Table 7.7 Water Treatment and Utilization in Beijing-Tianjin-Hebei Metropolitan Area in 2008
Source: China Urban Construction Statistical Yearbook 2008, Beijing Statistical Yearbook 2008, Tianjin Statistical Yearbook 2008 and Hebei Statistical Yearbook 2008.
Sewage treatment rate is the ratio of sewage treatment capacity to sewage discharge, and reclaimed water utilization rate is the ratio of reclaimed water consumption to reclaimed water output, which can be divided into broad sense and narrow sense. When calculating the utilization rate of reclaimed water in a broad sense, the consumption of reclaimed water includes the consumption of various purposes listed in Table 7.7, while when calculating the utilization rate of reclaimed water in a narrow sense, the consumption of reclaimed water does not include the supplementary source water in Table 7.7. The utilization rate of reclaimed water in Beijing-Tianjin-Hebei metropolitan area refers to the narrow utilization rate.
As can be seen from the above data, the sewage treatment rates in the three places are all above 70%, but the utilization rate of reclaimed water is low, only 29.25%. In a narrow sense, reclaimed water resources have not been fully utilized. The utilization ratio of reclaimed water in Beijing-Tianjin-Hebei metropolitan area is quite different, among which Beijing has the highest utilization ratio, reaching 57.55%, which is higher than the Beijing-Tianjin-Hebei metropolitan area and the national average. Hebei province and Tianjin are 12.08% and 1.65%, respectively, which are lower than the level of Beijing-Tianjin-Hebei metropolitan area.
7.3. 1 analysis of reclaimed water production capacity in Beijing-Tianjin-Hebei metropolitan area
The production capacity of reclaimed water is analyzed from three aspects: sewage treatment plant construction, sewage pipeline construction and sewage treatment capacity.
7.3. 1. 1 construction of sewage treatment plant
Sewage treatment plant is the unit and carrier of reclaimed water production, which is directly related to the coverage of sewage treatment and the development and utilization of reclaimed water.
The construction of sewage treatment plant in Beijing-Tianjin-Hebei metropolitan area has made great progress in recent years. In 2000, there were only 18 sewage treatment plants, and in 2009 it reached 20 1 plant. In 10, the number of sewage treatment plants increased by more than 1 1 times. The number of sewage treatment plants in the three places has increased year by year. Since 2005, the construction speed of sewage treatment plants in the three places has obviously accelerated, especially after 2007, due to the increased investment in sewage treatment plant facilities in Hebei Province, the construction of sewage treatment plants in the Beijing-Tianjin-Hebei metropolitan area has developed rapidly, and the number has doubled in two years (Table 7.8, Figure 7. 1).
Table 7.8 Changes of Sewage Treatment Plants in Beijing-Tianjin-Hebei Metropolitan Area from 2000 to 2009
Source: China Water Network.
Fig. 7.1trend chart of sewage treatment plant construction in Beijing-Tianjin-Hebei metropolitan area from 2000 to 2009
As can also be seen from Figure 7. 1, the starting point of sewage treatment plant construction in Beijing-Tianjin-Hebei metropolitan area is low and the construction speed is very fast. This is because since the Eleventh Five-Year Plan, China has paid more attention to energy conservation and environmental protection, and the circular economy has developed rapidly, which has provided a good macro environment for the infrastructure construction of reclaimed water production in the Beijing-Tianjin-Hebei metropolitan area.
7.3. 1.2 sewage pipeline construction
The large investment in sewage pipeline construction is the premise of reclaimed water production and the main source of sewage in sewage treatment plants. In recent years, the length and density of sewage pipes in Beijing-Tianjin-Hebei metropolitan area are on the rise. By 2008, the length of sewage pipes in Beijing-Tianjin-Hebei metropolitan area reached 14966km, and the density of sewage pipes was 4.3km/km2, exceeding the national average. Among them, the length of sewage pipes in Beijing is 4,458 kilometers, an increase of 1.800 kilometers compared with 2002, with a growth rate of 66.7%. The construction speed of Beijing-Tianjin-Hebei metropolitan area is the slowest, and the density of sewage pipes is 3.40km/km2, which is slightly lower than the average level of Beijing-Tianjin-Hebei metropolitan area and higher than the national average level. The length of sewage pipes in Tianjin reached 6 194km, an increase of 3648km compared with 2002, with an increase of 146.77%. The construction speed of Beijing-Tianjin-Hebei metropolitan area is the fastest, and the density of sewage pipes is 9.67km/km2, which is higher than the Beijing-Tianjin-Hebei metropolitan area and the national average. The length of sewage pipeline in Hebei Province is 43 14km, which is 2595.4km more than that in 2002, and the increase is 15 1.0 1%. The construction speed ranks second in Beijing-Tianjin-Hebei metropolitan area, and the density of sewage pipes is 2.82km/km2, which is lower than the Beijing-Tianjin-Hebei metropolitan area and the national average (Table 7.9, Figure 7.2
Table 7.9 Length and density of sewage pipes in Beijing-Tianjin-Hebei metropolitan area from 2002 to 2008
Note: The length of sewage pipes in China in 2005 is the theoretical value of reasonable estimation; The built-up area of Beijing in 2005 is a theoretical estimate.
Source: Statistical Yearbook of China Urban Construction from 2002 to 2008.
Figure 7.2 Variation trend of sewage treatment pipeline length in Beijing-Tianjin-Hebei metropolitan area from 2002 to 2008.
Figure 7.3 Variation trend of sewage pipe density in Beijing-Tianjin-Hebei metropolitan area from 2002 to 2008.
In addition, in Figure 7.3, we can see that although the density of sewage pipes in Tianjin is higher than that in the Beijing-Tianjin-Hebei metropolitan area and the national average, the density of sewage pipes has started to decline since 2007, because the construction speed of Tianjin urban area has been accelerated in recent years, and the construction of infrastructure such as sewage pipes has been relatively slow.
In short, since 200 1, the construction of sewage treatment facilities in Beijing-Tianjin-Hebei metropolitan area has achieved certain results.
7.3. 1.3 sewage treatment capacity
The annual sewage treatment capacity and daily sewage treatment capacity of Beijing-Tianjin-Hebei metropolitan area have been significantly improved.
First, the total amount of reclaimed water is an important indicator of the scale of reclaimed water treatment. From 20065438+0 to 2007, the total amount of sewage discharge in Beijing-Tianjin-Hebei metropolitan area showed an upward trend, and it began to show negative growth in 2008, but the total amount remained at a high level. The overall upward trend is relatively slow, with the fastest rising speed in 2004, reaching15.11%; 2007 was the slowest, only 0.47%. Since 200 1, the annual sewage treatment capacity has been on the rise, especially in 2004 and 2006, with an increase of more than 20%. In 2007, the growth rate was small, only 3.98%. It can be seen that with the change of sewage discharge, the total amount of sewage treatment in Beijing-Tianjin-Hebei metropolitan area basically changes in the same direction (Table 7. 10, Figure 7.4), and the scale of reclaimed water treatment increases year by year.
Second, the daily treatment capacity is an important indicator of regional sewage treatment efficiency. The daily sewage treatment capacity of Beijing-Tianjin-Hebei metropolitan area also showed an upward trend from 200 1 to 2008. Since 2003, the sewage treatment capacity has greatly increased, especially in Hebei Province and Tianjin, with a relatively fast growth rate. After 2005, the daily sewage treatment capacity of Hebei Province surpassed that of Beijing, ranking first in the Beijing-Tianjin-Hebei metropolitan area (Table 7. 10, Figure 7.5). There are two reasons for the increase in daily throughput. One is to speed up the construction of sewage treatment plants in the circle, and the other is to improve the actual treatment capacity of sewage treatment plants.
Thirdly, the sewage treatment rate is an important index to measure the sewage treatment capacity of a region. The sewage treatment rate of Beijing-Tianjin-Hebei metropolitan area is also rising, from 52.03% of 200 1 to 77.03% in 2008. From this indicator, the sewage treatment capacity of Beijing-Tianjin-Hebei metropolitan area has been higher than the national average since 200 1, and Beijing has the strongest treatment capacity in Beijing-Tianjin-Hebei metropolitan area (Table 7. 1 1, Figure 7.6).
Table 7.10 Sewage Treatment in Beijing-Tianjin-Hebei Metropolitan Area from 2006.5438+0 to 2008
Note: The annual sewage discharge in Hebei Province in 2005 is a theoretical estimate; The annual sewage treatment capacity of Beijing, Tianjin in 2002 and Tianjin in 2005 is a theoretical estimate.
Source: China Urban Construction Statistical Yearbook 200 1 ~ 2008.
Figure 7.4 Variation trend of annual sewage discharge and annual sewage treatment in Beijing-Tianjin-Hebei metropolitan area from 20065438+0 to 2008.
Figure 7.5 Trend of Daily Sewage Treatment in Beijing-Tianjin-Hebei Metropolitan Area from 38+0 to 2008.
Table 7.1120065438+0 Sewage Treatment Rate of Beijing-Tianjin-Hebei Metropolitan Area in 2008 Unit:%
Source: China Urban Construction Statistical Yearbook 200 1 ~ 2008.
Figure 7.6 Variation of Sewage Treatment Rate in Beijing-Tianjin-Hebei Metropolitan Area from 20065438+0 to 2008
In short, the total sewage treatment capacity and daily sewage treatment capacity of Beijing-Tianjin-Hebei metropolitan area are increasing year by year, and the sewage treatment capacity has been significantly improved. However, due to the late start and weak foundation, there is still a big gap between the reclaimed aquatic products in Beijing-Tianjin-Hebei metropolitan area and developed countries. For example, the sewage treatment rate of Beijing-Tianjin-Hebei metropolitan area was only 77.03% in 2008, and that of Israel 1987 was close to 90%, which was about 30 years behind that of developed countries. The eighth district of Beijing in the Beijing-Tianjin-Hebei metropolitan area reached 90% in 2007, which is also 20 years behind the developed countries.
7.3.2 Utilization of Reclaimed Water in Beijing-Tianjin-Hebei Metropolitan Area
The utilization of reclaimed water is mainly analyzed from three aspects: total utilization, utilization efficiency and reasons.
7.3.2. 1 total utilization rate
From 2006 to 2008, the total utilization of reclaimed water in Beijing-Tianjin-Hebei metropolitan area showed an increasing trend, from 4130,000 t to 720 million t, with an increase of 307 million t or 74.33%. However, the proportion of using recycled water and saving clean water in Beijing-Tianjin-Hebei metropolitan area is still small, reaching 2.5438+0% in 2008. Therefore, if the utilization rate of reclaimed water can be further improved, more clean water sources can be saved.
In 2008, according to the ratio of the total amount of reclaimed water used to the total amount of water used in the provinces and cities in Beijing-Tianjin-Hebei metropolitan area (the ratio of saving clean water), the total amount of reclaimed water used in Beijing was 600 million tons, more than five times that of Hebei Province and 75 times that of Tianjin. The ratio of total utilization rate of reclaimed water to total water consumption in Beijing is 17.09%, that in Tianjin is 0.37%, and that in Hebei is 0.56%. This shows that the utilization level of reclaimed water in Beijing is far ahead of other provinces and cities in Beijing-Tianjin-Hebei metropolitan area (Table 7. 12).
Table 7.12 Utilization of reclaimed water to save clean water in Beijing from 2006 to 2008 Table Unit: 100 million m3
Source: China Urban Construction Statistical Yearbook 2006-2008, Beijing Economic Yearbook 2006-2008, Tianjin Economic Yearbook 2006-2008 and Hebei Economic Yearbook 2006-2008.
From 2006 to 2008, the total water consumption in Beijing-Tianjin-Hebei metropolitan area was greater than the clean water resources. Therefore, the use of reclaimed water not only makes up for this gap, but also saves the use of clean water. By analyzing the situation of Beijing, which has the highest utilization rate of reclaimed water among the three places, it is found that the consumption of reclaimed water in Beijing is increasing year by year, while the consumption of purified water is decreasing year by year. The saving rate of purified water is increasing year by year, reaching 17.09% in 2008, and the substitution effect of reclaimed water is obvious year by year (Table 7. 12 ~ 7. 16). This is undoubtedly an encouraging gospel for a typical resource-based water shortage area.
Table 7.13 Tianjin reclaimed water saving and clean water table in 2006-2008 Unit: 100 million m3
Table 7.14 Water Saving and Clean Use of Reclaimed Water in Hebei Province from 2006 to 2008 Unit: 100 million m3
Table 7.15 Reclaimed water saving and clean water use in Beijing-Tianjin-Hebei metropolitan area from 2006 to 2008 Unit: 100 million m3.
Table 7.16 National Reclaimed Water Conservation and Clean Water Use in 2006-2008 Table Unit: 100m 3
With the development of economy and society and the increase of population, the gap between total water resources and water consumption will become larger and larger. If the reclaimed water is not increased to make up for it, the dependence of all localities on external water transfer will continue to increase. This will not only increase the cost of water use, but also lead to water conflicts due to uneven distribution of water resources between regions, which will lead to broader and deeper social contradictions. Therefore, increasing the amount of reclaimed water and saving the amount of clean water is the only way in the future.
Utilization ratio of reclaimed water in 7.3.2.2
The utilization rate of reclaimed water is equal to the ratio of reclaimed water consumption to total reclaimed water output (the reclaimed water output is calculated by 100% sewage purification into reclaimed water), which is an important index to measure the utilization rate of reclaimed water. See table 7. 17 and figure 7.7 for the changes of reclaimed water utilization rate in Beijing-Tianjin-Hebei metropolitan area in recent years.
The utilization efficiency of reclaimed water in Beijing-Tianjin-Hebei metropolitan area is also increasing year by year. The utilization rate of reclaimed water was 19.34% in 2006 and reached 29.24% in 2008, which was higher than the national average. However, the current utilization efficiency is still low, and the utilization rate of reclaimed water is less than 30%. In 2008 alone, the underutilized reclaimed water in Beijing-Tianjin-Hebei metropolitan area was 654.38+74.2 million m3, accounting for 7.9% of the total water resources in Beijing-Tianjin-Hebei metropolitan area in 2008, which is very huge for Beijing-Tianjin-Hebei metropolitan area which is seriously short of water. In addition, from the perspective of the utilization efficiency of reclaimed water in various provinces and cities in Beijing-Tianjin-Hebei metropolitan area, Beijing has the highest utilization efficiency, reaching 57.53% in 2008, 12.09% in Hebei Province and 1.65% in Tianjin.
In addition, compared with developed countries, there is also a huge gap in the utilization level of reclaimed water in Beijing-Tianjin-Hebei metropolitan area. For example, 1987, 72% of urban sewage in Israel has been reused, and Beijing, which has the highest water utilization rate in the Beijing-Tianjin-Hebei metropolitan area, is close to 60%.
Table 7.17 Utilization rate of reclaimed water in Beijing-Tianjin-Hebei metropolitan area from 2006 to 2008
Source: Statistical Yearbook of Urban Construction in China.
Figure 7.7 Histogram of Reclaimed Water Utilization Rate in Beijing-Tianjin-Hebei Metropolitan Area
7.3.3 Cause Analysis of Low Water Utilization Rate in Beijing-Tianjin-Hebei Metropolitan Area
By 2008, the construction of reclaimed water production facilities in Beijing-Tianjin-Hebei metropolitan area has achieved certain results, and the total amount of sewage treatment has also increased. The total utilization of reclaimed water in Beijing-Tianjin-Hebei metropolitan area is only 720 million m3, which is only 2.8 1% of the total water consumption in Beijing-Tianjin-Hebei metropolitan area. The utilization rate of reclaimed water is only 29.25%, and the utilization efficiency of reclaimed water is low (Table 7. 18). Let's briefly analyze the reasons for the low efficiency of reclaimed water utilization.
Table 7.18 Production and Utilization of Reclaimed Water in Beijing-Tianjin-Hebei Metropolitan Area in 2008
Source: China Urban Construction Statistical Yearbook 2008, Beijing Statistical Yearbook 2008, Tianjin Statistical Yearbook 2008 and Hebei Statistical Yearbook 2008.
First, the low price of reclaimed water affects the production of reclaimed water. At present, the price of tap water used by Beijing residents has risen to 4 yuan/ton (Table 7. 19), while the reclaimed water remains at 1 yuan/ton. However, in fact, the average operating cost of some reclaimed water production enterprises exceeds 1 yuan /m3, and the reclaimed water price is too low, which makes the reclaimed water production units run at a loss and affects their normal operations.
Second, although the water resources in Beijing-Tianjin-Hebei metropolitan area are in short supply at present, it has not reached the level of threatening drinking water, so the substitution function of reclaimed water is ignored.
Thirdly, because the production of reclaimed water in China is mostly invested by the government, the investment subject is single and the funds are limited, the construction of sewage treatment plants and pipe networks (including the reconstruction and new construction of old pipe networks) still cannot meet the development needs of reclaimed water industry.
Fourth, due to the lack of effective supervision, the water quality of some reclaimed water in the Beijing-Tianjin-Hebei metropolitan area is not up to standard, which affects the enthusiasm of water users.
Table 7. 19 Beijing tap water price list
Source: Beijing Municipal Development and Reform Commission website.