Qiantang River is the "mother river" of Zhejiang Province, with a drainage area accounting for 36% of the whole province, a population of140,000, accounting for 30% of the whole province and a total production of 35% of the whole province. The northern source of Qiantang River is Xin 'anjiang River, and its source is Liugujian Dongpo, the main peak of Huaiyu Mountain at the junction of Anhui and Jiangxi in Xiuning County, Anhui Province. Lanjiang River in the south and Qixi River in the upper reaches originate from the northern slope of Qingzhidaijian in the south of Xiuning County, Anhui Province. The north and south sources meet in Meicheng, Jiande County, and the total length from the north source to the estuary is 668 kilometers. In the midsummer of 2004, due to various reasons, cyanobacteria broke out in some reaches of the basin, which once affected our drinking water safety. Several years have passed. What is the water quality of Qiantang River now? Therefore, I made a simple investigation on the water quality in the upper, middle and lower reaches of Qiantang River, and completed this investigation report mainly through on-site water quality observation and data collection.
I. Field trip
At the end of July, 2009, my mother and I visited the source of Yungang River in Qiandao Lake, Chun 'an. Yungang River is a tributary of the upper reaches of Xin 'an River, the northern source of Qiantang River, and flows into Qiandao Lake. The stream of Yungangxi was crystal clear, so I went down and had a close contact. On such a summer day, the stream is still cool. I took a bottle from an empty mineral water bottle as a water sample, but I couldn't help taking a sip, which was a little sweet. I also took a bottle of water sample from Fuyang section of Fuchun River (middle reaches of Qiantang River). The water in Fuchun River looks far less clean than Yungang River, and there are still some rubbish floating on the water. I took a water sample at the third bridge of Qiantang River in Hangzhou. Look at that.
It looks more turbid than Fuchun River.
Fuyang section of Fuchunjiang River in Yungangxi, Chun 'an
Qiantangjiang Qianjiang bridge 3
Second, the water quality survey
1, experimental detection
I compared the water quality in the upper, middle and lower reaches of Qiantang River with that in Nongfu Spring, and observed the filtration, PH test paper and turbidity. The specific results are shown in the following table.
Water intake position
clean
Filter paper precipitation observation
PH value test color
Yungangxi
clean
Only a few tiny drops of sediment.
Light green (lighter than Nongfu Spring) 6.5-7.5
Fuyang section of Fuchunjiang River
A little cloudy
There are more fine-grained sediments.
Light green (lighter than Nongfu Spring) 6.5-7.5
Qiantangjiang Qianjiang bridge 3
A little cloudy
There are more fine-grained sediments.
Blue 8-9
Nongfu Spring
Transparent and colorless
not have
Light green 7-7.5
Comparison chart of PH test paper detection
From the observation of cleanliness and the test results of PH test paper, it can be seen that the water quality gradually becomes dirty from the upper reaches of Qiantang River to Fuyang section and then to Hangzhou section, especially in Hangzhou section, where the water quality is as high as 8-9, indicating that the water body has been polluted.
2. Data analysis
According to Zhejiang Water Resources Quality Bulletin (2009:11-12), there are 40 key water functional zones in Qiantang River system, of which 17 are water functional zones with water quality reaching the standard, accounting for 42.5% of the total. The total evaluation river length of the water function area is 653.6km, the river length that meets the standard is 258.8km, and the standard rate is 39.6%. Of the 40 key water functional areas, 9 are mainly Class II water, accounting for 22.5%; 9 kinds of water, accounting for 22.5%; 9 kinds of water, accounting for 22.5%; There are 13 places with water quality worse than Grade V, accounting for 32.5%. Among them, the monitoring water quality of Qiantang River sluice section is Grade IV, and ammonia nitrogen and manganese are not up to standard. In 2020, the target water quality of this section will be Grade II. The main over-standard items of water system are total phosphorus, dissolved oxygen, ammonia nitrogen, permanganate index, five-day biochemical oxygen demand and fluoride. In some river sections, zinc and mercury exceeded the standard.
From June 5438+0/KLOC-0 to June 5438+February, 2007, there were 40 key water functional zones in Qiantang River system, of which 22 water functional zones reached the standard, accounting for 55% of the total. The total evaluation river length of the water function area is 653.6 kilometers, and the river length that meets the standard is 322.2 kilometers, with the standard rate of 49.3%. Among the 40 key water functional areas, there are 14, accounting for 35%; Class III water has 1 1, accounting for 27.5%; 4 kinds of water in class IV, accounting for10%; The water worse than V is 1 1, accounting for 27.5%. Among them, the monitoring water quality of Qiantang River sluice section is Grade IV, and ammonia nitrogen and manganese are not up to standard. In 2020, the target water quality of this section will be Grade II. The main over-standard items of water system are ammonia nitrogen, total phosphorus, permanganate index, five-day biochemical oxygen demand and dissolved oxygen. Fluoride, zinc and mercury in some river sections exceeded the standard.
In the water quality bulletin of Zhejiang Province from May to June, 2003, there were 17 water quality sections in Qiantang River system, and the water quality sections of Class II and III were 10, accounting for 58.8%. The water quality was Grade IV in 3 cases, accounting for17.6%; Four of them are worse than V water, accounting for 23.5%. The main over-standard items in the water system are ammonia nitrogen, total phosphorus, permanganate index, five-day biochemical oxygen demand and volatile phenol.
Comparison Table of Qiantang River Water Quality in 2003, 2007 and 2009
Annual water quality
Class Ⅱ ~ Ⅲ
Class Ⅳ
ⅴ ~ inferior ⅴ class
2009. 1 1- 12
45%
22.5%
32.5%
2007.3-4
62.5%
10%
27.5%
2003.5-6
58.8%
17.6%
23.5%
As can be seen from the table and data, the water quality continues to deteriorate. In 2009, the grade II-III water decreased compared with that in 2007 and 2003, while the grade V-worse grade V water increased year by year. By 2020, the target water quality of Qiantang River will be Grade III and above, which will fully meet the standard.
Third, the reason analysis
The poor water quality of Qiantang River directly affects the drinking water safety of millions of people in the lower reaches of Qiantang River. At present, there are still 32.5% V-grade inferior water in Qiantang River system, which affects the water quality safety and water ecological environment in Qiantang River basin. Although our province has been taking remediation measures, such as 1996' s "10th Five-Year Plan" closure, 1998' s "Mrs. Governance", especially 1999-2000' s large-scale "one control and two standards" action and the special action to rectify illegal sewage enterprises for three consecutive years, to protect people's health and environmental protection. And the ongoing "8 1 1 Special Action for Environmental Pollution Control" (that is, eight major water system pollution, 1 1 cities with districts,1/provincial key environmental protection supervision areas) and the comprehensive management of the water environment in Taihu Lake Basin. The key area of the whole "8 1 1" action regulation plan is the Qiantang River waters. However, due to the cumulative effect of environmental pollution, the water quality is not optimistic.
According to Zhejiang Water Resources Bulletin (2006, 2007, 2008 and 2009), the wastewater discharge in Qiantang River Basin in 2009 was 65.438+80.7 billion cubic meters. See the following table for wastewater discharge in Qiantang River Basin from 200/kloc-0 to 2009:
age
200 1
2002
2003
2004
2005
2006
2007
2008
2009
discharge capacity
10.37
12.92
17.64
17.74
18. 10
17.85
17.45
20.8 1
18.07
As can be seen from the table, in 2009, the wastewater discharge in Qiantang River Basin was 200 1, 174%, and the wastewater increased greatly. According to the analysis, the main causes of pollution in Qiantang River are as follows:
1, industrial pollution.
The discharge of industrial pollution in Qiantang River basin is becoming more and more complicated, and the phenomenon of direct discharge and excessive discharge of sewage from industrial enterprises often occurs. Some enterprises, such as Hangzhou Xin 'anjiang monosodium glutamate factory, Zhejiang Bee Group and Juhua Group, have serious structural pollution, and the ammonia nitrogen emission is large and the concentration is seriously exceeding the standard, which has caused great pressure on the water environment in Qiantang River basin. The chemical industry in Jiande, electroplating in Tonglu, papermaking in Fuyang and printing and dyeing in Xiaoshan, which were formed in the process of traditional industrialization, also brought great pressure to the protection of Qiantang River's mother river. In addition, due to the objective reasons of low illegal cost and high compliance cost, some enterprises are still very serious.
2. Agricultural non-point source pollution
Compared with point source pollution, non-point source pollution has a wider space-time range, greater uncertainty, more complex components and processes, and more difficult to control. In agricultural activities, unscientific management concepts and backward production methods are important factors that cause non-point source pollution in agricultural environment, such as the use of highly toxic pesticides, the application of excessive chemical fertilizers, the annual abandonment of non-degradable agricultural films in the fields, and the random stacking of livestock manure in large farms without harmless treatment. These pollution sources have a great influence on the pollution of water environment.
3. Family pollution
At present, about 40% cities in the province have not built sewage treatment plants, and urban sewage is directly discharged without treatment. Rural domestic sewage is basically untreated and discharged directly, which increases the pollution of Qiantang River. We are keen on the lifestyle of using a lot of disposable plastic convenience bags, paper towels and tableware. These products are used in large quantities and quickly discarded and garbage, which brings serious recycling problems and directly harms the cleanliness of the water environment. The lifestyle of unrestrained use of detergents such as washing powder has also played a dual role in the deterioration of water environment-not only directly produced a large number of domestic sewage, but also the production of these products consumed water and sewage.
4. Other pollution
Now the rise of tourism and catering industry has also caused great pollution to the water environment. In particular, sewage in some scenic spots is not treated or not up to standard, and is directly discharged. In addition, there are some aquaculture and so on, which also increase the pollution of water bodies.
Four. Suggested measures
1, intensify publicity and raise people's awareness of protecting water resources.
We can publicize the environmental protection law and the water pollution prevention law through public service advertisements, lectures in communities and schools, questions and answers on water resources knowledge, etc., so that everyone can realize the importance of protecting the environment and water resources, start from the side, start from me, save water resources, use phosphorus-free washing products, etc. So as to prevent garbage from entering the river and let everyone take action to protect the water environment.
2. Strengthen public supervision.
Mobilize all social forces (including the media, news organizations, the public, etc.). ) Supervise all kinds of behaviors that destroy the water resources of Qiantang River, and form an atmosphere in which everyone has the obligation to supervise and protect the water resources.
3, the implementation of total sewage control.
According to the water environmental capacity of Qiantang River basin, the total amount of sewage discharge in each region is determined and the total amount is controlled in each region. So as to fundamentally solve the pollution problem of Qiantang River.
4. Increase penalties for illegal discharge and substandard discharge.
At present, due to the objective reasons of low illegal cost and high law-abiding cost, the phenomenon of direct evasion by some enterprises is still very serious. It is suggested that the punishment should be increased in the future to increase the illegal cost, and the illegal sewage discharge by enterprises is not worth the loss.
Knowledge link:
1, blue-green algae, also known as blue-green algae, has a special pigment, usually blue, which is the most primitive group of algae. There is no real nucleus in the cell, only nucleoplasm, no nucleoli and nuclear membrane. Cyanobacteria is an algae with wide adaptability, which exists in hot springs at 85℃, in mountains, snow and ice, in oceans and fresh water. Cyanobacteria can consume dissolved oxygen in water. When cyanobacteria multiply in large numbers, the concentration of dissolved oxygen in water also decreases rapidly, leading to the death of aquatic organisms such as fish, shrimp and snails, resulting in water pollution. Although it is a dead cyanobacteria, it will still produce toxins in the process of being decomposed by bacteria.
2. The water environmental capacity of Qiantang River Basin refers to the ability to accept water pollutants per unit time under the condition of meeting the water quality requirements of water environmental functional areas.
3. Chemical oxygen demand (COD) is the amount of oxygen consumed when oxidizable substances in water are chemically oxidized. Expressed in milligrams of oxygen consumption per liter of water, the greater the COD value, the more serious the water pollution (usually thought to be caused by organic matter).
4. Ammonia nitrogen refers to the combined ammonia in the form of ammonia or ammonium ions. Ammonia nitrogen is a nutrient in water, which can lead to eutrophication, is the main oxygen-consuming pollutant in water, and is toxic to fish and some aquatic organisms.