医疗垃圾焚烧炉飞灰水泥固化体的浸出特性研究

为检验医疗垃圾焚烧飞灰的水泥固化处理效果,对不同养生龄期及不同飞灰／水泥配比下飞灰水泥固化体重金属渗沥特性进行了实验研究。结果表明：随养生龄期的延长,水泥固化体中的Zn、Pb、Cu等重金属渗沥浓度总体上是逐渐降低的;掺40％飞灰、60％飞灰养生28d的水泥固化体中Pb渗沥浓度分别为5．634、6．032mg／L,超过5mg／L的限值。若按照目前国内生活垃圾焚烧飞灰水泥固化工艺的配比（水泥掺量40％以下）,重金属渗沥指标不能达到填埋要求。     

给水处理中含砷污泥的浸出毒性和初步处置研究

目的研究混凝微滤工艺处理高砷饮用水所产生的铁盐和铝盐含砷污泥的浸出毒性,以及含砷污泥的处置与利用方法。方法采用中国国家标准方法和USEPA的TCLP方法检验了含砷污泥的浸出毒性,并采用水泥固化的方法对含砷污泥的处置进行了初步研究。将铁盐含砷污泥添加到路用基材中,探讨其废物利用的可能性。结果铁盐和铝盐含砷污泥TCLP方法浸出液中砷的浓度分别为118μg/L和420μg/L,高于国家标准方法的9.5μg/L和11.8μg/L,但两种方法测定的浸出毒性均低于危险废物浸出毒性的国家标准。普通硅酸盐水泥固化体的TCLP浸出液中砷浓度仅为污泥的10%左右,固化体的无侧限抗压强度分别为3.25MPa和0.76MPa,可以满足堆放要求。掺入少量铁盐含砷污泥的路用基材强度提高12%左右。结论给水处理中含砷污泥不属于具有浸出毒性的危险废物,水泥固化是处置含砷污泥的有效方法,将少量铁盐含砷污泥添加到路用基材中使含砷污泥得到了有效利用,又避免了可能出现的环境污染问题。     

Assessment of the environmental hazard from municipal and industrial wastewater treatment sludge by employing chemical and biological methods

Chemical analyses and toxicity testing were employed in conjunction to evaluate the environmental hazard from the wasted sludge generated during the biological treatment of urban and industrial wastewaters. Chemical analyses included determination of seven polychlorinated biphenyls (PCBs), 13 polycyclic aromatic hydrocarbons (PAHs), total organic carbon (TOC), and seven heavy metals (As, Cd, Cr, Cu, Pb, Mn, and Zn) in sludge and sludge leachates deriving from two standard leaching procedures: (a) the mild leaching test EN-12457-2 proposed by EC and (b) the relatively aggressive toxicity characteristic leaching procedure (TCLP) leaching test proposed by US EPA. Acute toxicity measurements were performed in aqueous sludge elutriates and leachates by using bioluminescence bacteria. The urban sludge was found to be more enriched with PAHs than the industrial sludge, however, at levels below the EU limits for sludge application. The total PCB content (Sigma7PCBs) in both sludges, particularly in the industrial sludge, exceeded the proposed European limit for sludge use as soil amendment. With regards to their heavy metal content, both sludges met the requirements for use in agriculture. The urban sludge exhibited high ecotoxicity, while the industrial sludge with almost two times lower toxicity was classified as not toxic to slightly toxic. The EN and the TCLP leaching procedures resulted in different sludge characterizations both from chemical and from ecotoxicological points of view. The EN procedure appeared to be more sensitive to the potential environmental risk from sludge disposal. The results of the study revealed the necessity for combining chemical with ecotoxicological criteria for integrated characterization of wasted sludge and the need for harmonization of the methods employed for waste classification.     

Solidification as low cost technology prior to land filling of industrial hazardous waste sludge

The aim of this study is to stabilize and solidify two different treated industrial hazardous waste sludges, which were selected from factories situated close to Alexandria. They were selected to ensure their safe transportation and landfill disposal by reducing their potential leaching of hazardous elements, which represent significant threat to the environment, especially the quality of underground water. The selected waste sludges have been characterized. Ordinary Portland Cement (OPC), Cement Kiln Dust (CKD) from Alexandria Portland Cement Company, and Calcium Sulphate as a by-product from the dye industry were used as potential solidification additives to treat the selected treated waste sludges from tanning and dyes industry. Waste sludges as well as the solidified wastes have been leach-tested, using the General Acid Neutralization Capacity (GANC) procedure. Concentration of concerning metals in the leachates was determined to assess changes in the mobility of major contaminants. The treated tannery waste sludge has an acid neutralization capacity much higher than that of the treated dyes waste sludge. Experiment results demonstrated the industrial waste sludge solidification mix designs, and presented the reduction of contaminant leaching from two types of waste sludges. The main advantages of solidification are that it is simple and low cost processing which includes readily available low cost solidification additives that will convert industrial hazardous waste sludges into inert materials.     

固化污泥作为垃圾填埋场覆土材料的适用性研究

以2种固化污泥为研究对象,对其作为垃圾填埋场覆土材料的可行性进行了研究。一种是使用碱性固化剂形成的固化污泥（A固化污泥）,另一种是中性固化剂形成的固化污泥（N固化污泥）。研究表明N固化污泥更适合作为垃圾填埋场覆盖材料。     

自来水厂污泥的表征及其垃圾覆盖土可行性研究

对自来水厂污泥进行了较系统的试验研究,如浸出毒性实验、剪切试验、重金属含量的检测等,以及作为垃圾覆盖土的可行性。研究结果表明,自来水厂污泥在1～2kg／cm^3压力作用下,含水率从61．3％减少到46．3％,渗透系数达到10^-7cm／s,无渗透毒性。用该污泥作垃圾填埋场覆盖土的边坡稳定性能较好,基本上满足作为覆盖土的技术要求,使用后不会给垃圾渗滤液的处理增加负担。因此,以自来水厂污泥作为生活垃圾填埋场覆盖土。可同时解决平原型填埋场缺土和污泥的最终出路问题。     

固化污泥制作回填土及营养土的研究

采用镁系固化剂 (MI 固化剂) 对污泥进行固化预处理,对预处理后的污泥的物理性质、水力学性质和土力学性质以及重金属存在形态等进行监测,同时通过现场试验和监测确定未经填埋的固化污泥是否达到资源化利用的标准,是否具有制作回填土及营养土的可能性.     

施用城市污泥对土壤中重金属积累和迁移的影响

目的 了解城市污泥农用后土壤重金属的积累和迁移。方法 于1998年分不同季节，从苏州、无锡、常州3个城市污水处理厂采集污泥样本，用原子吸收光谱仪分析样本中重金属(Pb、Zn、Cu、Cd、Hg、As)含量和不同形态含量，分析污泥农用后土壤重金属积累及迁移特性。结果 城市污泥重金属含量远高于土壤背景值，3城市污泥中Zn含量均超标，分别达到1199，00、784．00、1216．00mg／kg。长期施用能导致土壤重金属积累。污泥中重金属具有一定的活性和潜在迁移性。结论 城市污泥农用可能会导致土壤和生物体重金属积累，存在着一定的环境重金属积累风险。     

生活垃圾焚烧飞灰特性分析

分别对炉排床垃圾焚烧炉飞灰(FA1)和流化床垃圾焚烧炉飞灰(FA2)的化学成分、物相、微观形貌、重金属含量及其渗沥行为等特性进行分析,结果表明:2种飞灰的主要化学成分为SiO2、CaO、Al2O3、Fe2O3等,FA2中高熔点成分含量比FA1高;飞灰的主要物相为SiO2、NaCl、CaSO4等晶体,飞灰颗粒为不规则形;飞灰中Cu、Pb和Zn的含量较多,按照硫酸硝酸法,FA1、FA2中重金属Pb的浸出浓度超过国家规定的危险废物鉴别标准;按醋酸缓冲溶液法,FA1、FA2中的浸出液重金属Pb、Cd浓度都远高于填埋场的限值,需处理后方可进入生活垃圾填埋场填埋。     

矿化垃圾的重金属淋溶试验研究

通过土柱实验模拟矿化垃圾以及矿化垃圾与污泥混合物在淋溶条件下重金属的淋失情况,并利用污染综合指数法分析矿化垃圾中重金属迁移对地下水的影响.结果表明淋溶的不同阶段对地下水易造成污染的金属元素有所不同,需要分阶段进行监控.淋溶初期需监测[As]、[Cr]、[Co]、[Cu]和[Mn];淋溶中期需监测[Ni]和[Pb];淋溶末期需对[Fe]进行监测.综合污染指数评价表明矿化垃圾以及矿化垃圾与污泥混合土壤的淋溶液对地下水造成潜在污染的最关键因子为Mn,其次是Fe.     

焦作垃圾焚烧厂焚烧灰渣及烟气污染分析

为确定焦作垃圾焚烧厂生活垃圾焚烧后主要二次污染物的种类及其含量,了解烟气处理设备的处理状况,于2005年10月对焚烧炉渣和飞灰及2006年3月对同批次生活垃圾焚烧炉渣、飞灰和烟气进行了监测,对灰渣浸出毒性的测定及烟气成分进行分析.结果表明:飞灰浸出液中总镉、总铅、总铍的浓度均高于焚烧炉渣浸出液及固体废物浸出毒性鉴别标准,认为飞灰是一种危险废物.在正常工况下,烟气成分中主要污染物是氯化氢气体,其含量略微超过了生活垃圾焚烧污染控制标准值.生活垃圾经焚烧后,重金属铅、镉在飞灰中富集的量最大,炉渣和烟气中分布较少.旋风 半干法脱酸 布袋除尘设施是值得提倡的组合.     

焚烧飞灰中重金属离子溶出试验方法论述

对国内外含重金属固体废物的溶出试验方法进行分类分析,探讨了浸出毒性测试、柱浸出试验、连续提取试验等静态和动态试验方法在评估焚烧飞灰中重金属离子溶出特性和长期稳定性的应用,并以飞灰中铅离子的溶出特性为例论述了溶出试验方法的适用性。     

Heterocypris incongruens as a tool to estimate sewage sludge toxicity

The toxicity of 13 sewage sludges was evaluated in relation to the crustacean Heterocypris incongruens. The bioassay used was a commercial, direct contact test that allows evaluation of solid-phase toxicity. Evaluation of sewage sludges included physicochemical properties (pH, total organic C, total N, cation-exchange capacity, total exchangeable bases, available forms of P and K, and electrical conductivity), heavy metal content (cadmium, chromium, copper, lead, nickel, and zinc), and content of polycyclic aromatic hydrocarbons (16 from the U.S. Environmental Protection Agency list). The evaluated parameters were then compared with bioassay results (mortality and growth inhibition). Sewage sludges were characterized by optimal physicochemical properties; low K (<5.64 mg/kg) and total organic C (177-253 g/kg) levels were noted. Contaminant content (heavy metals and polycyclic aromatic hydrocarbons) clearly differed between individual sewage sludges. Polycyclic aromatic hydrocarbon contents ranged from 3.8 to 36.4 mg/kg. Total concentrations of heavy metals in all sewage sludges (with the exception of one sludge) were lower than the pollutant concentration limits for land application. Heterocypris incongruens mortality when sludge was applied at doses of 6, 12, or 24% ranged from 0 to 70%, from 4.7 to 72.1%, and from 0 to 100%, respectively. Average growth inhibition was 39.7 to 46.6% (depending on the sludge dose applied). Any stimulating influence of two sewage sludges on the test organism was recorded. The median lethal concentrations calculated for individual sewage sludges ranged from 88 to 956 g sewage sludge/ kg.     

Evaluation of leaching and ecotoxicological properties of sewage sludge-fly ash mixtures

The objectives of this work were the evaluation of sewage sludge stabilization by mixing with fly ash, the examination of the physicochemical properties of the produced materials and their leachates and the assessment of their environmental impact by the evaluation of the ecotoxic characteristics. Different ratios of fly ash and sewage sludge (1:1, 1:2, 1:3, 1:6, and 1:9) were mixed for 48 and 72 h. After mixing, the liquid phase of the produced materials was analyzed for total coliforms and Escherichia coli, while the solid residue was dried and tested for the leaching characteristics by the application of TCLP and EN 12457-2 standard leaching methods. Furthermore, the produced leachates were analyzed for their content of specific metals, while their ecotoxicological characteristics were determined by the use of toxicity bioassays, using the marine photobacterium Vibrio fischeri and the crustacean Daphnia magna. The phytotoxicity of sewage sludge-fly ash mixtures was also determined by utilizing seeds of three higher plants (one monocotyl and two dicotyls). The mixtures exhibited low metal leaching in all cases, while the ecotoxic properties increased with the increase of fly ash/sewage sludge ratio. The phytotoxicity testing showed increased root length growth inhibition.     

生活污水处理厂固化污泥机械养护试验研究

采用FD300翻堆机对固化污泥进行翻抛养护,在固化污泥条垛宽度为3 m,高度为55 cm时翻堆机效率最高,平均处理能力可达464.2t/h;养护5d后,污泥的含水率由74.63％降至65％左右.pH由12.0降至9.2～9.4,几乎没有臭味,可满足填埋或资源化利用要求.     

重金属废水的危害及治理

论述了重金属废水的来源和危害 ,讨论了废水中微量元素的基本特性。介绍了重金属废水处理原则和技术方法。     

城市污泥中重金属的去除方法研究进展

简述了全国范围内污泥中重金属赋存水平以及污泥施用到农田后重金属产生的危害,重点阐述了采用物理、化学、微生物方法去除污泥中重金属,并对这几种方法的去除效率、处理成本以及环境安全性进行了比较,最后展望了今后进一步研究的发展方向和工作重点。     

Evaluation for Agricultural Usage with Speciation of Heavy Metals in a Municipal Sewage Sludge

This study was carried out to evaluate the agricultural usage of an anaerobically digested sludge in the contents and fractions of heavy metals. Therefore, a sequential extraction scheme according to the BCR's (Community Bureau of Reference) guidelines and total acid digestion were applied to sewage sludge samples. The results of total heavy metal concentrations in sewage sludge showed that the highest total concentrations were Fe, Zn and Mn. When Turkish, Europe and US EPA directives were compared with each other by depending on the use of sludge for agricultural purposes, all the heavy metals determined for this sludge were below the maximum permitted levels, except for Cd. This sludge should not be applied to land due to its high Cd content. The results of heavy metal fractions indicated that some metals (Cd, Mn, Pb, and Fe) distributed mainly in the residual fraction. All fractions of Zn showed no variation. Cu and Cr were most abundant in the oxidizable phase while Ni was in exchangeable phase. Although total content of Ni in the sludge is lower than the maximum levels allowed by all the directives, it tends to be easily moved and dispersed in the environment. Due to its high mobility, the examined sewage sludge may cause phyto-toxicity after its agricultural application.     

Distribution of urinary hippuric acid concentrations by ALDH2 genotype.

OBJECTIVES--To clarify the relation between the genetic polymorphism of ALDH2 (low Km aldehyde dehydrogenase) and toluene metabolism. METHODS--The study subjects were 253 toluene workers (192 men and 61 women with an age range of 18-66). The genotypes of ALDH2 were classified by artificial restriction fragment length polymorphism into the homozygous genotype of normal ALDH2 (NN), the homozygous genotype of an inactive ALDH2 (DD), and the heterozygous genotype of normal and inactive ALDH2 (ND). The concentrations of hippuric acid (HA), the main metabolite of toluene, was determined in urine specimens of 253 toluene workers. The HA measurements in previous occupational health examinations were also referenced. The HA concentrations corrected for creatinine (HA/C) were compared with the biological exposure index (BEI) for toluene, which is 2.5 g/g creatinine. To estimate the toluene exposures, urinary o-cresol concentrations were also determined and compared with another BEI for toluene--that is, 1.0 mg urinary o-cresol/g creatinine. RESULTS--Incidence of each genotype in the toluene workers was almost the same as that in non-exposed controls who lived in the same area as the toluene workers. The incidence of each of the three genotypes also did not differ by smoking habit. Mean urinary HA concentrations were not significantly different in the groups with the different genotypes of ALDH2. The HA concentrations of > 70% of the 890 total samples were < 1.0 g/l. The number of urine samples > 3.0 g/l was 28 (5.4%) in the NN group and 19 (6.4%) in the ND group. No urine samples in the DD group were > 3.0 g/l HA. The distribution of urinary HA in the DD group was significantly different from those in both the NN and ND groups (P < 0.05). Seven (4.9%) of the 136 total specimens in the NN group and four (4.7%) of the 82 total specimens in the ND group exceeded the BEI. There were, however, no urine specimens that exceeded the BEI in the DD group. The maximum HA concentration after correction for creatinine in the DD group was 1.86 g/g creatinine. The percentages of urine specimens in which o-cresol concentrations exceeded this BEI were 14.3% in the NN group, 9.1% in the ND group, and 15.4% in the DD group. Therefore, the exposure rate for all three genotypic groups of workers was almost the same. CONCLUSIONS--The HA concentrations of toluene workers with ALDH2 DD genotype were lower than those of the NN and ND genotypes when they were exposed to relatively high concentrations of toluene. The exposures of the DD group were suspected to be underestimates because they were based on the BEI for the NN genotype.     

Heavy Metals Contained Within a Pb–Zn Waste Heap Exhibit Selective Association with Microbial Modules as Revealed by Network Analysis

Heavy metal contamination is a global environmental concern due to its persistence and toxicity. To explore soil microbial interaction mechanisms and their association with heavy metals on a Pb–Zn waste heap, ecological network analysis tools were used to analyze high-throughput data in microbiology. The microbial network was divided into several modules, but heavy metals were associated with specific modules. The heavy metal-tolerant module (M2) had a more negative than positive relationship with the heavy metal-mid-tolerant modules (M1 and M3). Tight coupling between fungal and bacterial operational taxonomic units (OTUs) within M2 was critical for module stability and heavy metal bioremediation. Additionally, members within M2 needed to form a positive relationship to cope with heavy metal contamination (As, Pb, Zn, Cu, and Cd). The study provides fundamental information for a deeper understanding of heavy metal bioremediation mechanisms in the Pb–Zn waste heap.