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Ren L.-M.,China Agricultural University | Li G.-X.,China Agricultural University | Shen Y.-J.,China Agricultural University | Schuchardt F.,Johann Heinrich Von Thunen Institute | Lu Peng,Beijing Environmental Sanitation Engineering Research Institute
Waste Management and Research | Year: 2010

Aimed at controlling the nitrogen loss during composting, the mixture of magnesium hydroxide (Mg(OH)2) and phosphoric acid (H 3PO4) (molar ratio 1:2) were utilized as additives to avoid increasing total salinity. In trial TA, the additives were put into absorption bottles connecting with a gas outlet of fermentor (ex situ method); in trial TB, the additives were directly added to the composting materials (in situ method). During the 26 day composting period, the temperature, pH, total organic carbon (TOC), total nitrogen (TN), ammonium nitrogen (NH 4 +-N), total phosphorus (TP), available phosphorus (AP) and germination index (GI) were measured. The experimental results show that the additives reduced the pH, while NH4 +-N and TN were obviously improved. NH4 +-N was 11.9 g kg-1 and 3 g kg-1 in amended compost trial (TB) and unamended compost trial (TA), respectively; TN increased from 26.5 g kg-1 to 40.3 g kg -1 in TB and increased from 26.5 g kg-1 to 26.8 g kg -1 in TA. Analysis of the TOC and carbon mass revealed that absorbents accelerated the degradation of organic matter. The germination index test showed the maturity of TB (102%) was better than TA (82%) in final compost. Furthermore, TP and AP were also obviously improved. X-ray diffraction analysis of precipitation showed that the precipitation in absorption bottle of TA was newberyite (MgHPO4 3H2O), however, the crystal in the TB compost was struvite (MgNH4PO4 6H2O: magnesium ammonium phosphate). These results indicated that Mg(OH)2 and H 3PO4 could reduce the ammonia emission by struvite crystallization reaction. Optimal conditions for struvite precipitation should be determined for different systems. © The Author(s), 2010. Source

Mao X.,Qinghai Normal University | Yuan D.,Beijing University of Civil Engineering and Architecture | Wei X.,Qinghai Normal University | Chen Q.,Qinghai Normal University | And 2 more authors.
Sustainability (Switzerland) | Year: 2015

Nowadays, an increasing shortage of water resources intensifies the contradiction among different water-using sectors in the social-economic-ecological complex system. To adjust water used configuration in a holistic framework, a water use system (WUS) model was constructed with inclusive five water-using sectors including aquatic systems, primary industry, secondary industry, tertiary industry and resident consumption. The Baiyangdian Basin in Northern China was used as a case area. Six years data from 2008 to 2013 were used to quantify the model. By introducing the ecological network analysis (EAN), we holistically assessed the WUS under different water use configuration. System organization, activities and development degree, etc. were used to character the prosperities of the water use system. Results indicate that the WUS encountered a lasting degradation in system organization (AMI index decreased in an annual rate of 0.6%) and development degree though with an ascending system activities in the studies periods (with an annual growth rate of 11.3%). Scenario analysis results suggest several potential ways to achieve a better water use configuration in this basin, such as environmental and ecological restoration, water-saving technology and water recycling rate, etc. The current study may provide ways to optimize water use structure to balance the interests of different sectors both ecologically and economically. © 2015 by the authors; licensee MDPI, Basel, Switzerland. Source

Zhang H.,China Agricultural University | Lu P.,Beijing Environmental Sanitation Engineering Research Institute | Li G.,China Agricultural University | Zhang W.,China Agricultural University | And 3 more authors.
Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering | Year: 2011

If kitchen waste is composted alone, it will produce a large number of leachate and odor substances which seriously polluted the environment. In this study, two experiments were conducted, one experiment was that kitchen waste was composted alone, another experiment was that cornstalks as an additive according to the wet weight ration of 1:3 were added to the kitchen waste composting. The maturity indices, leachate and the main odors emission were analyzed in two experiments. The results indicated that compared with no additive, better compost product was obtained on the experiment having additive on the basis of temperature, pH value, electrical conductivity, C/N ratio and germination index, and cornstalks as additive could effectively dilution the salinity during kitchen waste composting. Furthermore, although the mean concentration of ammonia increased by 3.3% when cornstalks were added to kitchen waste composting, the mean concentration of dimethyl sulfide, hydrogen sulfide and methyl mercaptan decreased by 62.3%, 67.9% and 49.6%, respectively. There were 32.6% leachate generated during the kitchen waste composting, and adding cornstalks avoided the leachate generate. Therefore, cornstalks as an additive has a significant role in improving the maturity and controlling the leachate and odor emissions during kitchen waste composting. Source

Hu Z.,Huazhong University of Science and Technology | Zheng Y.,Huazhong University of Science and Technology | Yan F.,Beijing Environmental Sanitation Engineering Research Institute | Xiao B.,Huazhong University of Science and Technology | Liu S.,Huazhong University of Science and Technology
Energy | Year: 2013

Pyrolysis experiments of blue-green algae blooms (BGAB) were carried out in a fixed-bed reactor to determine the effects of pyrolysis temperature, particle size and sweep gas flow rate on pyrolysis product yields and bio-oil properties. The pyrolysis temperature, particle size and sweep gas flow rate were varied in the ranges of 300-700 °C, below 0.25-2.5 mm and 50-400 mL min-1, respectively. The maximum oil yield of 54.97% was obtained at a pyrolysis temperature of 500 °C, particle size below 0.25 mm and sweep gas flow rate of 100 mL min-1. The elemental analysis and calorific value of the oil were determined, and the chemical composition of the oil was investigated using gas chromatography-mass spectroscopy (GC-MS) technique. The analysis of bio-oil composition showed that bio-oil from BGAB could be a potential source of renewable fuel with a heating value of 31.9 MJ kg-1. © 2013 Elsevier Ltd. Source

Ma J.Y.,Beijing Environmental Sanitation Engineering Research Institute | Chen X.Y.,University of Science and Technology Beijing | Su W.,University of Science and Technology Beijing
Advanced Materials Research | Year: 2014

Garbage incineration is an effective minimization and resource processing methods, but there are no comparative analysises about the environmental impact of incineration processes. To investigate the environmental impacts of three typical MSW incineration processes, we modeled scenarios, calculated energy consumed and six aspects which classified as GWP, ODP, AP, EP, POCP and DUST. The classification results showed the value of the environment impact potential respectively. The impact potential of heat recover-dry absorption processes according to normalized results in descending order is GWP>EP>DUST>AP>POCP>ODP, in contrast the rank of heat recover-wet absorption and semidry processes is GWP>EP>AP>DUST>POCP>ODP, global warming impacts is the most significant penitential factor. The rank of impact potential according to weight factor in descending order is GWP>EP>DUST>AP>ODP>POCP. Dust potential became more significant. The weight factor of Dust is almost twice as much as that of AP. This is because there is a large gap between baseline level and the target level, the solid-waste are the focus of control in these years. In environmental terms, the environmental depletion index of heat recover-dry absorption process is lowest with minimal environmental impact and the heat recover-wet absorption process is the highest with largest environmental impact. The incineration with dry absorption program is the best environment-friendly process in term of environmental impact. Utilization of waste water and reducing total amount of water entering the system can effectively reduce the environmental implication for both HW and HS processes. © (2014) Trans Tech Publications, Switzerland. Source

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