外文翻譯---初始低碳氮比好氧堆肥化處理豬糞稻草（英文）

1、Effect of low initial C/N ratio on aerobic composting of swine manure with rice strawNengwu Zhu *College of Environmental Science and Engineering, South China University of Technology, Guangzhou 510640, PR ChinaReceived

2、25 August 2005; received in revised form 1 December 2005; accepted 2 December 2005 Available online 19 January 2006AbstractTwo pilot composting experiments were conducted to investigate the effect of low initial C/N rati

3、o on the composting of swine manure with rice straw by measuring physical and chemical parameters. The results showed that the thermophilic duration of bin 1 and bin 2 was long enough to satisfy the sanitary standard, an

4、d swine manure could reach maturity. Bin 1 containing larger amount of swine manure and less amount of rice straw showed a higher nitrogen loss (8%), shorter thermophilic phase, and longer maturity time (about 2 weeks) t

5、han bin 2. However, economical analysis showed a lower initial C/N ratio (20) could reduce 172 kg rice straw per ton fresh swine man- ure than a higher C/N ratio (25), and more swine manure could also be treated. Therefo

6、re, a low initial C/N ratio (20) could be suggested in the composting of swine manure with rice straw. ? 2005 Elsevier Ltd. All rights reserved.Keywords: Swine manure; Solid waste; C/N ratio; Aeration; Composting1. Intro

7、ductionIn PR China, swine manure is the main organic fertilizer in agriculture. But the large quantity of swine manure pro- duced by intensive industry is difficult to apply in limited nearby land, and fresh swine manure

8、 is also limited in agricultural use due to pathogens, unstable nutrients, and transportation and preservation difficulties (Zhu et al., 2004). Not long ago, corresponding national standard were produced for the livestoc

9、k and poultry industry and profes- sional legislation because the discharged swine manure has led to environmental concerns including odor pollution, methane emissions, and N and P pollution of waterways (Imbeah, 1998).

10、The high N and P discharges lead to eutro- phication, and adversely affect the growth and diversity of aquatic life (Huang et al., 2004). Therefore, environmen- tally sound and practically feasible technologies are calle

11、d for animal waste treatment and utilization.Composting, an aerobic, biological process that uses naturally occurring microorganisms to convert biodegrad- able organic matter into a humus-like product, can destroy pathog

12、ens, converts nitrogen from unstable ammonia to stable organic forms, reduces the volume of waste, and sat- isfies the needs of fertilizer for agricultural use seasonally. Obviously, composting has potential as an effect

13、ive method of treating swine manure prior to land application. The yield of paddy in China is about 0.2 billion ton, resulting enormous quantity of rice straw, which is rich in nitrogen, potassium, carbon and silicon. If

14、 rice straw is reused in composting, the nutrients can be recycled, and the cost of treatment of rice straw can be saved as well. Thus, rice straw is a kind of potential bulking agent for composting (Zhu et al., 2004). F

15、or a successful composting, key factors such as temper- ature, aeration, moisture and nutrients should be appropri- ately controlled. C/N ratio is one of the important factors affecting composting process and compost qua

16、lity. It is considered C/N ratio at 25–30 as the initial optimum ratio for composting (Fong et al., 1999). Huang et al. (2004) studied effect of C/N ratio on composting of pig manure0960-8524/$ - see front matter ? 2005

17、Elsevier Ltd. All rights reserved. doi:10.1016/j.biortech.2005.12.003* Tel.: +86 20 22236006; fax: +86 20 87111378. E-mail address: nwzhu@scut.edu.cnBioresource Technology 98 (2007) 9–133. Results and discussionOrganic c

18、arbon, total nitrogen, C/N ratio, pH value, and moisture content of swine manure were 371.5 g kg?1, 22.73 g kg?1, 16.34%, 7.39%, and 66.11%, respectively, which for rice straw were 399.4 g kg?1, 5.21 g kg?1, 76.58%, 7.87

19、%, and 13.57%, respectively.3.1. Physical changesFrom day 0 to day 2, swine manure looked filemot, formed conglomerate, had screwworms and thick malodor, and absorbed a great deal of flies. White fungi appeared on the 3r

20、d day, and flies disappeared on the 5th day. By the 9th day, the swine manure in the composting bins looked hoary, and only smelled light odor. However, color of inner conglomerate swine manure still appeared filemot. On

21、 15th day, they became loose and easy-to-pulverize, and smelled like the fragrant humus. On 63rd day, the vol- ume of the mixtures in bin 1 and bin 2 decreased by 62.46% and 65.71%, and weight loss 59.26% and 61.78%, res

22、pec- tively. In the final composts, Agrotis ypsilon (Rottemberg) was present. However, apparent characteristics of the mix- ture in bin 2 were superior to those in bin 1.3.2. Temperature, pH and moisture profilesTemperat

23、ure of the bins went through three classic phases: heating phase, thermophilic phase, and cooling phase (Fig. 1(a) and (b)). During the heating phase, the psy- chrophilic and mesophilic microorganisms in the waste bins t

24、ended to increase the temperature. As a result of biodegra- dation of organic compounds, the temperature increased and reached 40–50 ?C. It took 5.1 h and 3.6 h to reach 55 ?C of core temperature in bin 1 and bin 2, resp

25、ectively. During the thermophilic phase, the temperature exceeded the tolerance limit of the mesophilic microorganisms and promoted the development of the thermogenic microorgan- isms. In this study, the thermophilic pha

26、se (>50 ?C) pro- ceeded 306 h and 286 h in bin 1 and bin 2, respectively. The temperature of the bins fell with the environmental temperature at about 500 h. The decrease of temperature resulted from a depletion of or

27、ganic matters. The character- istics of core temperature are shown in Table 1. pH tended to be stable and appeared to be consistent in all the composts. It increased significantly from the initial 1st to 7th day, then gr

28、adually decreased, and increased slightly in the curing phase. pH was 7.30 and 7.36 at the composting raw mixtures of bin 1 and bin 2, respectively; peak value were 7.85 and 7.94 on the 1st and 7th day and 8.01 and 8.03

29、in the final composts, which matched the suggested criteria (Fong et al., 1999). In general, moisture content decreased in both the bins. The initial moisture content of the mixtures in the bin 1 and bin 2 was 61.24% and

30、 62.19%, respectively, which decreased gradually. As the experiments were conducted in summer, water loss was quite fast. In order to maintain per-fect microbiological activity, water was sprayed on day 3, 5, 8, and 12 i

31、nto both bins to keep 45–65% moisture content.3.3. Other propertiesTOC and OM decreased significantly during the compo- sting, which occurred mainly during the high-speed phase. Meanwhile WSC and WSN decreased gradually

32、during the composting, but water-soluble C/N ratio reached its peak value on 7th day (Fig. 2). Especially, KTN appeared to increase, which was caused by more decrease in TOC than that in KTN. TKN in the initial mixtures

33、in bin 1 and bin 2 was 18.73 and 15.07 g/kg, respectively; 17.64 and 17.91 g/ kg at the end of the high speed phase in bin 1 and bin 2, respectively, and 19.30 and 18.62 g/kg in the final composts in bin 1 and bin 2, res

34、pectively. Solid C/N ratio of bin 1 and bin 2 decreased from 20.16 to 15.02 and from 24.94 to 14.16, respectively, and; water-soluble C/N ratio of bin 1 and bin 2 decreased from 7.90 to 5.15 and from 8.54 to 4.57, respec

35、tively (Fig. 2).(a)202530354045505560650 100 200 300 400 500Time (h)Temperature (?C)Environment Top Core Bottom(b)202530354045505560650 100 200 300 400 500Time (h)Temperature (?C)Environment Top Core BottomFig. 1. Change

36、s of different locations temperature of the bins and environmental temperature. (a) C/N ratio of 20; (b) C/N ratio of 25.Table 1 Characteristics of core temperature of bin 1 and bin 2Bin no. Time to set temperature (h)Ra