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Yang Zhaojun Guo Xiaoting Sun Jun Zhang Yali 《Environment, Development and Sustainability》2021,23(8):12056-12076
Environment, Development and Sustainability - Sustainable supply chain emerges as a major business trend essential to long-term competitive advantage. Relevant corporate decisions concern a broad... 相似文献
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海(咸)水混入是河口河水重要的地质过程,深刻地影响河水地球化学过程。本文系统采集夹河河口水样,分析海淡水混合过程的地球化学特征。结果表明,远离河口段(J10~J14)为淡水性质,主要受水-岩作用及人类活动等影响;近河口段(J1~J8)海水混入严重,F~-、Cl~-、Br~-、SO~(2-)_4、Na~+、K~+、Mg~(2+)、Ca~(2+)、盐度等明显较高,主要受海水混入影响。近河口段存在Na-Ca离子交换过程,约占Na~+总量的0.9%~1.5%,离子交换量随海水混入比例增加而增加,Na~+离子交换量与K~+,Ca~(2+)、Mg~(2+)、Br~-、F~-、SO~(2-)_4离子交换量相关,且河水离子含量与盐度回归系数略低于与盐度、Na~+交换量回归系数,表明河口段河水离子交换影响河水地球化学特征。 相似文献
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为了解成渝地区中小城市VOCs污染特征及其来源,选取该区域典型代表城市-遂宁市为研究对象,利用2019年不同时间不同功能区106种VOCs离线观测数据,研究了该市VOCs污染水平和时空特征,分析了VOCs主要成分及其对臭氧的影响,并进行了源解析。结果显示:(1)遂宁市大气中VOCs平均体积分数为39.4×10-9,8月的浓度较高,其空间排序为工业区>城郊区≈文教区。(2)OVOCs和烷烃是VOCs主要组分,占比达73.4%,且不受时间和空间限制;工业区不同组分浓度均高于城郊区和文教区,城郊区和文教区的同组分占比相差较小;丙酮和乙烷是VOCs中体积分数最大的物种,占总体积分数的37.8%。(3)VOCs组分对OFP贡献率顺序为烯烃>芳香烃>OVOCs>烷烃>炔烃>卤代烃>有机硫,前4类组分对OFP贡献率达97.6%,烯烃对OFP贡献率不仅每日最大,而且还呈现“城郊区>文教区>工业区”空间分布态势;异戊二烯、乙烯是OFP最大的物种,在不同功能区其OFP均高于其他物种,是遂宁市臭氧防治关注重点。(4)VOCs排放源及... 相似文献
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Mercury(Hg), mainly in cinnabar species, has been used in medicine for thousands of years in China, and worldwide concern has been raised on its toxicity. In this work, the amount of bioaccessible mercury in 16 Chinese patent medicines(CPMs) was measured by using an in vitro simulated digestion system, consisting of simulated gastric and intestinal fluid, to investigate the bioavailability of mercury in CPMs and evaluate its potential risk to human health. Total mercury and mercury in the gastrointestinal extracts were measured by inductively coupled plasma mass spectrometry(ICP-MS). The levels of total Hg in 16 CPMs ranged from not detected to 11.89 mg/g, with a mean value of 1.13 mg/g, while the extractable Hg ranged from not detected to 4.37 μg/g, with a mean value of 0.42 μg/g.Mercury bioaccessibility varied significantly in the investigated CPMs, depending on the ingredient. Compared to the CPMs without cinnabar(2.5%–30.9%), the percentage of mercury in the gastrointestinal supernatants for CPMs with cinnabar was quite a bit lower(0.037%). By comparing with the Food and Agricultural Organization/World Health Organization Joint Expert Committee on Food Additives(FAO/WHO) safety guideline, the average daily intake dose(ADD) of Hg in the medicines was then calculated to access the risk of mercury to human health from taking CPMs. 相似文献
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为了解滴灌条件下不同微咸水矿化度及覆膜与否对盐碱地土壤水盐特性及油葵生长的影响,在宁夏平罗西大滩盐碱地进行不同灌水矿化度(0.2、1、2、3 g/L)膜下滴灌田间试验.结果表明,地膜覆盖比不覆盖处理土壤含水量高约2%,盐分表聚减缓,油葵株高、产量及其构成均高于不覆膜处理,产量最高增幅达82.5%;不同矿化度微咸水之间比较发现,利用矿化度为1 g/L的微咸水进行灌溉时,下层土壤含水量较高,微咸水滴灌不但没有为上层土壤带去过多盐分,反而由于土壤有一定的渗透性能,灌水将土壤上层盐分逐渐淋洗至下层.膜下滴灌微咸水矿化度为1 g/L时,油葵产量最大.因此在适宜条件、合理措施下,微咸水覆膜滴灌技术可以促进作物生长,确保作物产量,在淡水缺乏而微咸水较为丰富的盐碱地地区应积极推广利用. 相似文献
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本文报道了沱江上游青白江区水环境管理的现状,分析了水环境管理中存在的问题,提出了防治对策。 相似文献
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