In-depth observations of fermentative hydrogen production from liquid swine manure using an anaerobic sequencing batch reactor

In this study,experiments were designed to reveal in-depth information of the effect of pH and hydraulic retention time（HRT）on biohydrogen fermentation from liquid swine manure supplemented with glucose using an Anaerobic Sequencing Batch Reactor（ASBR）System.Five values of HRT（8,12,16,20,and 24 h）were first tested and the best HRT determined was further studied at five p H levels（4.4,4.7,5.0,5.3,and 5.6）.The results showed that for HRT 24 h,there was a dividing H2 content（around 37%）related to the total biogas production rate for the ASBR System running at p H 5.0.When the H2 content went beyond 37%,an appreciable decline in biogas production rate was observed,implying that there might exist an H2 content limit in the biogas.For other HRTs（8 through 20 h）,an average H2 content of 42%could be achieved.In the second experiment（HRT 12 h）,the highest H2 content（35%）in the biogas was found to be associated with p H 5.0.The upswing of p H from 5.0 to 5.6 had a significantly more impact on biogas H2 content than the downswing of p H from5.0 to 4.3.The results also indicated good linear relationships of biogas and H2 production rates with HRT（r=0.9971 and0.9967,respectively）.Since the optimal ASBR operating conditions were different for the biogas/H2 production rates and the H2 yield,a compromised combination of the running parameters was determined to be HRT 12 h and pH 5.0 in order to achieve good biogas/H2 productions.

FPGA-based Digital Implementation of Flexible Power Control for Three-phase to Single-phase MMC-based Advanced Co-phase Traction Power Supply System

A three-phase to single-phase modular multilevel converter based advanced co-phase traction power supply(MMC-ACTPS) system is an effective structure to address the concerns of phase splitting and poor power quality of the conventional electrified railway. Due to the large number of MMCACTPS system modules, I/O resources and computing speed have high requirements on processors. Moreover, the module capacitor balance is challenging because the sorting time is too long when the traditional sorting algorithm for voltage balance is used. To solve the above issues, a digital implementation scheme of flexible power control strategy for three-phase to single-phase MMC-ACTPS system based on field programmable gate array(FPGA), which has sufficient I/O resources, has been proposed. Due to the parallel execution characteristics of the FPGA, the execution time of the controller and the modulator can be greatly reduced compared with a digital signal processor(DSP) + FPGA or DSpace. In addition, an improved sorting algorithm is proposed to reduce the sorting time and the implementation steps are analyzed. Finally, simulation and experimental results are presented to demonstrate the effectiveness and correctness of the proposed control strategy.

LIVESTOCK AND POULTRY MANURE MANAGEMENT FROM THE PERSPECTIVE OF CARBON NEUTRALITY IN CHINA

The rapid growth of the livestock and poultry production in China has led to a rise in manure generation,which contributes to the emissions of GHGs(greenhouse gases including CH_(4),N_(2)O and CO_(2))and other harmful gases(NH_(3),H_(2)S).Reducing and managing carbon emissions has become a critical global environmental imperative due to the adverse impacts of GHGs.Unlike previous reviews that focused on resource recovery,this work provides an unique insight of transformation from resource-oriented manure treatment to integration of resource recovery with pollution reduction,carbon accounting and trading,focusing on the sustainable development of manure management system.Considering the importance of accounting methodologies for carbon emission and trading system toward carbon neutrality society,suggestions and strategies including attaching high importance to the development of more accuracy accounting methodologies and more practical GHG emission reduction methodologies are given in this paper.This work directs the establishment of carbon reduction methodologies and the formulation of governmental policies for livestock and poultry manure management system in China.

DEVELOPMENT OF AN AUTOMATIC WEIGHING PLATFORM FOR MONITORING BODYWEIGHT OF BROILER CHICKENS IN COMMERCIAL PRODUCTION

Bodyweight is a key indicator of broiler production as it measures the production efficiency and indicates the health of a flock.Currently,broiler weight(i.e.,bodyweight)is primarily weighed manually,which is timeconsuming and labor-intensive,and tends to create stress in birds.This study aimed to develop an automatic and stress-free weighing platform for monitoring the weight of floor-reared broiler chickens in commercial production.The developed system consists of a weighing platform,a real-time communication terminal,computer software and a smart phone applet userinterface.The system collected weight data of chickens on the weighing platform at intervals of 6 s,followed by filtering of outliers and repeating readings.The performance and stability of this system was systematically evaluated under commercial production conditions.With the adoption of data preprocessing protocol,the average error of the new automatic weighing system was only 10.3 g,with an average accuracy 99.5%with the standard deviation of 2.3%.Further regression analysis showed a strong agreement between estimated weight and the standard weight obtained by the established live-bird sales system.The variance(an indicator of flock uniformity)of broiler weight estimated using automatic weighing platforms was in accordance with the standard weight.The weighing system demonstrated superior stability for different growth stages,rearing seasons,growth rate types(medium-and slow-growing chickens)and sexes.The system is applicable for daily weight monitoring in floor-reared broiler houses to improve feeding management,growth monitoring and finishing day prediction.Its application in commercial farms would improve the sustainability of poultry industry.

VALORIZATION OF LIVESTOCK WASTE AND CARBON NEUTRALITY

Livestock production has rapidly developed along with improvements in living standards and people’s desire for a better life.Intensive livestock production is important to guarantee supply of meat,eggs and milk,and even vegetable production,in the modern society of China.Recently,the Ministry of Agriculture and Rural Affairs jointly with the National Development and Reform Commission,the Ministry of Finance,and the Ministry of Natural Resources in China formulated and released the National Modern Facility Agriculture Construction Plan(2023‒2030)[1],which proposed the construction of modern animal husbandry facilities with efficient and intensive operations,encouraging the development of three-dimensional facility farms for pigs and poultry,and promoting using multistory buildings according to local conditions.However,large-scale livestock and poultry farms have faced many challenges impacting its green and sustainable development,such as production environment,air quality,manure and sewage treatment and resource utilization.