Abstract: Establishment of exotic species in the natural secondary forest and Pinus kesiya forest regions is common in Lancang County, southwestern Yunnan province, but their effects on soil properties and quality have not been fully studied. This research analyzed the effects of Eucalyptus plantation on soil physical and chemical properties, and evaluated the soil quality after Eucalyptus plantation replaced natural secondary evergreen broad-leaved forest and Pinus kesiya plantation. It was found that soil porosity, soil water content, soil pH, soil organic matter, exchangeable calcium, exchangeable magnesium and microelement decreased, soil bulk density increased and soil aeration permeability became very low after establishment of Eucalyptus . However, with forest litter retained, the contents of soil N, P and K had been rising in the case of applying fertilizer at the initial stage of Eucalyptus introduction. The soil quality indexes ( SQI ) under Eucalyptus plantation were lower than those under the natural secondary evergreen broadleaved forest and Pinus kesiya plantation. The SQI of soils in Eucalyptus plantation which replaced Pinus kesiya plantation lands (SQI = 0.208) was lower than that of soils in Eucalyptus plantation which replaced natural secondary evergreen broad-leaved forest lands (SQI = 0.269). The study results showed that replacement of natural secondary evergreen broad-leaved forest and Pinus kesiya plantation by Eucalyptus plantation has changed soil properties and lowered soil quality. The secondary evergreen broad-leaved forest vegetation that restored naturally is more favorable to maintaining and improving soil quality

Abstract: Selected metals (Cr, Ni, Cu, Pb, Zn, Cd and As) in surface sediments from the Pearl River Estuary (PRE) and Daya Bay (DYB) were analyzed to observe their total concentrations and chemical phase portioning. It was shown that the amounts of all contents, except Pb, have decreased over the past decade. The mean concentrations in PRE, excluding Pb, were significantly higher than those in DYB. Based on the PLI and mERM-Q, it was revealed that the highest potential ecological risk zones were in the northwest of PRE and sub-basins of DYB. An overwhelming majority of sediments had a 21% probability of toxicity in PRE and 9% probability of toxicity in DYB. The speciation analyzed by the optimized BCR sequential extraction method showed that, in both areas, Cr, As and Ni were present dominantly in the residual fraction and thus of low bioavailability, while Cd and Pb were found to be abundant in the non-residual fraction and thus of high potential availability, indicating significant anthropogenic sources. The partitioning of Cu and Zn showed a significant difference between the two areas. The source analysis shows that the pollutants resulted primarily from anthropogenic material, and secondly from the input of natural weathering products in PRE, while being mainly attributed to natural geological sources of metals, followed by industrial wastewater and aquaculture activity in DYB.

Abstract: In order to support decision-making in design of wastewater and sludge management within the European Union, the EU FP7 project ROUTES has performed technical development aimed at sludge minimisation, the enabling of agricultural use of sludge and sludge resource recovery. Technical, economic and environmental assessment has been performed for ten case studies in which model (non-existent) reference plants of different size and configuration, representative of real wastewater treatment plants in Europe, have been considered to be upgraded to solve different common problems, based on the new knowledge from the technology development carried out within the project. This paper reports on the methodology used in the assessment with examples of obtained results for three of the case studies. The methodology in particular highlights some critical points that need further attention when similar upgrading is considered in real cases.

Abstract: In this study, residual polymer concentration in sludge filtrate was measured by measuring the absorbance of samples at 190 nm. In addition, the method was used to determine the optimum polymer dose required to condition sludge. The optimum dose determined by the UV-vis method was compared to the optimum doses determined by the capillary suction time (CST) and filtration tests. The results showed the UV-vis method was in close agreement with the CST and filtration tests in determining the optimum polymer dose. The advantage of the UV-vis method over other methods is that it can be used in-line at wastewater treatment plants for monitoring and optimizing polymer dose

Abstract: Landfill Leachates are a potential source of soil and water contamination. Biological remediation techniques are most often employed for treating landfill leachates. The nature of microorganisms dwelling in sludge flocs determines process performance. Samples were taken at different steps that constitute the nitrification-denitrification treatment of leachate in a municipal landfill located in Northern Spain. Process effectiveness was evaluated. Microbiological characterization of samples was performed by means of classical culturing. Also, molecular techniques (i.e., PCR-DGGE and DNA sequencing) were used to characterize the samples. An evolution of the microbial community composition was observed throughout the treatment process. Amplification, electrophoresis, and DNA sequencing steps were completed accurately and some β-proteobacteria related with waste treatment and composting processes could be identified

Abstract: Bioremediation of PAHs from oil-contaminated soils was investigated. Bacillus licheniformis and Bacillus mojavensis , were inoculated in rhizospheric soil with Festuca aroundiacea in a greenhouse study. The concentration of PAHs in the rhizosphere of soil inoculated with both bacteria were significantly (p < 0.05) reduced compared to the non-inoculated soil. PAH concentrations in shoots were largely independent of those in soil, roots, or rhizosphere soil. In the soil inoculated with both bacteria, the concentration of PAHs in roots and shoots of the plant was less than for other treatments. Results showed that the plant-promoted biodegradation was the predominant contribution to remediation of soil PAHs.

Abstract: Breaking the gel-like structure of sludge by disrupting the extracellular polymeric substances (EPS) with specific enzyme -protease- application was investigated. After 8 hours of incubation, the final cake solid content of sludge increased more than 20% with protease pretreatment.FESEM images taken from protease treated-unconditioned samples revealed the significance of proteins in sludge structure. Protease pre-treatment improved the removal of major sulfur odors. Decrease in total amount of MT, DMS, DMDS, CS 2 and H 2 S production in the headspace was found 32%, 41%, 36%, 34% (5 mg/l protease) and 58% (15 mg/l protease) respectively in the unconditioned samples. Addition of protease led to an increased rate of hydrolysis of the matrix by breaking the peptide bonds maintaining the integrity of sludge floc, resulting to an improvement in both odor removal and dewaterability.

Abstract: The objective of this study was to use sludge generated from the paper industry wastewater treatment plants as raw material for the synthesis of zeolites. Sludge samples were collected from the three main paper industries of the Metropolitan Zone of Mexico City and the one having the highest content of Si and Al was selected to conduct the zeolite synthesis tests. The selected sludge was calcined, leached with HCl solutions and used in the zeolites synthesis process. Sludge leaching with 1M HCl solution promotes the formation of zeolite A and 2 M HCl solution promotes zeolites P (calcium and sodium forms). The successful use of sludge generated from the paper industry in the synthesis process of zeolites will result in a reduction of the pollution associated to these residues. This represents important technical, economic and environmental advantages compared to other similar processes that use high purity commercial raw materials

Abstract: In urban areas, motor vehicle emissions have been identified as the major source of urban air pollution, for they disperse and gather near roadside microenvironments are influencing travelers’ health. In this paper, Random Forest was employed to build a-fine scale predicting model of roadside pollutant concentration, using traffic, meteorological and local geographic factors measured by a mobile monitoring platform in four urban roads with high spatial and temporal sampling interval. Models were built based on 700 5-min observations with MSE of CO prediction model being 8.3 and that of NOx model being 8.9. OOB examination assured its generalization ability and indicated that the models were converged with the tree number increased up to approximate 300 for CO model and 450 for NOx model, respectively. Models were validated by the other 125 5-min observations with desirable prediction results, which showed better prediction performance than ANN model. In urban area, traffic-related pollutants contribute a significant proportion to roadside microenvironment, which needs to be characterized since people spend a substantial percent of their outdoor time in this environment. Exposure to CO is associated with an increase in mortality from cardiovascular disease; exposure to NOx is directly associated with adverse effects on asthma disease [1] and respiratory system [2]

Abstract: Salinity management is becoming a critical environmental issue for municipalities across nations. Wastewater effluent must remain a viable water resource for irrigation of crops and indirect potable use through groundwater recharge. The aim of this study was to investigate to what degree Ceratophyllum demersum (C. demersum) decreases salinity in aquatic environments. Treatments included raw municipal wastewater (RMW), treated municipal wastewater (TMW), and diluted fresh latex (DFL). It was concluded that C. demersum could be used to remove salinity from wastewater and merits further study as a saline reduction method for wastewater.

Abstract: Biosolids are known to impact plant growth and drought tolerance. However, the underlying mechanisms are not well understood. This greenhouse study was designed to investigate whether biosolids improve antioxidant metabolism associated with drought tolerance in tall fescue (Lolium arundinaceum (Schreb.) S.J. Darbyshire]. All treatments in this experiment were applied with N availability equivalent to 75 mg N kg –1 soil: control (75 mg N kg –1 soil completely provided by NH 4 NO 3 solution); biosolids at 0.5x agronomic N rate (37.5 mg N kg –1 soil provided by biosolids, and 37.5 mg N kg –1 soil provided by NH 4 NO 3 solution); and biosolids at 1x agronomic N rate (75 mg N kg –1 soil completely provided by biosolids). Tall fescue was established and grown under well-watered or drought stress conditions. Biosolids improved tall fescue turfgrass quality and leaf relative water content (LRWC) under both water conditions and reduced leaf wilting rate under drought stress. Biosolids treatments also promoted leaf proline content and nitrate reductase activity under two moisture regimes and increased superoxide dismutase, catalase, ascorbate peroxidase, and peroxidase activity under drought stress. Biosolids increased tall fescue shoot and root biomass and improved root viability under drought stress. Tall fescue treated with biosolids showed better water status under drought stress. Biosolids application improved visual quality and leaf water status. The improvement of drought tolerance by biosolids treatments may be associated alteration in antioxidant enzyme activity.

Abstract: Anaerobic digestion is a solution for sludge management. It is organic matter converted into methane which is renewable energy. This energy is used to enhance performance of co-digestion of sewage sludge using rice straw and effective microorganisms (EM1). A study using a bench scale was installed at El-Berka waste water treatment plant (WWTP) in the El-Salam district, Cairo, Egypt with mesophillic conditions for thickened sludge. The bench scale was monitored for three stages over 20 days of operation to choose the most suitable rate of rice straw and EM1 mixed with thickened sludge. It was concluded that 20% rice straw and 1:250 EM1 mixing rate was the most suitable ratio based on COD and total VSS destruction percentage. Results showed a reduction of COD and total VSS up to 70 and 77%, respectively.

Abstract: Cr(VI) adsorption onto dried marble processig wastewater (non-treated wastewater) solids (MPW) and dried physicochemical marble sludge from coagulation- flocculation treatment (MPWT) of an andesite processing plant’s wastewater was investigated. MPW sludge and MPWT sludge were incorpotared as inorganic adsorbents in batch reactors containing aqueous Cr(VI) solutions varying between 1 and 25 mg/L. MPWT sludge was obtained with alum coagulant. A dry particulate (powder) form of sludge samples were used at a 5 g/100 mL dosage. Isotherm studies indicated that Cr(VI) adsorption by these andesite- oriented adsorbents may be characterized using a Freundlich model for MPW sludge and a Langmuir model for MPWT sludge.

Abstract: The tailings, which are small in particle size and exposed to natural environment, especially the extremely tiny weathered secondary mineral kernel, can easily react with air, water and living things. Up to now, the reactive tailings have caused a series of environmental problems for water and soil. In this paper, physical and chemical properties of the sulfide ore tailings were analysed. Leaching experiments in laboratory were carried out and the results showed that acidic condition can accelerate the oxidation and dissolution processes of the sulfide tailings, lead to more surounding releasion and migration of heavy metals from the tailings reservoir.

Abstract: In the present study, the removal of PAHs from industrial treatment sludge by using ultraviolet (UV) irridation and titanium dioxide (TiO 2 ) was investigated. Twelve PAHs (Σ 12 PAHs) were targeted and their levels in the sludge were studied. TiO 2 was added at the ratio of 5% and 20% of the dry matter (DM) of the sludge. At 45 ° C, 35% of the Σ 12 PAHs were removed with only UV light. Higher PAH removal ratios were obtained employing TiO 2 as a photocatalyst. At 45 ° C, Σ 12 PAH removal ratio was reached to 83% with using TiO 2 at the ratio of 20%.

Abstract: The Cr, Cu, Zn, and Ni accumulations in three different grass types were investigated with doses of 0% (control), 5%, 10%, 25%, and 50% tannery sludge compost (TSC) application to soil. The pot experiments showed that 5% and 10% TSC amendment enhanced the grass seed mixture (GSM) and Ecopalmix species while 50% TSC disrupted the plant growth. The TSC addition considerably increased the Cr concentrations in plants depending on the extreme Cr level in the TSC. The order of metals mobility according to the transfer coefficient ( T c ) values was found as Zn > Cu > Cr > Ni.

Abstract: Treatment and disposal/beneficial use are the most important aspects of municipal sludge management. Particularly, the application guidelines and limit values for treatment systems and the major disposal routes including landfilling, land application and incineration are covered in the legislations. This study aims to review the legislations about municipal sludge treatment and disposal from different counties such as Turkey, USA, EU, Canada and South Africa. Evaluations show that the current legislations place a greater emphasis on the beneficial use of sludge, rather than the mere disposal. The specifics of regulations related to combustion changes between different countries such that in some countries separate regulation for sludge combustion is implemented, whereas in others sludge is not specifically mentioned but included among the big group of wastes to be combusted. Similarly, some countries have particular regulations for landfilling of sludge, whereas the others consider sludge within the greater category of biodegradable wastes together with the organic fraction of solid wastes. This study compares and contrasts these issues and current legislations of the aforementioned countries.