新型地下水及设施的污染控制技术

利用核辐射法治理生物堵塞地下水井,在众多有希望的辐射净水技术中被证明是成功的和具有明显经济效益的工艺方法。描述了此项技术在德国、捷克、美国和俄国的应用和获得的经验．利用核辐射水力屏障法成功地就地净化了被氰化物污染的地下水,使出水中的氰化物浓度降低了一数量级。     

Phytotoxicity of Cyanide to Weeping Willow Trees

Background Cyanide is found predominantly in industrial effluents generated by metallurgical operations. It is an extremely toxic compound, so that problems and catastrophic accidents have recently occurred all around the globe. The goal of this study was to determine the toxicity of cyanide to a Chinese willow species, and to determine the removal capacity. Methods The toxicity of potassium cyanide (KCN) to weeping willow trees (Salix babylonica L.) was tested. The normalized, relative transpiration of the plants was used to determine the phytotoxicity of cyanide. The cyanide removal capacity of weeping willows was also determined. Results and Discussion In hydroponic solution, no chlorosis of leaves and only a small reduction in normalized relative transpiration was observed when weeping willows were exposed to low doses of cyanide (0.93 mg CN/L). Severe signs of toxicity were found for the treatment groups exposed to higher doses of cyanide (9.3 mg CN/L). Weeping willows grown in sandy soils survived the entire period (216 hours) without any toxic effect when irrigated with low doses of cyanide (3.72 mg CN/L). High doses of cyanide (18.6 mg CN/L) in irrigation water were fatal for the weeping willows within 216 hours. EC50 values for a 50% inhibition of the transpiration of the trees were estimated to be between 3.27 and 8.23 mg CN/L, depending on the duration of the exposure. Conclusions The results obtained for the Chinese willow species Salix babylonica were very similar to those obtained for the European species S. viminalis in earlier studies. Phytotoxic effects were only found at high doses of cyanide. A large proportion of applied cyanide was removed from the contaminated media in the presence of weeping willows. This gives rise to the conclusion that the metabolism of cyanide by weeping willows is possible. Recommendations and Outlook Cyanide elimination with trees seems to be a feasible option for cleaning soils and water contaminated with cyanide. A full-scale treatment has been installed in Denmark. For phytoremediation projects in China, weeping willow could be a suitable species. The tree can tolerate and remove cyanide, and it is a native Chinese species. Besides, the tree is of outstanding beauty and is planted as a common park tree in many parts of the world.     

二氧化氯处理含铁氰化物废水的研究

在有助剂焦磷酸钠存在时进行了用二氧化氯处理含铁氰化物废水的研究。实验结果表明 ,在废水pH值为5— 9,焦磷酸钠∶铁氰化物 (摩尔比 ) =1.2∶1,处理时间为 6 0min ,二氧化氯加入量大于理论量 2 0 %的工艺条件下 ,处理后水中总氰化物含量在 0 .5mg/L以下。     

Natural cyanide degradation and impact on Ili River drainage areas from a Goldmine in Xinjiang autonomous region,China

The Ili River is a very important river to the northwest of China and Kazakhstan. The Axi Goldmine is located in the upstream of a branch of the Ili River. The cyanide from the goldmine effluent is a threat to the downstream areas. According to our study, the natural degradation of cyanide conforms to a negative exponential equation in the tailings impoundment, second wastewater pond and even in the receiving streams if the dilution action from other streams were deducted. In the combined action of dilution and natural decomposing, the cyanide from the goldmine effluent does not pose a hazard to the trunk of the Ili River in the normal producing states. The equations of cyanide degradation in the streams and the hydrology parameters could be used to assess the environmental impact on the downstream areas if accidental discharges of cyanide occurred. The available way of decreasing the cyanide impact on the streams is to increase the rate of recycled water so that the lower the wastewater level in the tailing impoundment and the second wastewater pond, the lower is the amount of leakage of wastewater to the streams.     

氮气吹出分离法测定氨化物

本工作对多级串联吹出分离法测定氰化物的可行性作了探讨。试验确定在磷酸－ＥＤＴＡ体系中用氮气吹出分离氰化氢的条件。一次可以同时处理四个样品，富集浓缩效率可达２０倍。标准水样试验结果的平均回收率为９５％，相对标准偏差为１．６—５．３％。环境水样测定结果本方法和标准方法基本相符．     

生物接触氧化法处理腈纶废水研究

腈纶废水中含有氰化物、单体聚合物等有毒有害物质,碱性氧化法、酸性回收法等处理含氰废水,难以达到国家排放标准。上海某腈纶厂采用硫氰酸钠一步法和二步法湿纺工艺生产腈纶,废水处理采用＂加药混凝沉淀法＋生物接触氧化法＂,氰化物、氨氮、COD、BOD5去除率分别为94.5%、89.9%、88.2%、97%,达到污水综合排放一级标准。     

氰化物污染土壤的化学氧化修复方法初步研究

利用漂白粉(Ca(ClO)2)、H2O2、二氧化氯消毒剂(ClO2)作为氧化剂,处理氰化物污染的土壤,使其分解成低毒物或无毒物,据此建立了二氧化氯消毒剂(ClO2)处理含氰土壤的新方法.结果表明,漂白粉大大提高了土壤的pH值,改变了土壤原有的理化性质,H2O2有较好的处理效果但是氧化效率低,综合考虑,选择低浓度ClO2强氧化剂来修复氰化物污染的土壤.同时研究了温度、反应时问、ClO2浓度对反应的影响.结果显示,常温下,0.1%的ClO2为氧化剂,反应时间为45 min时,去除率可以达到55.57%;当ClO2浓度仍为0.1%,将温度升高为65℃.反应时间为30min时,去除率即能够达到98.85%.研究结果表明,该方法对氰化物污染的土壤处理是一种可行的和有效的选择,具有实用意义.     

氰化钠泄漏污染调查及治理方案技术分析

对洛阳市洛宁县“11．1”NaCN泄漏污染吉家洼金矿下游麦张沟河道土壤CN^-残存量进行了布点、采样、化验;对提出的CN^-残存量治理方案,从CN^-的可氧化性、挥发性及生物降解性进行论述;对CN^-的挥发衰减做了模拟试验,结果令人满意。     

焦化废水除氰工艺的优化研究

对某焦化厂生化出水进行了除氰研究。对硫酸亚铁混凝除氰法进行了优化,采用沉淀净化法对其出水进行深度处理,考察了工艺中不同影响因素对总氰化物(TCN)去除效果的影响。结果表明,硫酸亚铁混凝除氰法的最佳反应条件为pH 5.00、FeSO4·7H2O投加量500mg/L、反应时间15min、沉淀时间30min;在此条件下,当原水TCN质量浓度为3.1~4.1mg/L时,出水TCN质量浓度达到0.60~0.70mg/L,需作进一步的深度处理。采用沉淀净化法处理硫酸亚铁混凝除氰法出水的最佳反应条件为先同时投加药剂A和药剂B,投加量分别为150、0.75mg/L,反应15min后,再按2mg/L投加药剂C,继续反应3min,最终出水TCN质量浓度低于0.1mg/L,达到《炼焦化学工业污染物排放标准》(GB 16171—2012)要求(氰化物排放限值为0.2mg/L);在此条件下,单位废水处理的药剂成本合计约为0.25元/t。     

Non-Cancer Health Risk Assessment from Exposure to Cyanide by Resident Adults from the Mining Operations of Bogoso Gold Limited in Ghana

Cyanide is a very toxic chemical that is used to extract gold from its ores. Wastewaters from gold mining companies such as Bogoso Gold Limited (BGL) contain cyanide and other potentially toxic chemicals that have adverse effects on human beings and aquatic organisms. This study was conducted to evaluate the human health risk assessment from exposure to free cyanide via oral and dermal contact of surface/underground water by resident adults within the concession of Bogoso Gold Limited. The chronic non-cancer health risk from exposure to cyanide in River Bogo Upstream is 230 and 43 (by Central Tendency Exposure (CTE) parameters respectively). This means that approximately 230 and 43 resident adults are likely to suffer diseases related to cyanide intoxication via oral and dermal contact respectively. For chronic exposure to River Bogo Downstream by resident adults, the non-cancer health risks are: 0.031 and 0.57 via oral and dermal contact for CTE parameters respectively, which also means that, the non-cancer health risks associated with cyanide intoxication is negligible as the hazard index is less than 1.0 via oral and dermal contacts respectively. The results showed that health risk for acute exposure to cyanide by the resident adults is very high. Hence the residents attribute most of the unexplained deaths in the communities to accidental ingestion and dermal contact of cyanide water.