许昌市典型区域土壤磁化率与有机质含量的相关性研究

为探讨土壤磁化率对有机质含量的指示作用,对许昌市典型区域土壤磁化率与有机质含量的相关性进行研究,结果显示:研究区域土壤样品Xlf变化范围在15×10~(-8)~125×10~(-8)m~3/kg,平均值为64×10~(-8)m~3/kg,说明研究区土壤样品中磁性矿物含量较低。Xfd值在4.67%~26.67%之间,平均值为10.02%,反映了样品中超顺磁颗粒含量很高,说明研究区域土壤磁性矿物主要由自然成土作用形成,现代工业生产活动和人类的生活活动贡献较小。土壤有机质含量范围为3.74~31.93 g/kg,均值为17.09 g/kg。研究区域土壤磁化率与有机质含量呈不显著正相关性,反映了在长期人工施肥活动和城市化进程中人类活动导致土壤各理化因子之间发生学联系的弱化。     

北京地区大气飘尘中检出潜在致癌物——硝基多环芳烃

用两种方法(GC-MS法和还原-HPLC-荧光法)首次从北京大气飘尘中检出了数种硝基多环芳烃。虽然它们的含量低,但是由于其中例如1-硝基芘和3-硝基萤蒽系已知的动物致癌物,因此它们在环境中的存在值得注意。     

Microbiological parameters and maturity degree during composting of Posidonia oceanica residues mixed with vegetable wastes in semi-arid pedo-climatic condition

The aim of this study was to characterize the biological stability and maturity degree of compost during a controlled pile-composting trial of mixed vegetable residues (VR) collected from markets of Tunis City with residues of Posidonia oceanica (PoR), collected from Tunis beaches. The accumulation in beaches (as well as their removal) constitutes a serious environmental problem in all Mediterranean countries particularly in Tunisia. Aerobic-thermophilic composting is the most reasonable way to profit highly-valuable content of organic matter in these wastes for agricultural purposes. The physical, chemical, and biological parameters were monitored during composting over 150 d. The most appropriate parameters were selected to establish the maturity degree. The main result of this research was the deduction of the following maturity criterion: (a) C/N ratio < 15; (b) NH₄⁺-N < 400 mg/kg; (c) CO₂-C < 2000 mg CO₂-C/kg; (d) dehydrogenase activity < 1 mg TPF/g dry matter; (e) germination index (GI) > 80%. These five parameters, considered jointly are indicative of a high maturity degree and thus of a high-quality organic amendment which employed in a rational way, may improve soil fertility and soil quality. The mature compost was relatively rich in N (13.0 g/kg), P (4.74 g/kg) and MgO (15.80 g/kg). Thus composting definitively constitutes the most optimal option to exploit these wastes.     

富营养化湖泊藻华腐解产生的溶解性有机质动态变化及其环境效应

富营养化和有害藻华是湖泊面临的主要环境问题,富营养化湖泊藻华在后期会发生衰亡和腐解并产生大量藻源溶解性有机质（DOM）,影响水体DOM的质量和活性,并对关键元素的生物地球化学循环产生重要调控作用.为探究不同富营养化程度湖泊水体藻华腐解过程,对藻华腐解过程中水体DOM总量、生物有效性、相对分子质量和组分的动态变化进行分析,并探讨了藻华腐解引发的环境效应.结果表明,藻华腐解显著提高DOM浓度、生物有效性和各荧光组分强度.随着腐解的进行,DOM浓度逐渐降低,而相对分子质量逐渐增大.在分子水平上,超高分辨率质谱结果显示腐解过程中不饱和烃和脂肪族化合物优先被微生物利用,并生成木质素、缩合烃和高O/C值的单宁酸等惰性分子.藻华腐解过程中细菌群落主要优势种从变形菌门（46%）逐渐变为拟杆菌门（42%）.此外,藻华腐解还导致水体CO₂和CH₄排放显著升高1.2~5倍,且排放量可以由DOM光学指标a₂₅₄预测.该结果为全面揭示藻华腐解过程中DOM特征的动态变化,以及湖泊富营养化治理和环境效应预测提供理论依据和科学支撑.     

Effect of straw addition on nitrous oxide and methane emissions from stored farmyard manures

Stored solid manure heaps can be a significant source of nitrous oxide (N₂O) and methane (CH₄) emissions. The manure characteristics influence emissions and solid manure heaps can be managed to promote aerobic decomposition during storage. Increasing the carbon (C) content of the manure heap with high-C additives, such as straw, may provide the opportunity for N₂O and CH₄ emission reduction. Greenhouse gas (GHG) emissions from conventionally produced farmyard manure (FYM) have been quantified, but there is little data on emissions from organically produced FYM. N₂O and CH₄ emissions were measured using a small-scale storage method from FYM collected from organic and conventional dairy units under a range of storage conditions with and without extra straw addition.The organic and the conventional FYM were similar in composition except for the higher C and dry matter content in the organic FYM and in the FYM with added straw. This resulted in mean total emissions of N₂O and CH₄ being lower from the organic (27 g N t⁻¹) than the conventional FYM (52 g N t⁻¹) and from the treatments with straw added (32 g N t⁻¹) than those without (47 g N t⁻¹). The initial C:N ratio and dry matter content of the stored FYM were the most important factors affecting N₂O and CH₄ emissions although the FYM temperature also affected CH₄ emissions. Adding high-C additives, such as straw could be a promising strategy for reducing GHG emissions because it influences the dry matter content, C:N ratio and aeration of the manure. The small-scale FYM storage method were shown to be a reliable and an easy method to quantify emissions under a range of environmental conditions and manure manipulations and so develop effective manure management practices to reduce GHG emissions.     

Large and small particle size screening of organic compounds in urban air

A gas chromatographic (GC)-mass spectrometric (MS) study of the large (> 7.2 μm) and small (< 0.5 μm) particle fractions of aerosols collected in Barcelona (Catalonia, Spain) has allowed the identification of the major sources of airborne organic matter in urban environments. The extracts have been column chromatography separated in three fractions encompassing aliphatic hydrocarbons, aromatic hydrocarbons+semi-polar compounds, and polar products. The whole analytical procedure has allowed the identification of 186 molecular species that have been grouped according to their precursors. The study has also afforded the characterization of organic source-particle size associations as well as the effects of seasonality on the occurrence of the compounds identified.     

前处理方法对马兰黄土粒度测量影响的实验研究

采用9种不同的前处理方法对延安新区马兰黄土样品进行了粒度分析,以探讨不同前处理方法对马兰黄土粒度测量结果的影响。结果表明,除去有机物、碳酸盐或加分散剂后,马兰黄土的粒度分布发生明显变化,表现为中值粒径和平均粒径显著减小,粒度分布曲线向细粒方向偏移;马兰黄土中含有一定量的有机质,会影响粒度测量结果。因而,在粒度测量前处理时,需要加双氧水去除有机质;在使用盐酸进行前处理时,可能与矿物发生反应,使得所测粒径变大,且使细颗粒含量减少。综合考虑除去有机物、碳酸盐和加分散剂,前处理方法 7使样品中值粒径、平均粒径和细粒含量变化最为显著。因此,对马兰黄土进行粒度分析时,建议使用方法 7,即给样品加入15 m L浓度为10%的H_2O_2溶液(除去有机质)煮沸使其充分反应,冷却后给烧杯注满蒸馏水,静置24 h,抽去蒸馏水,加入15 m L浓度为4%的(Na PO_3)_6(分散剂)溶液后测量。     

2020年成都市典型臭氧污染过程特征及敏感性

2020年4月24日至5月6日成都市臭氧(O3)和细颗粒物(PM2.5)复合污染过程期间,在成都市城区开展大气臭氧及其前体物(NO,、VOCs)和气象参数观测实验,基于观测数据采用OBM模型对市区臭氧敏感性和主控因子进行识别,并采用PMF模型对关键VOCs物种进行来源解析.结果表明,臭氧超标日各污染物浓度均有所上升,VOCs物种中芳香烃和含氧(氮)化合物上升幅度较大;成都市城区O3超标天对应的臭氧处于显著VOCs控制区,芳香烃和烯烃对O3生成最为敏感,且存在削减NOx的不利效应;结合VOCs来源解析,城区VOCs主要来源:移动源(22.4％)、餐饮及生物质燃烧源(21.8％)、工业源(15.1％)和溶剂使用源(9.3％),臭氧超标天溶剂使用源、餐饮及生物质类燃烧源贡献率明显上升.成都市城区春季应以VOCs减排为重点,并加大芳香烃和烯烃相关源控制力度.     

Greenhouse gas emission and its potential mitigation process from the waste sector in a large-scale exhibition

As one of the largest human activities, World Expo is an important source of anthropogenic Greenhouse Gas emission (GHG), and the GHG emission and other environmental impacts of the Expo Shanghai 2010, where around 59,397 tons of waste was generated during 184 Expo running days, were assessed by life cycle assessment (LCA). Two scenarios, i.e., the actual and expected figures of the waste sector, were assessed and compared, and 124.01 kg CO₂-equivalent (CO₂-eq.), 4.43 kg SO₂-eq., 4.88 kg NO₃^--eq., and 3509 m³ water per ton tourist waste were found to be released in terms of global warming (GW), acidification (AC), nutrient enrichment (NE) and spoiled groundwater resources (SGWR), respectively. The total GHG emission was around 3499 ton CO₂-eq. from the waste sector in Expo Park, among which 86.47% was generated during the waste landfilling at the rate of 107.24 kg CO₂-eq., and CH₄, CO and other hydrocarbons (HC) were the main contributors. If the waste sorting process had been implemented according to the plan scenario, around 497 ton CO₂-eq. savings could have been attained. Unlike municipal solid waste, with more organic matter content, an incineration plant is more suitable for tourist waste disposal due to its high heating value, from the GHG reduction perspective.     

塔里木盆地南缘绿洲土壤酶活性与理化因子相关性

基于塔里木盆地南缘于田绿洲土壤酶活性与水盐、养分等理化因子数据,利用冗余分析技术(RDA)全面分析了土壤酶活性与理化因子间的关系. 结果显示:①于田绿洲土壤酶活性总体水平较低,过氧化氢酶(以KMnO₄计)、转化酶(以Na₂S₂O₃计)、脲酶(以NH₃-N计)和碱性磷酸酶(以C₆H₆O计)活性平均值分别为9.37、2.04、0.27和0.18 mg/g;研究区土壤水分含量(15.46%,以w计)较少且盐渍化严重〔w(全盐)平均值为19.39 g/kg〕. ②w(有机质)、土壤水分含量、地下水埋深和w(有效磷)是影响土壤酶活性的主要因素,w(有机质)、土壤水分含量、w(有效磷)与土壤酶活性呈正相关,地下水埋深与土壤酶活性呈负相关. ③各理化因子对土壤酶活性影响的重要性排序为w(有机质)、土壤水分含量、地下水埋深、w(有效磷)、pH、w(全盐)、电导率、w(速效钾). 综合分析表明,研究区强盐渍化的土壤性质对土壤酶活性的抑制并不显著,土壤碳、磷等养分与水分状况才是限制土壤酶活性的关键因素.      

某沿海城市典型行业NMHCs排放特征及对二次污染物生成潜势研究

采用SUMMA罐采样、GC-FID技术分析了威海市渔具、造船和橡胶等6种典型行业代表企业废气中59种非甲烷碳氢化合物(NMHCs)组分及占比,并计算了各行业NMHCs的臭氧(O3)和二次有机气溶胶(SOA)生成潜势,提出了NMHCs治理建议.结果表明,涉及溶剂使用的渔具、造船、汽车制造业喷涂工序的NMHCs组分以芳香烃...     

污水厂二级出水中难凝聚有机物的臭氧化特性

以城市污水处理厂二级出水为原水,研究臭氧化处理对水中难凝聚有机物的去除效果.结果表明单独混凝对水中有机物的去除率较低,混凝过程中未被去除的有机物属于难凝聚有机物,加入臭氧进行氧化,随着臭氧投加量的增加,二级出水色度和UV254去除率逐渐增大,而DOC去除率变化较小.当臭氧投加量(以O3/DOC计)增加至1.5 mg·mg-1时,色度、UV254和DOC的去除率分别为45%、34%和20%,说明臭氧易于与不饱和结构有机物反应,而直接氧化的矿化能力较弱.为进一步明确二级出水有机物种类和含量的变化,测定了混凝和不同臭氧投加量下有机物的相对分子质量和三维荧光光谱.结果表明混凝对有机物含量的影响很小,而臭氧能够优先氧化分解难凝聚有机物中的大分子物质,明显减弱腐殖质类物质的荧光峰强度,但不改变荧光峰位置.同时采用光电子能谱分析有机物结构的变化规律,结果表明混凝能够去除含羧基类官能团有机物,而臭氧则易于与含苯环类难凝聚有机物反应,随着臭氧投加量的增大,脂肪类饱和有机物含量有所升高.     

臭氧对有机物混凝的影响

采用PDA(Photometric Disperse Analysis)和有机物表观分子量分级、有机物化学极性分级技术从絮体形成过程、絮体表现、有机物分子水平变化等方面研究了臭氧预氧化对混凝过程的影响;并对比了不同混凝剂在预臭氧条件下的混凝过程和效率.结果表明:臭氧预氧化对混凝过程有复杂的影响,其剂量和水体有机物特征决定了其对混凝的整体影响效果.有机物分级显示,臭氧化对有机物结构有重要影响,导致有机物极性、亲水性组分含量大幅提高(36.7%),小分子量组分(<10×10³)大幅增高(100%左右);但总的DOC去除率不高(3.28%).对PACl而言,在中、低剂量(O₃/TOC<0.7)下,臭氧对絮体形成过程影响较小,但对絮体沉降性和浊度去除已经有阻碍作用.在中、高剂量下(O₃/TOC>0.7),对絮体形成有显著滞后,浊度、有机物去除效率下降.AlCl₃对臭氧化作用反应敏感,臭氧化在试验剂量条件下,对絮体形成和浊度、有机物去除都有明显的阻碍作用.     

光合细菌和螺旋藻对啤酒废水的净化与利用研究

应用ＰＳＢ将啤酒废水中的有机质降解处理为无机质，用甲壳絮凝沉降除去ＰＳＢ后加入螺旋藻进行培养。小型动态模拟实验结果表明ＰＳＢ和螺旋藻不仅能高效地净化啤酒废水。     

Advanced oxidation of bromide-containing drinking water：A balance between bromate and trihalomethane formation control

Addition of H2O2 has been employed to repress bromate formation during ozonation of bromide-containing source water. However, the addition of H2O2 will change the oxidation pathways of organic compounds due to the generation of abundant hydroxyl radicals, which could affect the removal efficacy of trihalomethane precursors via the combination of ozone and biological activated carbon （O3-BAC）. In this study, we evaluated the effects of H2O2 addition on bromate formation and trihalomethane formation potential （THMFP） reduction during treatment of bromide-containing （97.6-129.1 μg/L） source water by the O3-BAC process. At an ozone dose of 4.2 mg/L, an H2O2/O3 （g/g） ratio of over 1.0 was required to maintain the bromate concentration below 10.0 μg/L, while a much lower H2O2/O3 ratio was sufficient for a lower ozone dose. An H2O2/O3 （g/g） ratio below 0.3 should be avoided since the bromate concentration will increase with increasing H2O2 dose below this ratio. However, the addition of H2O2 at an ozone dose of 3.2 mg/L and an H2O2/O3 ratio of 1.0 resulted in a 43% decrease in THMFP removal when compared with the O3-BAC process. The optimum H2O2/O3 （g/g） ratio for balancing bromate and trihalomethane control was about 0.7-1.0. Fractionation of organic materials showed that the addition of H2O2 decreased the removal efficacy of the hydrophilic matter fraction of DOC by ozonation and increased the reactivity of the hydrophobic fractions during formation of trihalomethane, which may be the two main reasons responsible for the decrease in THMFP reduction efficacy. Overall, this study clearly demonstrated that it is necessary to balance bromate reduction and THMFP control when adopting an H2O2 addition strategy.     

Greenhouse gas emission and its potential mitigation process from the waste sector in a large-scale exhibition

As one of the largest human activities, World Expo is an important source of anthropogenic Greenhouse Gas emission (GHG), and the GHG emission and other environmental impacts of the Expo Shanghai 2010, where around 59,397 tons of waste was generated during 184 Expo running days, were assessed by life cycle assessment (LCA). Two scenarios, i.e., the actual and expected figures of the waste sector, were assessed and compared, and 124.01 kg CO₂-equivalent (CO₂-eq.), 4.43 kg SO₂-eq., 4.88 kg NO₃⁻-eq., and 3509 m³ water per ton tourist waste were found to be released in terms of global warming (GW), acidification (AC), nutrient enrichment (NE) and spoiled groundwater resources (SGWR), respectively. The total GHG emission was around 3499 ton CO₂-eq. from the waste sector in Expo Park, among which 86.47% was generated during the waste landfilling at the rate of 107.24 kg CO₂-eq., and CH₄, CO and other hydrocarbons (HC) were the main contributors. If the waste sorting process had been implemented according to the plan scenario, around 497 ton CO₂-eq. savings could have been attained. Unlike municipal solid waste, with more organic matter content, an incineration plant is more suitable for tourist waste disposal due to its high heating value, from the GHG reduction perspective.     

Preface

A new method for generating reactive species to destroy toxic organic chemicals has been developed. This method reacts yellow phosphorus with O₂, in moist air to produce species such as O,O₃, PO, and PO₂, which are capable of reacting with various types of organics. Toxic organic com-pounds are converted to small molecular wight organic acids, aldehydes, and/or alcohols, while yel-low phosphonis is oxidital into phosphoric acid, which may be recovered as a valuable byproduct.This technique has ben demonstrated to be effective for destroying many types of toxic organiccompounds. including PAH, aromatic chlorides, amines, alcohols, and acids, nitro-aromatics,heterocyclic hydrocarbons, PCB, aliphatic chlorides and sulfides, dyes, and pesticides.     

模拟氮沉降对森林土壤有机物淋溶的影响

在重庆铁山坪马尾松林内施加与大气氮沉降量相当的硝酸铵(NH4NO3)和硝酸钠(NaNO3),研究氮沉降加倍对土壤溶液可溶性有机物浓度的影响,分析氮沉降对森林土壤碳库的潜在作用.2005年起为期5a的现场观测表明,施氮后凋落物层土壤溶液的可溶性有机碳(DOC)浓度和通量在起初2a内与对照样区相比有明显升高,但之后反而降低.施氮还会降低凋落物层土壤溶液的DOC与DON(可溶性有机氮)比值,以及矿质土壤上层的DOC浓度,但对矿质土壤下层的DOC淋溶通量几乎没有影响.总体来看,在试验期内氮沉降对土壤碳库无显著影响,但土壤有机物可能有从富碳有机物向富氮有机物转化的趋势,氮沉降的成分(NH4+和NO3-)对土壤有机物的影响则没有明显差异.     

中国主要背景区域冬季大气PM2.5中非极性有机化合物组成及来源解析

本研究于2019年12月至2020年1月在5个区域大气本底站：临安、金沙、龙凤山、上甸子和瓦里关,同步采集了PM_2.5样品,分析了其中的非极性有机物：多环芳烃、正构烷烃和藿烷类化合物。结果表明,上甸子和龙凤山的多环芳烃平均浓度显著高于其他站点,分别为35.2±25.6 ng/m³和27.5±16.8 ng/m³;藿烷类物质的浓度在上甸子和临安出现高值,分别为2.72±1.78 ng/m³和2.47±0.990 ng/m³;正构烷烃浓度以临安最高,为86.7±40.6 ng/m³。对各站点多环芳烃和藿烷类化合物采用比值法,正构烷烃采用主峰碳数（C_max）、碳优势指数（carbon preference index,CPI）和植物蜡贡献率（% Wax C_n）,结合主成分分析-多元线性回归模型（PCA/MLR）综合进行源解析。结果显示采样期间除瓦里关外,其余站点燃烧源均以化石燃料源为主,贡献率分别为临安（94.9%） > 金沙（75.3%） > 龙凤山（74.7%） > 上甸子（62.5%） > 瓦里关（35.6%）。后向轨迹聚类分析（HYSPLIT）和潜在源贡献因子分析法（PSCF）表明各站点主要受到外来传输气团的影响,并查明了各站点的潜在污染源区。对背景站点的研究表明,东北地区和京津冀地区PM_2.5中非极性有机物来源相似,京津冀地区的生物质燃烧源贡献率高于东北地区;长江中下游地区化石燃料贡献率显著高于生物质燃烧;华中地区燃煤和交通排放源排放贡献率均低于长江三角洲地区;青藏高原地区生物质燃烧贡献率远高于其他地区。     

温度对汞抑制土壤脲酶动力学影响研究

以不同施肥方式、不同有机质含量的草甸棕壤和黑土4个土样为对象,研究了不同温度条件下,汞(Hg)对土壤脲酶动力学特征的影响.结果表明,同一类型、有机质含量高的土壤脲酶活性、酶促最大反应速度(V_max)和V_max/K_m均高于有机质含量低的土壤,表明有机质对脲酶的吸附能力较强;黑土V_max和V_max/K_m值总体上大于草甸棕壤,但酶活性和米氏常数(K_m)值在不同土壤类型之间规律性较差,反映出酶活性由总酶量和酶-底物亲和力等因素共同决定;黑土K_m值大小与有机质含量相一致,而草甸棕壤则相反,表明有机质含量和施肥方式均会对K_m值产生影响;在最适温度以下,随温度升高,土壤的脲酶活性、V_max和V_max/K_m值均增加;Hg对土壤脲酶表现出典型的反竞争性抑制现象;Hg对脲酶活性的抑制作用及对K_m、V_max和V_max/K_m的负效应均随温度升高而有增加的趋势,揭示出土壤对脲酶的保护能力随温度升高而有所下降.