国际通用卫生填埋技术规范的实践与探索

深圳市下坪固体废弃物填埋场按九十年代国际通用的卫生填埋技术规范和标准设计建设 ,经几年的工程建设和垃圾填埋运行管理实践中 ,在人工水平防渗结构层的设计、渗滤液处理工艺、虫害控制、填埋区清污分流及分层压实覆盖技术等方面取得了重大的研究突破 ,探索出适合我国国情的现代化卫生填埋技术规范和运作管理模式 ,建成了我国第 1座城市生态填埋场。     

生活污泥干化与生活垃圾协同焚烧研究分析

我国城市化的快速发展导致城市人口的迅速膨胀,城市生活污水产生量也迅速增加,在污水处理过程中自然而然的产生了大量的污泥。据不完全统计,每年一座中等城市产生的污泥量大约在25~30万t。本文通过对生活污泥干化的研究与生活垃圾协同焚烧的研究,有助于形成积极的公众舆论和认同,为垃圾协同污泥焚烧技术在全国的推广实施提供便利。     

一体化设备在农村生活污水治理中的应用

随着中国农村经济的发展,生活污水排放量的日益增长,农村水环境治理成为新农村建设亟需解决的主要问题之一。本文分析了我国农村生活污水治理现状及水质水量特点,着重探讨了一体化设备在农村生活污水治理中的优势,可为加快推进其在农村生活污水治理中的应用提供参考。     

垃圾分类收费推进我国城市垃圾分类收集的探讨

我国城市生活垃圾产生量逐渐增大,严重威胁人体健康及城市环境。分类收集是实现废弃物减量化、资源化、无害化的有效手段。我国城市生活垃圾分类收集状况不佳,大部分城市均为混合收集,给垃圾处理和城市环境带来了巨大压力。本文从国外发达国家城市生活垃圾分类收费促进生活垃圾分类收集的成功经验出发,提出几点推动我国垃圾分类的对策。     

筛分法和显微镜法对矿化垃圾粒径分布的比较

为寻求合理有效的矿化垃圾粒径分布分析方法,分别采用筛分法和显微镜法两种测量手段对其进行比较研究。结果发现,两种方法所得的粒径分布结果差异较大,筛分法可能由于颗粒间静电吸附、聚合成团等因素影响而对小粒径颗粒区分能力较差,主要适用于大粒径颗粒的粒径分布测量(dp>100μm);显微镜法能够直观地观察到颗粒的显微图像,但测量时只是随机选择区域进行局部颗粒的测量,不宜分析粒度范围宽的样品,更适用于测量粒径较小的颗粒(dp<20μm)。     

矿化垃圾对渗滤液的吸附试验及其动力学研究

应用矿化垃圾吸附处理实际渗滤液中的COD和氨氮,分别研究了粒径、投加量、pH对吸附效果的影响,并在最佳吸附条件下对吸附过程进行动力学分析。结果表明,反应360min时,COD吸附达到平衡,去除率达到69.01%,单位吸附量为87.91mg/g;反应510min时,氨氮吸附达到平衡,去除率达到71.45%,单位吸附量为16.86mg/g,这表明用矿化垃圾作为吸附剂吸附垃圾渗滤液中的COD和氨氮是可行的;用COD和氨氮动力学数据拟合吸附过程,均符合伪二级动力学方程。     

矿化垃圾生物反应床处理印染废水的工艺参数优化及优势菌群

为了探讨矿化垃圾再利用于印染废水处理的可行性,研究了矿化垃圾生化反应床处理模拟印染废水的工艺参数,进行了优势菌群的镜检和提取、培养,实验结果表明,适宜的工艺运行参数如下为水力停留时间12~24 h,水力负荷100~140 L/(m3·d),COD污染负荷240~360 g/(m3·d),布水周期为24 h条件下的进水历时为6 h;适宜的工艺运行参数条件下,矿化垃圾生化反应床对模拟印染废水的COD去除率97%以上,总磷去除率95%以上,氨氮的去除率在98%以上;处理模拟印染废水的矿化垃圾生化反应床内的微生物群落以球菌为主,该菌体对模拟印染废水具有良好的专性降解作用。研究结果将对矿化垃圾的再利用和印染废水的处理提供一定的技术参考。     

Assessment of domestic water quality: case study, Beirut, Lebanon

In urban cities, the environmental services are the responsibility of the public sector, where piped water supply is the norm for urban household. Likewise, in Beirut City (capital of Lebanon) official water authorities are the main supplier of domestic water through a network of piping system that leaks in many areas. Beirut City and its suburbs are overpopulated since it is the residence of 1/3 of the Lebanese citizens. Thus, Beirut suffers deficiency in meeting its water demand. Water rationing, as a remedial action, is firmly established since four decades by the Lebanese Water Authorities. Consumers resorted then to private wells to supplement their domestic water needs. Consequently, household water quality is influenced by external factors relating to well water characteristics and internal factors depending on the types of the pipes of the distribution network and cross connections to sewer pipes. These factors could result in chemical and microbial contamination of drinking water. The objective of this study is to investigate domestic water quality variation in Beirut City emerging form the aforementioned factors. The presented work encircles a typical case study of Beirut City (Ras Beirut). Results showed deterioration pattern in domestic water quality. The predicted metal species and scales within the water pipes of distribution network depended on water pH, hardness, sulfate, chloride, and iron. The corrosion of iron pipes mainly depended on Mg hardness.     

Environmental assessment of water-courses of the Turvo Limpo River basin at the Minas Gerais State, Brazil

A study was performed to evaluate the environmental contamination in the Turvo Limpo River basin which receives effluent discharges from domestic (residential and commercial) activities. The watercourses examined were the São Bartolomeu Stream, Turvo Sujo River, and Turvo Limpo River, located in the Minas Gerais State, Brazil. Water samples were collected at the river-side and analyzed for evaluation of pollutant inputs. The pH, temperature, electrical conductivity, redox potential (Eh), dissolved oxygen (DO), total and settleable solids, visual color, hardness, chemical oxygen demand (COD), biochemical oxygen demand (BOD), chloride, total phosphate, total nitrogen, ammonia nitrogen, nitrate, total coliforms and E. coli, as well as the Cd, Pb, Cu, and Zn speciation were determined in the watercourses. The data obtained were compared with those of the Brazilian Environmental Standards and with data from non-contaminated areas. River water characteristics in some sites were far from the limit values established for superficial waters with satisfactory quality. For instance, the BOD values reached 411 mg L^?1 for a maximum limit of 10.0 mg L^?1, while the ammonia nitrogen concentration reached 28 mg L^?1 for a maximum limit of 13.3 mg L^?1. Some sites showed E. coli values above those of non-contaminated regions. Besides the effects of sewage discharges into the water-courses, agriculture activities and the use of the area for cattle husbandry influenced the quality of the river waters, for instance, the pH of a spring-water sample reached the value of 4.3. The São Bartolomeu Stream has been contributing to the deterioration of the water quality of the Turvo Sujo River, while the Turvo Limpo River has also been affected by anthropogenic discharges in the Turvo Sujo River. The speciation of Cd, Cu and Pb showed that these metals were mainly found in the particulate fraction (i. e., associated with the suspended material). Fifty five percent of the water samples showed labile Zn concentrations greater than that of the nonlabile Zn.     

Comparative Electrochemical Methods to Determine Fluoride Traces in NaCl

Fluoridated salt is an effective method to reduce dental decay in the population at large, in particular in settings where the more frequently used method of fluoridated water is not feasible due to unreliable water supplies. A salient problem of regular dosage and monitoring of fluoride in salt is its variable level at the industrial level. To evaluate the relative advantages of the present monitoring method used in Mexico, samples of domestic fluoridated salt were analysed by two comparative methods to determine their fluoride content. One of the methods employed was the relevant Mexican Offcial Norm (based on an acetic acid, sodium chloride, trans-1,2-diamine, cyclohexane N,N,N',N' tetracetic acid buffer solution) and the other was an alternative electrochemical methodology (based on an acetic acid, sodium chloride, sodium citrate buffer solution). The cost of the chemicals involved and simplicity of the alternative method, along with the equivalent precision of its results, makes it an interesting choice for the large scale analysis of fluoridated salt.