生态农业园区放心弃物资源化处理利用研究

本文介绍了蟹岛生态园区农业废气物及生活污水的资源化处理工艺方案，通过对沼气池和生活污水厌氧，好氧－生态塘处理系统进行综合设计，实现了节能环保和废弃弃物无害化综合处理利用，形成了种植业，养殖业，肥料加工，能源利用和休闲度假有机结保的生态农业经济，为实现农村经济可持续发展提供了一种新模式。     

好氧-缺氧-闲置运行模式处理生活污水

在3个序批式反应器中,利用好氧-缺氧-闲置的运行模式处理实际生活污水,比较了不同曝气时间（2、3和4h）条件下的处理效果,结果表明,在R2（2 h）反应器中成功实现了单级好氧除磷和内聚物驱动的短程硝化反硝化。采用此反应器运行模式,对实际生活污水进行长期处理,反应器的COD、TN和TP的平均去除率分别为85.29%、74.09%和87.97%。本研究表明,在好氧-缺氧-闲置的运行模式下处理生活污水,能成功地实现单级好氧除磷与内聚物驱动的短程硝化反硝化的结合,并且在长期运行的过程中,能稳定地取得较好的脱氮、除磷效率。     

生物生态耦合系统对分散式农村生活污水的深度净化

针对分散式农村生活污水排放标准的提升,通过集约式立体生物生态耦合系统对农村生活污水二级处理出水进行深度净化,采用国家标准方法对系统进出水中的COD、氨氮、TN和TP进行了测定,评价了系统对各污染物质的去除效果。结果表明:在实验进水COD,氨氮,TN和TP均属于《城镇污水处理厂污染物排放标准》(GB 18918-2002)一级B标准时,系统稳定后实验出水的COD,氨氮,TN和TP的浓度分别可降至9～35、1～7、8.0～14.9、0.20～0.47 mg·L~(-1),均满足一级A标准。随着流水分区不同,COD,氨氮,TN和TP的浓度逐渐降低。采用集约式立体生物生态耦合系统可使农村生活污水二级处理出水水质达到一级A排放标准,实现深度净化的需求。     

连锁控制的A~2/O-MBR工艺处理石化社区生活污水

采用连锁控制的A2/O-MBR工艺处理石化社区低浓度的生活污水并回用,处理规模520 m3/h。工程运行监测结果表明,该工艺对低浓度生活污水处理效果良好,出水水质达到了《城镇污水处理厂污染物排放标准》(GB18918-2002)的一级B标准和《污水再生利用工程设计规范》(GB50335-2002)标准要求。通过连锁控制,系统运行稳定,具有较强的耐冲击负荷能力,实现了污水处理厂正常运行。     

两级混凝-化学氧化处理生活污水的研究

采用两级混凝-化学氧化组合工艺处理城市生活污水，在混凝试验中确定了两级不同混凝剂的适宜投加量，并对自制混凝剂Inx进行了氧化再生重复利用实验。结果表明：经两级混凝-化学氧化组合工艺处理后的城市污水达到国家污水综合排放标准，并且自制混凝剂Inx可以重复利用。     

气升循环分体式膜生物反应器污水处理与回用技术

介绍了一种新型膜生物反应器——气升循环分体式膜生物反应器污水处理和再生回用技术。该技术膜单元和生物单元分置，生物单元和膜单元间的水力循环利用气升动力，无需循环水泵，系统具有维护方便、运行能耗低和建设投资省等特点。采用该技术处理生活污水和厕所污水，处理水质可达到建设部颁布的《生活杂用水水质标准》(CJ25．1-89)。给出了该技术处理生活污水和厕所污水的工程建设投资指标、水处理成本和水处理能耗指标，处理能耗0．6-0．8kWh／m^3。该新型膜生物反应器污水再生回用技术具有良好的市场应用前景，技术经济可行。     

气升循环分体式膜生物反应器污水处理与回用技术

介绍了一种新型膜生物反应器———气升循环分体式膜生物反应器污水处理和再生回用技术。该技术膜单元和生物单元分置 ,生物单元和膜单元间的水力循环利用气升动力 ,无需循环水泵 ,系统具有维护方便、运行能耗低和建设投资省等特点。采用该技术处理生活污水和厕所污水 ,处理水质可达到建设部颁布的《生活杂用水水质标准》(CJ2 5 1 89)。给出了该技术处理生活污水和厕所污水的工程建设投资指标、水处理成本和水处理能耗指标 ,处理能耗 0 6～ 0 8kWh/m3 。该新型膜生物反应器污水再生回用技术具有良好的市场应用前景 ,技术经济可行。     

低温条件下生态槽深度处理农村生活污水的日变化特性

针对农村生活污水处理设施出水水质偏高污染环境的现状,构建了以水生植物为主体的生态槽深度处理农村生活污水,研究了低温条件下生态槽深度处理生活污水过程中DO、pH、COD、NH4+-N、TP等指标的日变化特性。结果表明,生活污水COD为37.67～60.23 mg/L、NH4+-N为13.66～16.76 mg/L、TP为1.32～1.78 mg/L、水温为9～11℃,HRT为5 d时,生态槽出水COD、NH4+-N和TP平均为21.07 mg/L、0.99 mg/L和0.19 mg/L,均可达《地表水环境质量标准》(GB3838-2002)之Ⅳ类水标准。各级生态槽内DO浓度夜间低于昼间。夜间植物对NH4+-N和TP具有较强的吸收作用,平均去除率分别达94.83%和89.87%;而TN去除效果稍差,平均去除率为59.9%。     

Phytosystem生态池处理西北某中小型车站生活污水

远离市区的中小型铁路车站通常无条件配套接入市政管网,这些车站的生活污水还具有水量小、水质波动大等特点,需自行处理达标后就近排放或贮存。介绍Phytosystem生态池在西北某中小型车站对其生活污水进行处理的示范工程运行效果。该系统由表层植物床和底层生物反应床构成,应用旋转式水流,将密闭和开放式处理池相结合。示范装置运行效果良好,对于该车站生活污水中化学需氧量、氨氮、总磷和悬浮物的去除率达90%左右,经处理后的出水可以达到《城镇污水处理厂污染物排放标准》中的一级排放B标准。Phytosystem是一套高度集约、占地面积小、耗能低的生态处理系统,其外型美观且不产生污泥及气味,对于车站生活污水的处理不仅能达到要求,还具有稳定的处理能力,可广泛推广其应用。     

蚯蚓生态滤池处理农村生活污水现场试验研究

对蚯蚓生态滤池处理太湖流域农村生活污水进行现场试验研究.通过对蚯蚓同化容量与污染负荷进行单因素分析,得出蚯蚓生态滤池处理农村生活污水的运行参数与运行方式,并据此进行连续运行试验.结果表明,在表面水力负荷1 m3/(m2*d)、湿干比(布水时间和落干时间之比)1∶3、蚯蚓负荷(以单位体积填料中蚯蚓的质量计)12.5 g/L的条件下,蚯蚓生态滤池处理农村生活污水具有可行性与高效性,单级系统的COD、总氮、氨氮和总磷的去除率分别在81%、66%、82%和89%左右.改进蚯蚓床填料、设计通风结构和采取适宜运行方式,是蚯蚓生态滤池成功应用于农村生活污水处理的三大重要因素.     

Effect of soil-use on deep groundwater quality in Southern Chile

This study evaluated the effects of farming activities on the quality of deep well water in Southern Chile. In this area, the use of fertilisers is becoming more widespread and the accumulation and poor management of cattle slurry and silage sub-products increases the risk of contamination. The study was carried out in the province of Osorno, where rainfall occurs all year round (maximum in winter); total annual rainfall exceeds 1300 mm. The soil is of volcanic origin and this province includes areas used for intensive farming and cattle raising activities, residential and recreational purposes and extensive farming practices. Water quality was analysed over a 15 month period in deep wells in either intensive farming areas and residential/recreational zones or extensive farming land. Although levels of nitrate were higher in deep wells located in intensive farming areas, levels of phosphor and pH were lower than those of wells located in extensive farming areas. Nevertheless, the range of nutrient concentration (nitrite, iron, manganese and phosphor) revealed significant statistical differences between both types of farming land; nitrite dominated in well samples located in intensive farming areas, while iron and manganese dominated in extensive farming areas. Seasonal differences were registered in temperature, nitrate, total coliforms and Escherichia coli. Maximum levels of nitrate and bacteria were reached in spring and autumn, respectively. No significant relationships were established between nutrient and bacterial levels with meteorological factors such as temperature, rainfall and number of days when rainfall occurred. Variations in nutrients and bacteria, both temporal and between locations (spatial), are associated to soil use and proximity to septic well wastewaters. Iron and manganese concentrations exceeded permitted drinking-water standards in a considerable percentage of samples, which may be due to soil composition. Bacterial pollution occurred infrequently in autumn and winter. The quality of deep-well waters in Southern Chile is generally good. Nevertheless, evidence indicates that intensive farming practices, slurry, silage and poor management of rural residential areas, constitute a significant potential risk.     

Knowledge gaps and management recommendations for future paths of sustainable seaweed farming in the Western Indian Ocean

Farming of eucheumatoid seaweeds is a widespread, promising activity and an important livelihood option in many tropical coastal areas as for example in East Africa, Western Indian Ocean (WIO). Compared to other types of aquaculture, seaweed farming has generally low impact on the environment. Nonetheless, there are potential direct or indirect negative effects of seaweed farming, such as introduction of alien species and changes in local environmental conditions. Although farming has been practiced in this region during several decades, the knowledge concerning the actual environmental impacts from faming non-native eucheumatoid haplotypes and consequently how to manage farming activities to mitigate those is highly limited. In this review, we provide a summary of the current scientific knowledge of potential direct and indirect negative environmental effects linked to eucheumatoid seaweed farming such as alterations of benthic macrophyte habitats and loss of native biodiversity. Furthermore, we highlight knowledge gaps that are of importance to address in the near future, e.g., large-scale ecosystem effects and farms as potential vectors of pathogens. We also provide a number of feasible management recommendations to be implemented for a continued development of environmentally sustainable seaweed farming practices in the WIO region, which includes spatial planning of farms to avoid sensitive areas and farming of native haplotypes of eucheumatoids instead of introduced specimens.     

Improving marine water quality by mussel farming: a profitable solution for Swedish society

Eutrophication of coastal waters is a serious environmental problem with high costs for society globally. In eastern Skagerrak, reductions in eutrophication are planned through reduction of nitrogen inputs, but it is unclear how this can be achieved. One possible method is the cultivation of filter-feeding organisms, such as blue mussels, which remove nitrogen while generating seafood, fodder and agricultural fertilizer, thus recycling nutrients from sea to land. The expected effect of mussel farming on nitrogen cycling was modeled for the Gullmar Fjord on the Swedish west coast and it is shown that the net transport of nitrogen (sum of dissolved and particulate) at the fjord mouth was reduced by 20%. Existing commercial mussel farms already perform this service for free, but the benefits to society could be far greater. We suggest that rather than paying mussel farmers for their work that nutrient trading systems are introduced to improve coastal waters. In this context an alternative to nitrogen reduction in the sewage treatment plant in Lysekil community through mussel farming is presented. Accumulation of bio-toxins has been identified as the largest impediment to further expansion of commercial mussel farming in Sweden, but the problem seems to be manageable through new techniques and management strategies. On the basis of existing and potential regulations and payments, possible win-win solutions are suggested.     

Levels of polychlorinated biphenyls (PCB) and polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/F) in fillets of farmed Southern Bluefin Tuna (Thunnus maccoyii)

Southern Bluefin Tuna (SBT) (Thunnus maccoyii) is the only farmed tuna species in the southern hemisphere, with production centred offshore of Port Lincoln, South Australia. SBT farming is a quota-based fishery where farmers fatten wild-caught stock for subsequent sale as fresh-chilled or frozen product, mainly to Japanese markets. Fillets from wild-caught and farmed SBT were analysed and the concentration of polychlorinated biphenyls (PCBs), polychlorinated dibenzo-p-dioxins (PCDDs) and polychlorinated dibenzofurans (PCDFs) are reported for the first time. Time of farming was separated into two periods: a typical farming period of approximately five months and an experimental scenario that involved holding (farming) these fish for an additional 12 months. WHO-PCB and WHO-PCDD/F TEQ concentrations in fillets on a fresh weight basis at the same times and over the same periods were, 0.67-1.18pg-TEQg(-1) and 0.16-0.29pg-TEQg(-1), respectively. All WHO-PCB congeners, and only three WHO-PCDD/F congeners, were found to biomagnify during farming, after blank correction. Caution should be exercised when extrapolating these results to SBT farming as a whole because of the use of varying husbandry and feeding practices employed by different companies.     

Towards a control model for the highly cybernetic farming ecosystems

A dynamic model based on the linear systems theory is developed in designing a highly cybernetic farming strategy to efficiently manage residuals generated in farm ecosystems. A linear cybemetic model would be used to describe the dynamic behavior of resource flow in the farm ecosystem in which the state variables are resource quantities, and the control variables are residual quantities. The controlled process is defined as the controlled management strategy change. Cybemetic mechanism shows the application of residuals as control measures have determinate effects on the controlled process as along as the farming system is observable and controllable in the control sense. To illustrate the model algorithm the idea is applied to simulate the dynamic response of residual phosphorus concentrations in an integrated pig/corn farming system located in the south Taiwan region. General results show that the residual phosphorous concentration is influenced by farming activities which are controlled by a system of gross input and net output parameters. This paper demonstrates using input-output analysis technique that residuals generated in the farming system is the most important cybemetic variable,     

Organic Farming and Soil Carbon Sequestration: What Do We Really Know About the Benefits?

Organic farming is believed to improve soil fertility by enhancing soil organic matter (SOM) contents. An important co-benefit would be the sequestration of carbon from atmospheric CO₂. Such a positive effect has been suggested based on data from field experiments though many studies were not designed to address the issue of carbon sequestration. The aim of our study was to examine published data in order to identify possible flaws such as missing a proper baseline, carbon mass measurements, or lack of a clear distinction between conventional and organic farming practices, thereby attributing effects of specific practices to organic farming, which are not uniquely organic. A total of 68 data sets were analyzed from 32 peer-reviewed publications aiming to compare conventional with organic farming. The analysis revealed that after conversion, soil C content (SOC) in organic systems increased annually by 2.2% on average, whereas in conventional systems SOC did not change significantly. The majority of publications reported SOC concentrations rather than amounts thus neglecting possible changes in soil bulk density. 34 out of 68 data sets missed a true control with well-defined starting conditions. In 37 out of 50 cases, the amount of organic fertilizer in the organic system exceeded that applied in the compared conventional system, and in half of the cases crop rotations differed between systems. In the few studies where crop rotation and organic fertilization were comparable in both systems no consistent difference in SOC was found. From this data analysis, we conclude that the claim for beneficial effects of organic farming on SOC is premature and that reported advantages of organic farming for SOC are largely determined by higher and often disproportionate application of organic fertilizer compared to conventional farming.     

Assessment of semi-natural habitats and landscape features on Irish farmland: New insights to inform EU Common Agricultural Policy implementation

Concerns over the loss of biodiversity and ecosystem services in farmland have prompted the development of agri-environment policy measures aimed at reducing farming pressure and maintaining semi-natural habitats in farmed landscapes. However, further knowledge is needed to guarantee successful agri-environment measures implementation. The current study assessed the quantity and the quality of semi-natural habitats in farms across a gradient of farming intensities in two contrasting regions in Ireland. Policy protection seemed fundamental for semi-natural habitats preservation. Habitats not protected by agricultural policy relied on extensive farming and are in danger of disappearing if they are intensified or abandoned. Due to the lack of policy incentives for habitat quality, no correlations were found between farming intensity and share of semi-natural habitats with habitat quality. Therefore, extensive farming and retention of habitats alone may not reverse the decline of farmland quality and biodiverisity and, thus, measures incentivising the environmental quality may be more successful.Electronic supplementary materialThe online version of this article (10.1007/s13280-020-01344-6) contains supplementary material, which is available to authorized users.     

生物材料治理镉污染研究进展

近年来,生物材料以其经济、有效和无二次污染等特点,在重金属废水处理和土壤修复方面显示出了众多的优势·可替代传统的镉污染处理方法.综述了目前国内外生物材料在处理镉污染方面的研究进展,并对今后应用生物材料治理镉污染提出了一些建议.     

施肥过程中的污染控制

农业生产造成的自身污染是一个不可忽略的环境问题,化肥施用不当造成植物体内硝酸盐含量增加以及水源的污染,城市活性污沁的农用处理,扩大了农田重金属污染的途径和范围,因此要提介科学种田,合肥施肥,以减轻对农业环境的污染。     

Towards a control model for the highly cybernetic farming ecosystems

Abstract

A dynamic model based on the linear systems theory is developed in designing a highly cybernetic farming strategy to efficiently manage residuals generated in farm ecosystems. A linear cybernetic model would be used to describe the dynamic behavior of resource flow in the farm ecosystem in which the state variables are resource quantities, and the control variables are residual quantities. The controlled process is defined as the controlled management strategy change. Cybernetic mechanism shows the application of residuals as control measures have determinate effects on the controlled process as along as the farming system is observable and controllable in the control sense. To illustrate the model algorithm the idea is applied to simulate the dynamic response of residual phosphorus concentrations in an integrated pig/corn farming system located in the south Taiwan region. General results show that the residual phosphorous concentration is influenced by farming activities which are controlled by a system of gross input and net output parameters. This paper demonstrates using input‐output analysis technique that residuals generated in the farming system is the most important cybernetic variable, so that the proper management of residuals alone has the potential to maintain future productivity and sustainability.