基于工艺过程分析的废旧塑料再生利用污染源研究

在分析废旧塑料再生利用工艺过程的基础上,确定了废塑料综合利用工艺的产污节点,并通过物流平衡和水平衡计算,得出了总的产排污量,为环境保护措施提供重要依据,以实现保护环境和资源合理再生利用。     

Ammonia and phosphorus removal from agricultural runoff using cash crop waste-derived biochars

• Orange tree residuals biochar had a better ability to adsorb ammonia. • Modified tea tree residuals biochar had a stronger ability to remove phosphorus. • Partially-modified biochar could remove ammonia and phosphorus at the same time. • The real runoff experiment showed an ammonia nitrogen removal rate of about 80%. • The removal rate of total phosphorus in real runoff experiment was about 95%. Adsorption of biochars (BC) produced from cash crop residuals is an economical and practical technology for removing nutrients from agricultural runoff. In this study, BC made of orange tree trunks and tea tree twigs from the Laoguanhe Basin were produced and modified by aluminum chloride (Al-modified) and ferric sulfate solutions (Fe-modified) under various pyrolysis temperatures (200°C–600°C) and residence times (2–5 h). All produced and modified BC were further analyzed for their abilities to adsorb ammonia and phosphorus with initial concentrations of 10–40 mg/L and 4–12 mg/L, respectively. Fe-modified Tea Tree BC 2h/400°C showed the highest phosphorus adsorption capacity of 0.56 mg/g. Al-modified Orange Tree BC 3h/500°C showed the best performance for ammonia removal with an adsorption capacity of 1.72 mg/g. FTIR characterization showed that P = O bonds were formed after the adsorption of phosphorus by modified BC, N-H bonds were formed after ammonia adsorption. XPS analysis revealed that the key process of ammonia adsorption was the ion exchange between K⁺ and NH₄⁺. Phosphorus adsorption was related to oxidation and interaction between PO₄^3– and Fe³⁺. According to XRD results, ammonia was found in the form of potassium amide, while phosphorus was found in the form of iron hydrogen phosphates. The sorption isotherms showed that the Freundlich equation fits better for phosphorus adsorption, while the Langmuir equation fits better for ammonia adsorption. The simulated runoff infiltration experiment showed that 97.3% of ammonia was removed by Al-modified Orange tree BC 3h/500°C, and 92.9% of phosphorus was removed by Fe-modified Tea tree BC 2h/400°C.     

再生资源回收行业经营现状及政策建议

在充分调研的基础上,分析阐述了再生资源回收行业新税收政策实施一年来,对再生资源回收行业产生的巨大影响。为促进行业健康发展,提出了完善再生资源回收行业税收政策的建议。     

我国资源再生产业集群辨识研究

资源再生产业是解决资源危机、能源短缺和环境污染等问题的有效途径.近年来,我国资源再生产业发展迅速,在一些区域产业集群特征凸显.因此,本文采用产业集中度和区位商法,对我国资源再生产业在省域层面的集群情况进行定量分析.结果表明:我国资源再生产业集群特征非常明显,2007年产业集中度CR_4达到71.15%,广东、浙江和湖南三省已形成资源再生产业集群,2007年三省的区位商分别达到1.781、1.987、8.491;同时还发现重庆、湖北、天津、江苏、上海也初具集群雏形,为从产业集群角度探索我国资源再生产业发展模式提供依据.此外,在对广东、浙江和湖南三省产业集群进行深入分析和验证时还发现:广东、浙江模式与湖南模式具有明显不同,前者是再生资源禀赋和地方需求主导模式.而后者则是交易成本、区位交通优势和政府扶持共同作用的结果.     

含二甲胺工业废水的回收及再利用技术研究

为了消除工业二甲胺废水带来的巨大污染,使其达到回收利用的目的,利用精馏技术,采用BH型高效填料作为分离介质,连续从废水中脱除二甲胺,并将塔顶二甲胺提浓。结果表明,采用本技术可使塔顶二甲胺提浓至47%(质量百分含量),达到满足40%二甲胺水溶液质量要求的目的;塔釜二甲胺含量降低至≤50 mg/L,此水可作皮革工业生产回用水。由于含二甲胺废水经处理后可以全部回收利用,表明该高效精馏技术用于清洁生产中具有可靠性和实用性。     

Toward maximizing the recycling rate in a Sapporo waste plastics liquefaction plant

Sapporo Plastics Recycling Co., Ltd., (SPR) started its commercial operation of waste plastics liquefaction in 2000. At first only hydrocarbon oil was reclaimed, this being derived from the waste plastics liquefaction process under the Japanese Containers and Packaging Recycling Law. Presently, thermal degradation residue and hydrochloric acid are being produced as by-products in addition to the hydrocarbon oil. As a result, the SPR plastics liquefaction plant has achieved a high reclamation rate of 96%, and 93% of the recycled products have been reused in Hokkaido, where SPR is located. The technical problems caused by corrosion and clogging have been solved. Chemical Feedstock Recycling & Other Innovative Recycling Techniques 6     

Organic Agriculture’s Approach towards Sustainability; Its Relationship with the Agro-Industrial Complex, A Case Study in Central Macedonia, Greece

Up to now, several scientific works have noted that the organic sector resembles more and more conventional farming’s structures, what is widely known as the “conventionalization” thesis. This phenomenon constitutes an area of conflict between organic farming’s original vision and its current reality and raises ethical and social questions concerning the structure of agricultural systems of production and their interactions with the socio-economic and natural environment. The main issue of this dialogue is the concept of sustainable agriculture, which for scientists and policymakers is a means to express their vision of a better agriculture. In this article we focus on agricultural sustainability in the context of capitalist production as conducted by the two subsystems of agro-industrial system. As we have proposed in this article, the relationship between organic agriculture, defined by two essential components (prevention and direct marketing), and the agro-industrial complex, defined by two subsystems, indicates the degree of agricultural sustainability. The investigation of this relationship can be extremely useful as it may lead those involved in the discussion of sustainability to identify the key aspects of sustainable agriculture. In order to investigate the interaction of organic farming with the agro-industrial complex, a survey was conducted in Central Macedonia, Northern Greece, involving local organic farms. The results of our study indicate that a large proportion of organic producers did not differ substantially from their counterparts in conventional agriculture in so far as their relationship with the agro-industrial complex is concerned. Finally, this research highlights two scenarios for the evolution of organic farming. The first is the full absorption of organic farming to the existing economic system and the second one is the development of organic farming in a radically opposite direction to conventional farming.     

AgInput: An Agricultural Nutrient and Pesticide Source Model

Agriculture can be a major nonpoint source (NPS) of nutrient and pesticide contamination in the environment. Available databases do not provide accurate and dynamic data on fertilizer and pesticide application, which limits the ability of complex watershed models to simulate contaminant loads into impaired water bodies. A model for estimating agricultural nutrient and pesticide input for watershed modeling has been developed. Climate, soils, and major agricultural operations are considered within the model, so that it can be adapted to any watershed or subregion within a watershed. The timing of the agricultural operations is a function of the weather data, providing realistic results at daily, monthly, or annual application rates. The model also predicts irrigation demand and biomass production, which can be used to calibrate the model. Model output can be used in any watershed model that considers agricultural land uses. Two case studies were evaluated, using grape vineyards in the Napa River and strawberry production in Newport Bay as examples. The predicted time to maturity corresponded well with actual data. Irrigation and fertilizer needs were very sensitive to weather input. Although the model can generate weather from long-term averages, the simulated results are best when at least observed precipitation and temperature are provided, to capture extreme events. The model has data for 98 crops and 126 pesticides, based on the California Department of Pesticide Regulation database. The databases are easily modifiable by the user to adapt them to local conditions. The output from AgInput is much needed for watershed modeling and for development of total maximum daily loads (TMDLs), based on realistic targets of irrigation, nutrient, and pesticide inputs. The model is available for free download at .     

农产品产地土壤重金属外源污染来源解析及防控策略研究

分析了工业生产排放、污水灌溉、矿产资源开发、农业投入品施用、大气颗粒物降尘及固体废弃物堆放等农产品产地土壤重金属主要外源污染来源,在此基础上构建了包括工业过程源、固定燃烧源、灌溉水源、废弃物堆放源、流动源和农业投入品源的来源清单,并从建立健全源头预防和强化过程控制2个方面,提出了加强农产品产地土壤重金属污染监管的相关建议。     

基于能值计算的循环农业发展个例分析

能值分析能够更好地量化分析和评价循环农业。利用该方法对湖北省武汉银河生态有限公司的循环农业进行了实证分析。结果表明,实施循环农业后的集约养殖场结合农地流转发展起来的“猪-沼（能）肥-地-菜（藕、果、粮）-鱼-村”六位一体的循环农业典型模式,与实施循环农业前当地分离的水稻、小麦、油菜、棉花、蔬菜、柑橘、猪、鱼的农业生产系统相比,在能值转化率、可更新率、能值投资率、能值自给率、净能值产出率、环境负载率、能值交换比率方面均表现出明显优势,并从能值的角度提出了完善循环农业体系的对策建议