摘要
近年来中国大部分区域大气硫、氮沉降速率趋于平稳甚至下降,但西北地区煤炭行业的快速发展使得硫、氮沉降速率加快。燃煤电厂作为酸前体物的主要排放源之一,在其周围开展硫、氮沉降效应研究,可为合理评价煤矿区大气污染物控制措施的实施效果提供数据支撑。该文以宁东能源化工基地3个燃煤电厂为采样点,研究了电厂周围土壤化学和生物学性质的变化特点,分析了其与降水降尘中硫、氮沉降量的关系。结果表明:研究区土壤pH变化范围分别为8.14—9.94,NO_(3)^(−)-N质量分数、NH_(4)^(+)-N质量分数、速效P质量分数变化范围分别为0.34—1.32、0.37—0.67、0.18—1.18 mg·kg^(−1),蔗糖酶活性变化范围为109.53—372.73 mg·kg^(−1)·h^(−1)。电导率、脲酶活性和磷酸酶活性变异系数较大,变化范围分别为51.60—3890.00μS·cm^(−1)、12.36—51.80 mg·kg^(−1)·h^(−1)和13.98—77.26 mg·kg^(−1)·h^(−1);各土壤指标在电厂间差异较大,在取样距离间差异较小,且无明显的规律性;土壤电导率、NH_(4)^(+)-N质量分数、速效P质量分数和磷酸酶活性与降水降尘中SO_(4)^(2−)沉降量显著正相关(P<0.05)。土壤速效P质量分数、蔗糖酶活性和磷酸酶活性与降水降尘中NO_(3)^(−)沉降量显著负相关(P<0.05)。总体上,土壤pH与降水降尘中硫、氮沉降量相关性较弱。以上结果意味着,当前硫沉降强度有助于提高土壤磷酸酶活性、促进速效养分积累,氮沉降则表现出相反的效应,但二者均未对土壤pH产生明显影响。考虑到高架源大气污染物的长距离迁移性、酸沉降的时间累积性、土壤污染成分组成的复杂性等,今后还需延长取样距离,并结合土壤污染源成分分析,从较长时间尺度上深入探讨工业排放源周边硫、氮沉降的生态效应。
In recent years,the rates of sulfur(S)and nitrogen(N)deposition have stabilized or even declined in most regions of China,but the rapid development of the coal industry has accelerated the rates of both S and N deposition in northwest China.As coal-fired power plants are one of the main emission sources of acid precursors,studying the effects of S/N deposition around them can provide scientific evidence for rationally evaluating the implementation effects of air pollutant control measures in coal-mining regions.In this paper,we sampled three coal-fired power plants in the Ningdong Energy and Chemical Industry Base to study the changes in soil pH,electrical conductivity,the availability of nutrients,and enzyme activities and their relationships with the seasonal deposition of S and N in precipitation and dustfall.Results showed that,the variation coefficients of soil pH,NO_(3)^(−)-N mass fraction,NH_(4)^(+)-N mass fraction,available phosphorus(P)mass fraction,and invertase activity in the study area were relatively small(8.14‒9.94,0.34‒1.32 mg·kg^(−1),0.37‒0.67 mg·kg^(−1),0.18‒1.18 mg·kg^(−1) and 109.53‒372.73 mg·kg^(−1)·h^(−1) respectively).In contrast,the values of soil electrical conductivity(51.60‒3890.00μs·cm^(−1)),urease activity(12.36‒51.80 mg·kg^(−1)·h^(−1)),and phosphatase activity(13.98‒77.26 mg·kg^(−1)·h^(−1))varied greatly.There were large differences in soil properties among power plants,but the differences among the sampling distances were small and without a clear trend.Soil electrical conductivity,NH_(4)^(+)-N mass fraction,available P mass fraction,and phosphatase activity were significantly and positively correlated with SO_(4)^(2−)deposition(all P<0.05).Soil available P mass fraction,invertase activity,and phosphatase activity were significantly and negatively correlated with NO_(3)^(−)deposition(all P<0.05).In general,the correlation between soil pH and the deposition of S and N was week.These results indicated that the current S deposition might help increase soil phosphatase and promote the accumulation of nutrients available,whereas N deposition might show an opposite effect.Neither S nor N deposition had a significant impact on soil pH.Due to the long-distance mobility of air pollutants from elevated sources,the time accumulation of acid deposition,and the complexity of soil pollution composition,it is necessary to extend the sampling distance in the future and adopt composition analysis of soil pollution sources in order to explore,in depth,the ecological effects of S and N deposition around the industrial sources of acid emission in the long term.
作者
李春环
王攀
韩翠
许艺馨
黄菊莹
LI Chunhuan;WANG Pan;HAN Cui;XU Yixin;HUANG Juying(School of Ecology and Environment,Ningxia University,Yinchuan 750021,P.R.China;School of Geography and Planning,Ningxia University,Yinchuan 750021,P.R.China;School of Agriculture,Ningxia University,Yinchuan 750021,P.R.China)
出处
《生态环境学报》
CSCD
北大核心
2022年第1期170-180,共11页
Ecology and Environmental Sciences
基金
中国科学院“西部青年学者”(XAB2019AW03)
国家自然科学基金(32160277,41961001)。
关键词
大气酸沉降
土壤速效养分
土壤酶活性
土壤PH
工业酸排放源
atmospheric acid deposition
soil available nutrients
soil enzyme activity
soil pH
the industrial sources of acid emission
