广东清远电子垃圾处理地沉积物对伸展摇蚊的慢性毒性效应

电子垃圾拆解引起的环境污染和生态风险已成为全球关注的热点问题,不适当的电子垃圾拆解过程造成处理区水体沉积物受到多类有机化合物和重金属污染,直接威胁生活在沉积物中的底栖动物。在典型电子垃圾处理地广东清远采集沉积物,测定样品中以烃类为主的色谱难分离混合物(unresolved complex mixture,UCM)的含量,开展伸展摇蚊全生命周期慢性毒性测试。结果表明,清远沉积物中的UCM浓度(0.08±0.01)%接近于这类污染物对伸展摇蚊的慢性半致死性效应浓度(0.073±0.022)%。同时发现清远沉积物对以摇蚊为代表的底栖无脊椎动物具有显著慢性毒性效应,且可通过测定UCM含量初步估算。这为开展以电子垃圾处理地沉积物为代表的,受到以麻醉作用为主要致毒机制的混合物污染的沉积物的毒性评价提供了一种有效方法。     

利用SOS/umu测试评价某电子垃圾处理地土壤的遗传毒性

由电子垃圾不当处理引起的环境污染问题已经引起普遍关注.采用SOS/umu测试方法对我国南方某电子垃圾处理地23个土壤样品的有机提取物的直接和间接遗传毒性进行了初步的评估和筛选.结果表明,在有机提取物最高暴露浓度相当于100mg·well-1时,只有很少一部分样品检出直接遗传毒性,而绝大多数样品的有机提取物经过代谢活化后,表现出遗传毒性.与对照地区土壤相比,从事电子垃圾回收处理的地区土壤中存在间接致突变物质的积累,这可能与当地粗放形式的电子垃圾处理活动有关.     

Distribution of polychlorinated biphenyls and polybrominated diphenyl ethers in soils of a previous E-waste processing center

Surface soil samples were taken from a previous electronic waste (E-waste) recycling centerin Taizhou area, Zhejiang province, China. Concentrations, profiles, and possible sources of 19 polychlorinated biphenyls and 7 poly-brominated diphenyl ethers were analyzed to assess their current state in the soil after phase out of massive dismantling of E-wastes. The concentrations of the 7 polybrominated diphenyl ethers ranged from 11 to 128 µg kg^?1 with an average of 41 ± 10 µg kg^?1 (dw), with 2,2′,4,4′-tetrabromdiphenyl ether being the most abundant. These values were substantially lower than the levels in 2006. The concentrations of the 19 polychlorinated biphenyls ranged from 36 to 760 µg kg^?1, with an average of 181 ± 68 µgkg^?1 (dw) which was also lower than the levels in 1995 or 2006. However, the concentrations of some tetra-, penta- and hexa-chlorobiphenyls were comparable or even higher than before. Furthermore, the average concentration of 7 indicator polychlorinated biphenyls was 108 ± 41 µg kg^?1(dw) which exceeded the New Dutch List target value of 20 µgkg^?1. Principal component analysis indicated that polychlorinated biphenyls were mainly distributed into three groups in accordance with the number of chlorine atoms and anthropogenic source. Therefore, the impact of the historical dismantling of E-wastes is still significant.     

Nitrogen recovery from wastewater using microbial fuel cells

Nitrogen is one of major contaminants in wastewater; however, nitrogen, as bio-elements for crop growth, is the indispensable fertilizer in agriculture. In this study, two-chamber microbial fuel cells (MFCs) were first operated with microorganisms in anode chamber and potassium ferricyanide as catholyte. After being successfully startup, the two-chamber MFCs were re-constructed to three-chamber MFCs which were used to recover the NO3−−N and NH4+−N of synthetic wastewater into value-added nitrogenous fertilizer from cathode chamber and anode chamber, respectively. Ferric nitrate was used as the sole electron acceptor in cathode, which also was used to evaluate the NO3−−N recover efficiency in the case major anion of NO3− in cathode. The output voltage of these MFCs was about 600–700 mV at an external load of 500 Ω. About 47% NH4+−N in anode chamber and 83% NO3−−N in cathode chamber could be recovered. Higher current density can selectively improve the recovery efficiency of both NH4+−N and NO3−−N. The study demonstrated a nitrogen recovery process from synthetic wastewater using three-chamber MFCs.     

Sustainability in manufacturing processes: practices performed in metal forming,casting, heat treatment,welding and electrostatic painting

ABSTRACT

This article aims to list the main sustainable practices developed in the processes of metal forming, casting, heat treatment, welding and electrostatic painting. When analysed the literature about sustainable manufacturing, a predominance of studies about machining is observed and the processes mentioned are few explored in academic studies. The research strategy used to reach the objective was systematic literature review, conducted for each process cited. Many sustainable practices were identified with prominence of better materials use and energy efficiency. The authors of this article believe that the information presented here can be useful for researches in their future studies and for industry professionals interested in improving manufacturing processes.     

Sustainability of Nations

SUMMARY

A method is presented to interrelate the development of economy, environment and social quality in communities. Economy and environment, in initial development stages, oppose each other. Social welfare and economy generally develop simultaneously. To assess overall progress in sustainable development, an integrated and quantifiable framework is presented which defines five levels of sustainability. Increasing sustainability is characterized by growing responsibility for the impacts of man's actions in space and time. Through increased eco-efficiency and changed awareness, nations and companies arrive at a synergistic relationship between environment and economy. It is indicated that social security benefits expenditure increases by a factor 3.5 and carbon dioxide emissions per capita decreases by a factor 3 at each higher level of sustainability. Quantified differences in sustainability levels of 24 nations are shown. Priorities for improving and safeguarding sustainability are indicated.     

龙塘镇电子垃圾拆解区土壤和河流底泥重金属赋存形态及生态风险

龙塘镇是珠三角电子垃圾拆解区之一,采用AAS方法对该地土壤和河流底泥沉积物中5种重金属(Cd、Cr、Cu、Zn和Pb)含量进行测定分析,结果显示周围农田土壤中Cd含量是《国家土壤质量标准》二级标准的3倍左右,是广东省土壤背景值的20倍左右;拆解区土壤Cd超标最为严重,最高达5.67倍,超过广东省土壤背景值达36.17倍;拆解区下游0—1500 m河流底泥中Cd、Cr、Cu、Zn和Pb含量大幅增加且部分金属超标,Cd在0—40 cm深度内含量总体逐渐降低,仍远超背景值,Cu含量采样深度内递减规律最显著且在0—10 cm内含量超标,Cr、Zn和Pb除部分点位在表层积累较多外,其余与背景值相差不大且未超标.采用BCR(the Community Bureau of Reference)法提取重金属不同形态可知,底泥中Cd主要以弱酸溶态和可还原态为主,Cu主要以可氧化态存在,Cr主要以残渣态存在,而Zn和Pb则以可还原态为主;其中Cd的可提取态比例较高(60%),容易释放出来形成"二次污染".潜在生态风险结果表明,河流底泥中Cd生态危害程度属于极强(Ei320);其他金属Cr、Cu、Zn和Pb危害风险程度属于轻微(Ei40);金属Cd对整个RI值贡献最大(88%),应重点加强对Cd污染的防控.     

Bioenergy recovery from landfill gas: A case study in China

Landfill gas (LFG) utilization which means a synergy between environmental protection and bioenergy recovery was investigated in this study. Pressure swing adsorption technology was used in LFG purification, and laboratory experiment, pilot-scale test, and on-site demonstration were carried out in Shenzhen, China. In the laboratory experiment, A-type carbon molecular sieve was selected as the adsorbent by comparison of several other adsorbents. The optimal adsorption pressure and adsorption time were 0.25 MPa and 2 min, respectively, under which the product generation rate was 4.5 m³/h and the methane concentration was above 90%. The process and optimization of the pilot-scale test were also reported in the paper. The product gas was of high quality compared with the National Standard of Compressed Natural Gas as Vehicle Fuel (GB18047-2000), when the air concentration in feed gas was under 10.96%. The demonstration project was composed of a collection system, production system, and utilization system. The drive performance, environmental protection performance, and economic feasibility of the product gas — as alternative fuel in passenger car, truck, and bulldozer—were tested, showing the feasibility technology for LFG utilization.     

Enhanced hydrogen production in microbial electrolysis through strategies of carbon recovery from alkaline/thermal treated sludge

• High hydrogen yield is recovered from thermal-alkaline pretreated sludge. • Separating SFL by centrifugation is better than filtration for hydrogen recovery. • The cascaded bioconversion of complex substrates in MECs are studied. • Energy and electron efficiency related to substrate conversion are evaluated. The aim of this study was to investigate the biohydrogen production from thermal (T), alkaline (A) or thermal-alkaline (TA) pretreated sludge fermentation liquid (SFL) in a microbial electrolysis cells (MECs) without buffer addition. Highest hydrogen yield of 36.87±4.36 mgH₂/gVSS (0.026 m³/kg COD) was achieved in TA pretreated SFL separated by centrifugation, which was 5.12, 2.35 and 43.25 times higher than that of individual alkaline, thermal pretreatment and raw sludge, respectively. Separating SFL from sludge by centrifugation eliminated the negative effects of particulate matters, was more conducive for hydrogen production than filtration. The accumulated short chain fatty acid (SCFAs) after pretreatments were the main substrates for MEC hydrogen production. The maximum utilization ratio of acetic acid, propionic acid and n-butyric acid was 93.69%, 90.72% and 91.85%, respectively. These results revealed that pretreated WAS was highly efficient to stimulate the accumulation of SCFAs. And the characteristics and cascade bioconversion of complex substrates were the main factor that determined the energy efficiency and hydrogen conversion rate of MECs.     

Assigning results of the Tool for Sustainability Impact Assessment (ToSIA) to products of a forest-wood-chain

A Tool for Sustainability Impact Assessment (ToSIA) has been developed for assessing sustainability impacts of forest-wood-chains (FWCs). Sustainability is determined by analysing environmental, economic, and social sustainability indicators for all the production processes along the FWC. Results of the tool can be analysed at an aggregated level for complete FWCs, but for some applications it is useful to assign the indicator results to products of the chain.This paper presents a procedure in ToSIA to assign sustainability impacts to multiple output products of FWC. The procedure was tested and demonstrated with an example FWC from Scandinavia that included furniture and bio-energy production. Two different allocation criteria, carbon-based and economic value-based, were applied with different options for assigning the impacts on the sub-products of the chain. Three indicators representing the three pillars of the sustainability were chosen to demonstrate the procedure: production costs (economic), employment (social) and transport intensity (environmental).The results indicated that the allocation criteria greatly affect the indicator results assigned to the different products of FWCs. The selection of the allocation criterion depends on the question approached and on the availability of the needed process related data. The data availability is assured for the carbon-based allocation within ToSIA, as following the carbon flows within the chain is mandatory for any ToSIA application. Economic values of products, on the other hand, are more closely linked to the aims of the production processes of the value chains and are thereby meaningful allocation criteria in many cases. The allocation procedure of ToSIA was proved to be flexible allowing different criteria and still consistent in allocation of the various sustainability impacts of the FWCs.     

Sustainability assessment of entire forest value chains: Integrating stakeholder perspectives and indicators in decision support tools

The optimization of value chains is an important process to promote sustainable development, since value chains are closely linked to the satisfaction of human needs and combine different driving forces for environmental change. This article presents a methodological approach for the participatory development of value-chain wide sustainability indicator sets and their integration into a decision support tool in the specific case study of the chain “construction and refurbishment with wood”. There are numerous indicator sets for sustainable development of forests and sustainable forestry available at different levels, ranging from local, regional and national to global scale assessments. Some efforts were also made to integrate later production stages of forest value chains (such as wood processing) in the assessment scope (e.g. for chain-of-custody certification). However, no indicator set has so far been available covering environmental, social and economic aspects for the entire value chain of building with timber. This gap was closed through applied sustainability research in the project “Holzwende 2020: Sustainable future markets for wood in the building sector”.     

Emerging electrochemical processes for materials recovery from wastewater: Mechanisms and prospects

• Mechanisms for selective recovery of materials in electrochemical processes are discussed. • Wastewaters that contain recoverable materials are reviewed. • Application prospects are discussed from both technical and non-technical aspects. Recovering valuable materials from waste streams is critical to the transition to a circular economy with reduced environmental damages caused by resource extraction activities. Municipal and industrial wastewaters contain a variety of materials, such as nutrients (nitrogen and phosphorus), lithium, and rare earth elements, which can be recovered as value-added products. Owing to their modularity, convenient operation and control, and the non-requirement of chemical dosage, electrochemical technologies offer a great promise for resource recovery in small-scale, decentralized systems. Here, we review three emerging electrochemical technologies for materials recovery applications: electrosorption based on carbonaceous and intercalation electrodes, electrochemical redox processes, and electrochemically induced precipitation. We highlight the mechanisms for achieving selective materials recovery in these processes. We also present an overview of the advantages and limitations of these technologies, as well as the key challenges that need to be overcome for their deployment in real-world systems to achieve cost-effective and sustainable materials recovery.     

Sustainability measurement of product-service systems: Brazilian case studies about electric car-sharing

Modifying the traditional production system and the culture of consumption is necessary to achieve a sustainable society. The product-service system (PSS) business model allows companies to progressively add services to physical products, thus promoting more pro-sustainable business outcomes. The purpose of this work is to verify how a PSS model can contribute to sustainability by analyzing two electric car-sharing projects using a set of five factors. As a methodological strategy, a Systematic Literature Review and a case study of the two projects (VAMO and EMOTIVE) were performed. Findings show benefits generated by both projects as to environmental aspects, mainly related to gases emission. It was also possible to observe social benefits due to income development and environmental awareness. This paper thus contributes to the discussion of the potential of the PSS models and how they can leverage business models toward a more sustainable society. Although the results are applicable only in this case, this article can motivate new projects and contribute to enriching the debate about sustainable solutions, as the literature in this field still provides few case studies showing these types of applications.     

广东电子废物处理处置地区环境介质污染研究进展

广东省汕头市贵屿镇和清远市龙塘镇和石角镇是我国电子废物处理处置(EWT)典型地区,国内外学者对这些地区EWT活动造成的环境介质污染给予了相当的关注,尤其是近两、三年来开展了比较多的调查和研究.论文对相关调查研究的主要发现进行了系统的综述,内容包括广东EWT活动的主要特征、EWT活动可能释放的主要污染物、EWT活动产生的有机污染(多溴联苯醚、多氯联苯、多环芳烃和二噁英)、重金属污染(Cu、Pb、Zn、Ni、Cd、Cr)以及复合污染特征等,并讨论了未来的研究方向.     

Occurrence of veterinary antibiotics in struvite recovery from swine wastewater by using a fluidized bed

Antibiotics in wastewater pose pharmacological threats to phosphorous recovery. Recovered struvite particles possessed significantly antibiotic residues. Smaller granules contained much more antibiotics than the larger ones. Organic matters and struvite granulation process exerted significant impacts. Recovering phosphorus from livestock wastewater has gained extensive attention. The residue of veterinary antibiotics in the wastewater may be present in the recovered products, thereby posing pharmacological threats to the agricultural planting and human health. This study investigated antibiotic occurrence in the struvite particles recovered from swine wastewater by using a fluidized bed. Results revealed that tetracyclines possessed significant residues in the struvite granules, with the values ranging from 195.2 mg·kg⁻¹ to 1995.0 mg·kg⁻¹. As for fluoroquinolones, their concentrations varied from 0.4 mg·kg⁻¹ to 1104.0 mg·kg⁻¹. Struvite particles were of various sizes and shapes and displayed different antibiotic adsorption capacities. The data also showed that the smaller granules contained much more antibiotics than the larger ones, indicating that the fluidized granulation process of struvite crystals plays an important role on the accumulation of antibiotics. For tetracyclines, organic matters and struvite adsorption exerted significant impacts on tetracyclines migration. The outcomes underscore the need to consider the residues of antibiotics in resource recovery from wastewater because they exert pharmacological impacts on the utilization of recovered products.     

生物样品中含PBDEs在内的复合污染组分的抗雌激素效应

为初步探讨电子废物拆解导致的多溴二苯醚(PBDEs)及其类似物构成的复合污染的潜在生态/健康风险,从电子废物拆解区的三黄鸡血液和肝脏样品中提取了包含PBDEs在内的复合污染组分,分别体外暴露乳腺癌MCF-7细胞和MDA-MB-231细胞6d,检测细胞增殖和雌激素靶基因pS2的mRNA表达.结果表明,包含多种PBDEs在内的复合污染组分在不产生细胞毒性的前提下,可显著抑制MCF-7细胞增殖和雌激素靶基因pS2的mRNA表达,表现出抗雌激素活性.此结果提示由电子废物拆解造成的复合污染对生物体和人体可能存在潜在的生态/健康风险.     

Technologies for pollutant removal and resource recovery from blackwater: a review

● Blackwater is the main source of organics and nutrients in domestic wastewater. ● Various treatment methods can be applied for resource recovery from blackwater. ● Blackwater treatment systems of high integration and efficiency are the future trend. ● More research is needed for the practical use of blackwater treatment systems. Blackwater (BW), consisting of feces, urine, flushing water and toilet paper, makes up an important portion of domestic wastewater. The improper disposal of BW may lead to environmental pollution and disease transmission, threatening the sustainable development of the world. Rich in nutrients and organic matter, BW could be treated for resource recovery and reuse through various approaches. Aimed at providing guidance for the future development of BW treatment and resource recovery, this paper presented a literature review of BWs produced in different countries and types of toilets, including their physiochemical characteristics, and current treatment and resource recovery strategies. The degradation and utilization of carbon (C), nitrogen (N) and phosphorus (P) within BW are underlined. The performance of different systems was classified and summarized. Among all the treating systems, biological and ecological systems have been long and widely applied for BW treatment, showing their universality and operability in nutrients and energy recovery, but they are either slow or ineffective in removal of some refractory pollutants. Novel processes, especially advanced oxidation processes (AOPs), are becoming increasingly extensively studied in BW treatment because of their high efficiency, especially for the removal of micropollutants and pathogens. This review could serve as an instructive guidance for the design and optimization of BW treatment technologies, aiming to help in the fulfilment of sustainable human excreta management.     

Hydrothermal treatment of MSWI fly ash for simultaneous dioxins decomposition and heavy metal stabilization

Researches on the hydrothermal treatment of municipal solid waste incineration (MSWI) fly ash were conducted to eliminate dioxins and stabilize heavy metals. In order to enhance decomposing polychlorinated dibenzodioxins (PCDDs) and polychlorinated dibenzo-furans (PCDFs) during hydrothermal process, a strong reductant carbohydrazide (CHZ) is introduced. A hydrothermal reactor was set up by mixing raw MSWI fly ash or the pre-treated fly ash with water and then heated to a pre-set temperature; CHZ was spiked into solution according to specially defined dosage. Experimental results showed that under the temperatures of 518 K and 533 K, the decomposition rates of PCDDs/PCDFs were over 80% and 90%, respectively, by total concentration. However, their toxic equivalent (TEQ) decreased only slightly or even increased due to the rising in concentration of congeners 2, 3, 7, 8-TCDD/TCDF, which might be resulted from the highly chlorinated congeners losing their chlorine atoms and being degraded during the hydrothermal process. Better results of TEQ reduction were also obtained under the higher tested temperature of 533 K and reactor with addition of 0.1%wt CHZ was corresponded to the best results. Good stabilization of heavy metals was also obtained in the same hydrothermal process especially when ferrous sulphate was added as auxiliary agent.     

Ammonia removal from low-strength municipal wastewater by powdered resin combined with simultaneous recovery as struvite

• Powdered resin was employed for ammonia recovery from municipal wastewater. • Powdered resin achievedefficient ammonia removal under various working conditions. • Co-existing cations indicated competitive adsorption of ammonia. • Ammonia was recoveredby two-stage crystallization coupled with ion exchange. Low-strength municipal wastewater is considered to be a recoverable nutrient resource with economic and environmental benefits. Thus, various technologies for nutrient removal and recovery have been developed. In this paper, powdered ion exchange resin was employed for ammonia removal and recovery from imitated low-strength municipal wastewater. The effects of various working conditions (powdered resin dosage, initial concentration, and pH value) were studied in batch experiments to investigate the feasibility of the approach and to achieve performance optimization. The maximum adsorption capacity determined by the Langmuir model was 44.39 mg/g, which is comparable to traditional ion exchange resin. Further, the effects of co-existing cations (Ca²⁺, Mg²⁺, K⁺) were studied. Based on the above experiments, recovery of ammonia as struvite was successfully achieved by a proposed two-stage crystallization process coupled with a powdered resin ion exchange process. Scanning electron microscopy (SEM) and X-ray diffractometry (XRD) results revealed that struvite crystals were successfully gained in alkaline conditions (pH= 10). This research demonstrates that a powdered resin and two-stage crystallization process provide an innovative and promising means for highly efficient and easy recovery from low-strength municipal wastewater.     

扎龙河滨湿地水体营养化污染特征及水环境恢复对策

对扎龙湿地水体富营养化污染状况进行调查，指出沼泽湿地、湖泊湿地TN、TP、BOD，等多项水质指标都已严重超标；阐明了营养物年季变化特征；总结了扎龙湿地水体富营养化发展趋势；提出了保障湿地供水、生态工程恢复及控制流域地表水污染的多项管理策略。