Feedforward control for nitrogen removal in a pilot-scale anaerobic-anoxic-oxic plant for municipal wastewater treatment

To improve the efficiency of nitrogen removal with lower energy consumption, the study of feedforward control was carried out on a pilot-scale anaerobic-anoxicoxic (AAO) plant for the treatment of municipal wastewater. The effluent qualities of the pilot plant under different control strategies were investigated. The results indicated that the change of external recycle was not a suitable approach to regulate the sludge concentration of plug-flow reactors; adjusting the aeration valve and dissolved oxygen set-point according to ammonia load could overcome the impact of influent fluctuation; and the denitrification potential could be estimated based on the transit time of anoxic zone and the relative content of carbon resource entering the anoxic zone. Simple feedforward control strategies for aeration and internal recycle were subsequently proposed and validated. The nitrogen removal was successfully improved in the pilot plant. The effluent total nitrogen had decreased by 29.9% and was steadily controlled below 15 mg·L⁻¹. Furthermore, approximately 38% of the energy for aeration had been saved.     

巴氏醋酸杆菌发酵处理甲醇废水合成细菌纤维素的研究

介绍了巴氏醋酸杆菌以甲醇为唯一碳源、以酵母膏或蛋白胨为氮源合成细菌纤维素,同时净化甲醇废水的方法,并对合成细菌纤维素的培养条件进行了研究。试验得出巴氏醋酸杆菌的适宜发酵条件为：发酵培养基中甲醇质量分数为3．5％左右,发酵培养基初始pH为5．0～6．0。接种量为5％,发酵培养温度为30℃,振荡器转速为100r／min。     

深圳龙岗多媒体环境信息管理系统的总体设计及其技术特点

比较详细地介绍了深圳龙岗多媒体环境信息管理系统的设计思想,设计方法及其研制内容与主要功能,剖析了该系统的技术特点。     

燃煤陶瓷隧道窑的烟气净化技术

主要论述了某陶瓷厂新建成的燃煤隧道窑的除尘脱硫设施。采用湿式除尘脱硫与陶瓷微孔过滤除尘技术相结合 ,同时通过在循环水中加生石灰的方法进行脱硫 ,净化后的烟气通过 35米烟囱排放。经当地环保部门监测 ,净化后的烟气完全达标排放。该套设备除尘效率不低于 94.94% ,平均达到 95 .87% ;脱硫效率不低于 56 .2 5% ,平均达到 63 .69%     

Improved product selectivity of electrochemical reduction of carbon dioxide by tuning local carbon dioxide concentration with multiphysics models

Environmental Chemistry Letters - Electrochemical reduction of carbon dioxide (CO2) is promising to alleviate carbon emissions and produce fuels and materials in a circular way, yet effective...     

A pyrazine based metal-organic framework for selective removal of copper from strongly acidic solutions

● pz-UiO-66 was synthesized facilely by a solvothermal method. ● Efficient capture of copper from highly acidic solution was achieved by pz-UiO-66. ● pz-UiO-66 exhibited excellent selectivity and capacity for copper capture. ● Pyrazine-N in pz-UiO-66 was shown to be the dominant adsorption site. The selective capture of copper from strongly acidic solutions is of vital importance from the perspective of sustainable development and environmental protection. Metal organic frameworks (MOFs) have attracted the interest of many scholars for adsorption due to their fascinating physicochemical characteristics, including adjustable structure, strong stability and porosity. Herein, pz-UiO-66 containing a pyrazine structure is successfully synthesized for the efficient separation of copper from strongly acidic conditions. Selective copper removal at low pH values is accomplished by using this material that is not available in previously reported metal–organic frameworks. Furthermore, the material exhibits excellent adsorption capacity, with a theoretical maximum copper uptake of 247 mg/g. As proven by XPS and FT-IR analysis, the coordination of pyrazine nitrogen atoms with copper ions is the dominant adsorption mechanism of copper by pz-UiO-66. This work provides an opportunity for efficient and selective copper removal under strongly acidic conditions, and promises extensive application prospects for the removal of copper in the treatment for acid metallurgical wastewater.     

水上交通事故分析研究进展

为更好地开展水上交通事故分析研究,提高我国水上交通安全水平,从船舶风险评估与事故预测、事故分析以及事故及通航安全数据的组织与数据库建立3个方面对国内外的相关研究进行论述和分析。提出以建立水上交通事故时空数据平台为基础,结合数据挖掘和安全工程的理论方法研究事故发生机理,评估事故风险,并将研究事故模拟再现技术作为事故分析的重要技术手段。     

Variations in the coral community at the high-latitude Bailong Peninsula,northern South China Sea

Environmental Science and Pollution Research - High-latitude coral communities have attracted much attention due to their potential as refuges during global climate change. However, this function...     

乡村绿色住区示范区污水就地处置回用--黄土高原干旱半干旱乡村绿色住区水资源开发利用研究

探讨了乡村绿色住区污水就地处置技术的可行性,结合西北黄土高原乡村绿色住区示范区建设,设计了黄土高原干旱半干旱乡村聚居区污水就地处置回用的工艺型式.     

高填方多级挡墙路堤变形及稳定性分析

针对高填方路堤回填料分层碾压施工中呈现出超固结、剪胀和时间相依等复杂变形特征,以高填方多级挡墙路堤为例,通过现场勘查、室内试验以及变形监测获得回填土石料的力学性质,分别采用摩尔库仑、修正剑桥以及基于下负荷面的弹粘塑性二次开发本构模型,逐步表征路堤回填料的超固结、剪胀以及时间相依变形行为,并结合单元试验以及现场沉降监测数据反演综合确定三种本构模型材料,对比分析三种本构模型模拟高填方路堤施工及工后变形的差异,最后利用有限元强度折减法分析该高填方多级挡墙路堤的稳定性。计算结果表明:在路堤填筑初期(21 d),基于下负荷面的弹粘塑性模型和修正剑桥模型相比摩尔库仑模型考虑了先期固结应力,计算沉降量结果稍小;随着施工填筑的进行(100 d),一旦超过先期固结应力后,三种模型的沉降量变化逐渐接近;随着时间的增长,仅基于下负荷面的弹粘塑性模型能计算路堤的长期沉降,预测该路堤顶10 a工后沉降17 cm,满足工后沉降要求;同时发现路堤水平侧移呈“S”型内倾的变化特点,且通过有限元法强度折减计算得到边坡稳定性最小安全系数和最危险滑动面,均满足边坡稳定性要求,路堤边坡的失稳预警位移为4.6 cm。