| Straw,pig manure,wet garbage,these are the common waste in our lives,if not handled in a timely manner,a great impact on our lives,and will destroy our living environment.These three kinds of raw materials are widely available,with huge output.Because of the special physical and chemical structure of straw,which is very difficult for the microorganism and enzyme adsorption,degradation,and thus limits the popularization and application of anaerobic digestion of straw;China’s aquaculture industry in large scale,because the feedlot can save cost and land,so in recent years,more and more large-scale farms,manure production is huge,great influence to the farms surrounding environment and the lives of the residents,seriously affect the quality of residents and farm management personnel;the improvement of people’s living standard,per person per day produced wet life more and more garbage,set in the process become a big problem.In the face of wet waste straw,farm manure,the daily life,we need to find a way to deal with timely environmental protection of the three kinds of wastes,which provides a new method for the regional variety of waste disposal problems,so the research on rice straw,pig manure,wet garbage as raw material,optimization of anaerobic fermentation process the application value and has high theoretical value.In this paper,pig manure and wet waste were used as raw materials.The wet garbage is mainly organic matter,such as fiber,bamboo and wood,kitchen residue,etc.,which is easy to decompose,and more than 50% of the urban domestic garbage is wet garbage.Based on the different proportion of the two factors as the influencing factors,the adaptability and feasibility of mixed fermentation of pig manure and wet waste were studied.Among them,the set temperature is 55 DEG C,focusing on pig manure and wet garbage in eight different mixed effects on mixed fermentation process,the methane volume fraction,the total gas production units,quality TS and VS methane production were characterized.The fermentation characteristics of the further study of the two.In the feed concentration 5%,fermentation temperature,fermentation temperature 55 200 g,the total weight of oscillation frequency is 100 R-min-1,the best ratio of raw materials for pig manure:wet waste is 4:3,under the condition of single pig group compared to the total gas production increased by 79%,the removal rate of SCOD can be increased by 12% the volume fraction of methane,third days can be increased to more than 50%,and from the third day volume fraction of methane has been stable at around 60% until the end of fermentation.In addition,the proportion of the fermentation system has a lower redox potential and a more stable weak alkaline environment,very beneficial for anaerobic fermentation.Secondly,with different proportion of pig manure and straw at 55 DEG C under the condition ofmixed fermentation,explore the impact of different ratio and basicity on the removal rate of total biogas production,the methane volume fraction,liquid SCOD,investigated by the two kinds of raw materials blending are beneficial to fermentation test.The results showed that when the ratio of pig manure and straw was 4:3,the total gas production rate could be increased,and the fermentation period of methane volume fraction exceeding 50% could be shortened rapidly.Compared with the different parameters,it was found that the mixture of two kinds of raw materials had a certain influence on the gas production rate,and the total gas production was more sensitive than the methane volume fraction.Fortunately,each of these groups can produce methane from each of these two ingredients,and methane is detected in any group from the beginning to the end.After the sequencing batch test was completed,the pig manure,wet garbage and straw were mixed with TS ratio of 4:3:3 to simulate the actual project feeding way.The experiment was divided into three stages,which were divided into pre acclimated sludge and medium feed,and the total time of feeding and fermentation was 90 days.In the continuous test of no trace elements,the fluctuation range of Nissan gas is different,but the range is from 900 ml to 2515 ml.During the first 31 days of fermentation,the fluctuation range is relatively large.There are 6 peaks of gas production,and the daily output gas is 2515 ml,1535ml,1742 ml,1637ml,1542 ml,1638ml,respectively.After 29 days,the daily output fluctuates steadily,maintaining in the range from 1123 ml to 1503 ml.The total gas production in the 60 days was 80686 ml,with an average daily output of 1345 ml.We can see that needs a continuous test of pre acclimation of sludge,namely the fermentation period,the time is about 30 days,after the gas production remained stable,as long as the late fermentation gas production does not have large fluctuations,can maintain a certain gas production,can be used in the engineering design.The volume fraction of methane in first days was 26%,rose rapidly after ninth days,the methane volume fraction is up to 50%,although also showed small amplitude fluctuation characteristics,but has been maintained at above 50%,fifteenth days,twenty-first days,twenty-sixth days of methane volume fraction peak,respectively 62%,63%,65%.Without the addition of trace elements in continuous test,30 days before the gas fluctuation of gas production,the late little fluctuation,can be seen as the experiment,showing a more stable state gas continuous fermentation reaction system,the unit volume of the reactor gas production is very similar,maintain in 100 ml fluctuation.The order of the first two batch of similar late gas fluctuation test,gas production increased,indicating that the pig manure,straw three,wet waste gas production performance of mixed fermentation to two kinds of raw materials mixed fermentation is better than the previous,more potential gas production.This is similar to the results of our initial trial and further demonstratesthe feasibility of this experimental procedure.But in the early continuous test unit volume of reactor gas production in a larger range,ranging from 100 ml to 150 ml range,later also prove that this fluctuation during the trial will be further reduced.In the continuous experiment of adding trace elements,the third stage is 60 days.Compared with the trace elements without adding the cycle of fermentation gas production more,gas production fluctuation is smaller,it is said that the trace elements added a certain amount of fermentation effect is better,better than adding group,was the addition of trace elements test for trace elements contained in itself can not fully meet the needs of anaerobic fermentation,how can be mixed the fermentation of raw materials due to their containing material can fully meet the requirements in anaerobic fermentation to further study.In summary,this paper studies the pig manure and wet garbage mixed gas production performance of pig manure and straw,mixed gas production performance,gas production performance of pig manure and straw mixed wet waste,and is better than the single effect of fermentation by mixed fermentation of raw materials the conclusion of the two raw materials,three hybrid materials due to the two kinds of raw material fermentation,but three trace elements in raw material mixing required now is not by itself contains material completely satisfied.At the same time,the addition of trace elements can improve the stability and gas production of the fermentation system.In addition,three kinds of raw materials mixed with another advantage of being able to better and more fully make up a single raw material fermentation of anaerobic fermentation can not be satisfied,so can a regional long-term stable gas supply,while reducing regional areas due to environmental pollution problems of pig manure and straw,wet garbage brought. |
