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Metal partitioning in plant–substrate–water compartments under EDDS-assisted phytoextraction of pyrite waste with Brassica carinata A. Braun Full text
2015
Vamerali, T. | Bandiera, M. | Lucchini, P. | Mosca, G.
Soil amendment with chelating agents can increase metal uptake and translocation in biomass species through increased metal bioavailability together with possible increases in metal leaching. In this study, we assessed the efficiency and environmental risk of the fast-degradable [S,S]-EDDS. Cu, Pb and Zn uptake in pot-cultivated Brassica carinata A. Braun, residual substrate metal bioavailability and leaching were investigated after one cycle of EDDS-assisted phytoextraction in mixed metal-contaminated pyrite waste, which is characterised by high Fe content. The chelator was supplied at doses of 2.5 and 5 mmol EDDS kg⁻¹waste 1 week before harvest and 1 mmol EDDS kg⁻¹waste repeated five times at 5- and 10-day intervals during the growing cycle. Here we demonstrate that EDDS generally increases shoot metal concentrations—especially of Cu—but only seldom improves removals because of markedly impaired growth. Considerable phytotoxicity and Cu leaching occurred under repeated EDDS treatments, although environmental risks may also arise from the single, close-to-harvest applications as Cu bioavailability in waste at plant harvest still remained very high (up to +67 % at 5 mmol EDDS kg⁻¹vs. untreated controls). The residual bioavailability of Zn and Pb was instead generally reduced, perhaps due to shifts in cation exchange, whereas Fe mobility was not apparently affected. The amount of metals removed by plants represented a small fraction of the bioavailable pool (<1 %), and mobilised metals quickly reached deep layers in the substrate. We conclude that EDDS assistance can provide only some limited opportunities for improving phytoremediation of pyrite waste, major benefits being achieved by low doses to be traditionally applied shortly before harvest, with due attention to limiting groundwater pollution.
Show more [+] Less [-]Methods for assessing the energy-saving efficiency of industrial symbiosis in industrial parks Full text
2015
Li, Wenfeng | Cui, Zhaojie | Han, Feng
The available energy resources are being depleted worldwide. Industrial symbiosis (IS) provides a promising approach for increasing the efficiency of energy utilization, with numerous studies reporting the superiority of this technology. However, studies quantifying the energy-saving efficiency of IS remain insufficient. This paper proposes an index system for the quantitative evaluation of the energy-saving efficiency of IS. Both energy-saving and financial indexes were selected, the former include the IS energy-saving index, the contribution rate of energy saved through IS, fractional energy savings, and cut rate of energy consumption per total output value; and the latter include the IS investment payback period, IS input–output ratio, net present value (NPV), and internal rate of return (IRR) of IS. The proposed methods were applied to a case study on the XF Industrial Park (XF IP), in the city of Liaocheng in Shandong Province of China. Three energy-saving channels using IS were found in the XF IP: (a) utilizing the energy of high-temperature materials among industrial processes, (b) recovering waste heat and steam between different processes, and (c) saving energy by sharing infrastructures. The results showed that the energy efficiency index of IS was 0.326, accounting for 34.6 % of the comprehensive energy-saving index in 2011, and the fractional energy-savings were 12.42 %. The index of energy consumption per total industrial output value varied from 90.9 tce/MRMB to 51.6 tce/MRMB. Thus, the cut rate of energy consumption per total industrial output value was 43.42 %. The average values of the IS input–output ratio was 406.2 RMB/tce, 57.2 % lower than the price of standard coal. Static investment payback period in the XF IP was 8.5 months, indicating that the XF IP began to earn profit 8.5 months after the construction of all IS modes. The NVP and IRR of each IS mode in the XF IP were greater than zero, with average values equal to 1,789.96 MRMB and 140.96 %, respectively. The computation result for each indicator revealed that IS could lead to the use of energy with high efficiency and lighten the financial burden of enterprises in the XF IP. And the proposed index system may help IPs and EIPs to make strategic decisions when designing IS modes.
Show more [+] Less [-]Statistical, time series, and fractal analysis of full stretch of river Yamuna (India) for water quality management [Erratum: Oct. 2020, v.27(33), pp.42189-42191] Full text
2015
Parmar, Kulwinder Singh | Bhardwaj, Rashmi
River water is a major resource of drinking water on earth. Management of river water is highly needed for surviving. Yamuna is the main river of India, and monthly variation of water quality of river Yamuna, using statistical methods have been compared at different sites for each water parameters. Regression, correlation coefficient, autoregressive integrated moving average (ARIMA), box-Jenkins, residual autocorrelation function (ACF), residual partial autocorrelation function (PACF), lag, fractal, Hurst exponent, and predictability index have been estimated to analyze trend and prediction of water quality. Predictive model is useful at 95 % confidence limits and all water parameters reveal platykurtic curve. Brownian motion (true random walk) behavior exists at different sites for BOD, AMM, and total Kjeldahl nitrogen (TKN). Quality of Yamuna River water at Hathnikund is good, declines at Nizamuddin, Mazawali, Agra D/S, and regains good quality again at Juhikha. For all sites, almost all parameters except potential of hydrogen (pH), water temperature (WT) crosses the prescribed limits of World Health Organization (WHO)/United States Environmental Protection Agency (EPA).
Show more [+] Less [-]Formation and removal of dissolved organic nitrogen (DON) in membrane bioreactor and conventional activated sludge processes Full text
2015
Han, Xiaomeng | Wang, Zhiwei | Ma, Jinxing | Zheng, Junjian | Wang, Pan | Wu, Zhichao
Dissolved organic nitrogen (DON) has become a growing concern due to its contribution to eutrophication and nitrogenous disinfection byproducts (N-DBPs) formation. However, information of DON in membrane bioreactors (MBRs) is very limited. In this study, occurrence, transformation and fate of DON in an MBR system were systematically investigated. MBR sludge showed a larger hydrolysis rate of particle organic nitrogen (PON) and also a higher transformation rate of DON to nitrate compared to conventional activated sludge (CAS). For long-term experiments, MBR achieved higher DON removal efficiency at low temperature than CAS; however, at high temperature, the effluent DON concentrations were almost the same in both systems. Batch tests on DON biodegradability showed that DON concentration increased and large molecular weight DON accumulated after 3-h aeration at low temperature, while DON concentration continuously decreased with the increase of aeration time at high temperature. The obtained results provide insights in DON removal in MBRs for meeting increasingly stringent regulations in terms of nitrogen removal.
Show more [+] Less [-]Effect of vinegar residue compost amendments on cucumber growth and Fusarium wilt Full text
2015
Du, Nanshan | Shi, Lu | Du, Lantian | Yuan, Yinghui | Li, Bin | Sang, Ting | Sun, Jin | Shu, Sheng | Guo, Shirong
Fusarium wilt of cucumber caused by Fusarium oxysporum f. sp. cucumerinum J. H. Owen is one of the major destructive soilborne diseases and results in considerable yield losses. Methyl bromide was once the most effective disease control method but has been confirmed as harmful to the environment. Using suppressive media as biological controls to assist crop growth is becoming popular. In this study, Fusarium wilt of cucumber was successfully controlled by a newly identified suppressive media: vinegar residue compost-amended media (vinegar residue compost mixed with peat and vermiculite in a 6:3:1 ratio (v/v) vinegar residue substrate (VRS). Greenhouse experiments were carried out to evaluate the effect of VRS on the growth of cucumber seedlings and disease suppression. The control was peat/vermiculite (2:1, v/v). To identify the mixed media most suitable for the growth of plants and their suppressiveness indicators, we evaluated the biological characteristics of cucumber, the physicochemical and biochemical properties of the growth media, and the enzyme activities. Total organic C (Cₒᵣg), microbial biomass C (Cₘᵢc), basal respiration (Rₘᵢc), and enzyme (catalase, invertase, urease, proteinase, phosphatase, β-glucosidase, and hydrolysis of fluorescein diacetate) activities increased significantly after vinegar waste compost amendment. The compost media also showed a significantly positive effect on the growth of cucumber seedlings and the suppression of the disease severity index (DSI, 38 % reduction). The cucumber rhizosphere population of F. oxysporum f. sp. cucumerinum (FOC) was significantly lower in VRS than in the control. These results demonstrate convincingly that vinegar residue compost-amended media has a beneficial effect on cucumber growth and could be applied as a method for biological control of cucumber Fusarium wilt.
Show more [+] Less [-]Indoor/outdoor relationships of bioaerosol concentrations in a retirement home and a school dormitory Full text
2015
Faridi, Sasan | Hassanvand, Mohammad Sadegh | Naddafi, Kazem | Yunesian, Masud | Nabizadeh, Ramin | Sowlat, Mohammad Hossein | Kashani, Homa | Gholampour, Akbar | Niazi, Sadegh | Zare, Ahad | Nazmara, Shahrokh | Alimohammadi, Mahmood
The concentrations of bacterial and fungal bioaerosols were measured in a retirement home and a school dormitory from May 2012 to May 2013. In the present work, two active and passive methods were used for bioaerosol sampling. The results from the present work indicated that Bacillus spp., Micrococcus spp., and Staphylococcus spp. were the dominant bacterial genera, while the major fungal genera were Penicillium spp., Cladosporium spp., and Aspergillus spp. The results also indicated that the indoor-to-outdoor (I/O) ratios for total bacteria were 1.77 and 1.44 in the retirement home and the school dormitory, respectively; the corresponding values for total fungal spores were 1.23 and 1.08. The results suggested that in addition to outdoor sources, indoor sources also played a significant role in emitting bacterial and fungal bioaerosols in the retirement home and the school dormitory indoor.
Show more [+] Less [-]Determination of in vivo estrogenic potential of Di-isobutyl phthalate (DIBP) and Di-isononyl phthalate (DINP) in rats Full text
2015
Sedha, Sapna | Gautam, A. K. (Anil Kumar) | Verma, Y. | Ahmad, R. | Kumar, Sunil
Estrogenic potential of Di-isobutyl phthalate (DIBP) and Di-isononyl phthalate (DINP) was studied using two different test systems. Two different doses of DIBP (250 and 1250 mg/kg) and DINP (276 and 1380 mg/kg) were administered to immature female rats (20 days old) orally once daily for 3 and 20 days in uterotrophic and pubertal assay, respectively. The animals were sacrificed on day 4 and day 41 in case of 3-day uterotrophic and 20-day pubertal assay, respectively. The results indicated that non-significant alterations in uterine and ovarian wet weight were observed in both the DIBP- and DINP-treated groups while the uterus weight increased significantly (i.e., 4–6 times) in the Diethylstilbesterol (DES)-treated group in both the assays. In the present study, precocious vaginal opening occurred at 26 days of age in the DES-treated group with a mean body weight of 30.39 ± 1.08 g. However, no precocious vaginal opening was found in any of the DIBP- and DINP-treated groups. The results indicated that both the phthalate compounds were unable to induce elevation in the uterine weight in both the assays and unable to cause vaginal opening indicating non-estrogenic potential of both the phthalate compounds, i.e., DIBP and DINP in vivo.
Show more [+] Less [-]Enhanced photodegradation of pentachlorophenol by single and mixed nonionic and anionic surfactants using graphene–TiO2 as catalyst Full text
2015
Zhang, Yaxin | He, Xin | Zeng, Guangming | Chen, Tan | Zhou, Zeyu | Wang, Hongtao | Lu, Wenjing
The photodegradation of pentachlorophenol (PCP) in a surfactant-containing (single and mixed) complex system using graphene–TiO₂ (GT) as catalyst was investigated. The objective was to better understand the behavior of surfactants in a GT catalysis system for its possible use in remediation technology of soil contaminated by hydrophobic organic compounds (HOCs). In a single-surfactant system, surfactant molecules aggregated on GT via hydrogen bonding and electrostatic force; nonideal mixing between nonionic and anionic surfactants rendered GT surface with mixed admicelles in a mixed surfactant system. Both effects helped incorporating PCP molecules into surfactant aggregates on catalyst surface. Hence, the targeted pollutants were rendered easily available to photo-yielded oxidative radicals, and photodegradation efficiency was significantly enhanced. Finally, real soil washing-photocatalysis trials proved that anionic–nonionic mixed surfactant soil washing coupled with graphene–TiO₂ photocatalysis can be one promising technology for HOC-polluted soil remediation.
Show more [+] Less [-]Phenolic profile of Dunaliella tertiolecta growing under high levels of copper and iron Full text
2015
López, Aroa | Rico, Milagros | Santana-Casiano, J Magdalena | González, Aridane G. | González-Dávila, Melchor
The present study investigates the phenolic profile of exudates and extracts of the green algae Dunaliella tertiolecta, harvested in natural seawater in the absence (control) and in the presence of Cu(II) (315 and 790 nmol L⁻¹) and Fe(III) (900 nmol L⁻¹) in order to identify and quantify the phenolic compounds produced under metallic stress conditions. The presence of metal ions modifies the growth of cells and changes cell metabolism by producing phenolic compounds adapted to the solution. The use of reversed-phase high-performance liquid chromatography (RP-HPLC) permitted the identification of 14 phenolic constituents. The concentration and type of polyphenols detected in cell extracts and in solution are directly related with the metal and its concentration during growth cultures, achieving 1.4 times higher levels of polyphenols under 790 nmol Cu(II) L⁻¹ with respect to the control experiments. Microalga excretes polyphenols to be adapted to the environmental conditions. Gentisic acid, (+) catechin and (−) epicatechin, the most prominent phenolic compounds detected in the algae extracts, showed high antioxidant activity in inhibiting 1,1-diphenyl-2-picrylhydrazyl (DPPH) radicals. This potent activity may be related to its presence in cells and exudates in high concentrations.
Show more [+] Less [-]Risks of large-scale use of systemic insecticides to ecosystem functioning and services Full text
2015
Chagnon, Madeleine | Kreutzweiser, David | Mitchell, Edward A.D. | Morrissey, Christy A. | Noome, Dominique A. | Van der Sluijs, Jeroen P.
Large-scale use of the persistent and potent neonicotinoid and fipronil insecticides has raised concerns about risks to ecosystem functions provided by a wide range of species and environments affected by these insecticides. The concept of ecosystem services is widely used in decision making in the context of valuing the service potentials, benefits, and use values that well-functioning ecosystems provide to humans and the biosphere and, as an endpoint (value to be protected), in ecological risk assessment of chemicals. Neonicotinoid insecticides are frequently detected in soil and water and are also found in air, as dust particles during sowing of crops and aerosols during spraying. These environmental media provide essential resources to support biodiversity, but are known to be threatened by long-term or repeated contamination by neonicotinoids and fipronil. We review the state of knowledge regarding the potential impacts of these insecticides on ecosystem functioning and services provided by terrestrial and aquatic ecosystems including soil and freshwater functions, fisheries, biological pest control, and pollination services. Empirical studies examining the specific impacts of neonicotinoids and fipronil to ecosystem services have focused largely on the negative impacts to beneficial insect species (honeybees) and the impact on pollination service of food crops. However, here we document broader evidence of the effects on ecosystem functions regulating soil and water quality, pest control, pollination, ecosystem resilience, and community diversity. In particular, microbes, invertebrates, and fish play critical roles as decomposers, pollinators, consumers, and predators, which collectively maintain healthy communities and ecosystem integrity. Several examples in this review demonstrate evidence of the negative impacts of systemic insecticides on decomposition, nutrient cycling, soil respiration, and invertebrate populations valued by humans. Invertebrates, particularly earthworms that are important for soil processes, wild and domestic insect pollinators which are important for plant and crop production, and several freshwater taxa which are involved in aquatic nutrient cycling, were all found to be highly susceptible to lethal and sublethal effects of neonicotinoids and/or fipronil at environmentally relevant concentrations. By contrast, most microbes and fish do not appear to be as sensitive under normal exposure scenarios, though the effects on fish may be important in certain realms such as combined fish-rice farming systems and through food chain effects. We highlight the economic and cultural concerns around agriculture and aquaculture production and the role these insecticides may have in threatening food security. Overall, we recommend improved sustainable agricultural practices that restrict systemic insecticide use to maintain and support several ecosystem services that humans fundamentally depend on.
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