北京城市地表河流硝酸盐氮来源的氮氧同位素示踪研究

为了有效防治城市地表河流硝酸盐氮的污染并进行针对性水体治理,利用δ15N和δ18O双同位素示踪技术,对北京城区地表河流硝酸盐污染进行了溯源。选取北京9条河流的10个监测点,分析了硝酸盐氮污染的浓度分布特征,并运用MAT253氮氧双同位素技术解析了硝酸盐的各种来源。研究结果表明,北京城区地表河流硝酸盐氮污染自上游至下游逐渐加重,上游8个监测点的硝酸盐氮平均浓度在0.7～3.4 mg/L之间,下游东护城河和通惠河2处硝酸盐氮的浓度均值分别达7.6 mg/L和7.0 mg/L。利用同位素质谱MAT253分析,得知北京城区地表河流δ15N值总体分布范围为-1.2‰～+28.88‰,δ18O值分布范围为+0.09‰～+6.62‰,依据δ15N和δ18O的特征范围,得出北京城区地表河流硝酸盐来源主要是粪肥和污水。     

掺固硫灰AC-13型沥青混合料配合比设计

固硫灰是循环流化床锅炉燃煤固硫产生的废弃物,具有自硬性、火山灰活性和膨胀性等特性,若以其替代矿粉制备沥青混合料并用于道路工程建设中,将有望为固硫灰处理处置提供新途径。选用固硫灰做填料等量替代普通矿粉,通过马歇尔实验研究固硫灰不同替代量(0%、25%、50%、75%、100%)对AC-13型沥青混合料性能的影响,并对机理进行了分析。结果表明,掺固硫灰沥青混合料在一定油石比范围内均能满足现行规范要求,与普通矿粉沥青混合料相比,掺固硫灰沥青混合料水稳定性良好,压实度相同时,掺固硫灰沥青混合料具有更好的抗车辙性。     

不同利用方式土壤中磷的吸附与解吸特性

研究不同利用方式土壤对磷的吸附解吸特性及其影响因素。采用室内恒温培养法研究了湖南典型土壤(红壤、潮土和紫色土)的不同利用方式(旱地、水田)土壤对P的吸附和解吸过程。土壤对磷的吸附解吸过程是分阶段进行的,用Langmuir方程拟合程度比Freundlich方程高,相关系数均在0.90(P<0.05)以上;从最大吸附量(Qm)、吸附反应常数(K)和最大缓冲容量(MBC)3项吸附参数综合考虑,旱地对P的吸附无论在强度还是容量方面均大于同母质的水田土壤;解吸率随着吸附量的增加而增大,其大小为旱地<水田。Qm与<0.002 mm粘粒及无定形铁含量呈正相关,相关系数分别为0.95和0.94(P<0.05)。不同利用方式土壤P吸附解吸特性差别较大,针对不同土壤应采取不同的磷素管理措施以实现作物增产和保护环境的双重效益。     

原位帽封材料对水体中Pb(Ⅱ)与Cd(Ⅱ)静态吸附

用无纺布包裹珊瑚和丙烯酸树脂制成帽封材料,将底泥中重金属离子原位固定的同时吸附水体中的重金属离子pb2和Cd2.通过红外光谱,电镜扫描和火焰原子吸收仪器来分析该帽封材料的吸附性能.通过改变pH值,吸附剂投放量来检测其吸附效果.结果表明,该帽封材料在pH等于5的时候,Cd2最大吸附量达到434.67 mg/g,pb2+最大吸附量达到524.27 mg/g.pH和吸附剂量保持不变,随着底物浓度增加吸附量也增加;电镜扫描图和红外光谱图表明,该材料能很好地吸附重金属离子.     

Removal of PCDD/Fs from contaminated sediment and released effluent gas by charcoal in a proposed cost-effective thermal treatment process

A novel cost-effective thermal treatment technology has been proposed for the removal of PCDD/Fs from contaminated sediment and released effluent gas using charcoal as both an adsorbent and a thermal source. When a reactor was used for thermal treatment, the PCDD/Fs removal efficiency exceeded 98% from the sediment at the three different air superficial velocities employed in this study. The total PCDD/F international toxic equivalent (I-TEQ) contents, both in the treated sediments and effluent gas, were below the Japanese emission standard limit. Analysis of the PCDD/F contents in different fractions showed that large quantities of PCDDs but not PCDFs were evaporated from the sediment and adsorbed in the moist sediment column. This difference was attributed to the formation of PCDDs from pentachlorophenol (PCP) during the cooling process following the thermal treatment process in the reactor. This proposed thermal process provides a promising alternative to the conventional methods.     

硫酸亚铁用于污水厂二沉池出水化学除磷

为了获得影响硫酸亚铁化学除磷效果的因素,研究了反应时间,溶液p H值以及碱度对硫酸亚铁化学除磷效果的影响。并研究了不同进水磷酸盐浓度下,硫酸亚铁投加β值与除磷率以及余P的关系,使用MATLAB软件对实验结果进行了模拟,获得了进水含磷量、硫酸亚铁投加β值以及出水余P含量三者之间的关系方程,并通过实验验证了该方程的准确性,该方程可用于指导计算水厂在使用硫酸亚铁化学除磷时的投加量。     

微气泡曝气 O3/ H2O2处理 RO 浓水的效能及影响因素简

采用O₃/H₂O₂高级氧化工艺处理炼油厂反渗透（RO）浓水,用溶气泵加压溶气并产生微气泡强化传质,确定装置运行条件,考察气体中臭氧浓度、H₂O₂/O₃初始摩尔比、pH和温度对O₃/H₂O₂处理RO浓水效果的影响,并对RO浓水处理效能进行研究。结果表明,随着气体中臭氧浓度的增加,COD的去除率基本呈线性增加;加入适当量H₂O₂能提高臭氧氧化RO浓水的效果,H₂O₂/O₃初始摩尔比在0~0.8范围内,COD的去除率先增加后下降,H₂O₂/O₃初始摩尔比为0.5时COD去除率最大;pH从6.84增加到9.01,COD去除率逐渐增大,pH为10.03时COD去除率反而降低;在14~28℃范围内,温度低时,升高温度COD去除率增加较大,温度较高时,升高温度对COD去除率的影响较小。为考察该工艺的稳定性,在H₂O₂/O₃初始摩尔比为0.5、溶液pH为8~9、臭氧浓度为80~100 mg/L、温度为10~28℃条件下,对COD为90~140 mg/L的RO浓水氧化处理4~10 h,出水COD维持在39.9~49.9 mg/L,达到《城镇污水处理厂污染物排放标准（GB 18918-2002）》中的一级A标准;去除1 g COD消耗O₃ 1.4~3.3 g,消耗O₃与H₂O₂的总氧量为2.2~4.4 g。     

高炉干法除尘系统噪声控制技术

高炉干法除尘系统主要噪声源为煤气调压阀组。在煤气调压阀组下游加装带整流栅的消声器,解决了此类消声器易被吹坏的问题,振动也得到缓解。另外采用隔声罩和局部包扎,可控制噪声。此项技术在鞍钢鲅鱼圈等厂应用,消声器下游噪声降至90 dB以下。经过进一步开发,研制成功了新型高炉煤气调压阀组与降噪减振成套装置,可在不加隔声罩的情况下,使噪声达到国家标准。     

Shipboard bilge water treatment by electrocoagulation powered by microbial fuel cells

Reveals the synergy between microbial fuel cells and electrocoagulation. Demonstrates MFC-ECC shipboard wastewater treatment is advantageous. MFC-ECC integration enables energy neutral bilge water treatment. Ships generate large amounts of wastewater including oily bilge water, blackwater and greywater. Traditionally they are treated separately with high energy consumption. In this study we demonstrate the feasibility that these waste streams can be treated using an integrated electrocoagulation cell (ECC) and microbial fuel cell (MFC) process, which not only synergized the contaminants removal but also accomplished energy neutrality by directly powering EC with MFC electricity. Results showed that MFC stack powered ECC removed 93% of oily organics, which is comparable to the performance of an external DC voltage powered ECC. In the meantime, more than 80% of COD was removed from MFCs when fed with either acetate or municipal wastewater. Moreover, the ECC electrode area and distance showed notable effects on current generation and contaminants removal, and further studies should focus on operation optimization to enhance treatment efficiency.     

外加气体对等离子体降解水相中有机污染物的影响研究

研究了等离子体在内电极通氧气、氮气、空气和氦气条件下降解甲基紫的机理。研究表明,在该等离子体发生器结构下,等离子体能降解甲基紫,且在不同气体气氛下的降解产物不同,在氧气氛围下为含—CO和—OH物质及直链烯烃,而氮气氛围下是含—N、—NH和—OH的芳香类物质及小分子烃类物质。研究同时表明,等离子体降解水相中有机物时应在氧气介质中进行,如用空气则有可能会造成水体中NO-3过高。