泄漏检测与修复(LDAR)检测数据准确性评估方法研究

泄漏检测与修复技术(LDAR)是控制石化企业设备与管线泄漏的最佳可行技术,检测数据准确度对于企业核算VOCs排放量及环境保护主管部门进行VOCs排污费征收和排污许可证管理至关重要.针对中国石化企业工艺装置特点和LDAR检测数据特征,设计了一套LDAR检测数据准确性评估方法,并运用该方法对24套石化装置的LDAR检测数据准确性进行抽测评估.结果表明该方法可以直观反映企业LDAR检测数据准确度,客观体现不同企业、不同装置在LDAR检测管理水平上的差异.     

无锡职教园区餐厨垃圾理化性质调查分析研究

为提高餐厨垃圾厌氧消化效率,应用理化方法分别测试了无锡职教园区大中餐、小中餐、西餐、汤锅和食堂餐厨垃圾的容重、含水率、pH值、有机干物质、含油率、盐分、氮磷含量等指标,此外,应用餐厨垃圾厌氧发酵模拟试验分析其产沼气效率.通过理化性质试验获得不同类型餐厨垃圾理化指标的异同点.通过产沼气试验可知,容积负荷由1 kgVS/m3·d逐渐提升到4 kgVS/m3·d时,日产气量从2.91 L提高到9.01 L,沼气中甲烷含量在65％以上.     

基于改进混合遗传-支持向量机的CMF产水预测研究

将模拟退火思想和加速遗传特性相结合,改进选择策略和遗传算子,建立加速遗传模拟退火算法（AGSA）;基于支持向量机（SVM）的非线性回归和改进混合遗传算法的因子筛选,构造了支持向量机模型参数的自适应优化算法,提出连续微滤系统（CMF）产水预测模型;通过实测中试规模连续微滤系统产水量变化对模型进行验证,结果表明：该模型较好...     

基于磁通量法的空间网架结构无损应力检测的试验方法研究∗

测试在役空间网架结构的轴力或应力是网架结构健康检测的核心内容之一,探究一种实用无损的应力检测方式对在役空间网架结构的健康状况进行合理的评估成为当前工程亟待解决的问题。磁通量法在桥梁索力检测的应用比较成熟,但没有应用于空间结构的杆件应力测试方面主要是由于网架结构杆件在长度、受力性质及约束的影响而使其杆件轴力的测试尚处于研究阶段。据此采用磁通量法对网架结构杆件轴力进行了试验研究。选取了可能影响轴力测试结果的感应线圈绕线匝数、激励线圈绕线匝数、激励电压、荷载工况四个因素开展了一系列的试验研究。结果表明:传感器的绕线匝数、激励电压都会直接影响到电磁感应响度的大小,实际工程中必须选择合适的绕线匝数和激励电压。磁通量传感器在套入杆件后对不同的荷载工况表现出了良好的敏感性,将其运用于杆件的轴力检测是可行的。     

Nanoscale zero-valent iron supported on biochar for the highly efficient removal of nitrobenzene

• Biochar supported nanoscale zero-valent iron composite (nZVI/BC) was synthesized. • nZVI/BC quickly and efficiently removed nitrobenzene (NB) in solution. • NB removal by nZVI/BC involves simultaneous adsorption and reduction mechanism. • nZVI/BC exhibited better catalytic activity, stability and durability than nZVI. The application of nanoscale zero-valent iron (nZVI) in the remediation of contaminated groundwater or wastewater is limited due to its lack of stability, easy aggregation and iron leaching. To address this issue, nZVI was distributed on oak sawdust-derived biochar (BC) to obtain the nZVI/BC composite for the highly efficient reduction of nitrobenzene (NB). nZVI, BC and nZVI/BC were characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS). For nZVI/BC, nZVI particles were uniformly dispersed on BC. nZVI/BC exhibited higher removal efficiency for NB than the simple summation of bare nZVI and BC. The removal mechanism was investigated through the analyses of UV-Visible spectra, mass balance and XPS. NB was quickly adsorbed on the surface of nZVI/BC, and then gradually reduced to aniline (AN), accompanied by the oxidation of nZVI to magnetite. The effects of several reaction parameters, e.g., NB concentration, reaction pH and nZVI/BC aging time, on the removal of NB were also studied. In addition to high reactivity, the loading of nZVI on biochar significantly alleviated Fe leaching and enhanced the durability of nZVI.     

石化企业挥发性有机物排放量核算常见问题分析

石化行业是我国工业源挥发性有机物（VOCs）排放管控的重点行业,也是VOCs排放量核算最为复杂的行业。本文梳理了石化行业12类排放源项VOCs排放核算方法的适用条件,依据广东省重点石化企业VOCs治理实施情况评估所掌握的情况,以实例对比分析的方式,总结了企业在实际VOCs排放量核算方面存在的问题,并就如何提高VOCs排放量核算的真实性和准确性提出了相关建议。     

Internet technology and green productivity in agriculture

The high-quality development of agriculture requires not only sustainable growth of agricultural productivity but also green agricultural production. Internet technology has played an essential role in agricultural production and marketing in China over the past decades. This paper estimates provincial agricultural green growth in China from 1997 to 2019 and decomposes it into technological progress (TP) and efficiency changes (EC) based on the Luenberger productivity indicator method. Then an econometric model is employed to analyze the impact of the Internet on the growth of agricultural green productivity and each sub-component, and moderating role of farmer education in such effect. The empirical results indicated that annual average growth rate of agricultural green productivity in China is 1.33% from 1997 to 2019, and technological progress dominates its growth. The development of Internet technology has a significant positive impact on agricultural green productivity and its decomposition. Farmer education has strengthened the effect of Internet technology on agricultural green productivity and its decomposition TP and EC.

     

Evaluating Green Productivity Gains with the Exponential By-Production Technology: an Analysis of the Chinese Industrial Sector

Environmental Modeling & Assessment - The conventional convexity assumptions frequently placed on piecewise linear frontiers of production technologies modeled using data envelopment analysis...