高品质再生水专用管网材质的选择

北京某再生水厂采用微滤+反渗透工艺生产高品质工业用再生水,并使用球墨铸铁内衬水泥砂浆材质的输送管网,在实际应用中出现了出厂水水质较好但输送至用户端时水质变差的现象。通过试验分析发现,上述现象是由于再生水自身特点与输送管材不匹配而导致的,再生水的酸碱缓冲能力较弱、化学稳定性较差,而管网水泥砂浆内衬表层的易溶性碱性物质含量较高,再生水对管网产生了腐蚀。对此从两方面进行改进:①在出厂水中投加NaOH将pH值调至7左右再进入输水管网,同时投加NaClO消毒剂以保证管网末端余氯值;②在再生水二期管网建设中改用耐腐蚀性更强的PE管。

Enhanced Field Emission from Printed Carbon Nanotubes by Hard Hairbrush

A method, the morphology of screen printed carbon nanotube pastes is modified using a hard hairbrush, is presented. In this way, the organic matrix material is preferentially removed. Compared to those untreated films, the turn-on electric field of the treated film decreases from 2.2V/μm to 1.6V/μm, while the total emission current of the treated increases from 0.6mA/cm2 to 3mA/cm2, and uniform emission site density image has also been observed.

给水管网中氯酸根和亚氯酸根消减因素研究

采用二氧化氯消毒的给水管网中氯酸根和亚氯酸根浓度在管网前后端存在明显差异,研究了管网中各因素对水中消毒副产物转化的影响,并在此基础上分析给水管网中氯酸根和亚氯酸根浓度的消减模型。研究结果表明,各因素中碳酸钙吸附和管网材质对氯酸根和亚氯酸根浓度的影响最大。在20℃、p H值=7、氯酸根或亚氯酸根初始浓度为1.5 mg/L时,碳酸钙对氯酸根和亚氯酸根的吸附率分别为23.3%、38.0%,纯铁管材管网中氯酸根和亚氯酸根的消减率分别为43.3%和48.0%。温度、p H值和紫外照射对氯酸根的影响微弱,而在30℃、p H值=5和紫外照射下的亚氯酸根分解率最高。