,15 0,93 0,42 3,00 III级
6 0,59 1,23 0,87 0,70 3,38 III级同安湾 0,61 1,57 1,13 0,64 3,94 III级同安湾营养质量指数站 号 COD DIN DRP Chla NQI 营养等级
Ai
1 0,70 2,85 1,67 1,14 6,63 Ⅳ 级
2 0,63 1,76 1,40 0,62 4,40 Ⅳ 级
3 0,62 1,45 1,00 0,75 3,82 III级
4 0,61 1,30 1,07 0,37 3,34 III级
5 0,51 1,15 0,93 0,42 3,00 III级
6 0,59 1,23 0,87 0,70 3,38 III级同安湾 0,61 1,57 1,13 0,64 3,94 III级同安湾海域营养指数( E)
站号 COD DIN DRP E
( mg/l)
1 1.40 0.570 0.025 13.3
2 1.26 0.351 0.021 6.2
3 1.24 0.289 0.015 3.6
4 1.21 0.260 0.016 3.4
5 1.01 0.230 0.014 2.2
6 1.17 0.245 0.013 2.5
同安湾 1.21 0.313 0.017 4.3
同安湾海域营养指数( E)
站号 COD DIN DRP E
( mg/l)
1 1.40 0.570 0.025 13.3
2 1.26 0.351 0.021 6.2
3 1.24 0.289 0.015 3.6
4 1.21 0.260 0.016 3.4
5 1.01 0.230 0.014 2.2
6 1.17 0.245 0.013 2.5
同安湾 1.21 0.313 0.017 4.3
í? 2 í? °2 í? N Q I ó? E?μ ·? 2?
0
2
4
6
8
10
12
14
í? °2 í? 1 2 3 4 5 6
o?
N
Q
I
ó?
E
μ
EQI
E
3.结语对同安湾水质监测的结果表明:
大部分监测项目符合二类海水水质标准,但无机氮超标,系该海域富营养化的主要因子。
应用营养质量指数( NQI)和营养指数( E)两种评价方法对同安湾海域营养状况评价,结果均表明该海域处于富营养状态,存在发生赤潮的潜在危险。
3,研究海域 N/P )R为 40.7,磷相对短缺,为该海域富营养化的控制因子。
4,关于保护同安湾海域的建议:应加强周边陆地污染源的治理,控制生活污水、工业废水及农业废水的排放,加强生态环境保护;控制海洋水产养殖规模,调整养殖结构,减少养殖污染环境;进一步加强海洋管理,防止发生赤潮。
3.结语对 策
近海水体富营养化科学,合理对策的制定,必须建立在仔细研究N,P等的来源 ( 陆地径流,工农业及生活排污和悬浮物,沉积物释放以及系统内N,P的再生等 ),归宿 ( 沉积,迁移到外海 )
及相互作用 ( N,P等与浮游植物,悬浮物及浮游植物与悬浮物及沉积物之间 )
的基础上 。
( 1 ) 加强科学研究和环境监测,对富营养化水体进行客观的评价 。
( 2 ) 某些海域富营养化程度较低,可能对渔业生产有一定的帮助,可不采取任何对策,但需加强监测 。
对策与方法
( 3 ) 制定相应的法令,法律来规范富营养化水域附近的排污及海水养殖,减少富营养化水域附近营养盐排放 ( 如建造污水处理厂等 ) 。
如改变排污点,增加海水交换能力,采用自然力量
( 如潮汐等 ) 或人工动能来增加海域的水交换能力及设置导流堤等 。 为减少突然增加的负荷量应充分利用海域的自净能力,把生活污水和生产废水分期分批排放 。
( 4 ) 向水中抛撒粘土矿物,一方面可以增加水的混浊度阻止藻类大量繁殖,另一方面粘土可以吸附水体中大量的P等营养物并沉降到底质中 。 实验证明,这些被吸附的营养盐的再释放是微不足道的 。
( 5 ) 在水体中养殖一些大型水生植物
( 如藻类,芦苇,水葫芦等 ),证明在湖泊中是可行的 。 经过研究筛选,这种措施在浅海也是可行的 。 (? )
( 6 ) 如想让遭到破坏的水域尽快地恢复到自然状态,除减轻N,P负荷外,还需清除含有成为二次污染源的大量N,P的海底泥 。
( 7) 海水养殖的,合理密植,,投饵的科学化及科学的饵料组成等都是预防海域发生富营养化的可行办法 。
总之,应在预防上下更多的功夫 ( 如更有效地利用各种能源和资源 ) 而不是在治理上:
治理的周期长,费用高 。
而且治理往往会产生新的问题 。 在使用一种物质来去除海域污染物时,一定要注意不要引进新的污染物,有时这种新的污染物对生态环境的破坏更大 。 如用来清除油污的非离子型分散剂对生物的影响就比流出的石油危害更大便是例子 。
控制近海海域富营养化的根本办法主要有两个:
一,N,P的有效利用 。 即采用废弃物,
污泥的肥料化等措施,减少在经济活动中利用N,P的绝对量,合理利用土地等 。
二,改变产品结构 。 即把洗涤剂,抑制剂等产品转换成不含N,P或含量较低的产品 。
Thanks for your attention.