Roles of manganese oxides in degradation of phenol under UV-Vis irradiation: Adsorption, oxidation, and photocatalysis

The effect of crystal structure on photocatalytic activities of manganese oxides and underlying reaction mechanism were investigated.     

人工湿地处理污水的研究

简要介绍了人工湿地的发展历史、原理及优点；并对沙井镇人工湿地进行探讨和检测，其ＣＯＤｃｒ去除率可达８３％，总氮去除率达４５％，出水水质达国家排放标准。     

Influence of low molecular weight anionic ligands on the sorption of heavy metals by soil constituents: a review

Environmental Chemistry Letters - The sorption of heavy metals by soil constituents reduces the absorption of these pollutants by crops and vegetables, and thus limit food contamination. Low...     

灰关联分析在故障树诊断中的应用

介绍一种灰色诊断法。在故障诊断模式识别中,运用灰关联分析,依据故障树的底事件重要度,通过关联度计算及排序,对故障树分析中,各种故障模式发生的可能性大小作出了准确的判断,从而为处理事故的先后、缓急提供了依据。     

Performance of completely autotrophic nitrogen removal over nitrite process under different aeration modes and dissolved oxygen

In this study, three sequential batch biofilm reactors (SBBRs) were operated for 155 days to evaluate the performance of completely autotrophic nitrogen removal over nitrite (CANON) process under different aeration modes and dissolved oxygen (DO). Synthetic wastewater with 160-mg NH4 ⁺-N/L was fed into the reactors. In the continuously-aerated reactor, the efficiency of the ammonium nitrogen conversion and total nitrogen (TN) removal reached 80% and 70%, respectively, with DO between 0.8–1.0 mg/L. Whereas in the intermittently-aerated reactor, at the aeration/non-aeration ratio of 1.0, ammonium was always under the detection limit and 86% of TN was removed with DO between 2.0–2.5 mg/L during the aeration time. Results show that CANON could be achieved in both continuous and intermittent aeration pattern. However, to achieve the same nitrogen removal efficiency, the DO needed in the intermittently-aerated sequential batch biofilm reactor (SBBR) during the aeration period was higher than that in the continuously-aerated SBBR. In addition, the DO in the CANON system should be adjusted to the aeration mode, and low DO was not a prerequisite to CANON process.     

印染污泥连续过滤压榨过程

研究了连续进料情况下,过滤压力、压榨起始点和压榨压力对印染污泥过滤效果的影响。研究发现,提高过滤压力可以改善过滤效率,缩短过滤时间,但滤饼含水率并无明显影响。过滤压力0.6 MPa下过滤2.3 h后滤液量达到2 900 g,此时过滤进入压密阶段。结果表明,若适当提前压榨,可在滤饼含水率变化不大的情况下显著缩短过滤时间,且该污泥在滤液量为2 750 g时开始压榨,滤饼含水率仅提高约1%,而过滤时间缩短为原来的87%(2 h)。进一步研究压榨压力对污泥脱水的影响,发现提高压榨压力也可以提高滤液流速,降低滤饼含水率,但因为在高压下更容易发生絮体破裂成细微粒子等现象,使过滤介质堵塞或滤饼中的一些孔变成盲孔,所以过高的压力不仅不能起到提高压榨效率的作用,反而会使滤饼含水率有所上升,且该污泥的最佳压榨压力为2.5 MPa。     

粉煤灰、电石渣及其配合物碳酸化特性

为了促进粉煤灰和电石渣建材化高效利用和协同矿化CO2减排,研究了粉煤灰、电石渣及其配合物的碳酸化特性。实验采用pH在线测试方法分别对粉煤灰、电石渣以及两者配合物的碳酸化过程的pH进行在线测试,并对原料和产物进行XRD、TGA和SEM表征。结果表明：相同条件下,粉煤灰碳酸化浆液pH降到7.0的平均速度约为电石渣的51倍;与等量电石渣单独碳酸化相比,粉煤灰与电石渣按照4:1（质量比）复配碳酸化pH降低到7.0的速度较纯电石渣提高了近5.6倍,且在相同电石渣配量的条件下,粉煤灰-电石渣复配料比碳酸钙-电石渣复配料的碳酸化反应完成时间缩短了31.6%,说明电石渣与粉煤灰复配后进行碳酸化反应具有明显协同促进作用。TGA分析表明,纯粉煤灰和纯电石渣的固碳率分别约为2%和61.3%,粉煤灰与电石渣复配料的固碳率较等量单一电石渣和粉煤灰的固碳率之和的计算值提高了19.6%。SEM分析表明,粉煤灰与电石渣复配料碳酸化产物碳酸钙颗粒在粉煤灰表面呈现异位分散附着形态,而单一电石渣碳酸化产物碳酸钙则在电石渣颗粒表面呈现原位聚集附着形态。这可能是复配料固碳率提高的主要原因。     

一种高速反硝化颗粒污泥的培养

以葡萄糖为碳源,在USB反应器内接种好氧活性污泥在40 d内培养出良好的反硝化颗粒污泥.颗粒污泥形成经历了2个阶段:起始阶段,接种的好氧活性污泥中非反硝化菌逐渐衰亡演变为"惰性固体",与原有的固体一起,成为反硝化菌附着生长的载体,与此同时,反硝化菌在载体表面渐渐繁殖,形成细颗粒污泥;随后,反硝化菌在细颗粒污泥表面不断增殖,颗粒长大,发育成为成熟的颗粒污泥.成熟的颗粒污泥密实,表面均为杆状菌,且排列紧密,当污泥床容积负荷为19.1 g N/L·d时,去除率高达98.4%(N).     

Cost-performance analysis of nutrient removal in a full-scale oxidation ditch process based on kinetic modeling

A full-scale oxidation ditch process for treating sewage was simulated with the ASM2d model and optimized for minimal cost with acceptable performance in terms of ammonium and phosphorus removal. A unified index was introduced by integrating operational costs (aeration energy and sludge production) with effluent violations for performance evaluation. Scenario analysis showed that,in comparison with the baseline (all of the 9 aerators activated), the strategy of activating 5 aerators could save aeration energy significantly with an ammonium violation below 10%. Sludge discharge scenario analysis showed that a sludge discharge flow of 250–300 m3/day (solid retention time (SRT), 13–15 days) was appropriate for the enhancement of phosphorus removal without excessive sludge production. The proposed optimal control strategy was: activating 5 rotating disks operated with a mode of "111100100" ( "1"represents activation and "0" represents inactivation) for aeration and sludge discharge flow of 200 m3/day (SRT, 19 days). Compared with the baseline, this strategy could achieve ammonium violation below 10% and TP violation below 30% with substantial reduction of aeration energy cost (46%) and minimal increment of sludge production (< 2%). This study provides a useful approach for the optimization of process operation and control.     

底泥原位洗脱过程中氮磷含量与形态变化特征

随着城市化进程的不断推进,城市河流底泥中内源氮磷污染问题日益突出.为研究原位洗脱技术对污染底泥中氮、磷物质和成分的作用效果,以北京市凉水河作为研究对象,分别比较了现场试验洗脱与对照组0~30 cm分层底泥以及实验室模拟洗脱处理前后0~10 cm底泥中pH、E_h（氧化还原电位）、容重、含水率、OM（有机质）、TN、TP和氮、磷形态分布的变化特征.结果表明:①现场洗脱对0~5 cm厚度底泥的处理和模拟洗脱处理均对底泥中pH、E_h、含水率的改变以及其中TN、TP的去除效果表现显著,其中,现场试验洗脱组0~5 cm范围底泥中w（TN）、w（TP）分别较对照组降低了66.4%±17.4%、40.8%±24.4%,模拟洗脱处理对底泥中OM、TN、TP的去除率分别达70.1%±4.8%、66.8%±2.0%、43.1%±3.1%.②原位洗脱技术对底泥中TN的去除主要通过对PON（颗粒态有机氮）的去除来实现,现场和模拟试验过程中PON对TN去除的贡献率分别达55.0%和73.6%.③原位洗脱对底泥中TP的去除主要通过对Al-P（铝结合态磷）、OP（有机磷）的去除来实现,现场和模拟试验中Al-P、OP对TP去除的贡献率分别达37.0%、66.2%和31.3%、43.7%.研究显示,原位洗脱技术可有效去除城市河流底泥处理层中的氮磷物质,并以有机氮、磷物质的去除为主.