苎麻骨纤维餐具降解性能研究

为了了解苎麻骨纤维餐具的降解规律,为其规模化生产提供依据,采用活性污泥法对其生物降解性能进行了研究。以生物降解率为考察指标,分析活性污泥对于聚丙烯(PP)、滤纸、苎麻骨纤维餐具、纸浆模塑餐具和塑料淀粉餐具的降解能力。结果表明,在降解期间（28天）,滤纸降解速度最快,纸浆模塑餐具次之,苎麻骨纤维餐具降解程度低于纸制,生物降解率达到60.59%。而聚丙烯餐具和塑料淀粉餐具基本不降解。增加降解物的表面积和提高活性污泥与降解物的比值,有利于苎麻骨纤维餐具的降解。     

城市污泥农用处置研究进展

城市污泥的处置方式主要有农业利用、陆地填埋、焚烧和排海。城市污泥中含有大量的植物营养元素,其土地利用能改善土壤的理化性质,提高作物产量,减少污泥对环境的二次污染,从而实现污泥的资源化、无害化、稳定化和减量化处置目标。虽然城市污泥中含有重金属等有害物质,但大量研究表明,经过无害化处理的城市污泥适量施用不会对土壤环境和作物品质造成影响。城市污泥的农林利用已成为最具潜力的污泥处置方式。     

AHP and fuzzy mathematical method to assess the potential of cleaner production of electroplating enterprises

In order to investigate the effect of quickly decrease temperature on activated sludge system, with the operation of sequence batch reactor (SBR) and mean DO value at 1.5 mg/L, the sludge volume index (SVI) and pollutants removal effect with quickly decreased and return normal temperature were analyzed. The results show that the SVI increases to activate sludge bulking, and activated sludge sedimentation property worsens when the system temperature quickly decreases from 25℃ to 14℃. The SVI slightly decreases, but it cannot return to normal range when system temperature returns to 25℃. The phosphorus and COD removal effects are slightly affected by quickly decreased temperature, whlle the activated sludge nitrification is severely affected by quickly decreased temperature. with the ammonia removal efficiency decreased to 20%. The activated sludge nitrification can return to normal level when system temperature returns to normal temperature.     

壳聚糖与硅藻土调理市政污泥

以污泥比阻为评价指标,综合考虑脱水率、泥饼含水率及过滤时间因素,研究使用壳聚糖与硅藻土对污泥单独调理的最佳条件及联合调理改善污泥脱水性能的效果,并与聚丙烯酰胺调理污泥的效果进行了对比。结果表明,先投加0.5 g/g硅藻土调理污泥,再投加5 mg/g壳聚糖以30 r/min搅拌反应150 s,污泥比阻下降了95.43%,脱水率上升至91.02%,泥饼含水率降至83.13%,过滤时间降至29.5 s。壳聚糖与硅藻土联合调理的效果明显优于壳聚糖或硅藻土单独调理的效果,且其联合调理改善污泥脱水综合性能的效果优于聚丙烯酰胺调理污泥的效果。     

Distribution of PAHs in Phragmites australis in Sludge Drying Reed Bed

The transfer of polycyclic aromatic hydrocarbons (PAHs) from sewage sludge to Phragmites australis and the distribution of PAHs in Phragmites australis were investigated in a field experiment. Tested phragmites australis were planted in a sludge drying reed bed (SDRB) with the size of 3 m×1 m×1.3 m (0.65 m media layer and 0.65 m extra height). The experiment lasted three years including two years' sludge loading and one year's resting period. Totally 8.4 meters surplus activatied sludge with 99.14% of moisture content was feed into the SDRB during loading time, and raw sludge contained 5.69 mg/kg (DW) of total PAHs. Native Phragmites australis contain higher PAHs in the stems and leaves, averaged 2.198 and 2.583 mg/kg (DW) which are 2.44 and 2.87 times of that in the roots, respectively. The results showed that Phragmites australis accumulated PAHs from sludge obviously. Lower molecular weight PAHs are the dominant contents in which of Phragmites australis. According to the experimental results in September, October and November of the second year, the PAHs contents in the roots, stems and leaves of tested Phragmites australis have the trend of increasing with plant growing time; the total PAHs in the roots, stems and leaves are averaged 7.642, 7.713 and 7.946 mg/kg (DW) in November of the third year, which are 8.5, 3.52 and 3.08 times of that in native ones, and also lower molecular weight PAHs are dominant with the percentages of 55.14%, 56.96% and 44.59%, respectively. PAHs contents in Phragmites australis are observed to be significant positive relations with their coarse fat contents and have no relationship with lipid percentages.     

Characteristics and Impact Factors of Sludge Adhesion During Thermal Drying

Sludge adhesion on the inside wall of drying equipments may affect sludge drying performance. Effects of drying conditions on sludge adhesion were investigated by thermal drying experiments. It was found that sludge water content was the main important factor impacting sludge adhesion quantity. When sludge water content decreased with thermal drying, the adhesion quantity increased. The adhesion quantity reached the maximum value when sludge water content decreased to about 60%. The further drying reduced the adhesion quantity gradually. The heating temperature had almost no impact on sludge adhesion when the heating temperature was no higher than 120℃, while the adhesion quantity increased with the increasing heating temperature when the heating temperature was higher than 120℃. Conduction heating would lead to more sludge adhesion compared with convection heating. Rough heating interface would also help sludge adhesion.     

Research on Main Microorganism Groups and Their Ecological Law im Aeration Sludge Composting Process

This paper emphatically probes into main microorganism groups and their characteristics in sewage sludge aeration composition system,and relationships between these groups and the environmental factors.Researches show that there exist interactions between microorganism groups and the environmental factors,such as organic matters,temperature and pH.Organic matters and temperature are two primary factors that effect on variations of microorganism groups. pH is a non-primary environmental factor.It is also found that microbial quantity variation curve in sludge composting process is different from that of in wastewater treatment process.     

中国城市污泥的性质和处置方式及土地利用前景

中国城市污泥产量巨大且成分复杂,如何对它进行合理利用已越来越受人们关注,若处置利用不当会对环境造成二次污染。笔者系统地阐述了中国城市污泥的性质、处置方式与利用现状,讨论了中国城市污泥土地利用的可行性和发展前景。认为将污泥作为肥料或土壤改良剂进行土地修复、林业利用、城市绿化和农田利用是中国城市污泥处置与利用的有效途径,并具有很好的前景。     

Parameter estimation of the carbon oxidation process of the activated sludge model using respirometry

A new hybrid respirometer is used to measure the oxygen uptake rate (OUR) of COD aerobic biodegradation process. Parameter identification and estimation of carbon oxidation process of an Activated Sludge Model are studied by combining the OUR data and mathematical fitting of curves. Coefficients of variation (CVs) for the three combined parameters estimated are below 13% for activated sludge from a laboratory and below 8% for activated sludge from a wastewater treatment plant. For single parameter estimation, the CVs are below 25% and below 10%, respectively. High measurement frequency and precision of the hybrid respirometer can improve the precision of parameter estimation. Initial concentrations of the substrate and the activated sludge of the respirometric experiment are key conditions that must be optimized to obtain high precision parameter estimation due to their effect on OUR curve characteristics.     

Enhanced Hydrolysis of Excess Sludge by Two Surfactants

The hydrolysis efficiency of excess sludge by the two surfactants (SDS and SDBS) was investigated according to COD dissolution rate, concentrations of soluble carbohydrate and soluble protein. The results showed that the hydrolysis of excess sludge was improved by using the two surfactants. When the dosage was in low range, SCOD concentration increased significantly with dosage increasing. But the increase of SCOD was not obvious when the dosage was higher than 50 mg/g dw. SCOD concentration increased from 638.5 mg/L to 6 446.8 mg/L (SDBS) and 4 857.2 mg/L (SDS) respectively. COD dissolution rate increased from 5.8% to 37.3%(SDBS) and 30.2%(SDS) respectively. With the increase of SDS and SDBS dosage in the range of 0~150 mg/g dw, the concentrations of the soluble protein and carbohydrate increased linearly. Soluble carbohydrate increased from 3.54 mg/L to 95.56 mg/L(SDBS) and 64.20 mg/L(SDS) respectively. Soluble protein concentration increased from 11.72 mg/L to 706.30 mg/L(SDBS) and 541.08 mg/L(SDS) respectively. The concentrations of ammonia and VFA also increased with the SDS and SDBS dosage. Ammonia concentrations increased from 4.21 mg/L to 130.33 mg/L(SDBS) and 102.74 mg/L(SDS) respectively. VFA concentrations increased from 21.27 mg/L to 358.30 mg/L(SDBS) and 283.12 mg/L(SDS) respectively.     

Analysis on the Bioleaching Mechanism of Heavy Metal in Sludge by Composite Thiobacillus

The variation of heavy metal speciation during the bioleaching of sludge were carried out. By virtue of heavy metal speciation transformation pattern, the transformation mechanism of heavy metal speciation during the bioleaching could be judged indirectly. The test results show that the bioleaching process of Cu, Ni, Cd are mainly dominated by direct mechanism, the bioleaching process of Zn is mainly dominated by indirect mechanism, and bioleaching process of Cr, Pb are mainly dominated by combined mechanism, while the chemical principle between Cr and Pb are different.     

Effects of Low- Intensity Ultrasound Treatment on Excess Sludge

In this study the influence of the low-intensity ultrasound treatment on excess sludge has been observed.The oxygen uptake rate(OUR),soluble chemical oxygen demand(SCOD),soluble total nitrogen(TN) and soluble total phosphorus(TP) were examined for three power levels of 0.03 W/mL, 0.05 W/mL and 0.1 W/mL as well as two time series of 0~5 min and 0~30 min.It showed that there were two stages of ultrasonic treatment: the first stage took place within the flocs in four minutes,in which SCOD,TN,TP were dissolved from flocs.In the second stage,the microbial activities have been strengthened,as well as OUR,TN,TP have increased greatly.     

活性污泥应用于农业前发酵处理过程中病原菌变化研究

采用黑曲霉为发酵剂对活性污泥进行全程无公害处理并对各种病原菌的生长变化进行监测。结果表明病原菌总量在发酵过程中呈“马鞍型”变化。由于不同堆肥处理组合的C/N比及添加辅料的不同,导致各种病原菌的生长规律出现差异;采用黑曲霉处理城市活性污泥可使病原菌数目减少,但不能达到完全杀灭的目的;对发酵污泥进行200℃高温物理处理后,病原菌存活量为零。因而活性污泥在堆肥后必须经过高温物理处理才能达到安全化和资源化。     

Research on Microbiological Method for Removing Heavy Metal from Sewage Sludge

A great quantity of heavy metal cause trouble when the sewage is used in agriculture as fertilizer. An experiment is carried out on green vitriol and sulfur as culture medium, different dosing ratio of the sewage sludge and inoculated or not the sewage sludge, the effect of heavy metal removal by microbe has been studied. It is shown that the microbes nursed under different environment have better effect on the heavy metal removal and the result of experiments is discussed.     

Effects of Sludge Composting on Bioavailability of Heavy Metals

With form analysis of heavy metals, the transportation experiment and theoretical analysis of heavy metals by simulated rain and acid rain showering were carried out, the effects of sludge composting on Bioavailability of heavy metals in sludge were studied. The results indicated that the ratio of the unsteady species of heavy metals in sludge is reduced after composting. The heavy metal elements in leachate of original sludge treated with acid rain had moved down to the layer of soil with the depth of 16 cm,while the content of heavy metal of treated one is lower and only a small quantity of elements had moved down to the deep layer of the soil. Both the volume and the depth of the composted sludge are lower apparently than those before composting. The experiment and theoretical analysis verified that both the transportation of heavy metals in soil and the bioactivity of heavy metals are reduced by sludge composting.     

Ein Beitrag zur Stickstoffwirkung nach unterschiedlichen Verfahren stabilisierter Klärschlämme*

A distribution to the availability of the nitrogen in sewage sludges stabilized with different processes In two pot experiments the availability of the nitrogen in sewage sludges stabilized with different processes was investigated. Further it was examined whether the Quantofix-N-Volumeter (method for rapid determination of ammonia in slurries) is able to determine the plant available nitrogen in sewage sludge. The following results were obtained: In the experiment where same amounts of total N were applied as sewage sludge a highly significant correlation existed between the amount of NH₄-N applied and the N uptake of the plants. When equal amounts of NH₄-N were applied the N uptake was lowest with the sewage sludges with a high relative part of NH₄-N of the total N (thermophile-aerob; mesophile-anaerob). However the reason for this result was not only the lower application rate of total N with these sewage sludges but also the lower efficiency of the organically bound nitrogen. A very highly significant correlation existed between the application rate of organically bound nitrogen and the N uptake. The values of nitrogen in sewage sludges measured by the rapid method gave information about the plant available nitrogen in the year of application. A close quantitative agreement existed between the available nitrogen determined with the rapid method and the values calculated with the formula of Furrer and Bolliger (1978).