Advanced Materials Research Vols. 864-867

Abstract: Hydrothermal treatment is a benefit process for the mass reduction, stabilization and recycling of biosolids, however, the mutual relation between mass transfer and physicochemical property are still unclear. Our work undertook the hydrothermal treatment of biosolids in batch reactors under different temperature ranged from 180-300°C. Result showed that protein and carbohydrate were the primary macromolecular compounds in initial hydrothermal reaction, and protein was richer but less stable than carbohydrate. Temperature is a key factor affecting the organic matter transferring process between solid and liquid phase, reaction efficiency markedly reduced when temperature drop to 180°C. Morphologic change of biosolids was observed, including a rapid dewatering process in initial reaction and disintegration process to small size particles.

Abstract: The problems of the high exhaust gas temperature in the biomass boiler which moves normally are analyzed, and the anti-balance method to get the boiler efficiency is used to get the relationship between the exhaust gas temperature and the boiler efficiency. Greater exhaust gas heat loss, smaller the boiler efficiency. According to 35t/h biomass grate boiler, the factors which affect exhaust gas temperature are analyzed and summarized

Abstract: This paper simulates the plastic and biomass pyrolysis and ignition characteristics in different atmosphere, by thermogravimetric analysis polypropylene and plane wood at different oxygen concentrations. Experiments show that, increase the concentration of oxygen can accelerate the pyrolysis reaction rate of biomass and plastics, and can also reduce the ignition temperature of them. But for high volatile substances, such as plastic, the increase of oxygen concentration make a smaller effect on the pyrolysis and ignition, and for relatively high fixed carbon content substances, such as plane woods, the increase of oxygen concentration make a larger effect on pyrolysis and ignition.

Abstract: It is annually produced 400 thousand tons of solid waste in the city of Rostov-on-Don, which is taken for disposal to landfill at the Northwest industrial area of the city. Nearly 60 tons of waste enters Rostov Material Recovery Facility every year for the sorting, extracting commercially attractive factions, pressing, briquetting and subsequent transportation of residue tail to the landfill. However, the percentage of recycling in Rostov (10%) remains low, as a result of the shortcomings of the system. Recently, the Administration of Rostov-on-Don has produced a development strategy of integrated municipal solid waste management to create a new system of waste management in Rostov-on-Don. The strategy focuses mainly at Resource efficiency, which is a blend of good infrastructure, collection and design, with a dash of innovation and a strong policy framework to back it up. For the successful implementation of the strategy it is necessary to introduce an integrated system of municipal solid waste management using GIS. The methodology of integrated system with using GIS was developed by specialists of City Planning and Community Development Department of the Rostov State University of Civil Engineering. It includes implementation of collection and storage of waste and environmental data along with vehicles navigation system through ArcGIS ESRI software. It helps to facilitate collection operations, to analyze optimal locations for transfer stations, to plan routes for vehicles transporting waste from residential, commercial and industrial customers to transfer stations and from transfer stations to landfills, to calculate amount of waste collection sites in accordance with the population density and volume of bins, to locate new landfills and to monitor the landfill. GIS is a tool that also provides a digital data bank for optimization of waste collection sites allocation according with implementation of General City Plan. The territory of Rostov-on-Don has been chosen for case study. GIS allowed to make situational (operational) decisions for implementing the strategic approach to the municipal solid waste management plan of the city and supported innovative accompaniment of the process of development and implementation of priority national projects, targeted programs of ecological reconstruction and strategic plans of socio-economic development of municipalities.

Abstract: In this study, sewage sludge samples were collected from 25 wastewater treatment plants (WWTPs) in Shanghai, and free and bound PBDEs were extracted in different ways. The concentrations of free and bound PBDEs were in the range of 111.69 to 13119.59 ng/g dry weight (dw) and 4.30 to 60.17 ng/g dw, respectively. BDE209 were the dominate congener and the concentrations of free and bound BDE209 ranged from 89.64 to 12424.84 ng/g dw and 0.85 to 44.00 ng/g dw, respectively. The concentrations of bound PBDEs were quite stable, indicating bound PBDEs werent high related with the input of total PBDEs. The fractions of bound PBDE congeners increased with the numbers of Br atoms, which suggested that PBDE congeners with low molecular weights were more prone to desorb from micro-pores of organic matters in sewage sludge. The fractions of bound PBDEs in total PBDEs were in the range of 0.16 to 22.73%, suggesting bound PBDEs played an important role in farmland soils after sludge application.

Abstract: To investigate the transfer of PBDEs from products into the aqueous media, experiments and analysis were carried out by contacting TV housing plastics with distilled and dissolved humic solution (DHS) in brown bottles in the artificial climate box. The leaching test conditions were a liquid-to solid ratio of 100:1, and a contact period of 1, 2, 4, 7, 10, 13, 16 and 20 day (s), with pH of 3, 5, 7, 9 and temperature of 15, 20, 25 °C. The leaching concentrations of PBDE increased with DHS rather than distilled water, and were found to be remarkably enhanced when TOC of DHS increased. Despite no detection of most of the lower BDEs in distilled water, most homologues could be detected in DHS, and their solubility increased according to the contact time; those of highly BDEs increased to 10 times their maximum solubility in distilled water. Temperature had limited influence for the limited range investigated. Lower pH generally resulted in higher transfer of PBDEs to aqueous phase.

Abstract: The chloride, oxide and metallic species of heavy metal Pb were taken as the research objects in this paper, the effect of incineration temperature, incineration time, HCl gas and moisture on the volatilization of heavy metal Pb was discussed. The results indicate that the volatilization rates of chlorides, oxides and metallic species of heavy metal Pb increase with temperature increasing, the total volatilization rates are in the order of Pb£34PbCl₂£34PbO. The effect of time on the volatilization rate of heavy metal Pb is notable before 50 minutes, and the effect of time on Pb is greater than PbCl₂ and PbO. The volatilization rates of heavy metal Pb show tendency to rise with increasing HCl, the increasing degree is in the order of PbCl₂£34PbO£34Pb. The volatilization rate of PbCl₂ increases by an increase in HCl concentration, but if the time is enough (more than 80 minutes), then there is no effect of HCl concentration on PbCl₂. The presence of moisture depresses the volatilization rates of chloride, oxide and metallic species of heavy metal Pb, the depressing degree is in the order of PbCl₂£34Pb£34PbO.

Abstract: An experiment was conducted to investigate the effect of regulated deficit irrigation (RDI) on yield and water use efficiency (WUE) of processing tomato in an arid climate. The results showed that crop yields of processing tomato were significantly (p<0.05) 11.0%~60.0% higher in the fully irrigated plots than RDI treatments except that subject to low level of RDI at seedling. When subject to RDI fruit number per plant, fruit weight, fruit longitudinal diameter and transverse diameter were the main components contributing to yield increase of processing tomato, while decayed fruit number was the key factor restraining tomato yield improvement. The WUE of processing tomato was significantly improved by 13.4% in RDI plants subject to low water deficit at seedling compared to full irrigation, but no difference (p>0.05) existed between fully irrigated crops and RDI plants subject to water deficit at seedling or late fruiting. However, in comparison with fully irrigated crops WUE was significantly reduced by 16.3%~23.3% in RDI plants subject to water deficits respectively at flowering and full fruiting as well as subject to high water deficit at late fruiting. Therefore, low level of RDI at seedling while full irrigation during flowering to late fruiting could be applied to effectively improve yield and WUE of processing tomato in arid areas.

Abstract: Raw micro-polluted water was sampled from a water treatment plant in Gaomi, a town in north China. The treatment with diatomite-enhanced coagulation was investigated, including the effect of dose and the dosing point of diatomite on enhanced coagulation. The results showed that the removal efficiencies of turbidity, color, UV₂₅₄ and COD_Mn could reach 78.99 %, 76.19 %, 29.63 % and 22.77 %, respectively, when 15 mg/L diatomite was added at 30 minutes before coagulation. It was found that the optimum pH of diatomite-enhanced coagulation was approximately 6~7.

Abstract: The composite ion-exchange regenerant FH-30 was made using the own patent technology. The effect of softened water quality and running cycle, after the use of FH-30, was studied under simulation of industrial boiler softened water preparation process conditions. The dynamic simulation experimental results showed that at room temperature, the flow speed of 35 cm/min, the running cycle would not change when the dosage of regenerant was changed, the sodium and ammonium ion content would decrease with the increase of the running time in the softened water preparation process, the sodium ion content would decrease a bit faster at the later running cycle when the dosage of regenerant was greater, the molar ratio of sodium and ammonium almost not changed in the softened water preparation process when the regenerant dosage was 2.1 gram per milliliter resin, composite regenerant can completely replace single sodium salt regenerant. Through the measurement of sodium and ammonium ion in the regeneration resin and failure resin, proved that sodium and ammonium ion were not accumulated in the resin layer.