资阳市大气污染源排放清单研究

采用实地调研、资料收集等方式获得了2017年资阳市典型污染源的活动水平数据,参照城市大气污染物排放清单编制技术手册建立了基于排放因子法和物料衡算法的资阳市大气污染源排放清单,分析了主要污染物的行业排放特征和空间分布特征。结果表明,2017年资阳市SO₂、NO_X、CO、PM₁₀、PM_2.5、VOCs、NH₃总排放量分别为3.58kt、13.91kt、94.91kt、25.51kt、8.67kt、23.84kt和46.44kt。SO₂排放主要来自工业源;NOX排放主要来自移动源;CO排放主要来自工业过程及移动源;PM₁₀和PM_2.5、排放来自扬尘源和露天秸秆焚烧;VOCs主要来自溶剂使用源;NH₃主要来自农业活动。资阳市主要污染物排放分布在工业点源较为集中的雁江区和安岳县,乐至县污染物排放量相对较小。     

成都平原西郊PM2.5载带水溶性离子污染特征

为探究成都平原西郊冬季颗粒物污染特征,采用离子色谱仪对选择点位冬季PM_2.5载带进行离子测定。结合空气站点PM_2.5、SO₂、NO₂质量浓度,分析其浓度特征、酸碱度、相关性及主要来源等情况。结果表明：采样期间,该区域大气PM_2.5质量浓度均值为73.1μg/m³,主要水溶性离子质量浓度均值为27.42μg/m³,占比为37.5%;阴阳离子当量比为1.003,PM_2.5呈酸性;二次离子(NH⁺₄、SO₄^2-、NO^-₃)占总水溶性离子质量浓度比值为71.7%且相关性较好,污染期间SNA主要以NH₄HSO₄和NH₄NO₃两种形式存在;主成分分析可知燃烧排放、建筑施工扬尘及机动车排放二次转换是造成西郊冬季...     

舟山绿色石化基地乙二醇装置副产二氧化碳资源化利用示范项目——二氧化碳资源化利用制备碳酸二甲酯和聚碳酸酯

石化行业生产过程排放大量的CO₂,将副产的CO₂回收和资源化利用对解决环境和能源问题有重要意义。舟山绿色石化基地将乙二醇装置副产的CO₂回收精制,采用绿色加工流程生产出碳酸乙烯酯、碳酸二甲酯、碳酸二苯酯、聚碳酸酯等高价值产品,形成上下游一体的“CO₂—EC—DMC—DPC—PC工程塑料”产业链,实现基地内节能减污降碳和二氧化碳高价值利用协同增效,是大型石化基地CO₂资源化利用的典型实践。     

浅析攀枝花市2015～2017年气象要素对空气污染的影响

利用2015～2017年攀枝花市污染因子和气象要素实测数据,运用GIS技术、相关分析以及统计分析等方法,分析攀枝花市空气污染因子和气象要素的时空特征及相关性。结果表明:攀枝花市首要污染物为PM₁₀,其次是NO₂;秋冬以PM₁₀和NO₂污染为主,春夏PM₁₀和O₃为主。不同季节,各气象要素对本地空气质量的影响程度及空间分布存在明显差异。弄弄坪一带PM_2.5和SO₂、CO浓度偏高,市中心炳草岗一带PM₁₀、O₃和NO₂浓度偏高。结合本地发展规划和实际情况,根据气象要素分析,为攀枝花市分区分季节的防污减排决策提供气象参考。     

我国化工行业碳排放评价核算问题与建议

在环境影响评价中开展建设项目碳排放核算,建立完善的评价指标体系,可以有效控制新增碳排放,推动企业尽早实现碳达峰。我国尚未建立国家层面统一的建设项目碳排放评价核算方法。文章以某乙烯项目为例,选用“国标方法”“发改委方法”“广东省方法1”“广东省方法2”“北京市方法”“上海市方法”6种温室气体核算方法,核算出CO₂排放量分别为399.49×10⁴,359.02×10⁴,345.65×10⁴,357.09×10⁴,375.33×10⁴,298.7×10⁴ t/a。6种方法在燃料燃烧、火炬燃烧、工业过程、净外购电力、热力等方面的核算内容、量化公式、排放因子上均有所不同,导致核算结果差异较大。考虑到环评阶段活动数据和排放因子等可获得性低、准确性差的特点,建议企业工业过程和装置层面碳排放核算统一采用碳质量平衡法,将委托第三方处置废弃物产生的碳排放纳入间接排放,增加装置层面的碳排放评价指标。     

汶川地震极重灾区震后10年环境承载力评估

采用大气污染物超标指数、水污染物浓度超标指数、污染物浓度综合超标指数等3个指标,针对汶川地震极重灾区10个县市,评价了区域环境系统对社会经济系统的支撑能力。结果表明:10个县市中,环境承载力超载的县市有7个,接近超载的县市有3个。其中,9个县市的大气存在环境质量问题,4个县市的水环境质量存在问题,整个区域大气环境质量改善形式更为严峻。10县市的大气污染物中,O₃、PM_2.5、PM₁₀普遍超标或接近超标,是影响区域大气质量的主要因素。在3指标中,又以PM₁₀和PM_2.5超标情况最为严重。大气污染在10个县市中具有明显的区域特征。都江堰市、彭州市、安县、绵竹市、什邡市等环成都城市圈的5县市大气污染物浓度超标指数普遍高于远离成都经济中心的5县市。根据影响水质的水污染物性质,及水环境影响因子排序分析,彭州市、什邡市在COD_Cr、P、N-NH₃上有较高载荷,平武县在CODMn、DO两因子上载荷较大;汶川县的主要水环境影响因子是BOD5。根据在水污染因子上的载荷,10县市水污染特征归为集中污染型和面源污染型,以及混合污染三种类型。     

油田集输系统油水沉降罐呼吸气排放规律分析

油水沉降罐是油田集输系统油水分离的主要生产设施。油水沉降罐生产过程中的呼吸会向大气中排放挥发性有机物（VOCs）和甲烷,是油田挥发性有机物和甲烷的主要排放源之一。目前,针对国内油田油 水沉降罐呼吸气的排放鲜有基于实测数据的规律分析。文章选择国内油田联合站内典型油水分离处理工艺中的沉降罐,通过对各类油水沉降罐进行现场监测和实验室内分析,总结得到了油水沉降罐呼吸气的排放规律,不同功能储罐、温度、液面高度、生产工艺等对排放规律的影响以及排放气体特征,为油田集输系统挥发性有机物、油气损耗核算和治理提供了依据。     

成都地区2014～2020年PM10变化特征及气象条件分析

利用相关分析、逐步回归等统计方法,考察了成都地区PM₁₀的变化趋势及不同气象要素对PM₁₀变化的作用。结果表明,成都地区PM₁₀逐年递减,月际尺度上呈典型的“U”型分布。PM₁₀质量浓度的变化与最大风速、降水量及气压、日照时数、平均风速的变化负相关,与气温及相对湿度的变化正相关。不同季节影响PM₁₀变化的典型气象因子不同,冬、春季最大风速影响最大,夏、秋季平均风速影响最大。通过建立PM₁₀变化的多元回归预测模型,为成都地区PM₁₀变化的预测及管控措施的制定提供了科学依据。     

聚丙烯酰胺与植物联合抑尘效果的试验研究

如今颗粒物是我国大气环境污染的首要污染物之一,而土壤扬尘是大气颗粒物的主要来源,已经严重影响到大气质量及人们的生存环境,而聚丙烯酰胺不仅能促进植物生长,还能使土壤颗粒和孔隙结构保持稳定,控制土壤扬尘,因此通过聚丙烯酰胺与植物联合作用控制土壤扬尘排放对提升城市环境大气质量具有重要意义。本文在基于现有文献数据的基础上,以四川彭州市附近农田边裸露土壤为研究对象进行人工模拟对照试验,探讨了聚丙烯酰胺不同用量下与植物联合作用对抑尘效果的影响,以期为土壤扬尘污染的控制提供科学依据。研究表明:PM_2.5和PM₁₀的排放浓度随着聚丙烯酰胺的浓度增加而增加,随植被覆盖度的增加而减小。与植被覆盖作用相比,聚丙烯酰胺和植被覆盖的同时作用能更好的降低PM_2.5和PM₁₀排放浓度,PM_2.5浓度较之前平均下降了32.9%,PM₁₀浓度较之前相比平均下降了37.1%。通过对比实验数据可知,聚丙烯酰胺浓度在20 g/m²到25 g/m²时,整体抑尘效果最好,在施工7天时,PM_2.5和PM₁₀浓度平均下降了63.4%和77.9%,在施工1个月时,PM_2.5和PM₁₀浓度平均下降了和43.8%和56.3%。实验结论为利用聚丙烯酰胺和植物联合作用可以显著降低各时间段的土壤扬尘含量,为科学的治理土壤扬尘提供了理论参考。     

2011～2020年昆山市酸雨变化特征及成因分析

酸雨，对人类生活和生产造成了巨大的影响。为了解昆山市酸雨污染状况及其变化特征，根据昆山市2011～2020年降水监测数据，对酸雨的变化特征、变化趋势、离子化学组成、各离子间的相关性及酸雨成因进行了分析。结果表明：2011～2020年昆山市降水的pH年均值总体呈升高趋势，酸雨频率总体呈下降趋势；酸雨呈季节性变化，冬季酸雨频率最高，夏季酸雨频率最低；大气降水中主要阳离子为NH⁺₄和Ca²⁺,主要阴离子为SO₄^2-和NO^-₃;降水中的SO₄^2-和NO^-₃的比值在逐年缩小，从2014年的3.80逐步下降到2020年的0.97,硝酸根离子浓度呈波动变化，但变化不显著，酸雨的特征由硫酸型转化为硫酸-硝酸复合型。因此，加快产业结构调整、优化能源结构、加强工业废气和机动车尾气等的综合治理，从而减少SO₂和NO_X的排放，是...     

Conditions affecting the release of phosphorus from surface lake sediments

Laboratory studies were conducted to determine the effect of pH and redox conditions, as well as the effect of Fe, Mn, Ca, Al, and organic matter, on the release of ortho-phosphates in lake sediments taken from Lakes Koronia and Volvi (Northern Greece). Results were evaluated in combination with experiments to determine P fractionation in the sediment. The study revealed the major effect of redox potential and pH on the release of P from lake sediments. Both lakes showed increased release rates under reductive conditions and high pH values. The fractionation experiments revealed increased mobility of the reductive P fraction as well as of the NaOH-P fraction, indicating participation of both fractions in the overall release of sediment-bound P, depending on the prevailing environmental conditions. The results were assessed in combination with the release patterns of Fe, Mn, Ca, Al, and organic matter, enabling the identification of more specific processes of P release for each lake. The basic release patterns included the redox induced reductive dissolution of P-bearing metal oxides and the competitive exchange of phosphate anions with OH- at high pH values. The formation of an oxidized surface microlayer under oxic conditions acted as a protective film, preventing further P release from the sediments of Lake Volvi, while sediments from Lake Koronia exhibited a continuous and increased tendency to release P under various physicochemical conditions, acting as a constant source of internal P loading.     

Microcosm studies on anaerobic phosphate flux and mineralization of lake sediment organic carbon

Lake sediment has long been recognized as an important source of nutrients such as phosphorus. To gain a better understanding of phosphorus flux at the sediment-water interface, it is crucial to investigate the sediment porewater. There is also growing concern and interest in identifying whether organic-rich sediment is an important source of greenhouse gases such as CO(2) and CH(4). In the present study, we took sediment samples from West Lake, a shallow hypereutrophic lake in Hangzhou, Zhejiang Province, China and incubated subsamples under anaerobic conditions at 25 degrees C for 182 d using a specially designed microcosm that permits repeated extraction of sediment porewater and sampling of headspace gases. Anaerobic phosphate fluxes and mineralization of sediment organic carbon were measured. Average diffusive flux of soluble phosphorus was 0.81 mg P m(-2) d(-1) during the initial 18 d of incubation. Decomposition of sediment organic C followed zero-order reaction kinetics and methane accounted for about 50% of the mineralization products. The results suggest that organic-rich sediments can be important sources of P and methane under anaerobic conditions. Laboratory studies simulating field conditions and field studies are necessary to determine the contribution of sediment as a source of P and greenhouse gases.     

DISTRIBUTION OF SEDIMENT PHOSPHORUS POOLS AND FLUXES IN RELATION TO ALUM TREATMENT1

ABSTRACT: The distribution of sediment physical characteristics, sediment phosphorus (P) pools, and laboratory‐based rates of P release from the sediments were used to identify regions and dosage for alum treatment in Wind Lake, Wisconsin. Using variations in sediment moisture content, we identified an erosional zone at depths < 1.4 m and an accumulation zone at depths > 2.6 m. Mean concentrations of porewater P, loosely‐bound P, iron‐ and aluminum‐bound P, and mean rates of P release from sediments under anoxic conditions were high in the accumulation zone compared to sediment P characteristics in the erosional zone, indicating focusing of readily mobilized sediment P pools from shallow regions and accumulation to deep regions. We determined that a future alum treatment for control of internal P loading would be most effective at depths > 2.6 in the accumulation zone. The mean rate of anoxic P release from sediments encountered in the accumulation zone (8.3 mg m^‐2 d^‐1) was used in conjunction with a summer anoxic period of 122 d, and a treatment area of 1.6 km² to estimate an internal P load of 1,600 kg to be controlled. Our results suggest that an understanding of the distribution of sediment P pools and P fluxes in lakes provides a strategy for estimating alum dosage and application areas.     

SEDIMENT TRANSPORT DURING A CONTROLLED RESERVOIR RELEASE1

The transport of bedload and suspended sediments and particulate organic matter was evaluated in Huntington Creek, Utah, during a controlled release of water from Electric Lake Reservoir from August 7–10, 1979. Effects of the release on channel geometry and riffle composition also were assessed. Bedload transport rates increased from zero to 1,650 and 1,500 kg/hr at two cross sections as discharge was increased from 0.4 to 4.9 m³/s; transport rates then decreased erratically as discharge was held constant. Cross section measurements and sediment size analysis indicate that flows were insufficient to transport riffle sediments. Rapid increases in the transport rates of suspended sediments and particulate organic matter also occurred during rising discharge and again decayed when discharge became constant. Suspended sediment concentrations for samples obtained with an automatic pumping sampler were generally less than those found for samples obtained with a DH-48 sampler. Biological measurements still are needed to determine if such a release can improve fisheries habitat by removing fine sediments.     

静态条件下持续时间对底泥中有机氯农药释放的影响

有机氯农药是广泛存在于环境中一类有机污染物，溶解度低，疏水性强，容易被颗粒物吸附，并随其在沉积物中积累，蓄积在沉积物中的有机氯农药在沉积物的再悬浮过程中会重新释放进入水体，造成二次污染。为了考察悬浮持续时间对沉积物中有机氟农药的释放的影响，采用沉积物释放模拟装置在60天内对微山湖沉积物中有机氯农药释放进行研究。结果表明，随着扰动时间的延长，上覆水中有机氯农药的含量在0—20天内增长很快，在60天左右含量趋于到稳定。不同的有机氟农药在扰动条件下，释放的速率和浓度是不一样的，其中水溶性大的农药更易向水体再次释放。     

THE FATE OF NITRATE IN LAKE SEDIMENT COLUMNS1

ABSTRACT: To investigate the magnitude of denitrification and assimilatory nitrate reduction as these reactions relate to the fate of nitrate reaching sediments via groundwater seepage, undisturbed core samples of sediments (40 cm length) from two lakes (Mendota and Tomahawk) were leached from the bottom (at 1.4 cm/day) with a solution of ¹⁵N-nitrate (10 mg N/liter). The sediment columns were fitted with Pt electrodes to measure the oxidation-reduction (Eh) potential. While leaching removed considerable ammonium-N and soluble organic N, essentially no ¹⁵N had passed through the columns by 50 days. The Eh readings indicated that denitrification was occurring in the lower portions of the columns. The ¹⁵N distribution of the sediment N after 50 days showed that about 15 to 26% of the added nitrate-N was converted to organic N and ammonium-N. The data show that denitrification can be a significant N sink in seepage lakes.     

The reduction of internal phosphorus loading using alum in Spring Lake, Michigan

The release of P from lake sediments, which occurs as a part of internal loading, may contribute a significant portion of the total P load to a lake. Phosphorus release rates from sediments in Spring Lake, Michigan, and the degree to which alum reduces P release from these sediments, were investigated during the summer of 2003. Triplicate sediment cores were sampled from four sites in the lake, and exposed to one of four treatments in the laboratory: (i) aerobic water column/alum, (ii) aerobic water column/no alum, (iii) anaerobic water column/alum, or (iv) anaerobic water column/no alum. Total P (TP) release rates were virtually undetectable in the alum treatments (both aerobic and anaerobic). Low, but detectable, release rates were measured in the aerobic/no alum treatment. The highest release rates were measured in the anaerobic/no alum treatments, and ranged from 1.6 to 29.5 mg P m(-2) d(-1) depending on how the calculations were derived. These fluxes translated to mean internal loads that ranged between 2.7 (low range) and 6.4 (high range) Mg yr(-1) when extrapolated to a whole-lake basis. Internal P loads accounted for between 55 and 65% of the total P load to Spring Lake. Although alum is a potentially effective means of reducing the sediment source of P, there is considerable uncertainty in how long an alum treatment would remain effective in this system given the current rates of external loading and the lack of information on wind-wave action and bioturbation in Spring Lake.     

Characteristics of heavy metals and Pb isotopic signatures in sediment cores collected from typical urban shallow lakes in Nanjing, China

To investigate the contamination levels and sources for heavy metals that have occurred during the development of cities, sediment cores collected from typical urban shallow lakes (Xuanwu Lake and Mochou Lake) in Nanjing, China were analyzed for Cu, Pb, Zn, Cd, Cr, Ni, and for Pb stable isotopic ratios. No significant differences were found in the concentrations of Cu, Ni and Cd among sediment layers from Xuanwu or in the levels of Cr and Ni among sediment layers from Mochou. However, there were significant differences among the layers in the concentrations of Cr, Zn and Pb in Xuanwu and Cu, Zn, Cd and Pb in Mochou. Based on geoaccumulation indexes and enrichment factors, Cd was the primary pollutant at all depths in the sediment cores. The ratios of (206)Pb/(207)Pb and (208)Pb/(206)Pb differ significantly among sediment layers in Xuanwu. No significant differences were found on the ratios of (208)Pb/(206)Pb in Mochou, but the ratios of (206)Pb/(207)Pb differ significantly among some of the sediment layers in Mochou. The range of (208)Pb/(206)Pb and (206)Pb/(207)Pb ratios was found to be 2.098-2.106 and 1.170-1.176, respectively, for sediment cores from Mochou Lake and 2.091-2.104 and 1.168-1.183, respectively, for cores from Xuanwu Lake. The differences in heavy metal concentrations and the Pb isotopic ratios with depth for the cores from Xuanwu and Mochou confirmed that the contamination sources changed during the formation of the different sediment layers. Furthermore, the ratios of (206)Pb/(207)Pb demonstrated that gasoline and vehicular Pb were not the primary sources of Pb contamination at different depths in the sediment cores in Xuanwu Lake and Mochou Lake.     

RATES OF RECENT SEDIMENTATION IN LAKE PEPIN1

ABSTRACT: Sedimentation rates since 1954 in Lake Pepin, as determined from the content of fallout cesium-137 in the sediment profile, have exceeded 2.5 cm/yr in the upper part of the lake. These rates, although somewhat less than those of the previous half century (1895–1954), are sufficiently large that the upstream portion of Lake Pepin is threatened with conversion to a marsh within a century. The density of the sediments measured increased with depth in the sampled profile from 1.1 to 1.2 g/ml at the sediment surface to 1.4 to 1.5 g/ml at 2- or 3-m depth. There was little or no change in the patterns of textural composition or density of the sediment profile with depth and age over the past 80 to 150 years.     

Chemical composition of organic matter in extremely acid, lignite-containing lake sediments impacted by fly ash contamination

In the Lusatian lignite mining district of eastern Germany, extremely acid lakes developed during ground water rising after exploitation of lignite in open-cast mines. The reasons of plant colonization (Juncus bulbosus L.) of some lakes exhibiting moderate pH values while others remain extremely acid and unvegetated are unknown. Alkalinity gain may be achieved by addition of alkaline materials and/or decomposition of organic matter. Our objective was to examine fly ash deposition and the resulting changes in organic matter composition in the uppermost 0 to 5 cm of the sediment sampled from vegetated and unvegetated lakes. Bulk soil and particle size fractions were analyzed for elemental composition, magnetic susceptibility, and chemical structure of the organic matter by 13C solid-state nuclear magnetic resonance (NMR) spectroscopy. The lignite content of the samples was estimated by 14C activity measurements. The pH values decreased with increasing depth and the changes in pH were found to be correlated with changes in magnetic susceptibility. Carbon and nitrogen contents were found to decrease with increasing depth. The C to N ratios are consistent with the (i) the presence of decomposing plant residues and/or microbial material such as algae in the upper 0 to 5 cm of the sediment and (ii) the dominance of lignite in the layers below this depth as confirmed by 14C activity measurements. The structural analyses of the particle size separates from the 0- to 5-cm depth were consistent with the presence of organic matter derived from plant material. This study confirms that fly ash is an important source of alkalinity in the upper 0 to 5 cm of the sediment that enhanced plant growth and led to enrichment of the sediment with organic matter derived from plant material.