Adsorption mechanism of phenolic compounds from aqueous solution on hypercrosslinked polymeric adsorbent

The adsorption of two phenols, namely, phenol and salicylic acid(SA) onto a water-compatible hypercrosslinked polymeric resin (NJ-8) were studied in terms of pseudo-second-order and first order mechanisms for chemical sorption as well as an intraparticle diffusion mechanism process. Kinetic analysis showed that the intraparticle diffusion process was the essential rate-controlling step. The activation energies of sorption have also been evaluated with the pseudo-second-order and intraparticle diffusion constants, respectively. Adsorption equilibrium data were well fitted by the Langmuir, Freundlich and Redlich-Peterson isotherms. Adsorption was exothermic and basically of a type of transition between physical and chemical character. The sorption capacity was higher for SA due to its more hydrophobic. Phenol has a higher adsorption enthalpy since it could form stronger hydrogen bonding on NJ-8.     

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。     

Dosing low-level ferrous iron in coagulation enhances the removal of micropollutants, chlorite and chlorate during advanced water treatment

Drinking water utilities are interested in upgrading their treatment facilities to enhance micropollutant removal and byproduct control. Pre-oxidation by chlorine dioxide (ClO₂) followed by coagulation-flocculation-sedimentation and advanced oxidation processes (AOPs) is one of the promising solutions. However, the chlorite (ClO₂^–) formed from the ClO₂ pre-oxidation stage cannot be removed by the conventional coagulation process using aluminum sulfate. ClO₂^– negatively affects the post-UV/chlorine process due to its strong radical scavenging effect, and it also enhances the formation of chlorate (ClO₃^–). In this study, dosing micromolar-level ferrous iron (Fe(II)) into aluminum-based coagulants was proposed to eliminate the ClO₂^– generated from ClO₂ pre-oxidation and benefit the post-UV/chlorine process in radical production and ClO₃^– reduction. Results showed that the addition of 52.1-µmol/L FeSO₄ effectively eliminated the ClO₂^– generated from the pre-oxidation using 1.0 mg/L (14.8 µmol/L) of ClO₂. Reduction of ClO₂^– increased the degradation rate constant of a model micropollutant (carbamazepine) by 55.0% in the post-UV/chlorine process. The enhanced degradation was verified to be attributed to the increased steady-state concentrations of HO^· and ClO^· by Fe(II) addition. Moreover, Fe(II) addition also decreased the ClO₃^– formation by 53.8% in the UV/chlorine process and its impact on the formation of chloro-organic byproducts was rather minor. The findings demonstrated a promising strategy to improve the drinking water quality and safety by adding low-level Fe(II) in coagulation in an advanced drinking water treatment train.     

非水相硝基苯在含水层中的迁移释放规律

通过室内模拟实验,探讨了在非水相硝基苯污染含水层的条件下,其在含水层中的迁移及释放规律。迁移规律表明,非水相硝基苯并非在含水层中直接进行垂向迁移,而是一方面在自身重力作用下向含水层下部迁移,另一方面在地下水流的作用下随地下水同向运移,整体表现为随地下水流的侧向运移,并最终迁移至含水层底部。释放规律表明,非水相硝基苯在含水层迁移的过程中会向地下水大量释放,释放出的硝基苯在水流的作用下随地下水同向运移,污染源及迁移至含水层底部的非水相硝基苯均存在再次释放。     

林丹短期暴露下的斑马鱼(Brachydanio rerio)组织学变化

以斑马鱼(Brachydaniorerio)为受试生物,初步探讨了林丹对斑马鱼的急性毒性以及不同浓度(0.01μg·L-1、1.0μg·L-1、100.0μg·L-1)的林丹暴露36d后对斑马鱼鳃和肝组织结构变化的影响.结果表明,林丹对斑马鱼96h-LC50为97.98μg·L-1,95%可信限为94.38￣101.72μg·L-1.当林丹浓度为0.01μg·L-1时,斑马鱼的鳃和肝组织结构未发生明显变化,而暴露在1.0μg·L-1和100.0μg·L-1林丹溶液中的斑马鱼的鳃和肝组织结构变化显著.斑马鱼鳃组织变化为:上皮细胞残损、脱落,鳃小片上皮细胞水肿,柱细胞变形.斑马鱼肝组织变化为:部分肝细胞肿大,细胞核萎缩变形或偏离细胞中心,胞质疏松,空泡明显增加,细胞质中可见脂沉积.与1.0μg·L-1林丹暴露相比,暴露在100μg·L-1林丹溶液中的斑马鱼鳃和肝组织结构受到的损害更为严重.     

促燃脱硫剂对煤炭清洁燃烧的功效及机理分析

用微机热天平和色谱方法测试和研究了促燃脱硫剂在降低煤炭的着水温度、改善煤炭燃烧特性、减少煤炭燃烧造成的环境污染等方面的节能和环保功效。试验结果表明：ＣＣＳ型燃煤促燃脱硫剂能降低煤炭着火温度３０℃～８０℃,提高煤炭利用率１０％～２５％,固硫率３０％～５０％,且明显降低ＣＯ排放量和排烟黑度。本文初步探讨了其作用机理。     

蔬菜对土壤镉铜锌富集能力的研究

调查了福建部分污染严重地区不同蔬菜对镉、锌、铜的富集能力。结果表明蔬菜对镉的平均富集系数为0.017,锌的平均富集系数为0.116.铜的平均富集系数为0.014。蔬菜对镉的富集系数的品种间差异最大,达315倍,远高于锌和铜的富集系数的品种间差异。茭白、豇豆和莲藕对镉的富集能力较低,可作为镉污染土壤优先选种的蔬菜品种,而青包菜、白包菜、芥菜、空心菜、芋头等对镉的富集系数较高,不宜在镉污染土壤上栽培。     

Biohydrogen production in continuous-flow reactor using mixed microbial culture.

The goal of the proposed project was to develop an anaerobic fermentation process that converts negative-value organic wastes into hydrogen-rich gas in a continuous-flow reactor under different operating conditions, such as hydraulic retention time (HRT), heat treatment, pH, and substrates. A series of batch tests were also conducted in parallel to the continuous study to evaluate the hydrogen conversion efficiency of two different organic substrates, namely sucrose and starch. A heat shock (at 90 degrees C for 15 minutes) was applied to the sludge in an external heating chamber known as a sludge activation chamber, as a method to impose a selection pressure to eliminate non-spore-forming, hydrogen-consuming bacteria and to activate spore germination. The experimental results showed that the heat activation of biomass enhanced hydrogen production by selecting for hydrogen-producing, spore-forming bacteria. The batch feeding at a shorter HRT of 20 hours (or higher organic loading rate) favored hydrogen production, whereas, at a longer HRT of 30 hours, methane was detected in the gas phase. The major organic acids of hydrogen fermentation were acetate, butyrate, and propionate. Up to 23.1% of influent chemical oxygen demand was consumed in biomass synthesis. Batch tests showed that the hydrogen-production potential of starch was lower than sucrose, and better conversion efficiency from starch was obtained at a lower pH of 4.5. However, addition of sucrose to starch improved the overall hydrogen-production potential and hydrogen-production rate. This study showed that sustainable biohydrogen production from carbohydrate-rich substrates is possible through heat activation of settled sludge.     

Probabilistic risk assessment of abalone Haliotis diversicolor supertexta exposed to waterborne zinc

This paper describes a risk assessment approach that integrates predicted tissue concentrations of zinc (Zn) with a concentration-response relationship and leads to predictions of survival risk for pond abalone Haliotis diversicolor supertexta as well as to the uncertainties associated with these predictions. The models implemented include a probabilistic bioaccumulation model, which linking biokinetic and consumer-resource models, accounts for Zn exposure profile and a modified Hill model for reconstructing a dose-response profile for abalone exposed to waterborne Zn. The growth risk is assessed by hazard quotients characterized by measured water level and chronic no-observed effect concentration. Our risk analyses for H. diversicolor supertexta reared near Toucheng, Kouhu, and Anping, respectively, in north, central, and south Taiwan region indicate a relatively low likelihood that survival is being affected by waterborne Zn. Expected risks of mortality for abalone were estimated as 0.46 (Toucheng), 0.36 (Kouhu), and 0.29 (Anping). The predicted 90th-percentiles of hazard quotient for potential growth risk were estimated as 1.94 (Toucheng), 0.47 (Kouhu), and 0.51 (Anping). These findings indicate that waterborne Zn exposure poses no significant risk to pond abalone in Kouhu and Anping, yet a relative high growth risk in Toucheng is alarming. Because of a scarcity of toxicity and exposure data, the probabilistic risk assessment was based on very conservative assumptions.     

滨海石化项目环境综合风险评估方法研究

研究针对国内目前的研究现状,运用环境风险评价指数法建立滨海石化项目环境风险评估体系,采用层次分析法和熵权法结合的组合赋权法,结合专家咨询法进行指标的修改与完善,运用线性加权组合法对评估体系中指标权重的赋值,并计算滨海石化项目的环境风险等级,确定项目的风险强弱.实例分析表明环境风险管理在环境风险的产生和预防占有十分重要的地位,通过加强和完善环境风险的管理体系,结合环境因素的敏感程度及风险源的产生和影响,能降低环境风险及事故的影响程度.