Utilization of UV‐A and UV‐C radiation in advanced oxidation processes with the intention of removing color and organic matter from the gross leachate of a stabilized sanitary landfill

The present work investigated color and biochemical oxygen demand (COD) removal from treated landfill leachate via advanced oxidative processes (AOPs) artificially emitted. The AOP H₂O₂/UV, TiO₂/UV, and photolysis were tested in two bench‐scale photoreactors: The first one with UV‐C lamp and the other with UV‐A lamp associated or not with coagulation / flocculation pretreatment. Crude leachate samples with pH ranging from 8 to 3 were used, and time varied in 30, 45, and 60 minutes. Experiments were performed in two stages: step 1 with a 20 mL volume from each sample and step 2 with repetition of the best results from the previous step, adopting the 150 mL volume. In step 1, the AOP applied in the crude leachate sample showed the best results, standing out H₂O₂/UV‐C with 30 minutes and TiO₂/UV‐A with 60 minutes. In step 2, H₂O₂/UV‐C had a 60% color removal and 25% COD reduction, while TiO₂/UV‐A had a 10% color removal and 20% COD reduction. Therefore, the H₂O₂/UV‐C process was the most efficient, because the complex characteristics of the effluent interfered in the TiO₂/UV‐A efficiency, but it is necessary to eliminate the process interferences. The use of artificial radiation is a viable alternative; however, it can be costly, being relevant in the associations between processes with artificial UV and solar UV, as the natural radiation becomes more attractive and allows the process operating costs reduction.     

卫生填埋场伊-灰复合土防渗层抗渗性能现场模拟试验研究

以伊（伊利土）－灰（粉煤灰）复合土和普通粘土作为对比进行了卫生填埋场防渗层抗渗性能现场模拟试验,防渗层密度１．８ｇ／ｃｍ＾３,模拟降水强度１．７－２．１ｍｍ／ｍｉｎ,试验结果表明：伊－灰复合土防渗层在抗渗性能上明显优于普通粘土防渗层;模拟降水发生后,卫生填埋场的渗滤液发生期可长达２５ｄ左右,８０５的渗滤液发生于前２／５时段。     

膜生物反应器处理生活污水的试验条件研究

研究了用MBR处理生活污水时,不同曝气时间、不同污泥浓度对生活污水中CODCr去除效果的影响,同时对比了膜出水和上清液的实验数据。实验结果表明,曝气7 h以后系统对CODCr的去除趋于稳定,污泥质量浓度在7-8 mg/L之间时,CODCr可以达到排放标准。操作简单,出水水质稳定,有很强的推广意义。     

Production and the application of anaerobic granular sludge produced by landfill

Sludge granulation is considered to be the most critical parameter governing successful operation of an upflow anaerobic sludge blanket and expanded granular sludge bed (EGSB) reactors. Pre-granulated seeding sludge could greatly reduce the required start-up time. Two lab-scale and a pilot-scale EGSB reactors were operated to treat Shaoxing Wastewater Treatment Plant containing wastewater from real engineering printing and dyeing with high pH and sulfate concentration. The microbiological structure and the particle size distribution in aerobic excess sludge, sanitary landfill sludge digested for one year, and the granular sludge of EGSB reactor after 400 d of operation were analyzed through scanning electron microscopy (SEM) and sieves. The lab-scale EGSB reactor seeded with anaerobic sludge after digestion for one year in landfill showed obviously better total chemical oxygen demand (TCOD) removal efficiency than one seeded with aerobic excess sludge after cation polyacrylamide flocculation-concentration and dehydration. The TCOD removed was 470.8 mg/L in pilot scale EGSB reactor at short hydraulic retention time of 15 h. SEM of sludge granules showed that the microbiological structure of the sludge from different sources showed some differences. SEM demonstrated that Methanobacterium sp. was present in the granules of pilot-scale EGSB and the granular sludge produced by landfill contained a mixture of anaerobic/anoxic organisms in abundance. The particle size distribution in EGSB demonstrated that using anaerobic granular sludge produced by sanitary landfill as the seeding granular sludge was feasible.     

WATER RECLAMATION BY PHYSICOCHEMICAL TREATMENT OF WASTEWATER1

ABSTRACT. Treatment of a high strength acidic industrial chemical waste, which had a COD of about 3000 mg/1 and a pH of 3, was attempted by activated carbon adsorption to evaluate the feasibility of yielding effluents of reusable qualities. The experimental methods which were employed in this investigation included batch and column studies. The former was used to evaluate the rate and equilibrium of carbon adsorption while the latter was used to determine treatment efficiencies and performance characteristics. Parallel operations of fixed-bed and expanded-bed adsorbers were contrasted in the column study. Results of this investication indicate that activated carbon was very efficient in removing the COD of the chemical waste. Initial pH adjustments for the wastewater to 7.0 or 11.4 did not increase the COD removal efficiency. Turbidity and nitrogen (total Kjeldahl- and ammonia-N) were removed to some extents by the carbon bed adsorbers while phosphorus (total-and ortho-P) was totally unaffected by the carbon treatment.     

Applying value analysis and fuzzy logic to select areas for installing waste fills

This article discusses a methodology for assessing and rankinga predefined universe of objects to assist in the selectionof suitable areas for the construction of sanitary landfills.The methodology is, in principle, for universal application. Its development was initially based on the `Value Analysis' methodology and then on the `Fuzzy Eigenvector Method', or `Fuzzy Logic' as it is sometimes referred to. The focus of thestudy herein is on the comparative appraisal of a group ofelements which are part of the guidelines to be adopted whendetermining the choice of the most suitable site for a sanitarylandfill. This set of guidelines includes technical, economical,environmental, social and political aspects. As an example of themethodology proposed, four different areas were chosen. They werestudied to determine which is the most appropriate site for thedevelopment of a new solid waste fill site. The results for thesefour areas, together with the functions chosen and functionweights, are presented here.     

How the multilateral development banks can improve their technology transfer operations for water/sanitation projects in developing countries

Based on some 60 years of consulting practice in the field of environmental/sanitary engineering, about half in the USA and other affluent industrialized countries (ICs) and half with non-affluent developing countries (DCs), the Consultant summarizes the lessons leaned on why the technology transfer (TT) operation of the Multilateral Development Banks (MDBs) and other International Assistance Agencies (IAAs) have failed to achieve effective transfer of appropriate technology to DC practicioners in the environmental/sanitary engineering field, and presents the Consultant’s recommendations on feasible measures by which MDBs can significantly improve their TT operations. Eleven specific measures are recommended, all believed to be feasible for use by MDBs, as follows: (i) post-construction monitoring of project performance, (ii) develop appropriate design criteria for key infrastructure sectors, (iii) be realistic on O&M expectations, (iv) increase infrastructure project budgets to support TT, (v) prepare appropriate technology textbooks, (vi) sponsor graduate university programs in appropriate TT, (vii) sponsor appropriate TT professional journal, (viii) furnish copies of selected 1C references to DC-ers, (ix) sponsor work-type training assignments in ICs, (x) plan TT projects as series of steps, (xi) utilize ratired IC-ers for peripatetic training in DCs.     

深圳玉龙坑垃圾填埋场填埋气体产生量预测研究

通过综合垃圾填埋量、垃圾组分、以及气候特点等因素，采用二阶段复合产气速率模型对玉龙坑填埋场封场前后填埋气体产生量情况进行了预测。预测结果表明玉龙坑填埋场在封场后10年内仍有较大量的填埋气体产生，若不加以妥善处理将会产生安全隐患，若加以利用会产生经济效益。该模型的应用可为垃圾填埋场进行填埋气体产生量预测及收集处理系统的设计、管理提供合理的依据。     

现代卫生填埋工程研究与分析

现代卫生填埋工程是一种安全、有效、有控制地处理城市固体废弃物的方法,其涉及众多学科,属于环境安全、生态安全、工业安全、卫生安全共同关注的问题。城市及工业废料的卫生填埋工程目的是实现减量化、无害化和资源化,形成一个安全、有效、严格控制、环境生态保护,经济化、无害化、资源化科学发展的循环体系。笔者介绍国内外现代卫生填埋工程的研究概况,详细论述现有填埋场的研究内容,指出其中存在的主要问题与不足,并在此基础上探讨了该领域的发展趋势及研究方向。     

单元包封密闭式填埋工艺在阿苏卫垃圾卫生填埋场的探索实践

针对传统垃圾填埋工艺存在分区作业时间长、填埋气引发臭气污染等问题,结合阿苏卫垃圾卫生填埋场实际情况,采用单元包封密闭式填埋工艺,利用旱季垃圾堤坝进行分区填埋操作、渗滤液导排盲沟作为填埋单元分隔、构建填埋气及渗滤液收集系统等技术措施,有效地实现了雨污分流. 实施单元包封密闭式填埋工艺后,2010年填埋场渗滤液产生总量减少了约76 000 t,比前4 a平均产生量减少了35%;填埋气收集量增加了12×106 m3,收集总量比前4 a平均值增加了139%;臭气排放指标达到GB 14554—1993《恶臭污染物排放标准》二级排放标准. 该工艺的实施可以使填埋场运行管理更加规范.