磷酸铁污泥的生物还原释磷及其影响因素研究

以污水处理厂化学除磷工艺产生的磷酸铁(FePO4)污泥为研究对象,在厌氧条件下,考察了铁还原细菌(IRB)还原FePO4释放磷的可行性,并探讨了不同碳源、C/Fe摩尔比、添加蒽醌-2,6-二磺酸盐(AQDS)对IRB利用FePO4还原释磷的影响.研究结果表明,通过驯化可从普通活性污泥富集IRB,且利用IRB可对难溶性沉淀FePO4进行生物还原.IRB能够利用葡萄糖、乙酸钠及丙酸钠作为唯一电子供体,使FePO4发生异化还原,产生Fe(Ⅱ)并释放磷酸盐,且泥水混合液中Fe(Ⅱ)累积量与上清液中磷累积量变化趋势一致.在等摩尔碳量前提下,葡萄糖为碳源时释磷率可达51.6%,比乙酸钠和丙酸钠分别高13.8%和20.3%;以葡萄糖为碳源,C/Fe摩尔比为5:1时释磷率最大;添加电子穿梭体AQDS可使FePO4污泥释磷率提高12.6%.     

长江中下游与云南高原湖泊沉积物磷形态及内源磷负荷

为揭示长江中下游与云南高原湖泊沉积物磷形态及沉积物-水界面磷负荷特征,探讨其区域差异性及主要影响因素,分析了区域内9个湖泊100个沉积物样品总磷(TP)及不同形态磷含量,比较了不同湖泊沉积物-水界面磷负荷.结果表明,云南高原湖泊沉积物ω(TP)为(1256±621)mg/kg,高于长江中下游湖泊[(601±76)mg/kg];前者沉积物磷形态以钙结合态磷(HCl-P)为主,主要受水土流失等影响,湖泊较高的矿化度易于磷埋藏,且沉积物有机质含量较高,减缓了磷的移动能力,其沉积物-水界面磷负荷为0.17~1.07mg/(m2·d),对湖泊富营养的贡献较小;而长江中下游湖区湖泊沉积物磷形态以可还原态磷(BD-P)等形态为主,主要由面源及浮游植物生长调控,其中可移动磷(Mobile-P,除残渣态磷(Res-P)和HCl-P以外的所有形态磷之和)相对含量占ω(TP)的60.60%,约为云南高原湖泊的2倍,其沉积物-水界面磷负荷为0.002~1.32mg/(m2·d),对湖泊富营养化贡献较大.由此可见,长江中下游湖区湖泊应该加强流域面源污染等外源治理,修复退化水生植被,而在云南高原湖泊则应重点加强流域水土流失治理,施行农田最佳施肥等措施.     

中国钢铁行业技术减排的协同效益分析

选取钢铁行业的22项节能减排措施,评估和比较了各项措施的减排潜力、减排成本和协同效益,力图得到钢铁行业减排的最优路径.研究结果表明:基于2012年的钢铁产量和生产结构,我国钢铁行业的技术减排潜力约为146.8Mt CO2、314.2kt SO2、265.7kt NOx和161.5kt PM10,分别占钢铁行业2012年总排放量的9.7%、13.1%、27.3%和8.9%;如果考虑节能收益,有10项措施具有经济可行性,累积减排潜力约为98.0Mt CO2、210.0kt SO2、211.0kt NOx和89.0kt PM10;如果综合考虑节能收益和协同效益,有14项措施具有经济可行性,累计减排潜力约为123.4Mt CO2、264.0kt SO2、234.0kt NOx和130.0kt PM10.钢铁行业开展技术减排时,需要综合考虑减排成本、节能收益和协同效益,参考减排成本选择最成本有效的措施.     

2011年中国钢铁行业典型有害重金属大气排放清单

根据中国钢铁工业年鉴等统计资料,采用排放因子法,对2011年我国钢铁行业生产活动导致的汞(Hg)、铅(Pb)、镉(Cd)、砷(As)、铬(Cr)、镍(Ni)等6种有害重金属的大气排放及其分布特征进行了研究,并给出了分省区排放清单.结果表明,2011年中国钢铁行业汞、铅、镉、砷、铬、镍大气排放量分别约为18.8, 3745.8, 39.4, 132.2, 241.2, 105.3t;钢铁行业重金属大气排放集中在环渤海经济圈以及长三角地区,其中河北东部及中南部、山东中部等钢铁冶炼企业集中地区重金属大气排放强度较大;钢铁企业内部炼钢工艺对重金属大气排放贡献率较高,其中转炉工序对砷、铅排放贡献率较大,电炉工序对于镉、镍贡献率较大.     

厌氧折流内循环反应器(ABIC)处理木薯淀粉废水试验

对自主研发的厌氧折流内循环反应器(anaerobic baffled internal circulation,ABIC)处理木薯淀粉废水的运行特性进行研究,结果表明:ABIC在水力停留时间为20~24 h、进水ρ(COD)为3 000~15 000 mg/L、有机负荷为3.0~20.0kg/(m3·d)时COD去除率均高于80.0%,最高可达91.2%。ABIC对进水负荷的冲击具有良好耐受能力,最大可承受的容积负荷VLR为26.0 kg/(m3·d),运行稳定。反应器重新启动耗时较短,对处理木薯淀粉季节性生产废水有利。     

Preparation and application of a phosphorous free and non-nitrogen scale inhibitor in industrial cooling water systems

A novel environmentally friendly type of calcium carbonate, zinc (II) and iron (III) scale inhibitor Acrylic acid- allylpolyethoxy carboxylate copolymer (AA-APEL) was synthesized. The anti-scale property of the AA-APEL toward CaCO₃, zinc (II) and iron (III) in the artificial cooling water was studied through static scale inhibition tests. The observation shows that both calcium carbonate, zinc (II) and iron (III) inhibition increase with increasing the dosage of AA-APEL. The effect on formation of CaCO₃ was investigated with combination of scanning electronic microscopy (SEM), transmission electron microscopy (TEM), X-ray powder diffraction (XRD) analysis and fourier transform infrared spectrometer, respectively. The results showed that the AA-APEL copolymer not only influenced calcium carbonate crystal morphology and crystal size but also the crystallinity. The crystallization of CaCO₃ in the absence of inhibitor was rhombohedral calcite crystal, whereas a mixture of calcite with vaterite crystals was found in the presence of the AA-APEL copolymer. Inhibition mechanism is proposed that the interactions between calcium or iron ions and polyethylene glycol (PEG) are the fundamental impetus to restrain the formation of the scale in cooling water systems.     

Microbial electrolysis cells with biocathodes and driven by microbial fuel cells for simultaneous enhanced Co(II) and Cu(II) removal

Cobalt and copper recovery from aqueous Co(II) and Cu(II) is one critical step for cobalt and copper wastewaters treatment. Previous tests have primarily examined Cu(II) and Co(II) removal in microbial electrolysis cells (MECs) with abiotic cathodes and driven by microbial fuel cell (MFCs). However, Cu(II) and Co(II) removal rates were still slow. Here we report MECs with biocathodes and driven by MFCs where enhanced removal rates of 6.0±0.2 mg?L⁻¹?h⁻¹ for Cu(II) at an initial concentration of 50 mg?L⁻¹ and 5.3±0.4 mg?L⁻¹ h⁻¹ for Co(II) at an initial 40 mg?L⁻¹ were achieved, 1.7 times and 3.3 times as high as those in MECs with abiotic cathodes and driven by MFCs. Species of Cu(II) was reduced to pure copper on the cathodes of MFCs whereas Co(II) was removed associated with microorganisms on the cathodes of the connected MECs. Higher Cu(II) concentrations and smaller working volumes in the cathode chambers of MFCs further improved removal rates of Cu(II) (115.7 mg?L⁻¹?h⁻¹) and Co(II) (6.4 mg?L⁻¹?h⁻¹) with concomitantly achieving hydrogen generation (0.05±0.00 mol?mol⁻¹ COD). Phylogenetic analysis on the biocathodes indicates Proteobacteria dominantly accounted for 67.9% of the total reads, followed by Firmicutes (14.0%), Bacteroidetes (6.1%), Tenericutes (2.5%), Lentisphaerae (1.4%), and Synergistetes (1.0%). This study provides a beneficial attempt to achieve simultaneous enhanced Cu(II) and Co(II) removal, and efficient Cu(II) and Co(II) wastewaters treatment without any external energy consumption.     

Washing out heavy metals from contaminated soils from an iron and steel smelting site

Washing is a promising method for separating contaminants bound to the particles of soil ex-situ by chemical mobilization. Laboratory batch washing experiments were conducted using deionized water and varying concentrations of oxalic acid, citric acid, tartaric acid, acetic acid, hydrochloric acid and ethylenediaminetetra acetic acid (EDTA) to assess the efficiency of using these chemicals as washing agents and to clean up heavy metals from two heavily polluted soils from an iron and streel smelting site. The toxicity reduction index and remediation costs were analyzed, and the results showed that the soils were polluted with Cd, Pb and Zn. Hydrochloric acid and EDTA were more efficient than the other washing agents in the remediation of the test soils. The maximum total toxicity reduction index showed that 0.5 mol·L^-1 hydrochloric acid could achieve the remediation with the lowest costs.     

舍铁固废千法生产氧化铁红新工艺技术研究

针对冶金企业在生产过程中发生的含铁尘泥,提出了与之相适应的处理新工艺。利用部分种类的尘泥成功制取了符合磁性材料行业要求的氧化铁红,并广泛应用于磁材预烧料企业,从而为含铁尘泥的综合利用提供了新的思路和有效途径。     

欧盟各国废钢铁用量和国际贸易

近年来,欧盟各国的废钢铁贸易十分活跃。根据《欧盟27国废钢铁贸易统计》2012的统计,列出欧盟各国2010年的粗钢产量、炼钢用废钢量、国际贸易量以及欧盟成员国之间的废钢铁贸易量,供行业参考。