A detailed field-based evaluation of naphthenic acid mobility in groundwater

An anaerobic plume of process-affected groundwater was characterized in a shallow sand aquifer adjacent to an oil sands tailings impoundment. Based on biological oxygen demand measurements, the reductive capacity of the plume is considered minimal. Major dissolved components associated with the plume include HCO₃, Na, Cl, SO₄, and naphthenic acids (NAs). Quantitative and qualitative NA analyses were performed on groundwater samples to investigate NA fate and transport in the subsurface. Despite subsurface residence times exceeding 20 years, significant attenuation of NAs by biodegradation was not observed based on screening techniques developed at the time of the investigation. Relative to conservative tracers (i.e., Cl), overall NA attenuation in the subsurface is limited, which is consistent with batch sorption and microcosm studies performed by other authors. Insignificant biological oxygen demand and low concentrations of dissolved As (< 10 µg L^− 1) in the plume suggest that the potential for secondary trace metal release, specifically As, via reductive dissolution reactions driven by ingress of process-affected water is minimal. It is also possible that readily leachable As is not present in significant quantities within the sediments of the study area. Thus, for similar plumes of process-affected groundwater in shallow sand aquifers which may occur as oil sands mining expands, a reasonable expectation is for NA persistence, but minimal trace metal mobilization.     

对苯二甲酸生产废水回用实验研究

采用高级氧化工艺对对苯二甲酸生产废水进行处理,系统考察了氧化剂投加量、废水pH等对处理效果的影响,得出了最佳工艺条件。经过处理的PTA废水,水质达到了车间用水的要求。本方法具有处理效果好、操作简单和环境友好等优点。     

厌氧序批式反应器内挥发性脂肪酸积累特性研究

小试规模的厌氧序批式反应器（ASBR）,通过人工配水,研究了启动3个月时间以及一个运行周期内反应器内挥发性脂肪酸（VFA）的积累情况,并通过分析期间产甲烷活性的变化说明了控制VFA积累的重要性。经过近120 d的运行,乙酸和丙酸的最大比产甲烷活性分别提高了1.8和2.2倍,说明反应器的启动过程即是微生物群落的优化和选择的过程,ASBR的抗冲击的能力较强说明随启动的进行和种群的优化,活性污泥凝聚性能增强,对VFA的降解能力增强。     

Dechlorination of polyvinyl chloride in NaOH/ethylene glycol solution by microwave heating

This study investigated the dehydrochlorination of flexible polyvinyl chloride (PVC) containing 59.2% PVC, 29.7% dioctyl phthalate (DOP), and approximately 12% stabilizers. Flexible PVC was treated with NaOH/ethylene glycol (NaOH/EG) solutions at NaOH concentrations in the range 0.5–4 mol/l and was heated in a microwave heater at a temperature between 100° and 160°C for 0–30 min. All chlorides were completely eliminated by internal heating at 160°C using microwaves for 10 min in a 1 mol/l NaOH/EG solution, and the residue was made up of hydrocarbons. The weight loss rate reached a maximum of 74.7% at a temperature of 160°C. It was discovered that the use of microwaves significantly shortened the reaction time compared to using conventional electric heaters or other external heating systems and also allowed the use of lower concentrations of NaOH. Chemical Feedstock Recycling & Other Innovative Recycling Techniques 6     

The Effect of Masterbatch Addition on the Mechanical, Thermal, Optical and Surface Properties of Poly(lactic acid)

There has been considerable interest in the use of the biodegradable polymer poly(lactic acid) (PLA) as a replacement for petroleum derived polymers due to ease of processability and its high mechanical strength. Other material properties have however limited its wider application. These include its brittle properties, low impact strength and yellow tint. In an attempt to overcome these drawbacks, PLA was blended with four commercially available additives, commonly known as masterbatches. The effect of the addition of 1.5 wt% of the four masterbatches on the mechanical, thermal, optical and surface properties of the polymer was evaluated. All four masterbatches had a slight negative effect on the tensile strength of PLA (3–5% reduction). There was a four fold increase in impact resistance however with the addition of one of the masterbatches. Differential scanning calorimetry demonstrated that this increase corresponded to a decrease in the polymer crystallinity. However there was an associated increase in polymer haze with the addition of this masterbatch. The clarity of PLA was improved through the addition of an optical brightener masterbatch, but the impact resistance remained low. The glass transition and melting temperatures of PLA were not affected by the addition of the masterbatches, and no change was observed in surface energy. Some delay in PLA degradation, in a PBS degradation medium at 50 °C, was observed due to blending with these masterbatches.     

过氯乙烯滤膜采样-酸消解-钼蓝光度法测定磷酸雾

建立了过氯乙烯滤膜采样 -酸消解 -钼蓝分光光度法测定磷化车间磷酸雾的监测方法。实验室模拟采样的捕集效率为 95 7%～ 99 1 %。单个实验室对含 5μg和 1 5μg样品进行多次测定 ,其相对标准差小于 5% ,样品加标回收率为 98 2 %～ 1 0 0 5% ,方法检测限为 0 0 0 7mg/m3。对标样测定 ,结果均在给定值范围内。用该法与等离子发射光谱法(ICP)对 5个样品进行比对测定 ,结果均令人满意。     

胭脂红酸分光光度法测定废水中硼

用胭脂红酸分光光度法测定废水中的硼,着重进行了方法的条件和干扰试验。方法检测限为0.063mg/L,线性范围为0.21mg/L-1.25mg/L。5个实验室对5.00mg/L硼标准样品测得重复性相对标准差为3．4％,再次性相对标准差为3．6％;相对误差为－0．8％－1．4％,回收率在95．2％－104．6％之间。     

青岛市降水中的铅及其变化规律

对青岛市四个站位 1 997年 1 1月～ 1 998年 1 0月 33次降水中铅浓度进行了监测 ,降水中铅浓度在 <0 .5～2 7.7μg/ L之间 ,均值为 4 .2μg/ L,降雪高于降雨。讨论了 p H、交通和季节对铅浓度变化的影响 ,并与其它城市地区降水中铅进行了比较     

硫氰酸盐-抗坏血酸体系流动注射光度法测定水中钼

建立了水中钼的硫氰酸盐一抗坏血酸体系流动注射分光光度测定法,优化了试验条件。方法在0mg／L～16mg／L范围内线性关系良好,检出限为0．19mg／L,废水样品测定的RSD≤I．6％,加标回收率为96．3％～104％,与国家标准方法的测定结果一致。     

环境水系统中氯氟烃替代品降解产物TFA的测定

三氟乙酸为氯氟烃替代品的降解产物,对植物和土壤微生物群落的生长有一定抑制作用.建立测定TFA质量浓度的实验方法,将样品中的三氟乙酸与甲醇在硫酸溶液中衍生化为三氟乙酸甲酯(MTFA),利用三氟乙酸甲酯的易挥发性,以顶空进样进行富集浓缩.使用质谱定性手段确定出峰时间,再通过电子捕捉检测器ECD对实际样品进行分析.仪器检测限为30μg/L,方法检出限约为30ng/L,加标回收率60%～90%.