苯甲酸生产废水的处理与资源化

为有效地回收甲苯液相氧化法生产苯甲酸的工业废水中的苯甲酸和乙酸,并配合废水生物降解的末端处理技术,研究了20%,30%和50%磷酸三丁酯(TBP)/煤油的混合溶剂、正辛醇和甲苯萃取苯甲酸稀溶液特性,以及对工业废水处理的实验.结果表明,TBP对苯甲酸稀溶液具有良好的萃取作用,而纯溶剂体系与溶剂的极性有关,正辛醇的萃取能力与30%TBP相当;残液中的COD_Cr值由萃取剂在水中的溶解和苯甲酸自身的COD_Cr值组成,其中残液中溶剂溶解导致的COD_Cr值随其中苯甲酸浓度变化不明显,且COD_Cr值的大小为:50%TBP≈30%TBP>正辛醇>20%TBP>甲苯.针对工业废水中主要含有苯甲酸和乙酸的工况,提出了废水资源化的处理工艺流程,即首先采用甲苯进行废水中苯甲酸的回收,之后,再利用三烷基氧磷/煤油为萃取剂回收废水中的醋酸,进一步生产绿色化学品乙酸钙镁盐.     

北京市夏季空气微生物粒度分布特征

着重研究了夏季空气微生物的粒度分布特征,比较分析了北京市空气微生物粒度分布的变化状况.结果表明:空气细菌、空气真菌和空气放线菌的粒度分布特征各不相同, 并且不随着时间和空间的变化而变化.空气细菌呈偏态分布,大于2.0 μm的粒子约占总数的80.0%,小于1.0 μm的粒子最少,约占9.0%.空气真菌呈对数正态分布,1.0～6.0 μm的粒子约占70.0%,小于1.0 μm的粒子最少,约占5.0%.空气放线菌粒度分布与正态分布恰好相反,大于8.2 μm和小于1.0 μm的粒子约占60.0%;3.0～6.0 μm的粒子最少,约占10.0%.此外不同功能区优势真菌粒度分布规律基本一致.枝孢属(Cladosporium),青霉属(Penicillium)和曲霉属(Aspergillus)粒度主要分布在F3,F4和F5(1.0～6.0 μm)中,约占总数的85.0%,呈对数正态分布.而交链孢属(Alternaria)和无孢菌(nonsporing)主要分布在前4级(>2.0 μm),分别约占总数的90.0%和75.0%,呈偏态分布.在过去10年的城市化进程中,北京市空气微生物粒度分布的基本趋势没有变化,但是空气真菌粒度分布的峰值由原来的3.0～6.0 μm降低到2.0～3.0 μm.     

渗滤液生化特性在Fenton处理过程中的变化

采用电解呼吸仪分析早、晚期渗滤的生化特性在Fenton过程前后的变化。根据BOD累积曲线 ,由非线性最小二乘法求解出第一阶段生化需氧量BODu 和一级生化动力学常数K。结果表明早期渗滤液易于生化降解 ,经Fenton氧化后 ,由于产生了毒性更强的中间产物 ,渗滤液的驯化时间反面延长 ,K值也略有下降。晚期渗滤液很难生化降解 ,经Fenton处理后其生化特性得到很大的改善。     

微生物菌剂对生活污水的除臭实验

利用微生物菌剂对生活污水进行除臭处理,结果表明:对于嗅阈值比较高的混合生活污水,利用XM液体菌剂和XM固体菌剂都可以消除生活污水的臭味,二者都取得较好的效果。但在实际的应用方面,固体菌剂更具有使用方面的优越性。应用XM固体菌剂对混合生活污水进行除臭处理时,添加0.2%的除臭效果为最好。     

电子垃圾拆解回收VOCs排放特征与排放因子

电子垃圾拆解回收过程中的高温处理往往产生大量挥发性有机物(VOCs),对周边环境及人体健康产生不可忽视的影响.本研究选取某电子垃圾集中拆解回收场,对场区加热烤板车间、塑料制粒车间、湿法提取车间和火法冶炼车间废气处理设施排放口的VOCs浓度和组分进行监测,分析了不同生产工艺VOCs排放特征及其总VOCs排放因子.结果表明...     

A pyrazine based metal-organic framework for selective removal of copper from strongly acidic solutions

● pz-UiO-66 was synthesized facilely by a solvothermal method. ● Efficient capture of copper from highly acidic solution was achieved by pz-UiO-66. ● pz-UiO-66 exhibited excellent selectivity and capacity for copper capture. ● Pyrazine-N in pz-UiO-66 was shown to be the dominant adsorption site. The selective capture of copper from strongly acidic solutions is of vital importance from the perspective of sustainable development and environmental protection. Metal organic frameworks (MOFs) have attracted the interest of many scholars for adsorption due to their fascinating physicochemical characteristics, including adjustable structure, strong stability and porosity. Herein, pz-UiO-66 containing a pyrazine structure is successfully synthesized for the efficient separation of copper from strongly acidic conditions. Selective copper removal at low pH values is accomplished by using this material that is not available in previously reported metal–organic frameworks. Furthermore, the material exhibits excellent adsorption capacity, with a theoretical maximum copper uptake of 247 mg/g. As proven by XPS and FT-IR analysis, the coordination of pyrazine nitrogen atoms with copper ions is the dominant adsorption mechanism of copper by pz-UiO-66. This work provides an opportunity for efficient and selective copper removal under strongly acidic conditions, and promises extensive application prospects for the removal of copper in the treatment for acid metallurgical wastewater.     

Highly efficient and selective removal of phosphate from wastewater of sea cucumber aquaculture for microalgae culture using a new adsorption-membrane separation-coordinated strategy

● A new adsorption-membrane separation strategy is used for phosphate removal. ● PVC/Zr-BT shows a selective adsorption ability to low-concentration phosphate. ● Low concentration of P below 0.05 mg/L was achieved in actual wastewater treatment. ● Algal biomass production served as a demonstration of phosphorus recycling. Enhanced phosphorus treatment and recovery has been continuously pursued due to the stringent wastewater discharge regulations and a phosphate supply shortage. Here, a new adsorption-membrane separation strategy was developed for rational reutilization of phosphate from sea cucumber aquaculture wastewater using a Zr-modified-bentonite filled polyvinyl chloride membrane. The as-obtained polyvinyl chloride/Zr-modified-bentonite membrane was highly permeability (940 L/(m²·h)), 1–2 times higher than those reported in other studies, and its adsorption capacity was high (20.6 mg/g) when the phosphate concentration in water was low (5 mg/L). It remained stable under various conditions, such as different pH, initial phosphate concentrations, and the presence of different ions after 24 h of adsorption in a cross-flow filtration system. The total phosphorus and phosphate removal rate reached 91.5% and 95.9%, respectively, after the membrane was used to treat sea cucumber aquaculture wastewater for 24 h and no other water quality parameters had been changed. After the purification process, the utilization of the membrane as a new source of phosphorus in the phosphorus-free f/2 medium experiments indicated the high cultivability of economic microalgae Phaeodactylum tricornutum FACHB-863 and 1.2 times more chlorophyll a was present than in f/2 medium. The biomass and lipid content of the microalgae in the two different media were similar. The innovative polyvinyl chloride/Zr-modified-bentonite membrane used for phosphorus removal and recovery is an important instrument to establish the groundwork for both the treatment of low concentration phosphate from wastewater as well as the reuse of enriched phosphorus in required fields.     

矿化垃圾床反应器厌氧甲烷氧化协同生物脱氮的研究

垃圾卫生填埋过程中逸散的甲烷与渗滤液处理过程中反硝化段不够彻底产生的硝酸盐对周围环境具有严重的威胁,反硝化厌氧甲烷氧化技术可实现甲烷与硝酸盐的同步去除,极具应用前景.本研究通过模拟垃圾填埋过程,以矿化垃圾作为垃圾填埋的覆土层与反硝化厌氧甲烷氧化微生物的接种源,建立了矿化垃圾床系统.结果表明,反应系统在140d的运行期间...     

广东东部重要渔业水域叶绿素变化特征的研究

根据1997年8月至2003年5月对粤东近海重要渔业水域生态环境研究的资料,对叶绿素的含量、组成和季节变化进行了分析讨论。结果表明,广东东部近海的叶绿素平均含量6.45mg/m3,其中柘林湾水域的叶绿素含量最高(9.12mg/m3),大亚湾水域的含量最低(3.61mg/m3)。考洲洋、珠江口水域叶绿素含量有季节/年度差异;大亚湾、红海湾水域叶绿素含量的季节差异较小。叶绿素a是叶绿素的主要组分,占60%～80%,叶绿素b、c分别占7%～24%和6%～19%。研究水域的叶绿素含量和季节变化与营养盐、水体的温盐等理化因子的变化有关,而叶绿素组成的变化与浮游植物的生长状况、群落结构以及环境条件的变化有关。     

西藏自治区措勤县日阿布洗铜多金属矿床地质特征及成因类型

西藏自治区日阿布洗铜多金属矿位于冈底斯山脉北缘斑岩型铜矿成矿带,含矿斑岩体为晚喜山期花岗斑岩,具全岩矿化特征,斑岩体与构造蚀变岩带形成矿床。研究表明,地表和浅部出露含矿斑岩体只是岩枝,矿区剥蚀程度低,主斑岩体尚未出露,深部找矿潜力巨大。经深部钻孔工程及地表槽探验证,矿体品位和厚度沿走向和倾向变化系数较小,伴生组份较多,并对其资源量进行了初步估算。喜山晚期第一阶段花岗斑岩侵入体是主要成矿物质来源,矿床成因类型应为斑岩型铜矿床。