固体废物相关概念的基本特点

固体废物法对废物的一些概念进行了定义,在固体废物环境管理当中,对这些概念缺乏深入认识,导致在实际管理中对固体废物和危险废物的调查、认定、统计、管理、预测、设施建设等一系列与废物相关的行动出现偏差甚至不准确。对固体废物、危险废物以及废物利用、处置、贮存、排放等概念包含的内容进行了研究,提出了一些新的认识观点。     

中国灌区粮食生产水足迹及用水评价

以1998、2005 及2009 年459 个灌区资料为基础,从区域尺度计算粮食生产水足迹,建立粮食生产用水水平综合评价指标I对灌区粮食生产与水资源利用之间的关系进行评价。结果显示:粮食生产水足迹及其组成的区域间差异均较大,大值省区主要分布于东北、华南,小值省区以黄淮海平原为核心集中分布;全国粮食生产水足迹多年均值为1.336 m³/kg,蓝、绿水比例分别为63.7%和35.8%,有35.1%的水足迹损失于粮食生产过程。空间自相关分析表明,粮食生产用水水平综合评价指标I相似的省区在空间上显著地聚集,局部自相关属性为HH和LL的省区超过了20 个,不同年份总体和局部的空间分异特征随时间变化均不明显;省区间粮食生产综合用水水平差异大,I值介于0.079~0.889 之间,变异系数为0.59,黄河中下游省区用水水平较高而东北及西北大部分省区则相反。结合人均粮食占有量与I值在全国的地位,对各省区粮食生产与农业用水发展方向进行了讨论。     

Co-fermentation of waste activated sludge with food waste for short-chain fatty acids production: effect of pH at ambient temperature

Effect of pH ranging from 4.0 to 11.0 on co-fermentation of waste activated sludge (WAS) with food waste for short-chain fatty acids (SCFAs) production at ambient temperature was investigated in this study. Experimental results showed that the addition of food waste significantly improved the performance of WAS fermentation system, which resulted in the increases of SCFAs production and substrate reduction. The SCFAs production at pH 6.0, 7.0, 8.0, and 9.0 and fermentation time of 4 d was respectively 5022.7, 6540.5, 8236.6, and 7911.7 mg COD·L^-1, whereas in the blank tests (no pH adjustment, pH 8.0 (blank test 1), no food waste addition, pH 8.0 (blank test 2), and no WAS addition (blank test 3)) it was only 1006.9, 971.1, and 1468.5 mg COD·L^-1, respectively. The composition of SCFAs at pH from 6.0 to 9.0 was also different from other conditions and propionic acid was the most prevalent SCFA, which was followed by acetic and n-butyric acids, while acetic acid was the top product under other conditions. At pH 8.0 a higher volatile suspended solids (VSS) reduction of 16.6% for the mixture of WAS and food waste than the sole WAS indicated a synergistic effect existing in fermentation system with WAS and food waste. The influence of pH on the variations of nutrient content was also studied during anaerobic fermentation of the mixture of WAS and food waste at different pH conditions. The release of NH4+-N increased with fermentation time at all pH values investigated except 4.0, 5.0 and in blank test one. The concentrations of soluble phosphorus at acidic pHs and in the blank test one were higher than those obtained at alkaline pHs. Ammonia and phosphorus need to be removed before the SCFAs-enriched fermentation liquid from WAS and food waste was used as the carbon source.     

Use of thermal analysis techniques (TG-DSC) for the characterization of diverse organic municipal waste streams to predict biological stability prior to land application

The use of organic municipal wastes as soil amendments is an increasing practice that can divert significant amounts of waste from landfill, and provides a potential source of nutrients and organic matter to ameliorate degraded soils. Due to the high heterogeneity of organic municipal waste streams, it is difficult to rapidly and cost-effectively establish their suitability as soil amendments using a single method. Thermal analysis has been proposed as an evolving technique to assess the stability and composition of the organic matter present in these wastes. In this study, three different organic municipal waste streams (i.e., a municipal waste compost (MC), a composted sewage sludge (CS) and a thermally dried sewage sludge (TS)) were characterized using conventional and thermal methods. The conventional methods used to test organic matter stability included laboratory incubation with measurement of respired C, and spectroscopic methods to characterize chemical composition. Carbon mineralization was measured during a 90-day incubation, and samples before and after incubation were analyzed by chemical (elemental analysis) and spectroscopic (infrared and nuclear magnetic resonance) methods. Results were compared with those obtained by thermogravimetry (TG) and differential scanning calorimetry (DSC) techniques. Total amounts of CO₂ respired indicated that the organic matter in the TS was the least stable, while that in the CS was the most stable. This was confirmed by changes detected with the spectroscopic methods in the composition of the organic wastes due to C mineralization. Differences were especially pronounced for TS, which showed a remarkable loss of aliphatic and proteinaceous compounds during the incubation process. TG, and especially DSC analysis, clearly reflected these differences between the three organic wastes before and after the incubation. Furthermore, the calculated energy density, which represents the energy available per unit of organic matter, showed a strong correlation with cumulative respiration. Results obtained support the hypothesis of a potential link between the thermal and biological stability of the studied organic materials, and consequently the ability of thermal analysis to characterize the maturity of municipal organic wastes and composts.     

计算机废弃物的处理与利用

介绍计算机废弃物的来源、组成、污染,重点阐述了计算机废弃物的拆卸技术和塑料、线路板、贵金属的回收利用方法。对计算机废弃物处理有重要的参考借鉴价值。     

城市生活垃圾好氧堆肥中氨气变化及其影响

堆肥过程中氮素损失比较严重,而氨气挥发是氮损失的主要途径。利用城市生活垃圾进行好氧堆肥,研究其堆肥过程中氨气变化规律及其对堆肥性质的影响。结果表明:在堆肥期间,氨气含量先增加后减小,最后基本稳定在5 mg/kg左右;而全氮含量先降低后增加;硝态氮含量先降低后增加;铵态氮是先快速增加,后缓慢减小至稳定;pH值先下降后升高,最终稳定在中性范围内;w(C)/w(N)先增加后下降;有机质含量显著下降。     

有机固体废弃物的热解处理研究

通过对锯末、稻壳、纸屑、橱芥、塑料和橡胶6种具有代表性的有机固体废弃物原料的热解实验,测量了它们三相产物收率,并分析了它们固体、液体和气体三相产物的组成.特别对液体产物,针对它们的特殊性分别采用了层析、模拟蒸馏和全烃气相色谱分析,详细探讨了热解焦油的具体组分,得到了热解法处理有机固体废弃物的一些有意义的数据.     

Arsenic trophodynamics along the food chains/webs of different ecosystems: a review

In drinking water, arsenic (As) food chain accumulation may pose a risk to human health. An attempt was made to synthesise the published information concerning As trophic transfer along the food chain/web of various marine, freshwater, and terrestrial ecosystems. Some investigations included As speciation. Further objectives were to outline the factors potentially influencing As trophodynamics and to understand the consequence of As trophic transfer in the environment.     

Life cycle assessment of food waste home composting in Greece

Home composting is a waste prevention measure related to the management of the household's food waste, garden trimmings, and other smaller organic household waste streams. Thus, home composting is an alternative way of exploitation of the “biomass” generated from the households. It is an alternative to centralized composting. Biomass utilization is explicitly stated as a principle of green chemistry. The aim of this paper is presentation of the results of a case study dealing with the life cycle environmental assessment of home composting of food waste in households in Greece. The results of the study indicate that home composting is environmentally preferable over the current organic waste management situation in Greece.     

The potential of current legal structures to support Aboriginal and Torres Strait Islander interests in the Australian bush food industry

There are complex connections between Australia’s native plants and first peoples, the Aboriginal and Torres Strait Islander peoples. The maintenance of these connections is central to Aboriginal and Torres Strait Islander culture and well-being and the tangible realisation of Australian policy commitments. Diverse cultural connections combine with other motivations to underpin an array of Aboriginal and Torres Strait Islander interests in the commercial development of traditional plant foods (‘bush foods’). Despite nation-wide policy support for these interests, there is no national legal framework to support them. This fortifies the popular call for a new (sui generis) law that transforms the interests of Aboriginal and Torres Strait Islander peoples into enforceable legal rights. It is unclear the extent to which a single sui generis law might help Aboriginal and Torres Strait Islander peoples realise their diverse interests in the development of gourmet bush food products and new bush food varieties. It is also unlikely that Australia will implement such a law in the near future. This paper offers a preliminary study of the capacity of current legal structures to support some key Aboriginal and Torres Strait Islander interests that might arise in these two development contexts. The study can inform the future development of practical legal strategies to support the diverse interests of Aboriginal and Torres Strait Islander peoples in the bush food industry.