水土资源匹配视角下中国省域农产品供需平衡分析及其政策启示

粮食安全关系到中国稳定与发展和国际贸易秩序。以省级行政区为基本单位,基于2016—2018年各省份常住人口、农产品消费量、农业数据及相关参数,采用生态足迹和水足迹评价方法,在只考虑食用和再生产消费且不考虑地区耕地质量差异的条件下,核算各省份农产品自给的水土资源需求,评价中国省域水土资源承载力状态。结果显示：（1）中国现有耕地资源总量可满足自身耕地总需求（前者是后者1.81倍）,但省际差异大,东部沿海省市耕地不足。（2）农业可用水资源总量亦可满足农业可持续生产需求,但区域严重不平衡,华北平原与宁夏水资源赤字严重,而青藏高原地区、长江以南省份农业可用水资源丰富。（3）水土资源空间不匹配制约了中国农业的粮食生产潜力,不考虑环境净化用水,水土资源匹配状态可满足全国粮食自给需求;但考虑环境净化用水,中国粮食难以实现自给,承载力赤字达33715.50万人。以资源环境可持续为导向,未来中国应从农业生产布局优化、农业结构调整、农业科技、产业与人口转移、农产品进口和农业国际合作等方面着手,解决中国农产品需求问题。     

栅藻LX1和雨生红球藻的胞外产物产生特性及其对藻细胞生长的影响

基于微藻在资源化大规模培养过程中,其胞外产物对藻细胞生长影响的不确定性,对比研究了两株高含油脂藻种,栅藻LX1（Scenedesmus sp.LX1）和雨生红球藻（Haematococcus pluvislis）的生长特征、胞外产物的产生特性,以及胞外产物对藻细胞生长的影响。研究结果表明,在相同培养条件下,栅藻LX1与雨生红球藻的内禀生长速率基本相当,分别为0.16和0.17 d-1。两株藻在不同生长期的胞外产物（以DOC值表征）产生速率不同,其中栅藻LX1胞外产物的对数期产生速率（1.4 mg·L-1·d-1）﹥稳定期后期产生速率（0.56 mg·L-1·d-1）﹥稳定期产生速率（0.48 mg·L-1·d-1）;雨生红球藻胞外产物的稳定期后期产生速率（2.3 mg·L-1·d-1）﹥稳定期产生速率（0.88 mg·L-1·d-1）﹥对数期产生速率（0.66 mg·L-1·d-1）。栅藻LX1胞外产物对其整个生长过程都有明显抑制;雨生红球藻胞外产物则在稳定期后期才对其生长产生明显抑制作用。     

高铁酸盐对生活污水中药品和个人护理品（PPCPs）的降解研究进展

药品和个人护理品（PPCPs）类新兴污染物在水环境中被频繁检出,其种类繁多,许多组分具有较强的生物活性。虽然PPCPs在环境中大多以痕量浓度存在,但因其生物累积性和潜在的生态风险性,近年来受到高度关注。文中阐述了高铁酸盐对污水环境中PPCPs的降解,并介绍了高铁酸盐与其他技术联用降解PPCPs的研究进展及高铁酸盐的发展前景,为其实际应用于污水中PPCPs的降解去除提供思路。     

Intra-industry trade in intermediate products, pollution and internationally increasing returns

This paper examines the relationship between intra-industry trade in intermediate products, pollution and increasing returns. We develop a two-country model in which production occurs in two stages, final and intermediate good production. Intermediate goods are produced under monopolistic competition and final good production exhibits increasing returns with respect to the number of varieties of intermediates. Pollution occurs in the production of the final good when polluting intermediates are used. We analyze the effects of international trade in intermediate products on pollution, output and welfare under an endogenous tax scenario and with two types of pollution functions. The results show that, because of increasing returns, international trade either leads to lower total pollution in each country or lower pollution per unit of output in at least one country. In addition, intra-industry trade causes countries to import the environmental quality of their trading partners.     

Effects of Harvest of Nontimber Forest Products and Ecological Differences between Sites on the Demography of African Mahogany

Abstract: The demographic impacts of harvesting nontimber forest products (NTFP) have been increasingly studied because of reports of potentially unsustainable harvest. Nevertheless, our understanding of how plant demographic response to harvest is altered by variation in ecological conditions, which is critical for developing realistic sustainable‐use plans, is limited. We built matrix population models to test whether and how variation in ecological conditions affects population responses to harvest. In particular, we examined the effect of bark and foliage harvest on the demography of populations of African mahogany (Khaya senegalensis) in two contrasting ecological regions of Benin, West Africa. K. senegalensis bark and foliage harvest significantly reduced its stochastic population growth rates, but ecological differences between regions had a greater effect on population growth rates than did harvest. The effect of harvest on population growth rates (Δλ) was slightly stronger in the moist than in the drier region. Life‐table response experiments revealed that the mechanism by which harvesting reduced λ differed between ecological regions. Lowered stasis (persistence) of larger life stages lead to a reduction in λ in the drier region, whereas lowered growth of all life stages lowered λ in moist region. Potential strategies to increase population growth rates should include decreasing the proportion of individuals harvested, promoting harvester‐owned plantations of African mahogany, and increasing survival and growth by promoting no‐fire zones in gallery forests. Our results show how population responses to harvest of NTFP may be altered by ecological differences across sites and emphasize the importance of monitoring populations over the climatic range in which they occur to develop more realistic recommendations for conservation.     

The effect of 4-Nonylphenol on the pigmentation of<Emphasis Type="Italic">Ocimum basilicum</Emphasis> (Basil)

BACKGROUND, AIM AND SCOPE: Tests during the last few years have confirmed that 4-nonylphenol (4-NP) can have oestrogen-like effects (xeno-hormone) on animal organisms. The objective was to firstly evaluate the ecotoxicological effects of 4-NP on plants such as hydrocultures. To clarify how this substance interferes with the photosynthetic system of plants, various tests were carried out using the basil plant (Ocimum basilicum). METHODS: The effect of the pollutant 4-NP on the pigment content in the leaves of the basil plant was analysed with the use of High-Performance-Liquid-Chromatography (HPLC). RESULTS AND DISCUSSION: A general assessment of the HPLC data revealed that plants that came in contact with the 4-nonylphenol showed a change in pigmentation. More chlorophyll a and b was produced, although at the same time a higher production of degradation products and by-products of the chlorophylls was observed. These occurrences can therefore be seen as an impairment of the photosynthetic process. The contaminated plants produced less xanthophylls than the non-contaminated ones, though these differences were statistically not significant. CONCLUSION AND PERSPECTIVE: The variations on the pigment content in the leaves of the basil plant can be interpreted as a consequence of the 4-NP application. It was, however, not investigated whether the plants absorbed the pollutants directly. The effect could have been caused by adsorption of the oily substance to the roots, and this could have led to a hindrance of the uptake of nutrients and possibly water. In order to clarify this further, biochemical experiments are being conducted.     

临沂市夏季羰基化合物来源及其对大气氧化性的影响

羰基化合物在大气光化学中扮演着重要角色,影响大气自由基丰度、大气氧化性强度以及臭氧（O₃）光化学反应产率.通过对2022年8月临沂市大气羰基化合物及相关物种外场观测,结果发现甲醛（HCHO）体积分数φ（HCHO）和乙醛（CH₃CHO）体积分数φ（CH₃CHO）分别为（4.95±2.01）×10^-9和（3.34±1.40）×10^-9.根据多元线性回归结果发现二次生成是HCHO和CH₃CHO主要来源,分别贡献其总体积分数的34.28%和35.95%.用基于观测约束的模式（Observation-Based Model,OBM）分析发现影响甲醛二次净生成速率的主要前体物为生物源烯烃和人为源烯烃（主要是正丁烯、乙烯和丙烯）.影响乙醛二次净生成速率的主要前体物是人为源烯烃（正丁烯和丙烯）、烷烃（正己烷和正丁烷）和苯.烯烃类物质是影响临沂市羰基化合物体积分数水平的关键前体物物种.羰基化合物对大气氧化性的贡献最强,占比高达为74.64%.本研究强调了烯烃对羰基化合物污染的重要影响,并指出光化学污染日,羰基化合物对大气氧化性的重要作用,对未来国内外中小城市羰基化合物污染控制具有指导意义.     

山东某污水处理厂中环型和线型甲基硅氧烷的行为归趋

本文研究了山东某污水处理厂污水及污泥中3种环型甲基硅氧烷（D4—D6,CMS）和12种线型甲基硅氧烷（L5—L16,LMS）的行为归趋.进水中总甲基硅氧烷（∑MS）的浓度为15.7—65.7 μg·L-1（平均值：39.2 μg·L-1）,其中∑LMS占比为98.2%.进水中∑MS浓度夏季最高（65.7 μg·L-1）,其次分别是秋季（41.7 μg·L-1）、冬季（33.7 μg·L-1）和春季（15.7 μg·L-1）.出水中∑MS浓度为6.24—14.3 μg·L-1（平均值：10.6 μg·L-1）,平均去除率为73.0%.污泥中∑MS的浓度为14.1—48.4 μg·g-1（平均值：20.3 μg·g-1）,D4—D6的泥水分配系数（lg Kd）为3.84—4.44,L6—L16的lg Kd为2.24—4.30.此外,通过计算甲基硅氧烷的危险商数（hazard quotients,HQ）评估了其对水生生物的危害,发现污水处理厂出水中目标化合物的潜在危害较低.     

典型药物与个人护理品(PPCPs)的厌氧降解转化研究进展

药物与个人护理品(pharmaceuticals and personal care products, PPCPs)的污染和环境归趋问题备受关注。其中厌氧降解转化作为疏水性PPCPs在自然环境介质中的主要消解方式尤为重要。本文以典型PPCPs为例,分析了城市污水处理厌氧工艺对PPCPs的去除情况,主要包括污泥吸附和厌氧生物转化;总结了化学结构、微生物、碳源和氧化还原电位等多种因素对PPCPs厌氧降解转化效率的影响,其中氧化还原电位发挥重要作用,因其与氧化还原酶密切相关;同时,重点归纳了磺胺甲噁唑、苯并三唑和三氯生等3种典型PPCPs在不同氧化还原电位下的厌氧降解转化途径,并对PPCPs厌氧微生物降解的未来研究重点和发展方向进行展望：(1)强化PPCPs的有机质-厌氧微生物共代谢降解机制研究;(2)聚焦PPCPs厌氧降解菌群筛选及其功能研究;(3)深入开展厌氧降解菌群培养体系构建和原位厌氧降解研究。本研究相关结果有望为PPCPs的污染防治提供科学依据。