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201.
农药草甘膦废水具有TP浓度高、难降解COD浓度高等特点,比较难于处理.采用Fe/Cu体-CAST工艺对目前工艺厌氧放磷池废水进行了研究.结果表明,系统对COD,难降解COD,TP和PO4-3的去除率分别高达88.4%,70.4%,83.3%和96.6%.利用Fe/Cu体微曝气强化CAST工艺对草甘膦原有废水处理工艺进行改造,固定成本投资较低,每吨废水增加的日常运行费用为0.11元. 相似文献
202.
用于评价水污染的生物指数 总被引:13,自引:0,他引:13
对各国学者所建立的应用较广泛的生物指数作了综述 ,通过分析各种生物指数的优点与缺陷 ,指出了目前建立生物指数方法上的不足 ,并提出了建立生物指数应该采用的更合理的方法。 相似文献
203.
针对我国生物质气化发电行业的现状,总结诸多风险的影响因素,建立了我国生物质气化发电行业综合风险评价体系。该评价体系主要包括5个一级风险影响因素:市场风险、技术风险、安全风险、管理风险、环境风险,每个一级影响因素包括4个二级风险影响因素。由层次分析法获得各个一级影响因素和二级影响因素的权重值,根据所构建的评价集和评分标准,结合模糊综合评价法对我国生物质气化发电行业现状的综合风险等级做定量定性分析。综合风险评价研究结果表明,生物质气化发电行业处于"较高"的风险等级,与实际情况相符。综合风险评价体系的构建合理,所建立的评价方法以及相应对策分析可为决策者提供参考依据。 相似文献
204.
The pollution status and characteristics of PAEs (phthalate esters) were investigated in indoor air of offices, and PAEs of both gas-phase and particulate-phase were detected in all the samples. The concentration (sum of the gas phase and the particulate phase) was 4748.24 ng/m3, ranging between 3070.09 and 6700.14 ng/m3. Diethyl phthalate, dibutyl phthalate, and di(2-ethylhexyl) phthalate were the most abundant compounds, together accounting for 70% of the Σ6PAEs. Dividing the particulate-phase PAEs into four size ranges (<2.5, 2.5-5, 5-10, >10 μm), the result indicated that PAEs in PM2.5 were the most abundant, with the proportion of 72.64%. In addition, the PAE concentration in PM2.5 correlated significantly with the total particulate-phase PAEs (R2 = 0.85). Thus, the amount of PAEs in PM2.5 can be estimated from the total amount of particulate-phase PAEs using this proportion. In a comparison between the offices and a newly decorated study room, it was found that pollution characteristics were similar between these two places. Thus, it is implied that the PAE concentration decreased by 50% 2 yr after decorating. 相似文献
205.
Xi Yang Ping Xie Yunzhen Yu Hong Shen Xuwei Deng Zhimei Ma Peili Wang Min Tao Yuan Niu 《环境科学学报(英文版)》2015
We conducted an experiment to study the interaction effects of Microcystis aeruginosa and Pseudomonas pseudoalcaligenes on off-flavors in an algae/bacteria co-culture system at three temperatures (24, 28 and 32°C). Gas chromatography–mass spectrometry was applied to measure off-flavor compounds dimethyl sulfide (DMS), dimethyl trisulfide (DMTS), 2-methylisoborneol, geosmin (GEO) and β-cyclocitral. During the lag phase of co-cultured M. aeruginosa (first 15 days), P. pseudoalcaligenes significantly increased the production of DMS, DMTS and β-cyclocitral at all three temperatures. In the exponential phase of co-cultured M. aeruginosa (after 15 days), M. aeruginosa became the main factor on off-flavors in the co-culture system, and β-cyclocitral turned to the highest off-flavor compound. These results also indicated that DMS, DMTS and β-cyclocitral were the main off-flavor compounds in our M. aeruginosa/P. pseudoalcaligenes co-culture system. Univariate analysis was applied to investigate the effects of M. aeruginosa and P. pseudoalcaligenes on the production of off-flavors. The results demonstrated that both M. aeruginosa and P. pseudoalcaligenes could increase the production of DMS and DMTS, while β-cyclocitral was mainly determined by M. aeruginosa. Our results also provide some insights into understanding the relationship between cyanobacteria and heterotrophic bacteria. 相似文献
206.
In order to find effective measures to control diatom blooms, a better understanding of the physiological characteristics of nutrient uptake in diatoms is needed. A study of P and Si-uptake kinetics for diatom species from two light regimes was conducted at low (LL), moderate (ML) and high light intensities (HL) (2, 25 and 80 μmol photons/(m2·sec)), respectively. The results showed that P uptake of diatoms was heavily influenced by historic light regimes. P affinity changed with growth and photosynthetic activity. The lowest half saturation constant for P uptake (Km(P)) was under HL for high-light adapted diatoms while the lowest half-saturation constant for low-light adapted diatoms was observed under LL. The Si half-saturation constant (Km(Si)) increased with increasing light intensities for pennate diatoms but decreased for centric diatoms. Diatom volumes were correlated with the maximum Si uptake rates (Vm(Si)) at HL and Km(Si) at ML and HL for six diatom species. Our results imply that when we assess the development of diatom blooms we should consider light intensity and cell volume in addition to ambient Si or P concentration. The relationship between light intensity and P-uptake suggests that we can find suitable methods to control diatom blooms on the basis of reducing phytoplankton activity of P-uptake and photosynthesis simultaneously. 相似文献
207.
Min Song Chenchen Chi Min Guo Xueqing Wang Lingxiao Cheng Xueyou Shen 《环境科学学报(英文版)》2015,28(2):157-162
The pollution status and characteristics of PAEs(phthalate esters) were investigated in indoor air of offices, and PAEs of both gas-phase and particulate-phase were detected in all the samples. The concentration(sum of the gas phase and the particulate phase) was4748.24 ng/m3, ranging between 3070.09 and 6700.14 ng/m3. Diethyl phthalate, dibutyl phthalate, and di(2-ethylhexyl) phthalate were the most abundant compounds, together accounting for 70% of the ∑ 6PAEs. Dividing the particulate-phase PAEs into four size ranges( 2.5, 2.5–5, 5–10, 10 μm), the result indicated that PAEs in PM2.5were the most abundant,with the proportion of 72.64%. In addition, the PAE concentration in PM2.5correlated significantly with the total particulate-phase PAEs(R2= 0.85). Thus, the amount of PAEs in PM2.5can be estimated from the total amount of particulate-phase PAEs using this proportion. In a comparison between the offices and a newly decorated study room, it was found that pollution characteristics were similar between these two places. Thus, it is implied that the PAE concentration decreased by 50% 2 yr after decorating. 相似文献
208.
利用历史数据,选取合适计算模型,定量预测了2014年-2020年江苏省城镇化边际资源环境影响,即以与城镇化发展密切相关的资源使用量或者城镇生活污染物排放量较上一年的增量,除以当年城镇化率增量,得到江苏省城镇化水平每提高一个百分点带来的资源环境影响,以期为江苏环境管理及政府综合决策提供切实有效的数据依据.结果表明:未来7年,江苏省城镇化率每上升1个百分点,增加城镇生活用水量约0.5亿立方米、城镇建设用地面积16万亩;增加城镇生活污水排放量1.15亿吨、生活氮氧化物排放量10 228吨、生活垃圾产生量36.4万吨;减少生活COD排放量7 549吨、生活氨氮排放量762吨、生活二氧化硫(SO2)排放量371吨. 相似文献
209.
Houyu Wang Chun-Gang Yuan Chenchen Liu Xuelei Duan Qi Guo Yiwen Shen Jingfu Liu Yongsheng Chen 《环境科学学报(英文版)》2022,34(5):286-293
The creation of an environmentally friendly synthesis method for silver nanomaterials (AgNPs) is an urgent concern for sustainable nanotechnology development. In the present study, a novel straightforward and green method for the preparation of silver nanoparticle/reduced graphene oxide (AgNP/rGO) composites was successfully developed through the combination of phytosynthesis, continuous flow synthesis and microwave-assistance. Oriental persimmon (Diospyros kaki Thunb.) extracts were used as both plant reducing and capping agents for fast online synthesis of AgNP/rGO composites. The experimental parameters were optimized and the morphologies of the prepared materials were investigated. The characterization results reveal that spherical AgNPs were quickly synthesized and uniformly dispersed on rGO sheets using the proposed online system. Fourier transform infrared spectroscopy analysis confirmed that phenols, flavonoids, and other substances in the plant extracts played a decisive role in the synthesis of AgNP/rGO composites. Using sodium borohydride (NaBH4) degradation of p-nitrophenol (4-NP) as a model, the catalytic activity of the prepared AgNP/rGO materials was evaluated. The complete degradation of 4-NP was achieved within 12 min through the use of AgNP/rGO materials, and the composite had a much better catalytic activity than the bare AgNPs and rGO had. Compared with the conventional chemical method, our online method is facile, fast, cost-efficient, and environmentally friendly. 相似文献
210.
沉积岩中的汞及其同位素常被用于指示大规模火山活动、海洋氧化还原演变等古环境演化事件,但现有研究主要聚焦总汞含量及相应的总汞同位素组成,缺少形态汞含量及其同位素组成数据,因此无法精准判别古环境中汞的来源、沉积环境和沉积过程。本研究开发了基于热解技术的沉积岩中不同形态汞的分离和同位素分析方法。首先通过沉积岩中典型形态汞(有机质、硫化物和粘土矿物结合态汞)单一标准建立热解温度曲线,然后将上述单一标准物质混合,通过调整升温速率以及形态汞采集的温度范围和时间优化热解分离方法,收集不同温度下析出的气态单质汞进行同位素分析。结果表明,分离的有机质结合态及硫化物结合态汞的δ202Hg和Δ199Hg值同参考值的平均差值分别小于0.20‰和0.03‰,因此该分离方法能有效分离上述形态汞并进行汞同位素组成分析。上述方法被进一步应用于分析天然标准物质(黄红壤、水系沉积物、海相沉积岩)的汞形态及其同位素组成,验证了该方法在自然样品中的广泛适用性。 相似文献