Monitoring Biofilm Thickness Using A Non-Destructive, On-Line, Electrical Capacitance Technique

Abstact The present study was designed to evaluate indirect, non-invasive, on-line measurement of biofilm thickness using an electrical capacitance technique. Several assays were carried out and the results showed that, at a frequency of 1 kHz, electrical capacitance could be used to measure biofilm thickness indirectly (with a correlation coefficient of 0.9495). The reproducibility revealed by the assays was also highly satisfactory.However, in contrast to what was expected, there was an inverse relationship between electrical capacitance and biofilm thickness, i.e. electrical capacitance diminished with the increase in the biofilm thickness.The tests were also carried out at different frequencies (1 kHz, 10 kHz and 100 kHz)     

Electroosmotic dewatering of dredged sediments: bench-scale investigation

The Indiana Harbor (Indiana, USA) has not been dredged since 1972 due to lack of a suitable disposal site for dredged sediment. As a result of this, over a million cubic yards of highly contaminated sediment has accumulated in the harbor. Recently, the United States Army Corps of Engineers (USACE) has selected a site for the confined disposal facility (CDF) and is in the process of designing it. Although dredging can be accomplished rapidly, the disposal in the CDF has to be done slowly to allow adequate time for consolidation to occur. The sediment possesses very high moisture content and very low hydraulic conductivity, which cause consolidation to occur slowly. Consolidation of the sediment is essential in order to achieve adequate shear strength of sediments and also to provide enough air space to accommodate the large amount of sediment that requires disposal. Currently, it has been estimated that if a one 3-foot (0.9-m) thick layer of sediment was disposed of at the CDF annually, it would take approximately 10 years to dispose of all the sediment that is to be dredged from the Indiana Harbor. This study investigated the feasibility of using an electroosmotic dewatering technology to accelerate dewatering and consolidation of sediment, thereby allowing more rapid disposal of sediment into the CDF. Electroosmotic dewatering essentially involves applying a small electric potential across the sediment layer, thereby inducing rapid flow as a result of physico-chemical and electrochemical processes. A series of bench-scale electrokinetic experiments were conducted on actual dredged sediment samples from the Indiana Harbor to investigate dewatering rates caused by gravity alone, dewatering rates caused by gravity and electric potential, and the effects of the addition of polymer flocculants on dewatering of the sediments. The results showed that electroosmotic dewatering under an applied electric potential of 1.0VDC/cm could increase the rate of dewatering and consolidation by an order of magnitude as compared to gravity drainage alone. Amending the sediment with polymers at low concentrations (0.5-1% by dry weight) will enhance this dewatering process; however, the optimal polymer concentration and the cost-effectiveness of using polymers should be investigated further.     

安全评价方法在危险废物处置环境风险评价中的应用探讨

对安全评价方法在危险废物处置建设项目环境风险评价中的运用进行初步探索。主要用"工艺过程风险因素分析表"对工艺过程潜在风险性识别;用蒙德法进行源项分析;用池火灾模型、蒸气云爆炸伤害模型对易燃、易爆物质的火灾、爆炸等重大事故后果进行计算,得出人员的伤亡半径和财产损失半径等参数,以便于判断风险的可接受水平。分析结果表明:采用安全评价方法对危险废物处置建设项目进行环境风险评价是适用的、可行的。     

兰州市大气污染特征与污染预报技术研究

结合兰州市大气污染特征,采用国际上较为先进的污染预报模式,分别建立了实时资料与数值产品相结合的实用统计预报模型.其系统预报结果准确程度较好,实用性强,时研究兰州市大气污染来源及政府决策都起着重要的作用.     

卫星遥感技术在管理长江流域水资源方面的应用研究

详细讨论了卫星遥感技术在长江流域水资源管理方面的应用问题，提出了两种实用的方法：①卫星遥感技术在灌溉水资源管理方面的应用；②长江流域地下水、地表水资源估算。进一步分析了两种方法的特点，介绍了卫星遥感技术的优点及用途，建议在长江流域水资源管理中加以利用。     

BiOBr分子印迹材料的制备及其降解诺氟沙星性能

为了有效处理低浓度抗生素残留废水,以水热法制备的BiOBr为载体,诺氟沙星（NOR）为模板,通过表面分子印迹法制备了BiOBr分子印迹材料（MIP）.同时,采用SEM与XRD对制备的材料进行相分析及显微结构分析,并利用XPS、FTIR、BET和UV-Vis DRS对所合成材料的微观结构进行观察.最后,以诺氟沙星（NOR）为目标污染物,对MIP在暗反应下的吸附性能及300 W Xe灯照射下的光催化性能进行测定,并探讨pH、投加量、初始浓度、是否印迹处理对NOR去除的影响.实验结果表明,在pH为中性,MIP投加量为2.5 g·L^-1的条件下,MIP对5 mg·L^-1 NOR溶液的去除率达到96.2%,且对低浓度（1 mg·L^-1）NOR溶液的去除率达到99%.综合表明,本文所制备的MIP适用于低浓度诺氟沙星废水的处理.     

焦化废水处理过程中固相物质的形成及处置方法评价

焦化废水处理过程中产生的焦油、污泥和结晶杂盐等固相物质,既有资源属性,又有污染特性,但目前缺乏基于能源、经济及环境影响方面的评估.本研究阐述了3类固相物质的形成机制,建立了质量当量计算及处置方法评价模型.以宝武集团韶关钢铁股份有限公司焦化厂（二期）焦化废水处理工程的A/O/H/O（厌氧/好氧/水解/好氧）流化床工艺作为考察对象,利用工程运行参数和水质统计数据进行固相物质的产量推算,结果发现,焦油、物化污泥、生物污泥（含水率为80%）和工业杂盐的产率分别为0.186、5.80、4.24和1.97 kg·m^-3.通过处置方法评价模型明确了焦油焚烧、污泥热解、结晶杂盐分盐提纯后工业应用是最佳处置方案,在60 m³·h^-1废水处理规模的固相物质处置过程中,每年约产生1177 MWh的能源,获得135.0万元的经济效益,排放627.0 t CO₂,表明能源回收、经济效益和环境影响的协同存在.     

基于野外原位抽注试验和同位素技术的含水层反硝化速率研究

反硝化作用是地下水硝酸盐污染去除最重要的过程.由于水文地质条件和水文地球化学环境的复杂性和不确定性,精准测定含水层反硝化速率是反硝化过程的研究难点.选取潮白河冲洪积扇中部中国环境科学研究院地下水创新野外基地作为研究区,基于野外原位试验和15N同位素示踪法提出一种含水层反硝化速率的测定方法.该方法综合体现了研究区实际水文地质条件和水文地球化学环境对反硝化作用的影响,并充分考虑了硝酸盐在含水层中稀释弥散作用对计算结果的影响.结果表明:①潮白河冲洪积扇中部某地地下26~28 m处于还原环境,含水介质以粉细砂为主,ρ（NO₃-N）平均值为2.77 mg/L.②地下26~28 m反硝化速率在349.52~562.99 μg/（kg·d）（以N计,下同）之间,平均值为450.31 μg/（kg·d）.通过与研究区含水介质、采样深度和硝酸盐背景值相似的国内外案例对比研究,初步评估结果处于合理区间.③测试结果具有一定不确定性,主要来自忽略中间产物NO₂-和NO的计算方法、扰动采样方法、N₂O的操作规范程度及采样频率等方面.研究方法为测定含水层硝酸盐速率研究提供了新的思路,研究结果可为地下水中硝酸盐转化过程机理研究、地下水硝酸盐污染修复及风险管控提供关键的理论支撑数据.      

亚铵法制浆造纸厂中段废水处理技术分析研究

通过对采用两级气浮做预处理 ,生物硫化床串联接触氧化做深度处理的治理技术的分析研究 ,结合废水处理工程实例 ,说明了用两级串联气浮 +硫化床 +接触氧化工艺处理造纸中段水技术切实可靠 ,该治理工艺对处理亚铵法麦草制浆造纸中段废水有较强的针对性和可行性。     

新疆番茄酱企业生产废水处理利用方式探析

近年来,新疆番茄酱加工业得到了迅速发展,目前番茄酱的产销量已占全国的90%以上。与此同时，新疆番茄酱生产企业的废水排放量也大幅增加,大量未经处理的废水直接排放,已对当地的水环境构成严重的污染隐患。本文分析了新疆番茄酱企业生产废水的排放特征与目前排放出路的可行性,并结合新疆的自然地理条件及番茄酱企业的分布情况，着重探讨了土地处理这一适合新疆的废水利用方式,以期有利于新疆的环境保护和废水资源的循环利用。