Advanced treatment of wet-spun acrylic fiber manufacturing wastewater using three-dimensional electrochemical oxidation

A three-dimensional electrochemical oxidation(3D-EC) reactor with introduction of activated carbon(AC) as particle micro-electrodes was applied for the advanced treatment of secondary wastewater effluent of a wet-spun acrylic fiber manufacturing plant. Under the optimized conditions(current density of 500 A/m~2, circulation rate of 5 mL/min, AC dosage of 50 g, and chloride concentration of 1.0 g/L), the average removal efficiencies of chemical oxygen demand(COD_(cr)), NH3–N, total organic carbon(TOC), and ultraviolet absorption at 254 nm(UV_(254)) of the 3D-EC reactor were 64.5%, 60.8%, 46.4%, and 64.8%, respectively; while the corresponding effluent concentrations of COD_(cr), NH_3–N, TOC, and UV_(254) were 76.6, 20.1, and42.5 mg/L, and 0.08 Abs/cm, respectively. The effluent concentration of COD_(cr) was less than 100 mg/L, which showed that the treated wastewater satisfied the demand of the integrated wastewater discharge standard(GB 8978-1996). The 3D-EC process remarkably improved the treatment efficiencies with synergistic effects for COD_(cr), NH_3–N, TOC, and UV_(254) during the stable stage of 44.5%, 38.8%, 27.2%, and 10.9%, respectively, as compared with the sum of the efficiencies of a two-dimensional electrochemical oxidation(2D-EC) reactor and an AC adsorption process, which was ascribed to the numerous micro-electrodes of AC in the 3D-EC reactor. Gas chromatography mass spectrometry(GC–MS) analysis revealed that electrochemical treatment did not generate more toxic organics, and it was proved that the increase in acute biotoxicity was caused primarily by the production of free chlorine.     

再生水中的Pb对萝卜根际土壤微生物群落结构的影响研究

采用盆栽方法研究再生水、再生水+Pb、清水+Pb处理浇灌萝卜,以清水浇灌为对照对萝卜根际土壤微生物群落的影响进行研究。结果表明:(1)土壤总PLFA含量及各菌群生物量从大到小依次为:再生水再生水+Pb清水清水+Pb。再生水灌溉有利于萝卜根际微生物各类群数量的增加,丰富微生物多样性。用含铅的溶液(再生水+Pb、清水+Pb)浇灌萝卜,可抑制土壤微生物各类群的数量,G-受到的抑制尤为明显。(2)主成分分析表明,再生水灌溉与对照相比,土壤微生物群落结构差异最大。(3)土壤微生物各类群与土壤速效钾、硝酸盐氮含量呈极显著正相关(P0.01),真菌、放线菌与土壤有机质含量,G~+、G~-菌与p H均呈极显著正相关(P0.01)。G~+、G~-与萝卜地下鲜重均呈极显著负相关(P0.01),土壤微生物各类群与地上部分硝酸盐含量、与根冠比呈极显著正相关(P0.01)。     

利用天然磁黄铁矿去除水中As (V)的研究

考察了时间、pH、温度、吸附剂投加量、无机阴离子等因素对磁黄铁矿去除As(V)过程的影响.同时,对去除过程的动力学和等温线进行分析,并探究了动态去除的效果.结果显示:磁黄铁矿对As(V)的去除在24 h达到平衡;在pH值3~9范围内去除率都达到80%以上;温度升高和吸附剂用量增加都对As(V)去除具有促进作用;PO_4~(3-)、SiO_3~(2-)、CO_3~(2-)对吸附有较强的抑制作用;在As(V)初始浓度为2 mg·L~(-1)时动态吸附出水浓度在150个吸附床体积(BV)内能达到国家饮用水标准;吸附去除过程符合拟二级动力学方程和Langmuir等温方程.能谱仪和X射线电子能谱分析表明,去除过程是一个自发吸热的配位离子交换反应.本实验表明,天然磁黄铁矿是一种有潜力的除砷吸附剂.     

Case Study Comparing Multiple Irrigated Land Datasets in Arizona and Colorado,USA

While there are currently a number of irrigated land datasets available for the western United States (U.S.), there is uncertainty regarding in how they relate to each other. To help understand the characteristics of available irrigated datasets, we compared (1) the Cropland Data Layer (CDL), (2) Moderate Resolution Imaging Spectroradiometer Irrigated Agriculture Dataset (IAD), (3) Digitized Irrigated Land (DIL), and (4) Consumptive Use for Irrigation (CUI) data in Arizona and Colorado, U.S. These datasets were derived from multiple sources at various spatial resolutions and temporal scales. We found spatial and temporal trends among all of them. The datasets showed decreases in irrigated land area in Arizona during the 2000–2010 time period. The change ranges and ratios were similar in all Arizona datasets. Irrigated land in Colorado decreased in DIL and CUI but increased in IAD and CDL. The agreement within the same type of dataset during different time periods was from 60% to 80% (R² from 0.35 to 0.72) in Arizona and from 50% to 80% (R² from 0.23 to 0.68) in Colorado. DIL had the highest agreement (80%) in both states. The agreement among different datasets acquired at approximately the same time frame ranged from 51% to 63% (R² from 0.14 to 0.31) in Arizona and from 47% to 69% (R² from 0.32 to 0.40) in Colorado. The results from this study support a greater understanding of the multiresolution and multitemporal nature of these datasets for various applications.     

浅议石油企事业HSE管理体系文件的编制

分析了企业在HSE管理体系文件的结构和形式、编制原则、步骤和方法上存在的问题,并有针对性地提出了国内石油企业在HSE管理体系文件编制过程中的注意事项。     

应用属性识别模型评价洛阳市大气环境质量

通过将熵值法与属性识别理论相结合,建立了基于熵权的属性识别理论模型,并根据"大气环境质量标准"(GB3095-1996),对洛阳市2005年至2009年的大气环境质量进行了综合评价。结果表明:2005年至2009年洛阳市的大气环境质量均为Ⅱ级。评价结果与模糊数学综合评判法分析结果一致,说明运用属性识别理论应用于大气环境质量评价是合理可信的。     

钢铁企业节水评价指标体系的构建

针对中国钢铁行业尚未建立节水评价指标体系的现状,在广泛查阅资料的基础上,遵循科学合理性、目标导向性、实用性和可比性的原则,构建了钢铁企业节水评价指标体系。指标体系的建立使钢铁企业的节水成效具有横向和纵向可比性,有利于调动企业的节水积极性,促进节水技术的发展和推广,为钢铁企业开展节水工作指明目标和方向。     

反渗透工艺在冷轧废水脱盐处理的应用

利用反渗透工艺对冷轧废水生化处理废水进行处理,获得了较好的脱盐效果。选取进水含盐量、回收率、pH值对系统脱盐率的影响。结果表明:当进水电导率为1 360μs/cm时,系统脱盐率可达94.7%;进水电导率为3 353μs/cm时,系统脱盐率为85.9%。当系统回收率低于77%时,除盐率受其影响较小在90%左右,但是若进一步增加系统回收率,则脱盐效果显著下降。当进水pH值越高脱盐效果越高,但为降低结垢风险,本系统进水pH值控制在7.1左右。     

对生活垃圾焚烧产物中重金属的探讨

以成都某生活垃圾焚烧厂为例,通过实验分别研究了焚烧产物中各主要重金属的含量和浸出毒性,由此分析了生活垃圾焚烧产物中的重金属对城市环境的危害。结果表明,该生活垃圾焚烧厂排放的飞灰和炉渣样品中,镉,铜,铅,锌的含量接近或超过国家土壤环境质量标准三级标准,其浸出液pH呈强碱性,镉和飞灰中铅量超过国家浸出液中危害成分浓度限值标准,在环境中存在潜在危害性。在此基础上探讨了生活垃圾中重金属的来源,提出了可行性建议。     

氢化物发生-原子荧光光谱法测定废水中砷探讨

砷是对人体有害的元素,当人体每天的摄入量超过100ug或更高时,对人体就会产生严重的危害,而有些工业废水中合有一定量的砷元素,如果这些工业废水不经处理排放到水中会我们的身体造成很大程度的伤害,所以我对某工厂的工业废水进行检测,检测其排放废水中所含有砷元素的多少。火焰原子荧光和石墨炉原子荧光的检测能力无法满足测定的要求,...