矿区重金属植被修复研究进展和趋势

植物修复是实现采矿区重金属修复以及综合治理的有效途径之一。国外常用的矿区土壤重金属植物修复技术包括植物固定、植物提取、植物挥发、植物过滤,以上技术理论和应用方面均起步较早。相比之下,我国在相关研究领域的研究均远落后于国外。迄今为止,国内外针对稀土矿区的生态修复研究比较缺乏,需在今后重点加强。     

对三池式UNITANK工艺的几点深入认识

提高生物除磷效率为三池式UNITANK工艺的运行控制目标。本文通过对UNITANK工艺运行控制方面的研究及工程经验,分析了三池式UNITANK工艺厌氧空间、时间,UNITANK反应器进水流态,工艺及自控运行方式,并得出了相关结论。     

突发性场地污染应急控制技术研究进展

随着中国社会经济水平的加速发展,近年来各类突发性场地污染事故频发,如何有效地在第一时间对污染物进行应急控制及场地修复显得尤为重要.以突发性场地污染为研究对象,探讨了土壤及地下水中污染物的应急控制及场地修复技术的研究状况,给出了各项应急控制技术在突发性场地污染事故中适用的目标污染物及土壤类型,以便在实际运用中根据场地的污染类型和土壤性质快速做出响应.最后还指出,应急控制技术作为一种暂时性处理手段,可在场地污染事故发生后对污染物扩散进行快速控制,但不可作为一种长期处置措施.     

超声波处理回流剩余污泥对SBR工艺的污泥减量效能

在SBR中试系统中,采用较高声能密度较短时间的超声波处理剩余污泥后回流至系统连续运行20 d的方式进行污泥减量,通过分析测定系统MLSS、累计排泥量以及系统出水水质指标,考察了系统污泥减量效果及污泥回流对系统污水处理效果的影响。结果表明,对SBR系统2/3的剩余污泥用声能密度为1 W/mL的超声波预处理6 min后回流至SBR系统。SBR系统最终需处置的污泥量减少了45.64%,获得了理想的污泥减量效果。污泥回流后SBR系统对SS、COD、TN以及NH4+-N的去除效果均无明显变化,仅出水TP含量略高于对照的SBR,出水水质仍能达到《城镇污水处理厂污染物排放标准》(GB18918-2002)一级B标准。     

Simulated seasonal variations in wet acid depositions over East Asia

The air quality modeling system Regional Atmospheric Modeling System-Community Multi-scale Air Quality (RAMS-CMAQ) was applied to analyze temporospatial variations in wet acid deposition over East Asia in 2005, and model results obtained on a monthly basis were evaluated against extensive observations, including precipitation amounts at 704 stations and SO4(2-), NO3-, and NH4+ concentrations in the atmosphere and rainwater at 18 EANET (the Acid Deposition Monitoring Network in East Asia) stations. The comparison shows that the modeling system can reasonably reproduce seasonal precipitation patterns, especially the extensive area of dry conditions in northeast China and north China and the major precipitation zones. For ambient concentrations and wet depositions, the simulated results are in reasonable agreement (within a factor of 2) with observations in most cases, and the major observed features are mostly well reproduced. The analysis of modeled wet deposition distributions indicates that East Asia experiences noticeable variations in its wet deposition patterns throughout the year. In winter, southern China and the coastal areas of the Japan Sea report higher S04(2-) and NO3- wet depositions. In spring, elevated SO4(2-) and NO3-wet depositions are found in northeastern China, southern China, and around the Yangtze River. In summer, a remarkable rise in precipitation in northeastern China, the valleys of the Huaihe and Yangtze rivers, Korea, and Japan leads to a noticeable increase in SO4(2-) and NO3- wet depositions, whereas in autumn, higher SO4(2-) and NO3-wet depositions are found around Sichuan Province. Meanwhile, due to the high emission of SO2, high wet depositions of SO4(2-) are found throughout the entire year in the area surrounding Sichuan Province. There is a tendency toward decreasing NO3- concentrations in rainwater from China through Korea to Japan in both observed and simulated results, which is a consequence of the influence of the continental outflow from Eurasia. The same tendency is not found for SO4(2-).     

Synthesis and enhanced visible-light responsive of C,N,S-tridoped TiO2 hollow spheres

C,N,S-tridoped TiO2 hollow spheres （labeled as C,N,S-THs） were synthesized using carbon spheres as template and C,N,S-tridoped TiO2 nanoparticles as building blocks. The structure and physicochemical properties of the catalysts were characterized by X- ray diffraction （XRD）, scanning electron microscopy （SEM）, UV-Vis diffuse reflectance spectrum （DRS）, N2 adsorption-desorption isotherms, X-ray photoelectron spectroscopy （XPS） and Photoluminescence emission spectroscopy （PL）. The results showed that the hollow spheres had average diameter of about 200 nm and the shell thickness was about 20 nm. The tridoped TiO2 hollow spheres exhibited strong absorption in the visible-light region. C,N,S-tridoped could narrow the band gap of the THs by mixing the orbit O 2p with C 2p, N 2p and S 3p orbits and shift its optical response from ultraviolet （UV） to the visible-light region. PL analysis indicated that the electron-hole recombination rate of TiO2 hollow spheres had been effectively inhibited when doped with C, N and S elements. The photocatalytic activities of the samples were evaluated for the degradation of X-3B （Reactive Brilliant Red dye, C.I. Reactive Red 2） aqueous solution under visible-light （λ 〉 420 nm） irradiation. It was found that the C,N,S-tridoped TiO2 hollow spheres indicated higher photocatalytic activity than commercial P25 and the undoped counterpart photocatalyst.     

三种有机磷萃取剂对水生生物的毒性效应

通过３种有机磷萃取剂：甲基磷酸二仲辛酯（P350）、异辛基磷酸单异辛酯（P507）和磷酸二异辛酸（P204）对不同营养级水平的单种生物：藻类（斜生棚藻）、草履虫（尾草履虫）、类（大型）、鱼类（鱼苗）的毒性试验,结果表明：３种有机磷萃取剂的毒性效应浓度（半致死浓度或半抑制浓度）为P350：0.40～9.30mg/L,P507：23.32～112.00mg/L,P204：59.50～138.00mg/L;毒性强弱的顺序为P350＞P507＞P204;建议把P350、P507、P204在水体中的安全浓度暂分别定为0.04mg/L、2.33mg/L和4.71mg/L。     

Effects of different sludge disintegration methods on sludge moisture distribution and dewatering performance

A key step in sludge treatment is sludge dewatering. However, activated sludge is generally very difficult to be dewatered. Sludge dewatering performance is largely affected by the sludge moisture distribution. Sludge disintegration can destroy the sludge structure and cell wall, so as change the sludge floc structure and moisture distribution, thus affecting the dewatering performance of sludge. In this article, the disintegration methods were ultrasound treatment, K₂FeO₄ oxidation and KMnO₄ oxidation. The degree of disintegration (DDCOD), sludge moisture distribution and the final water content of sludge cake after centrifuging were measured. Results showed that three disintegration methods were all effective, and K₂FeO₄ oxidation was more efficient than KMnO₄ oxidation. The content of free water increased obviously with K₂FeO₄ and KMnO₄ oxidations, while it decreased with ultrasound treatment. The changes of free water and interstitial water were in the opposite trend. The content of bounding water decreased with K₂FeO₄ oxidation, and increased slightly with KMnO₄ oxidation, while it increased obviously with ultrasound treatment. The water content of sludge cake after centrifuging decreased with K₂FeO₄ oxidation, and did not changed with KMnO₄ oxidation, but increased obviously with ultrasound treatment. In summary, ultrasound treatment deteriorated the sludge dewaterability, while K₂FeO₄ and KMnO₄ oxidation improved the sludge dewaterability.     

污水处理厂PPCPs的污染现状与去除技术

近年来,药品和个人护理品(PPCPs)作为一类新兴有机污染物在环境中被广泛报道.传统的污水处理厂处理工艺难以有效去除污水中的PPCPs,残留在污水处理厂出水中的PPCPs及其代谢物进入水环境会严重威胁人类健康和生态环境.介绍了PPCPs的类别、性质以及水环境中PPCPs的赋存水平及其潜在危害,提出风险熵法(RQ)是国内...     

深圳河典型内分泌干扰物分布和季节变化规律研究

2011年6月至2012年5月在深圳河沿程采集水样,采用固相萃取一氮吹一衍生化的预处理方法和气相色谱/质谱联用法,对壬基酚(NP)、辛基酚(OP)、双酚A(BPA)、雌酮(E1)、雌二醇(E2)、17α-雌二醇(17α-E2)、雌三醇(E3)、雌炔醇(EE2)等8种内分泌干扰物(EDCs)在深圳河的浓度分布和时空变化规律进行了研究.同时通过主成分分析考察了EDCs与常规水质污染物的关系.结果表明,NP、BPA、E1、E3、EE2在深圳河各河段均有检出,而OP、17α-E2、E2的检出率均低于20％,EDCs主要来源是NP和BPA;深圳河旱季和雨季EDCs的浓度变化大,其中NP浓度表现出旱季高雨季低的规律,旱季浓度是雨季的1.74～5.63倍,但BPA和3种甾醇类雌激素的浓度呈现出了雨季高旱季低的相反变化规律,这应该与污水处理厂雨季污水溢流有关;通过主成分分析发现,BPA与DO存在明显的负相关关系,生物作用可能在BPA去除和甾醇类雌激素转化中起到了重要作用,具体机制还有待进一步研究.