The cities of today present requirements that are dissimilar to those of the past. There are cities where the industrial and service sectors are in decline, and there are other cities that are just beginning their journey into the technological and industrial sectors. In general, the political and social realms have been restructured in terms of economics, which has resulted in an entirely different shape to the primitive structures of civilization. As people begin to understand the dynamic nature of landscapes, they stop seeing landscapes as a static scene. Sustainable cities must be simultaneously economically viable, socially just, politically well managed and ecologically sustainable to maximize human comfort. The present research suggests a multi-disciplinary approach for attaining a holistic understanding of urban environmental quality and human well-being in relation to sustainable urban development.

A rough estimate of the annual amount of sulfur, arsenic, mercury and fluoride emission from spontaneous combustion of coal gangue in China was determined. The weighted mean concentrations of S, As, Hg, and F in coal gangue are 1.01%, 7.98, 0.18, and 365.54 mg/kg, respectively. Amounts of S, As, Hg, and F emissions from coal gangue spontaneous combustion show approximately 1.13 Mt, and 246, 45, and 63,298 tons in 2013, respectively. The atmospheric release amount of sulfur from coal gangue is more than one tenth of this from coal combustion, and the amounts of As, Hg, and F are close to or even exceed those from coal combustion. China's coal gangue production growth from 1992 to 2013 show an obvious growth since 2002. It may indicate that Chinese coal gangue has become a potential source of air pollution, which should be included in emission inventories.

The purpose of this study was to assess the ecotoxic potential of a new zero-valent iron nanomaterial produced for the elimination of chlorinated pollutants at contaminated sites. Abiotic dechlorination through the newly developed nanoscale zero-valent iron material and its effects on dechlorinating bacteria were investigated in anaerobic batch and column experiments. The aged, i.e. oxidized, iron material was characterization with dynamic light scattering, transmission electron microscopy and energy dispersive x-ray analysis, x-ray diffractometry and cell-free reactive oxygen measurements. Furthermore, it was evaluated in aerobic ecotoxicological test systems with algae, crustacean, and fish, and also applied in a mechanism specific test for mutagenicity. The anaerobic column experiments showed co-occurrence of abiotic and biological dechlorination of the common groundwater contaminant perchloroethene. No prolonged toxicity of the nanomaterial (measured for up to 300 days) towards the investigated dechlorinating microorganism was observed. The nanomaterial has a flake like appearance and an inhomogeneous size distribution. The toxicity to crustacean and fish was calculated and the obtained EC50 values were 163 mg/L and 458 mg/L, respectively. The nanomaterial showed no mutagenicity. It physically interacted with algae, which had implications for further testing and the evaluation of the results. Thus, the newly developed iron nanomaterial was slightly toxic in its reduced state but no prolonged toxicity was recorded. The aquatic tests revealed a low toxicity with EC50 values ≥ 163 mg/L. These concentrations are unlikely to be reached in the aquatic environment. Hence, this nanomaterial is probably of no environmental concern not prohibiting its application for groundwater remediation.

Investigation of microbial communities of soils contaminated by antimony (Sb) and arsenic (As) is necessary to obtain knowledge for their bioremediation. However, little is known about the depth profiles of microbial community composition and structure in Sb and As contaminated soils. Our previous studies have suggested that historical factors (i.e., soil and sediment) play important roles in governing microbial community structure and composition. Here, we selected two different types of soil (flooded paddy soil versus dry corn field soil) with co-contamination of Sb and As to study interactions between these metalloids, geochemical parameters and the soil microbiota as well as microbial metabolism in response to Sb and As contamination. Comprehensive geochemical analyses and 16S rRNA amplicon sequencing were used to shed light on the interactions of the microbial communities with their environments. A wide diversity of taxonomical groups was present in both soil cores, and many were significantly correlated with geochemical parameters. Canonical correspondence analysis (CCA) and co-occurrence networks further elucidated the impact of geochemical parameters (including Sb and As contamination fractions and sulfate, TOC, Eh, and pH) on vertical distribution of soil microbial communities. Metagenomes predicted from the 16S data using PICRUSt included arsenic metabolism genes such as arsenate reductase (ArsC), arsenite oxidase small subunit (AoxA and AoxB), and arsenite transporter (ArsA and ACR3). In addition, predicted abundances of arsenate reductase (ArsC) and arsenite oxidase (AoxA and AoxB) genes were significantly correlated with Sb contamination fractions, These results suggest potential As biogeochemical cycling in both soil cores and potentially dynamic Sb biogeochemical cycling as well.

Size-segregated particulate pollutants (PM<0.95, PM0.95–1.5, PM1.5–3.0, PM3.0–7.2 and PM>7.2) were collected over Patiala (30.33°N, 76.40°E; 250 m amsl), a semi-urban city located in northwestern Indo-Gangetic Plain (IGP), during October, 2012 to September, 2013. Mass concentration of total suspended particulates (TSP), derived by summation of particulate (aerosol) mass in different size range, varied from 88 to 387 μg m−3 with highest mass concentration (∼55% of total mass) in submicron size (PM<0.95) during the entire study period, which broadly reflects relative higher contribution of various anthropogenic sources (emissions from biomass and bio-fuel burning, vehicles, thermal power plants, etc) to ambient particles. Concentration of SO42−, NO3−, NH4+, K+ and Ca2+ exhibited large variability ranging from 0.52 to 40, 0.20 to 19, 0.14 to 12, 0.06 to 5.3 and 0.08 to 5.6 μg m−3, respectively, in different size ranges with varying size distribution for most of the species, except NH4+. A strong linear correlation (r = 0.97) between (SO42− + NO3−) and (K+ + NH4+) concentrations has been observed in submicron particles collected in different seasons, suggesting the formation of secondary inorganic salts. However, relatively poor correlation is observed in higher size ranges where significant correlation between (SO42− + NO3−) and (Ca2+ + Mg2+) has been observed. These observations indicate the acid neutralization by dust in coarser modes of particles. Chemical composition of submicron particulates (PM<0.95) in different seasons as well as for whole year was used to identify PM sources through the application of Positive Matrix Factorization (PMF, version 5.0) model. Based on annual data, PMF analyses suggests that six source factors namely biomass burning emission (24%), vehicular emission (22%), secondary organic aerosols (20%), power plant emission (13%), secondary inorganic aerosols (12%) and mineral dust (9%) contribute to PM<0.95 loading over the study region. Such studies are important in dispersion modeling, health impact assessment, and planning of pollution mitigation strategies.

Several pollutants, which include metals, are present in the Antarctic atmosphere, snow, marine and terrestrial organisms. This work reports the elements incorporated by Usnea sp thalli in Potter Peninsula, 25 de Mayo (King George) Island, South Shetlands, Antarctica. Geological origin was analyzed as possible sources of elements. For this purpose, correlations were done using a geochemical tracer, principal component analysis and enrichment factors were computed. Lithophile elements from particulate matter were present in most of the sampling sites. Bromine, Se and Hg showed the highest enrichment factors suggesting other sources than the particulate matter. Mercury values found in Usnea sp were in the same range as those reported for Deception Island (South Shetlands) and remote areas from the Patagonia Andes.

Low tech photovoltaic panels (PVPs) installed in the early ’80s are now coming to the end of their life cycle and this raises the problem of their proper disposal. As panels contain potentially toxic elements, unconventional, complex and costly procedures are required to avoid environmental health risks and in countries where environmental awareness and economic resources are limited this may be especially problematic. This work was designed to investigate potential risks from improper disposal of these panels. To accomplish this aim an exhausted panel was broken into pieces and these were placed in water for 30 days. The resulting leached solution was analyzed to determine chemical release or used in toto, to determine its potential toxicity in established tests. The end points were seed germination (on Cucumis sativus and Lens culinaris) and effects on early development in three larval models: two crustaceans, Daphnia magna and Artemia salina, and the sea urchin Paracentrotus lividus. Our results show that the panels release small amounts of electrolytes (Na, Ca and Mg) into solution, along with antimony and manganese, with a concentration under the accepted maximum contaminant level, and nickel at a potentially toxic concentration. Developmental defects are seen in the plant and animal test organisms after experimental exposure to the whole solution leached from the broken panel. The toxic effects revealed in in vitro tests are sufficient to attract attention considering that they are exerted on both plants and aquatic animals and that the number of old PVPs in disposal sites will be very high.

The increasing emphasis on the assessment and monitoring of marine ecosystems has revealed the need to use appropriate biological indicators for these areas. Enzyme activities and histopathology are increasingly being used as indicators of environmental stress since they provide a definite biological end-point of pollutant exposure. As part of an ecotoxicological assessment of Mersin Bay, EROD enzyme activity and histopathological response in selected organs and tissues of two species of fish, Mullus barbatus (red mullet) and Liza ramada (thinlip grey mullet), captured from area were examined. Pollutant (Organochlorines (OC), alkylphenols (APs) and BPA) levels and biomarker responses in tissue samples were evaluated together for their potential to alter the metabolism and cellular aspects in liver and gonad. Elevated induction of EROD activity and histopathological alterations in contaminated samples from Mersin Bay was observed compared to reference site indicating the exposure to potential pollutants.

High levels of polychlorinated dibenzo-p-dioxins (PCDDs) and polychlorinated dibenzofurans (PCDFs) were detected in free-range eggs, and these levels reached a concentration of 29.84 ± 7.45 pg of WHO-TEQ/g of fat. This value exceeded the EU maximum permitted level of 2.5 pg of WHO-TEQ/g of fat for PCDD/F congeners by twelve-fold. A chemical analysis (HRGC-HRMS) revealed elevated amounts of OCDD, OCDF, HxCDD, HpCDD and HpCDF. During the investigation, samples of feed, soil, wall scrapings, wooden ceiling of the henhouse and tissues from laying hens were examined for dioxin contents (30 samples altogether). The long and complicated investigation found that the source of dioxins in the poultry farm was pentachlorophenol-treated wood, which was used as structural components in the 40-year-old farm building adapted to a henhouse. The wooden building material contained PCDD/Fs at a concentration of 3922.60 ± 560.93 pg of WHO-TEQ/g and 11.0 ± 2.8 μg/kg of PCP. The potential risk associated with dioxin intake was characterized by comparing the theoretically calculated weekly and monthly intakes with the toxicological reference values (TRVs), namely the Tolerable Weekly Intake (TWI) and Provisional Tolerable Monthly Intake (PTMI) values of 14 pg of WHO-TEQ/kg of bw and 70 pg of WHO-TEQ/kg of bw, respectively. The intake of dioxins estimated for high egg consumers (approximately 5–6 eggs/week) exceeded the TWI and PTMI values, which may pose a risk of delayed adverse health effects. The estimated dose of PCDD/Fs and DL-PCBs for children consuming 5 eggs per week exceeded the TWI by as much as 450% because of their nearly 5-fold-lower body weight. Although the dioxin intake estimated for the average consumption of eggs in the general population did not exceed any of the TRVs applied (58.7% TWI and 51.1% PTMI), such a situation should be considered unacceptable from a public health perspective because eggs are not the only source of these contaminants.

Antibiotic mycelial fermentation residues (AMFRs), which are emerging solid pollutants, have been recognized as hazardous waste in China since 2008. Nitrogen (N), which is an environmental sensitivity element, is largely retained in AMFR samples derived from fermentation substrates. Pyrolysis is a promising technology for the treatment of solid waste. However, the outcomes of N element during the pyrolysis of AMFRs are still unknown. In this study, the conversion of N element during the pyrolysis of AMFRs was tracked using XPS (X-ray photoelectron spectroscopy) and online TG-FTIR-MS (Thermogravimetry-Fourier transform infrared-Mass spectrometry) technology. In the AMFR sample, organic amine-N, pyrrolic-N, protein-N, pyridinic-N, was the main N-containing species. XPS results indicated that pyrrolic-N and pyridinic-N were retained in the AMFR-derived pyrolysis char. More stable species, such as N-oxide and quaternary-N, were also produced in the char. TG-FTIR-MS results indicated that NH3 and HCN were the main gaseous species, and their contents were closely related to the contents of amine-N and protein-N, and pyrrolic-N and pyridinic-N of AMFRs, respectively. Increases in heating rate enhanced the amounts of NH3 and HCN, but had less of an effect on the degradation degree of AMFRs. N-containing organic compounds, including amine-N, nitrile-N and heterocyclic-N, were discerned from the AMFR pyrolysis process. Their release range was extended with increasing of heating rate and carbon content of AMFR sample. This work will help to take appropriate measure to reduce secondary pollution from the treatment of AMFRs.