冶金固体废弃物资源化处理与综合利用

分析了我国冶金渣、冶金尘泥的资源化处理与综合利用状况以及发展趋势,指出冶金工业固体废弃物的资源化处理与综合利用是相关企业和机构必须重视和加大力度进行研究和突破的课题。     

基于DEA模型的城市用地经济效益比较研究

运用数据包络分析方法（DEA）,从城市土地的投入和产出角度,对全国30个省会城市的城市用地经济效益进行比较研究。研究结果表明：（1）在全国30个城市（包括直辖市和部分省会城市）,仅上海、杭州、广州和昆明等4个城市为DEA有效城市,即在现有的经济、社会、技术条件下,投入产出达到最佳状态,其余26个城市为非DEA有效城市;（2）南京和哈尔滨处于规模效益递减的发展阶段,上海、杭州、广州和昆明处于规模效益不变的发展阶段,其余24个城市都处于规模效益递增的发展阶段;（3）30个省会城市的城市土地利用经济效益发展极不平衡,呈现东高西低的格局,且城市土地利用普遍不集约;最后对如何提高城市用地经济效益提出了相应的改进措施。     

酸渣制备无水硫酸钠

采用炼油厂酸渣经水稀释后,添加含钠化合物进行中和反应,制备无水Na_2SO_4.最佳工艺条件为:将酸渣用水稀释20倍,按n(Na_2CO_3):n(SO_4~(2-))=1.10或n(NaOH):n(SO_4~(2-))=1.20的比例加入Na_2CO_3,溶液或NaOH溶液,油水分离去除油相后蒸发、干燥,在650℃下灼烧后溶解、过滤、蒸发、结晶,得到Na_2SO_4产品.NaCO_3法可将酸渣中约78%的SO_4~(2-)转化到产品Na_2SO_4中;NaOH法可将酸渣中约66%的SO_4~(2-)转化到产品Na_2SO_4中.制备的无水Na_2SO_4产品均达到GB/T6009-2003<工业无水硫酸钠>二类标准.     

氨浸出含锌烟尘制取活性氧化锌

采用氨浸出法处理含锌烟尘,浸出液在微波-超声波联合作用下蒸氨得碱式碳酸锌沉淀,再经煅烧制得活性氧化锌.实验结果表明:在总氨浓度为9.0 mol/L、浸出温度为40 ℃、浸出液初始pH为 11.0～11.5、搅拌转速为400 r/min、浸出剂体积与含锌烟尘质量比为4、浸出时间为60 min的浸出条件下,锌的浸出率为83.3%.浸出液经过两段净化除杂后,在超声波功率50 W、微波辐射(微波功率随温度的设定而自动变化)的联合作用下,使溶液体系恒温90 ℃,进行蒸氨,沉淀得到前驱体碱式碳酸锌,经煅烧,得到平均直径为0.4 μm、晶型为六方晶系、片状的活性氧化锌.     

重金属废水处理与资源化利用现状

重金属废水的排放是重金属污染的重要源头之一。介绍了目前国内外用于处理不同重坌属废水的方法,以及重金属废水资源化可采用的多种工艺。在重金属废水资源化技术中,膜分离技术起着十分重要的作用。     

People, power and timber: The politics of community-based forest management

The potential of devolved conservation to empower people, reduce poverty and protect forest resources has yet to be realized in much of the developing world. This is particularly evident in the Philippines where the central state paradoxically recentralizes political power through devolution at the policy, program and project level in forest management. We investigate how centralized state power emanates through devolved networks to affect the success of local timber utilization involving community-based forest management (CBFM) on Mindanao Island, the southern Philippines. By examining broader shifts from centralized to devolved forest management, results suggest that centralized political power continues to control and adversely affect local uses of timber through CBFM. We discuss how in the process of state authorities recentralizing devolved rights and responsibility over timber management, community-based logging operations were threatened but sustained by members relying on community-based structures and their own capabilities. The conclusion asserts that broader state processes of devolving power over timber management remains constrained by political motives and interests and so largely fails to fulfill the objectives of community-based forest management.     

膜吸收法处理高浓度甲醛废气资源化技术研究

采用疏水性中空纤维膜接触器,以NaHSO₃为吸收液处理高浓度甲醛废气。研究了吸收液流量、吸收液温度、吸收液浓度、气体进口流量和气体进口浓度等因素对甲醛去除率和总传质系数的影响。结果表明,当吸收液流量为4.17×10^-6m³/s,吸收液温度为60℃,甲醛进气流量为3.7×10^-6m³/s,甲醛进气浓度为566 mg/m³时,甲醛出气浓度可低至2.8 mg/m³,甲醛的去除率可达99.5%,总传质系数为4.46×10^-5m/s。反应产物（ɑ-羟基磺酸钠）易分离,并可作为重要的有机合成原料或用于制备高纯甲醛而得到充分利用,NaHSO₃溶液经适当稀释后仍可作为吸收液循环使用。表明膜吸收法可基本实现高浓度甲醛废气处理的资源化。     

长株潭地区城镇化对土地利用效率的影响

长株潭城市群作为全国"两型社会"建设综合配套改革试验区,对湖南省、对全国的发展都具有十分重要的意义。城镇化进程中土地利用问题作为"两型社会"研究中的重要方面,必然受到普遍关注。本文首先对国内外关于城镇化与土地利用关系的相关文献进行了评述,进而在对城镇化综合水平与土地利用综合指数进行测算的基础上,通过建立动态计量模型,采用协整分析与脉冲响应分析、方差分解分析相结合的方法对长株潭地区城镇化对土地利用的影响进行了实证分析。研究发现:近年来,长株潭地区城镇化综合水平逐步提高;城镇土地利用综合指数呈现出先平稳,然后急剧上升的倒"L"型变化趋势;城镇化综合水平与土地利用综合指数存在长期稳定的均衡关系;短期内,城镇化综合水平的提高会在一定程度上使土地利用状况恶化,但长期内,城镇化综合水平是影响土地利用综合指数的主导因素,它的提高有利于土地集约利用。由此提出相关的政策建议。     

Grey relational analysis of an integrated cascade utilization system of geothermal water

With the drastic decrease in fossil resources and rapid deterioration of the global environment, the utilization of geothermal resources has been strongly advocated. The combination of heat, power, and cold utility generation is commonly used to increase the utilization efficiency of geothermal resources. In this study, an integrated cascade utilization system of waste geothermal water (ICUWGW) from a flash geothermal power plant in China is established to increase the utilization efficiency of geothermal water. The waste geothermal water leaving the power plant is proposed for further use in cascade for two-stage LiBr/H₂O absorption cooling, agricultural product drying, and residential bathing. Twelve candidate temperature schemes showing different inlet and outlet temperatures of every subsystem are proposed for the ICUWGW. Several criteria are selected for the evaluation and screening of the candidate schemes. Grey relational analysis incorporating analytic hierarchy process is conducted to screen the optimal temperature scheme for the ICUWGW to meet the comprehensive criteria of thermodynamics and economics. Results show that the optimal scheme features significant improvement in energy efficiency, exergy efficiency, and equivalent electricity generation efficiency compared with those of the current geothermal power plant. The investment payback time of the additional subsystems for cooling, drying, and bathing is 1.85 years. Exergy analysis is also conducted to determine the further optimization potential of the optimal ICUWGW. Sensitivity analysis of electricity price on the performance of the optimal ICUWGW is also performed.     

Effects of palm oil mill effluent media on cell growth and lipid content of Nannochloropsis oculata and Tetraselmis suecica

In this study, palm oil mill effluent (POME) was used as an alternative medium for algal biomass and lipid production. The influence of different concentrations of filtered and centrifuged POME in sea water (1, 5, 10 and 15%) on microalgal cell growth and lipid yield were investigated. Both Nannochloropsis oculata and Tetraselmis suecica had enhanced cell growth and lipid accumulation at 10% POME with maximum specific growth rate (0.21 d^–1 and 0.20 d^–1) and lipid content (39.1 ± 0.73% and 27.0 ± 0.61%), respectively, after 16 days of flask cultivation. The total Saturated Fatty Acid (SFA) (59.24%, 68.74%); Monounsaturated Fatty Acid (MUFA) (15.14%, 12.26%); and Polyunsaturated Fatty Acid (PUFA) (9.07%, 8.88%) were obtained for N. oculata and T. suecica, respectively, at 10% POME. Algal cultivation with POME media also enhanced the removal of Chemical Oxygen Demand (COD) (93.6–95%), Biological Oxygen Demand (BOD) (96–97%), Total Organic Compound (TOC) (71–75%), Total Nitrogen (TN) (78.8–90.8%) and oil and grease (92–94.9%) from POME.