电渗透-过硫酸盐氧化对污泥胞外聚合物的影响

利用电渗透-高级氧化协同的方法,采用自制装置对市政污水厂的脱水污泥进行了深度脱水研究,系统研究了恒定电压和恒定电流对污泥脱水效果的影响,并分析了电渗透-高级氧化协同对污泥中胞外聚合物(EPS)的影响规律。结果表明,电压和电流的变化对于污泥脱水的影响显著,电渗透-高级氧化协同对污泥中的胞外聚合物有明显的破坏作用,其中电渗透作用对松散附着型EPS(LB-EPS)和黏液层EPS(S-EPS)的破坏明显,而高级氧化作用对于紧密黏附型EPS(TB-EPS)的破坏更为显著。     

Elman神经网络在矿井突水水源判别中的应用

矿井突水是矿建与生产过程中最具威胁的自然灾害之一,准确判别突水水源是防治水害的关键。选取6种离子的质量浓度作为突水水源的判别因素,将河南省焦作矿区不同水层的39组水化数据以2种样本设计方案进行Elman神经网络模型的构建与检验。以不同的35组水源样品作为训练样本,运用Matlab软件进行Elman神经网络训练,将所建立的判别模型应用于(相应的)4组待测样本的判别,并与DDA、FDA、Bayes三种判别方法的判别结果进行分析比较。2种方案应用结果表明:将具有非线性动态特征的Elman神经网络应用于突水水源判别,在结合相应的水文地质条件前提下,可以准确判断突水来源;矿井多年的开采促使地下各水层水质呈动态变化,Elman神经网络判别模型能够反映这种变化特性,对探寻地下水运移与演化具有一定的应用价值。     

Emission control strategies of hazardous trace elements from coal-fired power plants in China

China's energy dependents on coal due to the abundance and low cost of coal. Coal provides a secure and stable energy source in China. Over-dependence on coal results in the emission of Hazardous Trace Elements (HTEs) including selenium (Se), mercury (Hg), lead (Pb), arsenic (As), etc., from Coal-Fired Power Plants (CFPPs), which are the major toxic air pollutants causing widespread concern. For this reason, it is essential to provide a succinct analysis of the main HTEs emission control techniques while concurrently identifying the research prospects framework and specifying future research directions. The study herein reviews various techniques applied in China for the selected HTEs emission control, including the technical, institutional, policy, and regulatory aspects. The specific areas covered in this study include health effects, future coal production and consumption, the current situation of HTEs in Chinese coal, the chemistry of selected HTEs, control techniques, policies, and action plans safeguarding the emission control. The review emphasizes the fact that China must establish and promote efficient and clean ways to utilize coal in order to realize sustainable development. The principal conclusion is that cleaning coal technologies and fuel substitution should be great potential HTEs control technologies in China. Future research should focus on the simultaneous removal of HTEs, PM, SOx, and NOx in the complex flue gas.     

Mineralogical characteristics and photocatalytic properties of natural sphalerite from China

Different natural sphalerites have a range of photocatalytic properties that can potentially be exploited for environmental remediation purposes. To develop value in the exploitation of sphalerite, samples were collected from 19 ore deposits in China and characterized for their mineralogical and photocatalytic properties. X-ray diffraction (XRD) and electron probe micro analysis (EPMA) measurements indicated that all the natural sphalerites from various localities crystallized in cubic phases with various chemical compositions. The substitution of Fe for Zn ranged from 0.235% to 14.826% by weight, Mn from 0.004% to 4.868%, Cu from 0.009% to 5.529% and Cd from 0.133% to 1.576%. As Fe became more abundant, the color of natural sphalerite darkened, becoming almost black; and higher Fe content was associated with stronger visible light absorption. Photoluminescence spectra showed emission mainly related to S-vacancies and progressively decreasing fluorescence intensity with increasing Fe content. Tests of the photocatalytic degradation of methyl orange indicated that the sample with the highest Cd content but moderate Fe content had the highest photocatalytic activity. Specifically, the degradation of Methyl Orange (30 mg/L) attained 82.11% efficiency under visible light irradiation for 4 hr of natural sphalerite with 4.262% Fe and 1.576% Cd. Overall, the Fe content in sphalerite was found to contribute to the visible light absorption ability and the recombination rate of photo-generated electrons and holes, while substitution by Cd was observed to have a greater effect on the photocatalytic properties. These findings provide a scientific basis for the profitable utilization of base metal resources like sphalerite.     

Carbon reduction potential and cost evaluation of different mitigation approaches in China's coal to olefin Industry

Coal-based olefin (CTO) industry as a complement of traditional petrochemical industry plays vital role in China's national economic development. However, high CO₂ emission in CTO industry is one of the fatal problems to hinder its development. In this work, the carbon emission and mitigation potentials by different reduction pathways are evaluated. The economic cost is analyzed and compared as well. According to the industry development plan, the carbon emissions from China's CTO industry will attain 189.43 million ton CO₂ (MtCO₂) and 314.11 MtCO₂ in 2020 and 2030, respectively. With the advanced technology level, the maximal carbon mitigation potential could be attained to 15.3% and 21.9% in 2020 and 2030. If the other optional mitigation ways are combined together, the carbon emission could further reduce to some extent. In general, the order of mitigation potential is followed as: feedstock alteration by natural gas > CO₂ hydrogenation with renewable electricity applied > CCS technology. The mitigation cost analysis indicates that on the basis of 2015 situation, the economic penalty for feedstock alteration is the lowest, ranged between 186 and 451 CNY/tCO₂, and the cost from CCS technology is ranged between 404 and 562 CNY/tCO₂, which is acceptable if the CO₂ enhanced oil recovery and carbon tax are considered. However, for the CO₂ hydrogenation technology, the cost is extremely high and there is almost no application possibility at present.     

菌渣中青霉素对蔬菜种子萌发的生态毒性效应

为推动青霉素菌渣环境安全利用技术规范的建立,以油麦菜、油菜、白菜和生菜4种蔬菜为研究对象,以种子发芽率、幼苗鲜质量、芽长和根长为毒性敏感指标,研究了不同处理组〔ρ（PG）分别为10、100、200、400、800、1 200、1 600、2 000、2 400、3 200和4 000 mg/L〕和对照组的青霉素（Penicillin,简称“PG”）对4种蔬菜种子萌发的生态毒性响应关系.结果表明:①与对照组相比,各处理组4种蔬菜种子发芽率之间均无显著性差异（P>0.05）;当ρ（PG）≥1 200 mg/L时,油菜种子的芽长增长率在60%左右,且与对照组相比具有显著差异（P < 0.05）;在ρ（PG）为200 mg/L时,生菜鲜质量达到最大值（0.29 g）,较对照组增加了10.37%,白菜鲜质量在ρ（PG）为400 mg/L时达到最大值,较对照组增加了5.76%,而在试验浓度范围内,各处理组4种蔬菜种子的根长均随着ρ（PG）的增大表现出逐渐增强的抑制作用.②PG对4种蔬菜的根长抑制率剂量-效应关系均符合Allometric模型,即y=axb〔其中,x为ρ（PG）,y为根长抑制率,a和b均为常数〕.③油麦菜、油菜、白菜和生菜4种蔬菜对PG的根长半抑制浓度（IC₅₀）分别为1 675.11、995.67、3 736.40和2 510.24 mg/L,4种蔬菜根长抑制率对PG的敏感程度表现为油菜>油麦菜>生菜>白菜（P < 0.05）.研究显示,与油麦菜、白菜和生菜相比,油菜更适合作为PG的生态毒性指示植物.      

基于LCOE模型的光伏发电经济效益分析:以宜昌农村地区光伏扶贫电站项目为例

光伏发电是我国重要的清洁能源发展战略,也是资产收益扶贫的重要方式.为了探讨光伏发电项目对政策的依赖性及其在经济上的可持续性,采用平准化度电成本（LCOE）模型开展研究,并开发出平准化度电净现值（LNPVE）模型用于研究光伏发电项目的长期经济效益及其影响因素.将上网电价与补贴作为效益指标引入LCOE模型,即得到LNPVE,LNPVE为折现度电收入和折现度电成本之差.LNPVE模型不仅能将政策因素引入经济效益分析中,同时还能考虑效益变动,从而分析光伏发电项目的经济可持续性.以宜昌市长阳土家族自治县渔峡口镇村级光伏扶贫电站项目为案例的分析表明,从LCOE模型结果来看,案例项目能够实现经济效益;然而从LNPVE模型结果来看,现行补贴上网电价下案例项目的长期经济效益仍存在不确定性,且这种不确定性随着光伏发电上网电价补贴“退坡”政策的出台而有所强化.敏感性分析结果表明,影响案例项目经济效益的首要因素是技术因素,其次是政策因素,再者是经济因素.若案例项目以无补贴标杆电价平价上网,则需将单位造价降低19.3%或者年利用小时数提高14.8%;若要进一步实现以燃煤发电上网电价平价上网,则需将单位造价降低97.0%或者年利用小时数提高182.1%.因此,应当针对光伏发电特别是村级光伏扶贫项目实施必要的电价补贴,将补贴“退坡”与提高光伏发电效率相结合,并将有针对性地提高补贴效率作为光伏电价补贴的重点,同时高度重视技术改进及推广应用和运营维护的成本降低及质量提高,以持续实现光伏发电项目的经济效益.      

生活垃圾焚烧厂周边土壤中PCDD/Fs及重金属含量

为了解城市生活垃圾焚烧发电厂周边表层土壤中二噁英、重金属来源及分布特征,选取成都地区3座典型生活垃圾焚烧厂作为研究对象,开展了周边土壤中17种多氯二苯并对二噁英/呋喃（PCDD/Fs）及11种重金属含量监测.结果显示,土壤样品中的PCDD/Fs和重金属的浓度范围分别为0.25~7.5ng I-TEQ/kg和0.23～580.57mg/kg;3座垃圾焚烧厂周边土壤中多氯二苯并呋喃（PCDFs）的毒性当量浓度贡献率要高于多氯二苯并二噁英（PCDDs）,PCDFs毒性当量浓度平均贡献率达到55%;土壤样品中Cd、Hg、Pb、Cu、Zn之间具有良好的相关性,Hg、Pb、Zn与部分PCDFs具有良好的相关性,相关系数r分别为0.792、0.760、0.788,所对应的p值分别为0.034、0.047、0.035,并被归类为同一聚类,可将这部分重金属元素作为重金属示踪剂来表征PCDFs的来源.     

铜尾矿与陶瓷抛光泥复合蒸压加气混凝土的制备及其性能研究

利用废弃物铜尾矿与抛光泥复合取代粉煤灰,与水泥、石灰、石膏等材料制备蒸压加气混凝土。重点研究了铜尾矿与陶瓷抛光泥的颗粒细度、掺加量、工艺参数等对蒸压加气混凝土砌块抗压强度、绝干密度等性能的影响,通过XRD、SEM对其微观机理进行研究。结果表明:铜尾矿与抛光泥粉磨时间为20 min时,铜尾矿的比表面积达到244.5 m2/kg,抛光泥比表面积为350.4 m2/kg。原材料中铜尾矿、抛光泥、水泥、石灰、石膏的质量比为45∶20∶10∶22∶3时,制备的砌块最大抗压强度达到5.1 MPa,平均抗压强度达到4.7 MPa,绝干密度低于625 kg/m3,达到A3.5,B06的蒸压加气混凝土砌块的要求。砌块中的托贝莫来石与C-S-H （B）等水化产物与未反应的石英相互致密穿插,使砌块的微观孔结构更加致密,砌块的抗压强度更高。     

腐植酸改性生物质电厂灰固定化微生物修复石油烃污染土壤

以生物质电厂灰为载体,用腐植酸对其改性后,负载石油烃降解菌形成固定化菌剂对原油污染土壤进行修复,其中对生物质电厂灰改性的最佳条件以及固定化菌剂对原油污染土壤的修复效果进行了考察。结果表明:生物质电厂灰改性的最佳条件为:电厂灰粒径10~40目,固液比1∶1,改性时间4 h,改性后孔状结构增多且表面粗糙,有利于微生物的附着,固定的微生物数量可达1.5×109 CFU/g。进行60 d的修复后,固定化菌剂对污染土壤中石油烃的降解率达到51.9%,比游离菌提高了25.0%,对长链正构烷烃、芳香烃及胶质的降解率分别提高了9.6%、31.7%和37.5%。固定化生物质电厂灰的应用使石油烃降解菌得到保护和支撑,提高了土壤基础呼吸速率和土壤酶活性,实现了石油烃的高效降解。因此,腐植酸改性生物质电厂灰是一种在石油污染土壤修复方面具有应用潜力的微生物固定化材料。