Spatiotemporal distribution,environmental risk and carbon emission reduction potential of livestock manure in Shaanxi Province,China

Shaanxi is a leading province in animal husbandry(AH)in China.However,the lack of provincial information on the characteristics and utilization potential of livestock manure(LM)hinders crucial management decisions.Therefore,we investigated the spatiotemporal distribution,availability and biogas potential of LM in Shaanxi,and examine the carbon emission reduction potential of AH.There has been a 1.26-fold increase in LM quantities in Shaanxi over the past 35 years,reaching 4635.6×10^(4)t by 2021.LM was mainly concentrated in northern Shaanxi and the eastern part of Hanzhong.Cattle and pig manure were the primary sources of LM,with the average LM land-load of 14.57 t·ha^(−1)in 2021.While the overall AH in Shaanxi has not exceeded the environmental capacity,the actual scales of AH in Ankang and Hanzhong have already surpassed the respective environmental capacities,posing a higher risk of N and P pollutions.In 2021,the estimated biogas energy potential of LM was 1.2×10^(11)MJ.From 2012 to 2021,the average carbon emission reduction potential in Shaanxi was 22%,with an average potential scale of 10%.The results of this research provide valuable data and policy recommendations for promoting the intensive use of LM and reducing carbon emissions in Shaanxi.

Determination of biogas production potential from animal manure and GHG emission abatement in Turkey

This study was aimed to determine biogas amount and the energy value which could be made from animal manure in Turkey.For this purpose,biogas potential was calculated with the number of dairy cattle and laying hens taking into consideration,which have high availability manure.Turkey has a total of about 8.9 million dairy cattle and 98 million laying hens.Annual total 92.1 million tons of manure is obtained from these animals.There are 89.2 million tons of cattle manure and 2.9 million tons of laying hens manure.Annual 1.6 billion m3 of biogas can be produced from the usable amount of this manure.The heating value of biogas produced from this manure is about 36.7 PJ.These values can provide 1.1%of Turkey’s annual energy consumption(80.5 Mtoe).The distribution of these calculated data by province was mapped using a GIS Software’s mapping option.When provinces are ranked according to the amount of biogas production,the top 10 are Konya,Erzurum,İzmir,Balıkesir,Kars,Afyon,Diyarbakır,Aydın,Ankara and Ağrı.Furthermore,the greenhouse gas(GHG)emission abatement was calculated for demonstrating the environmental benefits of the biogas production from animal manure.It was determined that the CO2 emission abatement annually ranging between 17.2-25.3 million tons could be provided with the evaluation of biogas potential which was calculated.

Effect of a high strength chemical industry wastewater on microbial community dynamics and mesophilic methane generation

A high strength chemical industry wastewater was assessed for its impact on anaerobic microbial com- munity dynamics and consequently mesophilic methane generation. Cumulative methane production was 251 mL/g total chemical oxygen demand removed at standard temperature and pressure at the end of 30 days experimental period with a highest recorded methane percentage of 80.6% of total biogas volume. Volatile fatty acids （VFAs） analysis revealed that acetic acid was the major intermediate VFAs produced with propionic acid accumulating over the experimental period. Quantitative analysis of microbial communities in the test and control groups with quantitative real time polymerase chain reaction highlighted that in the test group, Eubacteria （96.3%） was dominant in comparison with methanogens （3.7%）. The latter were dominated by Methanomicrobiales and Methanobacteriales while in test groups increased over the experimental period, reaching a maximum on day 30. Denaturing gradient gel electrophoresis profile was performed, targeting the 16S rRNA gene of Eubacteria and Archaea, with the DNA samples extracted at 3 different time points from the test groups. A phylogenetic tree was constructed for the sequences using the neighborhood joining method. The analysis revealed that the presence of organisms resembling Syntrophomonadaceae could have contributed to increased production of acetic and propionic acid intermediates while decrease of organisms resembling Pelotomaculum sp. could have most likely contributed to accumulation of propionic acid. This study suggested that the degradation of organic components within the high strength industrial wastewater is closely linked with the activity of certain niche microbial communities within eubacteria and methanogens.