LDPE/有机金属降解剂/配合剂体系降解性的研究

以低密度聚乙烯（LDPE）／铁（或锡）的有机合物／含氮有机物为降解体系,制成薄膜样品,于模拟堆肥环境中降解,跟踪取样,测定其粘均分子量及氢过氧化物浓度([POOH])变化,另外,进行了傅立叶变换红外（FT－IR）和差示扫描量热分析（DSC）测试,结果表明,所选用的某些体系能够在堆肥条件下高效降解,薄膜样品在降解60d后分子量大幅度降低,羟基含量,结晶度呈现明显的增高趋势,降解程度受降解剂种类,配合剂种类及含量,降解环境等诸多因素影响,所测[POOH]变化趋势与分子量变化存在着关联性,这为降解机理的进一步讨论打下了基础。     

城市污水污泥与垃圾和粉煤灰堆肥在水稻施肥上的应用

对污泥、垃圾和粉煤灰进行成分及重金属含量检测,用污泥、垃圾和粉煤灰混合堆肥制成有机复合肥,并对水稻进行施肥试验,结果表明：桂林市城市污水污泥及垃圾中有机质和N、P、K含量丰富且不超标,堆肥制成的有机复合肥增产效果显著,具有广泛的应用价值。     

堆肥过程中产生的尾气

堆肥过程中产生大量的臭气,考察这些臭气的组成、含量对处理城市生活垃圾堆肥有重大意义。实验采用气相色谱质谱联用仪（GCMS）对收集的堆肥尾气进行检测,测得21种气体,其中含量较大的气体为NH3和H2S等。     

污泥堆肥处理影响因素研究

通过试验,考察了城市污水处理厂污泥中水分和pH值对污泥堆肥过程的影响。试验结果显示:污泥可堆肥的水分质量分数上限为80%,下限为30%,最佳含水率为60%;污泥可堆肥pH值为5.2~8.8,而最佳pH值为7.6~8.7。     

Evaluation by IR spectroscopy of the degradation of different types of commercial polyethylene exposed to UV radiation and domestic compost in ambient conditions

Different types of commercial polyethylene films, low-density polyethylene (LDPE), high-density polyethylene (HDPE), and biodegradable polyethylene (BIO-PE), were exposed to UV-B radiation at different exposure time and domestic composting during spring and fall at ambient conditions. The effects of UV-B radiation and domestic composting on LDPE, HDPE, and BIO-PE degradation were characterized by FTIR spectroscopy. LDPE, HDPE, and BIO-PE exposed to UV-B radiation underwent photo oxidation reactions leading to the formation of carbonyl (CO) and vinyl (CH₂CH) groups and hydrophilic surface modification. Also, the exposure of LDPE, HDPE, and BIO-PE to domestic composting at ambient conditions at different seasons suffered biodegradation reactions leading to the formation of polysaccharides. In both different seasons LDPE, HDPE, and BIO-PE underwent partial biodegradation, remaining in the domestic composting as unwanted polymer debris. However, biodegradation in domestic composting is not recommended as feasible disposal routes for nonbiodegradable and commercially labeled as biodegradable PE.     

食品包装用生物塑料研究进展

在白色污染和石油危机日趋严重的今天,具有生态友好特征和可持续性的生物基质-生物分解塑料有望替代部分石油基塑料成为一种新型基础原材料,在农业、包装、生物医用等领域已开始显示出巨大的市场潜力。本文介绍了聚乳酸、淀粉基塑料、聚羟基烷酸酯等几类最有可能率先实现产业化并用于食品包装材料的生物基质-生物分解塑料,对其在食品包装材料应用方面所具有的优势和存在的问题进行了评价,并对目前国内外在这几类材料的生产和应用技术及产业化等方面的最新进展进行了归纳。     

香蕉秸秆资源化利用的研究进展

对香蕉秸秆在纤维生产、堆肥、饲料、气化和厌氧发酵等方面的利用情况进行了综述,指出了香蕉秸秆厌氧发酵生产沼气是其资源化和能源化利用的途径和潜力。我国香蕉秸秆年产沼气潜力高达4亿m3,其推广和应用将产生巨大的经济、社会和生态效益。     

Impact of organic amendments on aerial biomass production,and phytoavailability and fractionation of copper in a slightly alkaline copper mine tailing

In the process of phytoremediation of mine tailing land, the bioavailability of heavy metals is an important factor. Greenhouse experiment was conducted to assess the availability and uptake of copper (Cu) by maize (Zea mays L.) grown on a slightly alkaline Cu-mine tailing amended with commercial compost and chelators. A second objective was to evaluate the distribution of Cu in cultivated Cu-mine tailings. The experimental design consisted of 12 treatments resulting from the combination of four rates (0, 5, 10 and 20%, by humid weight) of peat moss-shrimp wastes compost and three rates (0, 1.2 and 2.4 dm³) of organic complexing agents applied as a 0.0025 M EDTA + 0.001 M citric acid solution before plant harvest. The results showed that compost and chelators had a positive effect on top biomass production of maize. Compared with the control, the application of compost decreased Cu_CAR and increased Cu_ORG whereas the addition of chelating solution increased Cu_SOL and Cu_EXC and decreased Cu_CAR and Cu_ORG. The Cu lability in cultivated tailing and its availability to the maize plant are highly dependent on the metal speciation in tailing. In another series of experiments, sorption of Cu by cultivated mine tailings were examined. The amounts of Cu sorbed and K _d values were highest in tailing amended with highest compost rate, and were positively correlated with tailing organic matter (OM) content and Cu bound to Cu_ORG. The results indicate that peat moss and shrimp waste containing compost could be used as a phytostabilizer by supplying OM and nutrients and as a sorbent by mitigating Cu uptake by maize. This compost is able to improve the phytoremediation of Cu-mine tailings.     

Effect of using urban compost as manure on soil contents of some nutrients and heavy metals

The effect of adding annual doses of 14 000 kg ha^?1 of urban compost to a soil is compared with the addition of 500 kg ha^?1 of a 15–15–15 compound NPK fertiliser. Two rotation cycles of sorghum/wheat were carried out during the experiment, and the crop yields were not significantly affected by treatments. It is observed that compost added in the proportion used does not cause any statistically significant change in the initial level of available phosphorus in the soil, but causes an increase of the potassium potential. Soil total contents of copper and zinc as well as available levels of both metals show noticeable increases, but other metals are scarcely affected by the addition of compost. The results suggest that larger doses could be an important cause of pollution of the soil with heavy metals.