内蒙古巴彦淖尔市乌拉特中旗生态环境恶化的根源及其对策

通过对乌拉特中旗近20年来农牧业生产发展情况、气象环境质量状况等多方面调查，总结出乌拉特中旗生态环境恶化的根源，按照“围封轮牧，划区禁牧，舍饲养牧，移民休牧”的指导思想，并对如何改善乌拉特中旗生态环境提出具体的对策和措施。     

Synthesis of branched,nano channeled,ultrafine and nano carbon tubes from PET wastes using the arc discharge method

Upcycling polymer wastes into useful, and valuable carbon based materials, is a challenging process. We report a novel catalyst-free and solvent-free technique for the formation of nano channeled ultrafine carbon tubes (NCUFCTs) and multiwalled carbon nanotubes (MWCNTs) from polyethylene terephthalate (PET) wastes, using rotating cathode arc discharge technique. The soot obtain from the anode contains ultrafine and nano-sized solid carbon spheres (SCS) with a mean diameter of 221 nm and 100 nm, respectively, formed at the lower temperature region of the anode where the temperature is approximately 1700 °C. The carbon spheres are converted into long “Y” type branched and non-branched NCUFCTs and MWCNTs at higher temperature regions where the temperature is approximately 2600 °C, with mean diameters of 364 nm and 95 nm, respectively. Soot deposited on the cathode is composed of MWCNTs with a mean diameter of 20 nm and other nanoparticles. The tubular structures present in the anode are longer, bent and often coiled with lesser graphitization compared to the nanotubes in the soot on the cathode.     

供碳源载体及其在低碳氮比污水处理中的应用研究

为解决低C/N污水的脱氮问题,本实验自行研制开发了一种新型碳聚合物载体.对该载体进行低C/N污水的生物膜脱氮研究,考察了HRT、pH、DO、温度等因素对系统同步硝化反硝化脱氮效果的影响.结果表明:在C/N比为4、pH=8、DO=1 mg/L、HRT=6 h,T=24℃的条件下,氨氮及总氮的去除率分别可以达到90%和70...     

PAS-PDMDAAC复合混凝剂研究

以Al2（SO）4和PDMDAAC为原料进行了无机-有机复合絮凝剂的复合实验研制,确定其制备工艺条件,并对油田现场采集的钻井废水作絮凝沉降实验,所研制的PAS-PDMDAAC复合絮凝剂对COD的去除效率可大大提高.     

Sludge concentration dynamic distribution and its impact on the performance of UNITANK

UNITANK is a biological wastewater treatment process that combines the advantages of traditional activated sludge process and sequencing batch reactor, which is divided into Tank A, B and C. In this study, the sludge distribution and its impact on performance of UNITANK were carried out in Liede Wastewater Plant （WWTP） of Guangzhou, China. Results showed that there was a strong affiliation between Tank A and B of the system in sludge concentration distribution. The initial sludge concentration in Tank A could present the sludge distribution of the whole system. The sludge distribution was mainly influenced by hydraulic condition. Unsteady sludge distribution had an impact on variations of substrates in reactors, especially in decisive reactor, and this could lead to failure of system. Settler could partially remove substrates such as COD and NO3-N, but there was adventure of sludge deterioration. The rational initial sludge concentration in Tank A should be 4000-6000 mg/L MLSS.     

西北地区水资源—生态可持续发展的若干问题探讨

基于对西北地区大开发的关键性难题与一些违背自然规律的不良倾向的讨论 ,认为大开发的实施需要在系统科学思维的基础上综合考虑资源—环境—经济的协调发展。近年来 ,许多科学家从各种角度揭示了我国西北乃至北半球中纬度地区持续干旱的发展规律 ,对干旱化趋势与水盐失衡的分析表明 ,西北地区气候干旱化将长期存在 ,生态将继续退化 ,这种趋势是人力不可抗拒的。人为活动尤其是水资源的开发利用 ,对土壤生态的影响是非常明显的 ,应该在严格控制水资源利用总量的前提下 ,调整用水格局 ,发展节水经济 ,科学确定社会经济用水和生态用水的比例 ,保证必须的生态用水 ,大力发展生态植被。指出在分析西北生态环境问题时过于强调人为活动而忽视自然因素作用的倾向 ,讨论了水库兴修、灌溉、土地利用与改良、深层水利用、水环境脆弱性等水资源—生态建设与可持续发展中的若干关键性问题     

Processing and Properties of Mixtures of PHB-V with Post-consumer LDPE

Mixtures of poly-β-(hydroxybutyrate-co-valerate) PHB-V with virgin and post-consumer low density polyethylene (LDPE) were prepared by melt mixing in proportions of 100/0, 90/10, 80/20, 70/30 and 0/100 (wt/wt%). The mixtures were analysed by infrared spectroscopy, differential scanning calorimetry (DSC), dynamic mechanical thermal analysis (DMTA), melting flow index (MFI), tensile tests, scanning electron microscopy (SEM) and biodegradation in simulated soil. The DMTA and DSC curves of post-consumer LDPE suggested that this polymer was a mixture of LDPE and linear low density polyethylene (LLDPE). Virgin and post-consumer LDPE had lower MFI than PHB-V, but the blends showed higher index as the content of LDPE increased. The addition of LDPE reduced the tensile strength and Young’s modulus of the mixtures compared with PHB-V. SEM indicated poor interfacial adhesion between PHB-V and LDPE. PHB-V degraded slow and gradually, while both LDPE showed virtually no degradation under the conditions studied. The biodegradability of the blends depended on their composition and of the type of LDPE. LDPE improved the biodegradability of the mixtures.     

Recycling and reuse of waste from electricity distribution networks as reinforcement agents in polymeric composites

Of the waste generated from electricity distribution networks, wooden posts treated with chromated copper arsenate (CCA) and ceramic insulators make up the majority of the materials for which no effective recycling scheme has been developed. This study aims to recycle and reuse this waste as reinforcement elements in polymer composites and hybrid composites, promoting an ecologically and economically viable alternative for the disposal of this waste. The CCA wooden posts were cut, crushed and recycled via acid leaching using 0.2 and 0.4 N H₂SO₄ in triplicate at 70 °C and then washed and dried. The ceramic insulators were fragmented in a hydraulic press and separated by particle size using a vibrating sieve. The composites were mixed in a twin-screw extruder and injected into the test specimens, which were subjected to physical, mechanical, thermal and morphological characterization. The results indicate that the acid treatment most effective for removing heavy metals in the wood utilizes 0.4 N H₂SO₄. However, the composites made from wood treated with 0.2 N H₂SO₄ exhibited the highest mechanical properties of the composites, whereas the use of a ceramic insulator produces composites with better thermal stability and impact strength. This study is part of the research and development project of ANEEL (Agência Nacional de Energia Elétrica) and funded by CPFL (Companhia Paulista de Força e Luz).     

Polymer Barrier Films

Many polymers such as polyolefins (polyethylene, polypropylene), poly(vinyl chloride), aliphatic polyamides, poly(ethylene terephthalate), polycarbonate, and others are used as protective barrier films against the mass transport of small molecules of gases, vapors, and liquids (known as diffusates, permeants) in different applications. The barrier properties depend on the polymer characteristics such as solubility, diffusion, permeability, and others, the nature of the fluid, temperature, and other factors. Mainly polymer barrier film application in packaging, construction, and agriculture are discussed.     

Studies on enhanced degradable plastics: 1. The geographic variability in outdoor lifetimes of enhanced photodegradable polyethylenes

Studies on three types of enhanced photodegradable polyethylenes showed tensile elongation at break to be a suitable parameter for assessing disintegration due to outdoor weathering. Disintegration rates varied greatly with exposure location, with Arizona the harshest environment and Washington and New Jersey the mildest. The rate of breakdown of the enhanced degradable polyethylenes relative to unmodified plastic was termed an enhancement factor. For the materials studied, average enhancement factors generally ranged from five to fifteen. The location-dependent variability in rate parameters can be mostly explained in terms of different average radiation levels and temperatures at these locations. A duplicate exposure protocol was developed to determine if the test data were complicated by short-term fluctuations in sunlight or temperature during exposure.