对氯苯酚废水的电化学降解研究

实验利用电沉积法制备的不锈钢基PbO2电极,以对氯苯酚溶液为模型废水,通过静态实验研究外加电压、电解质浓度、曝气量及初始pH值对电化学氧化降解对氯苯酚效果的影响。结果表明,实验制备的PbO2电极具有较高的电催化活性,能够有效降解对氯苯酚;较低的操作电压有助于降低处理成本;随着电解质浓度和曝气量的增加,对氯苯酚去除率均呈...     

Modeling of a combined ultraviolet-biofilter system to treat gaseous chlorobenzene I: model development and parametric sensitivity

A new type of a combined ultraviolet (UV)-biofilter system for air pollution control is developed. In this paper, two conceptual mathematical submodels of the UV reactor and standalone biofilter are developed. All model parameters have been determined by independent experiments or have been taken from literature. Results from UV and the standalone biofilter submodels are in a good agreement with experimental data. However, the performance of the combined system has significantly deviated from those of the UV or standalone submodels because of the stimulating effects of UV irradiation products on the subsequent biofilter performance. A modified model that considers the stimulating effects has agreed well with experimental data over a wide range of operating conditions. Further analysis of the primary parametric sensitivity of the model has shown that inlet chlorobenzene concentrations, gas empty-bed residence time in the UV reactor, and light intensity are important operating conditions.     

利用甘蔗渣制备微生物絮凝剂的预处理方法研究

通过对甘蔗渣进行不同的预处理,确定了提高纤维素酶糖化率和酱油曲霉发酵液絮凝率的方法.利用正交实验对固液比、颗粒粒径、溶剂浓度和预处理时间及其交互作用进行考察,确定较优的工艺方案.结果表明,在相同条件下,碱处理能够有效提高纤维素酶的糖化率,处理后甘蔗渣的酶解液中还原性糖浓度和酱油曲霉发酵液的絮凝率分别为3.46 g/L和...     

烟气NO氧化催化剂Cu-V/Ti-PILCs的制备及其硫水稳定性

采用等体积浸渍法制备了以钛交联粘土为载体,Cu与V氧化物为活性组分的烟气NO氧化催化剂(Cu-v/Ti-PILCs),并考察了各种制备条件下催化剂的活性及稳定性.结果显示,当V水/V丙酮 =1∶2,负载4%CuO和2%V2O5,并在500℃煅烧时制得的Cu-V/Ti-PILCs催化剂,在NO浓度为350 mg/m3,O...     

油田回注水中优势硫酸盐还原菌的分离鉴定与生理特性研究

从胜利油田回注水中筛选得到一株硫酸盐还原菌,命名为zsz1209。经过16SrDNA序列分析,鉴定zsz1209为梭菌属（Clostridium）。实验研究了zsz109的生理特性,并对通过调节环境pH来抑制菌株zsz1209生长繁殖的可行性进行了探讨。实验结果表明：菌株zsz1209的理想碳源为乙酸钠,在30～60℃之间可较好地生长;SOi浓度低至50mg／L时,生长未受到明显抑制。当培养环境pH高至8．5～9．0或低至3．5～4．0时,检测菌株zsz1209对SO4^2-和碳源（COD）的利用情况,发现zsz1209的生长受到明显抑制,结果表明利用改变环境pH来抑制微生物对油田的腐蚀具有可行性。     

Effect of liquid-to-solid ratio on semi-solid Fenton process in hazardous solid waste detoxication

The liquid-to-solid ratio (L/S) of semi-solid Fenton process (SSFP) designated for hazardous solid waste detoxication was investigated. The removal and minimization effects of o-nitroaniline (ONA) in simulate solid waste residue (SSWR) from organic arsenic industry was evaluated by total organic carbon (TOC) and ONA removal efficiency, respectively. Initially, Box-Behnken design (BBD) and response surface methodology (RSM) were used to optimize the key factors of SSFP. Results showed that the removal rates of TOC and ONA decreased as L/S increased. Subsequently, four target initial ONA concentrations including 100 mg kg⁻¹, 1 g kg⁻¹, 10 g kg⁻¹, and 100 g kg⁻¹ on a dry basis were evaluated for the effect of L/S. A significant cubic empirical model between the initial ONA concentration and L/S was successfully developed to predict the optimal L/S for given initial ONA concentration for SSFP. Moreover, an optimized operation strategy of multi-SSFP for different cases was determined based on the residual target pollutant concentration and the corresponding environmental conditions. It showed that the total L/S of multi-SSFP in all tested scenarios was no greater than 3.8, which is lower than the conventional slurry systems (L/S ? 5). The multi-SSFP is environment-friendly when it used for detoxication of hazardous solid waste contaminated by ONA and provides a potential method for the detoxication of hazardous solid waste contaminated by organics.     

Solid waste management practices in Turkey

As an economically developing country, Turkey has very well operated integrated solid waste management applications structured on modern facilities, besides over 2,000 scattered open dump areas in the country. Integrated waste management applications seem eligible for the metropolitan cities like Istanbul and Izmit (Kocaeli). Attempts have not been encouraging for the scattered regional settlements using central storage sites due to financial shortages and received rejections from nearby settlements. Small-scale compact solid waste management systems with materials recycling and composting can be more suitable alternatives in the small-scale regional settlements. The major constituents of municipal solid waste are organic in nature and approximately a quarter of municipal solid waste is recyclable. Although paper, including cardboard, is the main constituent, the composition of recyclable waste varies strongly by the source or the type of collection point. Solid wastes need primary treatment in order to be suitable for incineration and composting. Turkey needs to give more emphasis on the usage of modern solid waste removal technologies to overcome the overgrowing solid waste disposal problems.     

A study on legislative and policy tools for promoting the circular economic model for waste management in China

The circular economy has been developing rapidly in recent years in China. A legislative system has been created to provide legal protection for the development of a circular economy, including a series of price and tax measures in the waste management area. These measures form the basic foundation for promoting better waste management under the circular economic model. Many challenges, however, remain. For instance, the legal system needs to incorporate more sophisticated science, and China lacks key waste treatment technology that could support the further development of a circular economy. There is also a need to educate the public about the concept of the circular economy and its benefits. Specific suggestions are made for the development and implementation of the circular economic model.     

Biohydrogen using leachate from an industrial waste landfill as inoculum

Since hydrogen is a renewable energy source, biohydrogen has been researched in recent years. However, data on hydrogen fermentation by a leachate from a waste landfill as inoculum are scarce. We investigated hydrogen production using a leachate from an industrial waste landfill in Kanagawa Prefecture. The results showed no methane gas production, and the leachate was a suitable inoculum for hydrogen fermentation. The maximum H₂ yield was 2.67 mol of H₂ per mol of carbohydrate added, obtained at 30°C and an initial pH of 7. The acetate and butyrate production was significant when the H₂ yield was higher. Oxidation–reduction potential analysis of the culture suggested that hydrogen-producing bacteria in the leachate were facultative anaerobic. Scanning electron microscope observations revealed that the hydrogen-producing bacteria comprised bacilli about 2 μm in length.     

Decomposition of dichloromethane and in situ alkali absorption of resulting halogenated products by a packed-bed non-thermal plasma reactor

For an effective decomposition and removal of organic halogenated compounds, a packed-bed non-thermal plasma reactor with in situ absorption of the resulting halogenated products by alkaline sorbent incorporated was proposed. In the plasma reactor, α-Al₂O₃ particles of 1 and 3 mm (mean particle diameter) were packed as solid dielectric medium to enhance the plasma power density in the reactor. Further, alkaline sorbent of Ca(OH)₂ was doped onto the surface of α-Al₂O₃ particles, in order to remove halogenated products by in situ absorption with Ca(OH)₂. A high-voltage and high-frequency pulsed power of −15 to 15 kV and 1 kHz was applied to the wire electrode of the plasma reactor by means of a DC power source. In the present study, as the sample of an organic halogenated compound that is most popularly used, we selected dichloromethane (CH₂Cl₂), and 500 ppm of the initial concentration of CH₂Cl₂ was fed into the reactor accompanied by air at a fixed flow rate of 500 × 10⁻⁶ m³ min⁻¹ at room temperature. As a result, it was recognized that the amount of CH₂Cl₂ decomposed by non-thermal plasma in an α-Al₂O₃ particle bed increased with an increase in plasma input power. The ratio of decomposition of CH₂Cl₂ was almost 100% at 13 kV of electric power and 1 kHz frequency, and CO₂, CH₃Cl, COCl₂, HCl, and Cl₂ were observed as the major reaction products. On the other hand, when CH₂Cl₂ was introduced into the plasma reactor where α-Al₂O₃ particles doped with Ca(OH)₂ were packed, the ratio of decomposition of CH₂Cl₂ became higher, compared to the case that α-Al₂O₃ particles were not doped with Ca(OH)₂. Moreover, there were no halogenated by-product gases detected in the outlet gas from the reactor. As the solid reaction products, CaClOH and Ca(ClO)₂·4H₂O were detected on Ca(OH)₂ by X-ray diffraction. From these findings, it was recognized that CH₂Cl₂ was decomposed more effectively without producing unwanted harmful halogenated by-products in the proposed non-thermal plasma reactor where α-Al₂O₃ particles doped with Ca(OH)₂ sorbent were packed.