Facilitating resilient rural-to-urban sustainable agriculture and rural communities

ABSTRACT

This article contributes to efforts to validate a common set of parameters and principles of sustainable agriculture. Comparisons between alternative forms of sustainable agriculture and rural-to-urban community resilience are investigated. Conclusions are drawn between multiple sustainable/alternative agriculture systems and evaluated. A set of common baseline parameters and principles is proposed as a method of evolving a common structural framework for strengthening sustainability of agriculture and rural contexts. Concepts of rural-to-urban community sustainability are proposed, supporting sustainable agriculture contexts as rural and urban. In the twenty-first century, agriculture is becoming more diversified and less typified as a rural occupation. Urban agriculture is expanding as the need for fresh, affordable, accessible agriculture produce increases in urban areas. Evidence supports symbiotic relationships between sustainable agriculture and rural/urban communities, although some claim this relationship has not been clearly defined.

This article investigates sustainable agriculture from two perspectives. We ask ‘what are common parameters and principles of the various forms of sustainable agriculture,’ and ‘why urban-to-rural context.’ Organic agriculture parameters and principles are proposed as a conceptual framework toward establishing baseline parameters and principles for sustainable agriculture. Best management parameters of urban and rural sustainable agriculture in the United States and the United Kingdom are examined for their potential to develop a strengthening framework of parameters and principles of agriculture and rural-to-urban sustainability. These results are compared and evaluated for their effectiveness in redefining current sustainable agriculture practices, and their value in strengthening sustainable agriculture symbiosis with rural-to-urban community systems.     

利用SOS/umu测试方法鉴定沙颍河河水中的遗传毒性物质

采用HPLC分割导向的SOS/umu测试方法鉴定了沙颍河河水中的遗传毒性物质。当采用TA1535/pSK1002菌株测定HPLC分割的各馏分时,如果不经大鼠肝微粒体酶(S9)代谢活化,只有馏分F10显示遗传毒性,加入大鼠肝微粒体酶代谢活化后,馏分F10和馏分F15都显示有遗传毒性,说明河水中存在某些需经过大鼠肝微粒体酶代谢活化才能显示出遗传毒性的物质。当采用过量表达O-乙酰转移酶(O-AT),对芳香胺类物质和硝基芳烃化合物有特殊响应的NM2009菌株测定时,馏分F8、F9和F10均呈现遗传毒性;特别是对于馏分F10,用NM2009菌株测定的遗传毒性远高于原始菌,说明这3个馏分中都含有芳香胺类或硝基芳烃类物质。     

PCDD/Fs emission, risk characterization, and reduction in China’s secondary copper production industry

Secondary copper production is one of the key polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) emission sources in China, but research and data on this issue are rare. In 2004, when the Stockholm Convention entered into force in China, PCDD/Fs emissions from secondary copper production contributed to 32.2% of the total release. In this paper, PCDD/Fs emission dynamics from secondary copper industry were discussed and cumulative risks were characterized. From 2004 to 2009, industrial policies played an indirect role in PCDD/Fs reduction, but its effects are still limited. The Yangtze River Delta, Pearl River Delta and central regions were among the top three of dioxin emissions from secondary copper production in China. Shanghai, Shandong, Zhejiang, and Jiangxi had comparatively higher accumulated risk and were recommended as the priority regions for promoting PCDD/Fs emission control in China. From 2009 to 2015, the PCDD/Fs emission dynamics in the secondary copper industry were presented through simulation. PCDD/Fs emission equations were established, resulting in the recommendation of control technology conversion rate at 30% for small scale smelters and 51%–57% for large and medium-sized enterprises in 2015. In conclusion, both indirect policy and direct control technology retrofitting should be integrated for more effective PCDD/Fs emission reduction in secondary copper industry.     

气浮-A~2/O~2工艺处理焦化废水

以玉田县古玉煤焦化工有限公司焦化废水处理站工程为例,介绍气浮-A2/O2工艺处理高浓度焦化废水的运行效果及工艺参数。运行结果表明:气浮-A2/O2工艺对焦化废水具有理想的处理效果,当进水ρ(COD)<3 500 mg/L、ρ(酚)<700 mg/L、ρ(氰化物)<20 mg/L、ρ(NH3-N)<300 mg/L时,出水ρ(COD)<100 mg/L、ρ(酚)<0.5mg/L、ρ(氰化物)<0.5 mg/L、ρ(NH3-N)<15 mg/L,各项指标均达设计要求,满足熄焦工段的用水要求和排放标准。     

TCP的污泥减量效果及其对出水水质的长期影响

向倒置A2/O中试系统中投加2,4,5-三氯苯酚(TCP),研究TCP对污泥的减量效果及进入处理系统后对系统出水水质长期影响。研究结果表明:与参照组相比,加药组投加TCP 2 mg/L时,污泥减量达62.5%,出水TN比参照组平均高0.8 mg/L,137 d后出水TP超过0.5 mg/L。TCP对污泥的减量效果好,需要加除磷药剂进行辅助除磷。     

A/O法处理水产品加工废水

采用A/O工艺处理水产品加工废水,处理量为500 t/d,运行两年来,效果稳定,处理结果表明:对COD、BOD5和氨氮的去除率分别为94.7%、98.1%和86.4%,出水达到GB 8978—1996《污水综合排放标准》中的一级排放标准,且该工艺具有运行费用低、处理效果好、操作管理方便等一系列优点。     

土壤中短链氯化石蜡的气相色谱-电子捕获负化学电离-质谱分析方法

通过考察层析柱对测定短链氯化石蜡(SCCPs)干扰物去除效果的影响,结合实际土壤样品的净化需求,建立了一套适合分析土壤中SCCPs的前处理方法.土壤样品使用索氏抽提,采用硅胶复合柱和弗罗里硅土柱净化,运用气相色谱-质谱(ECNI源)检测SCCPs.SCCPs的仪器定量限为100—600 pg.μL-1.空白加标和基质加标中SCCPs的回收率分别为130%±8.50%和108%±17.8%(SD,n=3).利用该方法分析了采自广州市郊区的6个土壤样品,其SCCPs的含量范围为12.9—34.5 ng.g-1,平均值为26.1 ng.g-1.     

响应面法在催化湿式氧化降解异佛尔酮中的应用

以Ru/TiZrO2为催化剂,采用催化湿式氧化法降解异佛尔酮废水,选择反应温度、氧气分压、反应时间、催化剂用量、初始pH为影响因素,以TOC去除率为响应值,采用响应面法研究影响因素及其交互作用对响应值的影响,建立二次多项式回归方程模型,并采用后退回归法进行模型精简.结果表明,反应时间和反应温度及其交互作用对TOC去除率影响极显著(P≤0.01);反应时间的二次项对TOC去除率影响显著(P≤0.05).随着反应温度的升高和反应时间的延长,TOC去除率逐渐提高.最后对模型进行验证,实验值与预测值具有很好的一致性,说明模型具有可靠的预测性,将该模型应用到催化湿式氧化中合理可行.质谱和离子色谱检测到异佛尔酮的降解产物主要为有机酮与小分子羧酸,由此提出对反应机理和降解途径的假设.     

不对称还原丙酮酸乙酯菌株的筛选及鉴定

以丙酮酸乙酯为底物,从成都某化工厂污水池及其附近土壤中分离到36株可将丙酮酸乙酯不对称还原成(S)-乳酸乙酯的菌株.经过多次复筛,最终获得了一株具有较高催化活性的酵母菌BTY18-6.在以该菌株静息细胞为催化剂,催化不对称还原丙酮酸乙酯合成(S)-乳酸乙酯的反应中,底物浓度为60 mmol/L时,底物转化率为86.9%,产物(S)-乳酸乙酯的ee值为88.7%.通过对其形态学、生理生化特征及其26S rDNA Dl/D2区域的分析表明,BTY18-6为胶红酵母.     

大鹏湾中溶解态总氮和总磷的多年调查结果分析

依据2000—2010年每月1次的调查资料,简要描述和讨论大鹏湾海水中溶解态总氮（DTN）和溶解态总磷（DTP）质量浓度的空间分布和时间变化。结果表明由于受到香港和深圳陆源排放的影响,DTN和DTP质量浓度在吐露港和沙头角附近水域1年4季都较高。DTN和DTP的平均质量浓度分别为0.21和0.03 mg.L-1,比溶解态无机氮（DIN）和溶解态无机磷（DIP）的高1倍以上,表明大鹏湾海水中溶解态有机氮（DON）和溶解态有机磷（DOP）分别是DTN和DTP的主要赋存形态。平均DTN/DTP原子比〉16,反映了大鹏湾海水中磷可能是海洋浮游生物生长繁殖的限制因素。夏季,由于南海北部陆架低温、高盐和高营养盐底层水潜入湾内,底层DTN和DTP质量浓度明显高于其他季节。11年调查期间,DTN质量浓度的年际变化趋势平稳,DTP质量浓度的年际变化呈较明显的下降趋势,而DTN/DTP原子比的年际变化呈较明显的上升趋势。