摘要
以某焦化厂生化出水为研究对象,考察了金属负载活性炭(简称负载炭)和Fenton氧化预处理等强化活性炭工艺对总氰化物(TCN)的去除效果。在TCN批式实验中,对负载炭的金属离子种类和固定方式进行了考察,同时研究了接触时间、DO对游离氰(KCN配水)、络合氰(K3Fe(CN)6配水)及焦化厂生化出水中TCN的去除效果。结果表明,负载金属离子可以有效提高活性炭对TCN的去除量,KI固定后的载铜活性炭对TCN的去除更有效。吸附作用在活性炭去除TCN过程中起着主要作用,同时TCN在活性炭表面也发生缓慢的催化氧化反应。在穿透实验中,采用了小型炭柱穿透和微型快速穿透实验方法,得到的TCN穿透曲线基本相同。含不同比例原煤炭和负载炭的小型炭柱处理经Fenton氧化预处理的焦化厂生化出水时,在18d的启动阶段后形成生物活性炭柱,其出水能长期达到《城镇污水处理厂污染物排放标准》(GB18918—2002)规定的要求。载铜活性炭可以提高活性炭工艺对TCN的去除能力,确保处理全程(57d)出水的TCN达标。
Activated carbon adsorption employing metal loaded carbon and/or with feed pretreatment was evaluated for removing total cyanide （TCN） from a biotreated coking plant effluent. Series of batch experiments were conducted first to determine the effects of metal loading and fixing methods, contact time and dissolved oxygen （DO） on the carbons＇ capacities for removing cyanide from KCN, K3 Fe（CN）6 solutions and the effluent samples. Metal loading enhanced the base carbon＇s adsorptive capacities for cyanides; the copper loaded and KI fixed carbon （Cu/KIGAC） was the most cost effective among all. Adsorption was the primary mechanism of cyanide removal; catalytic oxidation of the adsorbed cyanide on carbon surface also contributed to the observed removal. Continuous flow break-through experiments were then conducted to compare the TCN removal performance of the base carbon and Cu/KIGAC using the conventional method in small columns and the rapid breakthrough method in micro columns. The two methods produced nearly identical breakthrough curves in the common ranges of bed volume treated. After 18 d of start up in treating Fenton oxidized biotreated coking plant effluent, all four small adsorbers （filled with the base car- bon, two mixed the base and Cu/KI-GAC of different ratios, and Cu/KI-GAC） functioned as a biological activated carbon （BAC） adsorberand produced a high quality final effluent （COD〈 50 mg/L and TCN 〈 0.5 mg/L） that may be discharged directly or recycled for many reuses. The Cu/KI-GAC filled small column produced an effluent with 0.5 mg/L of TCN during the entire 57 d study.
出处
《环境污染与防治》
CAS
CSCD
北大核心
2009年第4期33-37,52,共6页
Environmental Pollution & Control
基金
上海市重点学科建设项目(No.B506)
关键词
焦化废水
总氰化物
金属负载活性炭
吸附
生物活性炭
coking wastewater
total cyanide
metal loaded activated carbon
adsorption
biological activatedcarbon
