Impact Analysis of Ambient Air and Mitigation Measures

4.3 Impact Analysis of Ambient Air and Mitigation Measures

4.3.1.1 Fugitive dust from construction

(1) Source

During the construction of air environment influence is fugitive dust from construction. fugitive dust from construction is the main source of earthwork excavation, site formation, construction materials handling and stacking, traffic, concrete mixing caused by dust. This project involving a large number of earth excavation and transportation, traffic, dust on the local air environment impact TSP, which is the main pollution factor.

Fugitive dust from construction dust amount is related to many factors, excavators and other at work in the dust quantity and the digging depth, excavator bucket and the ground relative height, wind speed, soil particle size, and other factors related to soil moisture. For slag yard, dust amount and stacking mode, starting wind velocity and yard without protective measures and so on. The research results at home and abroad and analogy investigation shows that, the main factors affecting dust amount respectively: protective measures, wind speed, soil moisture, soil or mounds of stacking mode. Besides, road dust quantity and the running speed of the vehicle, the faster the speed, the dust emission is also bigger.

(2) Impact analysis

During construction, the greatest impact for excavation step dust, open-air stacking and transport vehicles.

(i) Earth cutting

According to the experience, when excavation earthwork is 400t/d, its dust (TSP) on the air environment influence, generally its sphere of influence at around 500m, close TSP concentrations over level two times to 10 times, but at about 600m can reach level two standard.

(ii) stack dust by operation. By the influence of wind speed in wind field data, 3.6m/s, construction site under the direction of different distance of the dust concentration see Table 6-2-1. In open field, fugitive dust from construction can be in the range of 150m over Class II Ambient Air Quality Standard (GB3095-1996) on the environmental air quality standard, can cause adverse effects; 150m range, generally will not have much effect.

Table 6-2-1 Fugitive dust concentration at different distances in windward wind at construction site Unit: mg/m³

Distance	1m	25m	50m	80m	150m
TSP	3.744	1.630	0.785	0.496	0.246

(iii) Vehicle transportation

Construction vehicle transport process accounts for about 60% of total dust, in general, construction site, construction of road under natural wind generated dust impact within the range of 100m. If during construction on vehicle road dust suppression sprinkler implementation, every day 4-5 times, can make the dust reduction of 70%, fugitive dust from construction will be effective control of the effect on the surrounding atmosphere. Table 6-2-2 is watering dust test results at construction site.

Table 6-2-2 Test results of watering and dust suppression during construciton period

Distance (m)		5	20	50	100
Average concentration per hour of TSP (mg/m3)	Non-watering	10.14	2.89	1.15	0.86
	Watering	2.0l	1.40	0.67	0.60

It can be known from the above table that watering dust is carried out 4-5 times every day, which can effectively control fugitive dust from construction, thus to reduce the pollution distance of TSP to within the range of 20-50m.

(3) Impact on sensitive points

Shangrao Airport region average speed for 1.2m/s. according to the analog data, by fugitive dust from construction region around 150m range. The airport construction field out of bounds within the range of 150m Xujia of Tashui, Shanghuangwu group part of residents within the range of 500m, Shanghuangwu group, Xiawutang group, Xujia of Tashui part of the population distribution, in addition, the airport road supporting pipeline, alteration of country on both sides of the road are in the range of 150m residents will be affected certainly, during construction need watering dust.

Construction period effect is local, short, with the project completed and put into operation or disappear.

4.3.1.2 Other construction waste gas

Other construction of exhaust emissions from vehicle exhaust and construction team temporary canteen stove cooking fume.

During the construction, there will be a large number of vehicles entering and leaving the site, there will be a certain amount of emission in automobile exhaust pollutants are mainly carbon monoxide (CO), hydrocarbon (HC) and nitrogen oxides (NOx), the wind direction and transport along regional adverse effects. In addition, during the construction, construction personnel temporary the stove will also have a certain amount of canteen catering oil smoke on the surrounding environment, will produce adverse effect, but the effect is very small.

4.3.2 Impact Analysis of Airport Ambient Air during Operation

The evaluation mainly carries out forecast analysis of the following aspects.

(1) Adopt estimation mode recommended in Guidelines for Environmental Impact Assessment-Atmosphere Environment (HJ2.2-2008) to calculate the contribution value of maximum ground concentration of NO₂, SO₂ and TSP as well as the location;

(2) Analysis of impact of airplane exhaust, vehicle exhaust on airport ambient air;

(3) Impact analysis of volatile gas environment of fuel tank area

4.3.2.1 Impact analysis of boiler fume

(1) Impact analysis of boiler fume environment

Select Table 6-3-1 for estimation mode parameters of boiler air pollutant NO₂, SO₂ and PM₁₀.

Table 6-3-1 Parameters of estimation mode

Table 6-3-2 Maximum ground concentration of nitrogen oxides, sulfur dioxide and PM₁₀ in different distances

Table 6-3-3 Maximum ground concentration and location

4.3.2.2 Impact analysis of airplane exhaust and vehicles for approach and departure

According to the forecast, Shangrao Airport2020 movements of 4800 sorties . Aircraft exhaust emissions of major pollutants SO₂, CO, non-methane hydrocarbon, NO₂, its emissions were 1.02t/a, 19.83t/a, 5.47t/a, 12.04t/a.

The aircraft taking off and landing vehicles is less, the exhaust pollutants are few, and high-altitude emissions, pollutant diffusion conditions, aircraft tail gas on environment influence is very small.

According to the forecast, Shangrao Airport in 2020 airport traffic of about 201667 vehicles. In vehicle exhaust is the main component of CO, NO₂ and non-methane hydrocarbons (HCS). In vehicle exhaust emissions and vehicle driving conditions have a great relationship. THC in automobile exhaust emission concentration in the gap when the highest, CO concentration in neutral and low speed is the highest, the NO₂ concentration in high speed high, car parking lots is generally at low speed, thus the parking of non methane hydrocarbon and CO emission concentration is higher. According to engineering analysis, and out of the airport car tail gas of CO, NO₂, non-methane hydrocarbon emissions were 7.07t/a, 0.3t/a, 0.7t/a.

This project is for parking garage on the ground, the ground parking air circulation quickly, and the airfield traffic pollutants for intermittent discharge, automobile tail gas on environment influence is very small.

4.3.2.3 Impact analysis of volatile gas in fuel tank area

Airport fuel tank area non-methane hydrocarbon the fugitive emission of about 1.38t/a. without tissue surface source (cofferdam) area of 534.6m², height of 1.0m. by the environmental protection department of Environmental Engineering Assessment Center issued the atmospheric environment protection zone standard program calculation of airport oil tank air environment protection distance, the calculation results for non - punctuation, on environment influence smaller.

4.3.3 Measures to Reduce Environmental Air Effects

4.3.3.1Measures to Reduce Dust Effects during the Construction Period

To reduce the amount of dust and protect the air environment, the construction unit should take the following dustproof measures:

(1) During the construction period, spray water to the onsite stored cubic meter of earth in time to keep its surface wet, or use a cover to reduce the amount of dust.

(2) Do not pile up building materials outdoors, put fine granules in storage, handle with care, prevent from break of the package.

(3) Limit the running speed of transportation vehicles going into the airport, tightly cover the vehicles which are easy to produce dust (such as vehicles carrying lime, cement, cubic meter of earth or construction rubbish) to avoid leakage on the way.

(4) For vehicles running in and out of the construction area, clean or wash the wheels to avoid bringing mud to the roads through townships and towns.

(5) Setup barriers or partial barriers at the construction site to decrease the spread scope of the construction dust and to reduce dust pollution of the ambient air environment.

After adoption of the construction dust prevention measures mentioned above, dust pollution can be effectively reduced and the work environment of the construction site can be improved.

4.3.3.2 Measures to Reduce Environmental Air Effects during the Operation Period

Waste gas pollution sources within the airport mainly comprises of boiler smoke, airplane off-gas, vehicle off-gas, volatile oil and gas from the oil depot. The airport boiler uses natural gas, which belongs to clean energy, and the smoke can be exhausted through an 8m high chimney. All the pollutant drainage densities of the smoke can meet the Class-B Time-Period-II requirements of Boiler Gas Pollutant Exhaust Standard (GB13271-2001), with no need of desulphurization and dustproof measures.