The influence of spent household batteries to the organic fraction of municipal solid wastes during composting

The objective of this work was to investigate the potential transfer of 9 heavy metals from spent household batteries (zinc-carbon and alkaline-manganese batteries) to the organic fraction of municipal solid wastes during active composting. Six runs were performed including one control and 2 replications. Eleven types of alkaline and non-alkaline batteries were added at 3 different levels to the organic fraction of municipal solid wastes, namely at percentages equal to 0.98% w/w (low), 5.2% w/w (medium) and 10.6% w/w (high). Experiments were performed in 230 l insulated plastic aerobic bioreactors under a dynamic air flow regime for up to 60 days. Iron, copper and nickel masses contained in the organic fraction of the wastes were found significantly higher in the high level runs compared to the corresponding masses in the control. No metal transfer was obtained in the low and medium level runs. Metal mass balance closures ranged from 51% to 176%. Metals' concentrations in the leachates were below 10 mg l⁻¹ for most metals, except iron, while an increasing concentration trend versus time was measured in the leachates of the high level runs. In all cases, the contents of 5 regulated heavy metals in all end products were below the Hellenic limits.     

复合生物滤池处理垃圾恶臭的研究

笔者采用自主开发的复合生物滤池专利技术处理垃圾恶臭气体.实验表明,垃圾恶臭气体流量为0.7~2.2m3/h,H2S、NH3、甲苯和甲硫醇浓度分别为0.01~0.09mg/m3、1.50~3.50mg/m3、0.20~2.55mg/m3和0.20~1.90mg/m3时,它们的总去除率分别达到92.9%、93.7%、86.0%和90.0%.当垃圾臭气浓度增大时,其多种成分可以相互影响而改变其水溶性,即气体间相互起着助溶剂的作用.复合生物滤池用于处理实际垃圾恶臭气体(处理量为5000m3/h),出气达到《恶臭污染物排放标准(GB14554-93)》中的一级排放标准,与水滤 活性炭吸附塔相比,具有更好的处理效果.     

生命周期评价（LCA）与固废资源化

针对固体废弃物特点和近年来固体废弃物处理情况及废弃物资源化趋势,介绍了生命周期评价（LCA）的概念及特征,具体阐述了LCA的内容及框架,探讨了将LCA应用于固废资源化决策的合理性和可行性,以促进其在环保领域的推广应用。     

应变硬化垃圾堆体抗局部沉陷研究

通过三种不同材料堆体的局部沉陷模型试验发现局部沉陷条件下应变硬化材料可能产生"自支撑"现象。利用模型试验和退化情况下的解析解验证了数值分析模型模拟应变硬化材料堆体局部沉陷问题的有效性。在此基础上比较了采用不同垃圾应力应变模型的分析结果,考虑堆体材料应变硬化的复合指数模型和线弹性模型计算得到的沉陷区土压力明显小于与之对应的摩尔-库伦模型计算结果,采用传统摩尔-库伦模型计算得到的沉陷区衬垫系统挠曲变形和应变值偏大,因而针对砂土材料的Giroud(1990)Trapdoor土拱效应理论应用于垃圾堆体局部沉陷分析时存在一定的局限性。进一步分析了各种参数对衬垫系统表面土压力和变形的影响,发现沉陷区衬垫系统最大挠度和最大应变随垃圾堆体高度的增加而增加,随垃圾堆体模量和加筋体刚度的增加而减小。最后提出应变硬化垃圾堆体在局部沉陷条件下衬垫系统土工膜的应变计算和加筋层的设计方法,对于垃圾填埋场衬垫系统抗局部沉陷设计具有一定的指导意义。     

Understanding municipal solid waste production and diversion factors utilizing deep-learning methods

We propose a hybrid deep learning neural network model for accurately calculating municipal solid waste (MSW) production and diversions with socioeconomic and demographic factors across 220 municipalities of Ontario, Canada, from 2010 to 2021. The proposed SDAE model is constructed by layering multiple denoising autoencoders (DAEs) and Bootstrap aggregation (bagging). The proposed methodology is tested against benchmark ML techniques, including Decision Trees, ANNs, and SDEs. The findings indicate that deep learning techniques can develop solid waste models with high prediction accuracy. Moreover, it has been statistically confirmed that socioeconomic factors affect solid waste management.     

工业固体废弃物在建筑材料领域的应用

综述了工业固体废物在水泥、墙体材料、陶瓷材料及轻骨料生产中的利用现状,总结出在建筑材料领域工业固体废弃物资源化利用的主要出路。     

Continuous treatment of the organic fraction of municipal solid waste in an anaerobic two-stage membrane process with liquid recycle

The stability and performance of a two-stage anaerobic membrane process was investigated at different organic loading rates (OLRs) and Hydraulic Retention Times (HRTs) over 200 days. The Hydrolytic Reactor (HR) was fed with the Organic Fraction of Municipal Solid Waste (OFMSW), while the leachate from the HR was fed continuously to two Submerged Anaerobic Membrane Bioreactors (SAMBR1 and 2). The Total COD (TCOD) of the leachate varied over a wide range, typically between 4000 and 26,000 mg/L while the Soluble COD (SCOD) in the permeate was in the range 400-600 mg/L, achieving a COD removal greater than 90% at a HRT of 1.6-2.3 days in SAMBR1. The operation was not sustainable below this HRT due to a membrane flux limitation at 0.5-0.8 L/m² h (LMH), which was linked to the increasing MLTSS. SCOD in the recycled permeate did not build up indicating a slow degradation of recalcitrants over time. SAMBR2 was run in parallel with SAMBR1 but its permeate was treated aerobically in an Aerobic Membrane Bioreactor (AMBR). The AMBR acted as a COD-polishing and ammonia removal step. About 26% of the recalcitrant SCOD from SAMBR2 could be aerobically degraded in the AMBR. In addition, 97.7 % of the ammonia-nitrogen was converted to nitrate in the AMBR at a maximum nitrogen-loading rate of 0.18 kg NH₄⁺-N/m³ day. GC-MS analysis was performed on the reactor effluents to determine their composition and what compounds were recalcitrant.     

浅谈生活垃圾卫生填埋场选址中应注意几个问题

生活垃圾卫生填埋场多处于农村或城乡结合部,其选址涉及多方面因素,不仅要分析其是否符合相关政策、规划、规范、标准等要求,而且还要紧密结合所选场址各方面特征因素,全面分析其可能存在的影响,尤其应关注对农村、农业和农民的影响,并提出解决办法。本文结合环评实践,阐述选址中应该注意几个问题。     

In‐vessel composting under air pressure of organic fraction of municipal solid waste in Azemmour,Morocco

This study aims to evaluate the performance of laboratory‐scale in‐vessel composting bioreactor for the Organic Fraction of Municipal Solid Waste treatment in Azemmour, Morocco. The bioreactor was specially designed and used for this study, and it was operated semicontinuously under 0.6 bar pressure. The evaluations studied included the operational indices, the compost maturity indices and the quality of the final compost. Obtained results showed that organic fraction of municipal solid waste could be composted successfully in 12 days. Moreover, high CO₂ generations involve high temperature and high internal air pressure change, revealing vigorous microbial activity. The final compost was satisfactory for its agricultural application.     

分层填埋垃圾体中气体一维稳态运移规律

针对垃圾填埋场分层填埋特点,提出了填埋垃圾产气率和导气系数分层计算方法,建立了分层填埋垃圾体中气体一维稳态运移分析模型,分析了垃圾的产气率、导气系数和封顶覆盖层的气密性对气压力大小及分布的影响,并探讨了垃圾填埋龄期对气压力分布的影响规律。分析结果表明:对于均质垃圾体,产气率与导气系数的比值越大,则填埋气压力越大;对于含封顶覆盖层的垃圾体,产气率主要控制气压力大小,导气系数控制气压力沿填埋深度分布梯度。封顶覆盖层厚度的增加或其导气系数的降低将使填埋气释放量减少,则气压力整体提高。垃圾填埋龄期越大,则垃圾体中气压力越小。     

Contaminant mitigating performance of Chinese standard municipal solid waste landfill liner systems

In 2004, Chinese Government prescribed standard municipal solid waste (MSW) landfill bottom liners. However, very limited research has been conducted to evaluate the performance of the standard MSW landfill bottom liners prescribed by the Chinese Government. In this paper, the performance of the two types of Chinese MSW landfill bottom liner systems was evaluated based on: (1) the maximum leachate head; (2) leakage rate; (3) peak concentration of the target contaminant in an aquifer which was underlain the assumed landfill, and (4) total mass per unit area of the target contaminant discharged into the aquifer. The performance of the German standard MSW landfill bottom liner system was evaluated and compared with that of Chinese ones. It is found that the calculated maximum leachate head for the Chinese landfill liner systems was much higher than that for the German one. The calculated leakage rate, peak concentration and the maximum total mass per unit area in the aquifer of the target contaminant show that the performance of the Chinese standard landfill liner Type 2 is practically the same as that of the German standard landfill liner with holed geomembrane wrinkles, while the Chinese standard liner Type 1 is less effective, with regarding the mitigation of the impact of landfills to the groundwater quality. It is concluded that the overall performance of the Chinese standard landfill liner systems is less strict than that of the German standard landfill liner system.     

Health risk assessment of volatile organic compounds at daycare facilities

Children are particularly vulnerable to many classes of the volatile organic compounds (VOCs) detected in indoor environments. The negative health impacts associated with chronic and acute exposures of the VOCs might lead to health issues such as genetic damage, cancer, and disorder of nervous systems. In this study, 40 VOCs including aldehydes and ketones, aliphatic hydrocarbons, esters, aromatic hydrocarbons, cyclic terpenes, alcohols, and glycol ethers were identified and qualified in different locations at the University of Missouri (MU) Child Development Laboratory (CDL) in Columbia, Missouri. Our results suggested that the concentrations of the VOCs varied significantly among classrooms, hallways, and playground. The VOCs emitted from personal care and cleaning products had the highest indoor levels (2-ethylhexanol-1, 3-carene, homomenthyl salicylate with mean concentration of 5.15 µg/m³, 1.57 µg/m³, and 1.47 µg/m³, respectively). A cancer risk assessment was conducted, and none of the 95th percentile dose estimates exceeded the age-specific no significant risk levels (NSRL) in all classrooms. Dimensionless toxicity index scores were calculated for all VOCs using a novel web-based framework called Toxicological Prioritization Index (ToxPi), which integrates multiple sources of toxicity data. According to the method, homomenthyl salicylate, benzothiazole, 2-ethylhexyl salicylate, hexadecane, and tridecane exhibited diverse toxicity profiles and ranked as the five most toxic indoor VOCs. The findings of this study provide critical information for policy makers and early education professionals to mitigate the potentially negative health impacts of indoor VOCs in the childcare facilities.     

单一组分与多组分城市生活垃圾孔隙率特性对比研究

在长期压缩条件下,城市生活垃圾孔隙率的变化规律不同于传统土力学中的土,垃圾孔隙率的变化同时受到生化降解和应力压缩的影响。基于城市生活垃圾可降解组分一阶动力学水解模型,分析建立了两种城市生活垃圾生化降解模型：单一组分生化降解模型和多组分生化降解模型。在生化降解模型和应力降解压缩模型基础上,提出了城市生活垃圾孔隙率计算模型。通过分析不同上覆应力（10,50,100,200,400,800 kPa）长期作用下的孔隙率变化,综合比较了不同生化降解模型以及垃圾组分和降解特性对孔隙率变化规律的影响。对于国内现阶段生活垃圾而言,多组分生化降解模型基础上预测的孔隙率变化规律与单一组分生化降解模型的分析结果一致,孔隙率随着长期压缩和降解的进行逐渐增加。然而,相比于单一组分生化降解模型,多组分生化降解模型更能反映垃圾组分及可降解组分降解能力对孔隙率变化规律的影响。     

Time and space patterns of volatile organic compounds in a sewage treatment plant

47 regulated and non-regulated volatile organic compounds (VOCs) were characterised by closed-loop stripping analysis (CLSA) and high resolution gas chromatography coupled to mass spectrometry (HRGC/MS) in 28 aqueous samples from 4 sampling points along a sewage treatment plant in Manresa, Catalonia, Spain. A 4 x 2(2) factorial design (16 samples) was first prepared for the sampling, and reinforced with 12 additional samples at the plant influent. The total analyte weighted mean concentration was 232 microg x l(-1) at the plant influent, with a mass flow of 2231 kg x yr(-1). Petroleum solvents and terpenic compounds accounted for 79% of the influent analyte concentration. VOC concentration in influent was clearly higher for most VOCs from 12 to 22 h (high organic load hours), and lower from 24 to 10 h (lower organic load). Differences between time bands were confirmed through t tests. Differences between weekdays and the weekend were not so clear, and could not be confirmed through t tests. VOC concentrations along the plant are discussed. Overall analyte removal in the plant was 89%.     

Regional assessment of ambient volatile organic compounds from biopharmaceutical R&D complex

Biopharmaceutical R&D complexes are major emission sources of volatile organic compounds (VOCs), which may pose potential health risks for staff on site and residents nearby. In this paper health risk assessments were performed for the VOCs in the ambient air of a typical biopharmaceutical R&D complex in China. Results showed halogenated and alkyl compounds were dominant components among 24 major VOCs from 9 selected sampling sites, inside or around the complex. The principal component analysis (PCA) indicated VOCs were generated predominantly from the biopharmaceutical research activities (factor 1 (F1), 71.6%) and traffic vehicles (factor 2 (F2), 15.4%), which were confirmed by contour maps of five selected VOCs (benzene, toluene, chlorobenzene, methylene chloride and n-hexane) simulated by Golden Software Surfer. The cumulative cancer risks for the staff on site and residents nearby were investigated and results showed the risk value were 1.01E−5 and 2.03E−5, respectively, higher than the threshold value of 1.0E−6. These results indicated that elevated VOCs from biopharmaceutical R&D complex are potential risks to the public health. Furthermore, the human health risk assessment revealed that 1,2-dichloroethane, methylene chloride, carbon tetrachloride and benzene were the dominant risk contributors for staff on site, while methyl chloride, carbon tetrachloride, 1,2-dichloroethane and tetrahydrofuran for residents nearby. As a conclusion, this work suggests that proper control strategy should be taken for VOCs releasing to minimize the public health risks, especially for the halogenated compounds.     

挥发性有机化合物在复合衬里中的一维扩散解

土工膜和粘土衬里组成的复合衬里已广泛用于填埋场的防渗。有机挥发性化合物在复合衬里中迁移时,其主要的机理是分子扩散作用。本文建立了有机挥发性化合物在复合衬里中的一维扩散模型,并得到了解析解。将该解析解和以往给出的数值解法作了比较,发现两者得到的结果较为接近,从而验证了本文解的可靠性。基于本文计算模型,分析了三种常用复合衬里对挥发性有机化合物的防渗性能。研究发现对于挥发性有机化合物甲苯,土工膜和GCL组成的复合衬里的浸出液总量要比土工膜和较厚粘土衬里组成的复合衬里大好几个量级。     

Geo-environmental application of municipal solid waste incinerator ash stabilized with cement

The behavior of soluble salts contained in the municipal solid waste incinerator (MSWI) ash significantly affects the strength development and hardening reaction when stabilized with cement. The present study focuses on the compaction and strength behavior of mixed specimens of cement and MSWI ash. A series of indices such as unconfined compressive strength, split tensile strength, California bearing ratio (CBR) and pH value was examined. Prior to this, the specimens were cured for 7 d, 14 d, and 28 d. The test results depict that the maximum dry density (MDD) decreases and the optimum moisture content (OMC) increases with the addition of cement. The test results also reveal that the cement increases the strength of the mixed specimens. Thus, the combination of MSWI ash and cement can be used as a lightweight filling material in different structures like embankment and road construction.     

Degradation of C2-C15 volatile organic compounds in a landfill cover soil

The composition of non-methane volatile organic compounds (hereafter VOCs) in i) the cover soil, at depths of 30, 50 and 70 cm, and ii) gas recovery wells from Case Passerini landfill site, (Florence, Italy) was determined by GC-MS. The study, based on the analysis of interstitial gases sampled along vertical profiles within the cover soil, was aimed to investigate the VOC behaviour as biogas transits from a reducing to a relatively more oxidizing environment. A total of 48 and 63 different VOCs were identified in the soil and well gases, respectively. Aromatics represent the dominant group (71.5% of total VOC) in soil gases, followed by alkanes (6.8%), ketones (5.7%), organic acids (5.2%), aldehydes (3.0%), esters (2.6%), halogenated compounds (2.1%) and terpenes (1.3%). Cyclics, heterocyclics, S-bearing compounds and phenols are ≤ 1%. In the wells the VOC composition is characterized by higher concentrations of cyclic (7.6%) and S-bearing compounds (2%) and lower concentrations of O-bearing compounds. The vertical distribution of VOCs in the cover soil shows significant variations: alkanes, aromatics and cyclics decrease at decreasing depth, whereas an inverse trend is displayed by the O-bearing species. Total VOC and CH₄ concentrations at a depth of 30 cm in the soil are comparable, inferring that microbial activity is likely affecting VOCs at a very minor extent with respect to CH₄. According to these considerations, to assess the biogas emission impact, usually carried out on the sole basis of CO₂ and CH₄ emission rates, the physical-chemical behaviour of VOCs in the cover soil, regulating the discharge of these highly contaminant compounds in ambient air, has to be taken into account. The soil vertical distribution of these species can be used to better evaluate the efficiency of oxidative capability of intermediate and final covers.     

Sorption of quaternary ammonium compounds to municipal sludge

The sorptive behavior of four quaternary ammonium compounds (QACs) - hexadecyl trimethyl ammonium chloride (C₁₆TMA), dodecyl trimethyl ammonium chloride (C₁₂TMA), hexadecyl benzyl dimethyl ammonium chloride (C₁₆BDMA), and dodecyl benzyl dimethyl ammonium chloride (C₁₂BDMA) - to municipal primary, waste activated, mesophilic digested, and thermophilic digested sludges was assessed at 22 °C. Batch adsorption of all four separately tested QACs to primary sludge reached equilibrium within 4 h. At a nominal, initial QAC concentration of 300 mg/L and a sludge volatile solids concentration of 1 g/L, the extent of adsorption was 13, 88, 67, and 89% for the C₁₂TMA, C₁₆TMA, C₁₂BDMA, and C₁₆BDMA, respectively, and correlated positively to the QAC hydrophobicity and negatively to their critical micelle concentration. Equilibrium partitioning data were described by the Freundlich isotherm model. The adsorption capacity of the four sludges was very similar. In binary QAC mixtures, QACs with relatively high adsorption affinity and at relatively high aqueous concentrations decreased the adsorption of QACs with a low adsorption affinity. At pH 7, about 40% of the sludge-C₁₂TMA desorbed, whereas less than 5% of the sludge-C₁₆BDMA desorbed in 10 days. The effect of pH was negligible on the desorption extent of C₁₂TMA at a pH range 4-10 over 10 days, whereas increasing the solution pH to 10 resulted in more than 50% desorption of C₁₆BDMA. Given the fact that approximately 50% of the municipal biosolids are land-applied in the US, the data of this study would help in the assessment of the fate of QACs and their potential effect on human and environmental health.     

Statistical estimate of mercury removal efficiencies for air pollution control devices of municipal solid waste incinerators

Although representative removal efficiencies of gaseous mercury for air pollution control devices (APCDs) are important to prepare more reliable atmospheric emission inventories of mercury, they have been still uncertain because they depend sensitively on many factors like the type of APCDs, gas temperature, and mercury speciation. In this study, representative removal efficiencies of gaseous mercury for several types of APCDs of municipal solid waste incineration (MSWI) were offered using a statistical method. 534 data of mercury removal efficiencies for APCDs used in MSWI were collected. APCDs were categorized as fixed-bed absorber (FA), wet scrubber (WS), electrostatic precipitator (ESP), and fabric filter (FF), and their hybrid systems. Data series of all APCD types had Gaussian log-normality. The average removal efficiency with a 95% confidence interval for each APCD was estimated. The FA, WS, and FF with carbon and/or dry sorbent injection systems had 75% to 82% average removal efficiencies. On the other hand, the ESP with/without dry sorbent injection had lower removal efficiencies of up to 22%. The type of dry sorbent injection in the FF system, dry or semi-dry, did not make more than 1% difference to the removal efficiency. The injection of activated carbon and carbon-containing fly ash in the FF system made less than 3% difference. Estimation errors of removal efficiency were especially high for the ESP. The national average of removal efficiency of APCDs in Japanese MSWI plants was estimated on the basis of incineration capacity. Owing to the replacement of old APCDs for dioxin control, the national average removal efficiency increased from 34.5% in 1991 to 92.5% in 2003. This resulted in an additional reduction of about 0.86 Mg emission in 2003. Further study using the methodology in this study to other important emission sources like coal-fired power plants will contribute to better emission inventories.