煤化工废水中硫酸盐还原菌的分离及鉴定

从煤化工废水和厌氧污泥中分离出2株高效的硫酸盐还原菌,通过革兰氏染色、扫描电子显微镜观察其形态,通过16S r DNA序列分析法鉴定其种属,并研究其生长特性和硫酸盐还原性能。实验结果表明:菌株SRB-1为革兰氏阴性柠檬酸杆菌;菌株SRB-2为革兰氏阳性丁酸梭菌;两种菌株在最佳条件下培养4 d,菌液菌量均可达到1×106个/m L的水平;在SO2-4质量浓度为1 360 mg/L的条件下,两种菌株的SO2-4去除率分别达到93%和95%。     

马钢煤焦化公司新回收系统的清洁生产工艺和污染控制

介绍了 A - S循环系统脱硫工艺污染控制措施及污染物消减情况     

Modeling of partial nitrification and denitrification in an SBR for leachate treatment without carbon addition

A process of partial nitrification and denitrification in a sequencing batch reactor (SBR) treating leachate was simulated by applying a modified version of activated sludge model no. 3 (ASM3), named ASM3_2step. This model modifies the ASM3 model by separating nitrification and denitrification into two steps with nitrite as an intermediate substrate. Three periods, including long term period, steady state and cycle evolution, were used for calibration. Three main processes were observed, including biomass production, nitrification (focusing on nitrite accumulation) and denitrification. The kinetic and stoichiometric parameters ( m_{\textA_NH} \mu_{{{\text{A\_NH}}}} , Y_{\textA_NH} Y_{{{\text{A\_NH}}}} , Y_{\textA_\textNO2} Y_{{{\text{A}}\_{\text{NO}}_{2} }} , Y_{\textH_\textO2} Y_{{{\text{H}}\_{\text{O}}_{2} }} , b _A, K_{\textA_NH} K_{{{\text{A\_NH}}}} ), were determined from biokinetic and respirometry tests. Some of the default values of kinetic and stoichiometric parameters available in the ASM3 model and in the literature were kept constant, while some others were adjusted step by step until observed state variables fit with experimental data. The maximum specific growth rate of nitrite oxidizing bacteria (0.108 day⁻¹) (simulated by the model) and that of ammonium oxidizing bacteria (0.61 day⁻¹) (from biokinetic tests) are the parameters which have the highest influence on the nitrite accumulation, even more than oxygen supply intensity or Kla value. Other important parameters were K_{\textAO_NH} K_{{{\text{AO\_NH}}}} and K_{\textAO_\textNO2} K_{{{\text{AO}}\_{\text{NO}}_{2} }} , calibrated at the values of 1.37 and 1.59 mg O₂/L, respectively. The modified model and values of the kinetic and stoichiometric parameters obtained from the modeling process will be used for optimization of the partial nitrification in the next study.     

活性焦烟气脱汞的试验研究与数值模拟

采用固定床吸附系统,对自制褐煤活性焦的脱汞性能进行了试验研究,研究发现自制活性焦对烟气中Hg0有一定的吸附能力,随着Hg0的入口浓度的增加,活性焦质量的增加,活性焦的吸附量也在增加。40mg时3号活性焦由10ng/min汞入1：2浓度时26．68％的最大吸附效率提高到40ng／min汞入口浓度时的53．12％。10ng/min汞入口浓度时3号活性焦在40mg时的最大吸附效率为26．68％,而在80mg时吸附效率提高到43．2％。烟气中的SO2、NO气体对活性焦吸附汞有一定的促进作用。在试验的基础上建立了固定床吸附系统的数学模型,基于Lan—mguir吸附系数,考虑吸附过程中颗粒内、外的传质控制过程,建立质量平衡方程。通过Matlab模型计算,计算结果与试验结果基本吻合,计算的活性焦脱汞效率要优于试验数值,计算的是理想情况下活性焦对汞的吸附效率,实际情况会有所降低。     

我国石煤提钒废水的处理现状与展望

石煤提钒废水中含有大量的重金属、氨氮和盐类。介绍了石煤提钒中重金属废水、氨氮废水、高盐废水的处理技术,总结了各种废水处理技术在石煤提钒废水治理中的应用现状,并对石煤提钒废水的治理进行了展望。化学法应用广泛,但易造成二次污染;物理法具有广阔的应用前景,但处理效率低;生物法具有效率高、选择性强、废水处理成本低等优点,是一种极具发展潜力的废水治理方法,应加大在石煤提钒废水治理方面的研究。     

我国现代煤化工项目废水处理的误区和建议

介绍了我国现代煤化工项目的废水来源及特性,归纳了废水的处理技术路线,从废水"零排放"、废水处理技术与管理、蒸发塘的污染转移、废水处理与固体废物处理及废气处理的关系、污染物源头控制等方面阐述了我国当前煤化工废水处理存在的误区和建议。     

壳聚糖的絮凝性能及其在废水脱色处理中的应用

介绍了壳聚糖的理化性质及其作为絮凝剂的优点,探讨了壳聚糖的絮凝机理,分析了壳聚糖絮凝效果的影响因素(包括废水p H、絮凝温度、搅拌转速及时间、壳聚糖投加量、壳聚糖脱乙酰度及相对分子质量、废水浊度),总结了壳聚糖改性和复合后在废水脱色处理中的应用。指出:未来还需更深入地研究絮凝机理,同时也需进一步研究影响絮凝效果的因素;新型壳聚糖絮凝剂将向更高效、成本更低且环境友好的方向发展。     

彭城电厂废水零排放的实施及问题探讨

针对目前水资源短缺状况，以彭城电厂为例提出了利用废水和灰场回收水作循环冷却水补充水的优化方案。并就废水零排放的实施及运行中发现的问题进行了分析与探讨。     

Clay-sewage sludge co-pyrolysis. A TG-MS and Py-GC study on potential advantages afforded by the presence of clay in the pyrolysis of wastewater sewage sludge

Wastewater sewage sludge was co-pyrolyzed with a well characterized clay sample, in order to evaluate possible advantages in the thermal disposal process of solid waste. Characterization of the co-pyrolysis process was carried out both by thermogravimetric-mass spectrometric (TG-MS) analysis, and by reactor tests, using a lab-scale batch reactor equipped with a gas chromatograph for analysis of the evolved gas phase (Py-GC).Due to the presence of clay, two main effects were observed in the instrumental characterization of the process. Firstly, the clay surface catalyzed the pyrolysis reaction of the sludge, and secondly, the release of water from the clay, at temperatures of approx. 450-500 °C, enhanced gasification of part of carbon residue of the organic component of sludge following pyrolysis.Moreover, the solid residue remaining after pyrolysis process, composed of the inorganic component of sludge blended with clay, is characterized by good features for possible disposal by vitrification, yielding a vitreous matrix that immobilizes the hazardous heavy metals present in the sludge.     

Degradation of poly(3-hydroxybutyrate), PHB,by bacteria and purification of a novel PHB depolymerase fromComamonas sp.

Bacteria capable of growing on poly(3-hydroxybutyrate), PHB, as the sole source of carbon and energy were isolated from various soils, lake water, activated sludge, and air. Although all bacteria utilized a wide variety of monomeric substrates for growth, most of the strains were restricted to degrade PHB and copolymers of 3-hydroxybutyrate and 3-hydroxyvalerate, P(3HB-co-3HV). Five strains were also able to decompose a homopolymer of 3-hydroxyvalerate, PHV. Poly(3-hydroxyoctanoate), PHO, was not degraded by any of the isolates. One strain, which was identified asComamonas sp., was selected, and the extracellular depolymerase of this strain was purified from the medium by ammonium sulfate precipitation and by chromatography on DEAE-Sephacel and Butyl-Sepharose 4B. The purified PHB depolymerase was not a glycoprotein. The relative molecular masses of the native enzyme and of the subunits were 45,000 or 44,000, respectively. The purified enzyme hydrolyzed PHB, P(3HB-co-3HV), and—at a very low rate—also PHV. Polyhydroxyalkanoates, PHA, with six or more carbon atoms per monomer or characteristic substrates for lipases were not hydrolyzed. In contrast to the PHB depolymerases ofPseudomonas lemoignei andAlcaligenes faecalis T₁, which are sensitive toward phenylmethylsulfonyl fluoride (PMSF) and which hydrolyze PHB mainly to the dimeric and trimeric esters of 3-hydroxybutyrate, the depolymerase ofComamonas sp. was insensitive toward PMSF and hydrolyzed PHB to monomeric 3-hydroxybutyrate indicating a different mechanism of PHB hydrolysis. Furthermore, the pH optimum of the reaction catalyzed by the depolymerase ofComamonas sp. was in the alkaline range at 9.4.     

Analysis of metals and EOX in sludge from municipal wastewater treatment plants: a case study

The monitoring of extractable organic halogen (EOX) and heavy metal contents in sludge coming from 10 different municipal wastewater treatment plants (MWWTP) located in Friuli Venezia Giulia (Italy) is reported. In this work, sludge samples drawn from sludge treatment units have been digested and analyzed by Inductively Coupled Plasma-Mass Spectrometry (ICP-MS) for metal evaluation. Samples were also extracted and analyzed by microcoulometric titrations, following modified DIN 38414 T17 standard, for EOX analysis. Analytical results showed a slight enrichment of the contents of certain metals (Cd< 2mg/kg, Cr< 51.5mg/kg, Cu<105.8 mg/kg, Hg<1.4 mg/kg, Ni<35.9 mg/kg, Pb<58.7 mg/kg, Zn<410.1 mg/kg, Ba<317.1 mg/kg, Co<1 mg/kg, Mo< 5 mg/kg, Mn<106.7 mg/kg), so almost all of the sludge would be suitable for agricultural use following Italian and European regulations. The evaluation of EOX was carried out by using hexane and ethyl acetate as extraction solvents, and a measurable organic halogen content (ranging from 0.31 to 39.5 mg Cl/kg DM) was clearly detected in the sludge. The lowest concentrations of EOX were found in sludge coming from the smallest MWWTPs, which is to be considered more suitable for agricultural use. Additionally, analytical assays on composts, peat and soils were performed to compare EOX concentrations between these matrices and sludge.     

The development of WEEE management and effects of the fund policy for subsidizing WEEE treating in China

The consumption of electrical and electronic equipment is surging, so is the generation of waste electrical and electronic equipment (WEEE). Due to the large quantity, high potential risk and valuable capacity of WEEE, many countries are taking measures to regulate the management of WEEE. The environmental pollution and human health-harming problems caused by irregular treatment of WEEE in China make the government pay more and more attention to its management. This paper reviews the development of WEEE management in China, introduces the new policy which is established for WEEE recycling and especially analyzes the effectiveness of the policy, including huge recovery, formation of new recycling system, strict supervision to related enterprises, and the stimulation to public awareness. Based on the current achievement, some recommendations are given to optimize the WEEE management in China.     

Study to improve the reactivity of magnesium cations to CO2 for carbon capture and utilization technology using edible salt manufacturing plant wastewater

Journal of Material Cycles and Waste Management - This study aims to improve the formation of MgCO3 via inorganic carbon capture utilization (CCU) technology using industrial wastewater from an...     

Germination test on Komatsuna (Brassica rapa var. peruviridis) seed using water extract from compost for evaluating compost maturity: evaluating criteria for germination and effects of cultivars on germination rate

Germination tests on the Komatsuna (Brassica rapa var. peruviridis) seed using water extract from compost has often been performed in Japan to evaluate compost maturity; however, most of the germination tests have been carried out without using any rationally defined experimental criteria to determine germination and to explain the influence of cultivars. Here, we performed a series of germination tests to examine the applicability of the experimental criteria for germination and the influence of cultivars on germination rate. Germination rate varied according to the criteria introduced in this paper, and two criteria, "seed size (3)" and "5?mm (2)", were selected for testing. In addition, two types of inhibitory influence, stop and slowness, were observed and compared with the criteria. The logistic regression curve of Logit, a function of germination rate to logarithmic value of the dilution ratio of the water extract was parameterized to compare the effects of the cultivars on germination rate. The statistical analysis of the parameters showed that dilution ratio greatly influenced germination rate, and the cultivar itself also influenced the rate. Consequently, the specific experimental criteria for germination and determining the influence of cultivars were proven to be indispensable for evaluating compost maturity using the germination test.     

The use of failure mode and effects analysis to construct an effective disposal and prevention mechanism for infectious hospital waste

In recent times, the quality of medical care has been continuously improving in medical institutions wherein patient-centred care has been emphasized. Failure mode and effects analysis (FMEA) has also been promoted as a method of basic risk management and as part of total quality management (TQM) for improving the quality of medical care and preventing mistakes. Therefore, a study was conducted using FMEA to evaluate the potential risk causes in the process of infectious medical waste disposal, devise standard procedures concerning the waste, and propose feasible plans for facilitating the detection of exceptional cases of infectious waste. The analysis revealed the following results regarding medical institutions: (a) FMEA can be used to identify the risk factors of infectious waste disposal. (b) During the infectious waste disposal process, six items were scored over 100 in the assessment of uncontrolled risks: erroneous discarding of infectious waste by patients and their families, erroneous discarding by nursing staff, erroneous discarding by medical staff, cleaning drivers pierced by sharp articles, cleaning staff pierced by sharp articles, and unmarked output units. Therefore, the study concluded that it was necessary to (1) provide education and training about waste classification to the medical staff, patients and their families, nursing staff, and cleaning staff; (2) clarify the signs of caution; and (3) evaluate the failure mode and strengthen the effects.     

The effects of external costs on the system selection for treatment and disposal of municipal solid wastes: a deterministic case study for a pre-assessment

Journal of Material Cycles and Waste Management - Selecting a system for treatment and disposal of municipal solid wastes (i.e., selection of the capacity, location and type of the processes and...     

Possibility of using municipal solid waste for manufacturing wood-plastic composites: effects of natural weathering,wood waste types,and contents

Journal of Material Cycles and Waste Management - This work aimed to investigate the effects of wood waste types (twigs, leaves, and palm fronds) and contents (ranging from 40 to 60 wt%) on the...     

An assessment of the current and future options for domestic waste management in Kaunas, Lithuania.

The main purpose of this study was to carry out a retrospective analysis of solid waste generation in Kaunas city from 1994 to 2003 and to calculate the theoretical waste generation in the future. This paper also presents measurements of the annual variations of waste amounts and calculations on a theoretical waste incineration facility. Two waste treatment scenarios were considered. Scenario A: waste deposit at the landfill with 'implementation of domestic waste separation and recycling'. Scenario B: waste removal to a landfill with 'multi-treatment: household separation, recycling and energetic recovery'. Three levels of waste treatment were proposed. The first level was implementation of the recycling system, which included household waste separation. The next step involved mechanical-biological treatment. The third level was the construction and operation of a new waste incineration plant in Kaunas. Two sites in Kaunas city were proposed; however, more detailed analysis, including the economic factors, will need to be done.     

Preferential flow in municipal solid waste and implications for long-term leachate quality: valuation of laboratory-scale experiments.

In this paper, we study and quantify pollutant concentrations after long-term leaching at relatively low flow rates and residual concentrations after heavy flushing of a 0.14 m3 municipal solid waste sample. Moreover, water flow and solute transport through preferential flow paths are studied by model interpretation of experimental break-through curves (BTCs), generated by tracer tests. In the study it was found that high concentrations of chloride remain after several pore volumes of water have percolated through the waste sample. The residual concentration was found to be considerably higher than can be predicted by degradation models. For model interpretations of the experimental BTCs, two probabilistic model approaches were applied, the transfer function model and the Lagrangian transport formulation. The experimental BTCs indicated the presence of preferential flow through the waste mass and the model interpretation of the BTCs suggested that between 19 and 41% of the total water content participated in the transport of solute through preferential flow paths. In the study, the occurrence of preferential flow was found to be dependent on the flow rate in the sense that a high flow rate enhances the preferential flow. However, to fully quantify the possible dependence between flow rate and preferential flow, experiments on a broader range of experimental conditions are suggested. The chloride washout curve obtained over the 4-year study period shows that as a consequence of the water flow in favoured flow paths, bypassing other parts of the solid waste body, the leachate quality may reflect only the flow paths and their surroundings. The results in this study thus show that in order to improve long-term prediction of the leachate quality and quantity the magnitude of the preferential water flow through a landfill must be taken into account.