达标排放模式技术方式之厌氧处理

正废水厌氧生物处理,又称厌氧消化或沼气发酵,是在无分子氧的条件下,通过兼性厌氧微生物、厌氧微生物的作用,将废水中各种复杂的有机物分解转化成甲烷和二氧化碳等物质的过程。畜禽粪便中有机物浓度高,并且碳、氮的比例适中,厌氧处理时产气性能较稳定。通常将畜禽粪便污染治理与可再生能源开发结合起来,因此畜禽粪便厌氧处理工程一般是沼气工程。自20     

用地衣芽孢杆菌消化处理养殖场废弃物

规模化畜牧养殖业面临愈来愈严重的大量废物处理的问题。这些废物包括:排泄物、动物尸体、毛、羽毛和加工废料。这些大都为有机物质,可以转变成有用的资源。目前已经建立了一种高效的喜温厌氧消化体系,用于把动物粪便处理成沼气、固体残渣和富有营养的液体,分别用作能源、饲料添加剂和水生动物营养液。这种消化体系还可以消灭病原菌,保护环境卫生。在这种体系的建立过程中,发现了一种能够降解羽毛的喜热细菌,将其命名为地衣芽孢杆菌(Bacillus Licheni-     

利用黑水虻处理畜禽粪便中残留抗菌药物研究进展

抗菌药物具有预防和治疗动物疾病的作用,并在一定程度上可促进动物生长发育。畜禽粪便中残留的抗菌药物不仅会造成环境污染,还可导致动物源耐药性菌株在环境中的传播扩散,对公共卫生安全和人类健康带来威胁。采用高效便捷处理方法降低畜禽粪便中抗菌药物残留可在一定程度上减少生态环境污染。传统的处理方法有厌氧消化及好氧堆肥等,能有效减少畜禽粪便中抗菌药物的残留,但存在抗菌药物不能完全去除、处理条件要求高的缺点。近年来,利用黑水虻幼虫处理畜禽粪便中残留抗菌药物引起人们的关注。概述了畜禽粪便中常见的残留抗菌药物,分析了采用厌氧消化和好氧堆肥等传统处理畜禽粪便中抗菌药物的方法,以及利用黑水虻处理畜禽粪便中抗菌药物的新方法对残留抗菌药物的去除效率,以期为畜禽粪便中残留抗菌药物处理方法的研究与应用提供参考。     

农业部将推动大中型畜禽养殖能源环境建设

农业部官员近日指出，“十五”期间，我国将推动大中型畜禽养殖场能源环境工程建设，在全国建设３００个示范工程。大中型畜禽养殖场能源环境工程建设，关键技术是厌氧消化，目的是治理畜禽粪便污染，效益体现在粪便的资源化综合利用上。大中型畜禽养殖场能源环境工程，是将沼气生产、高效有机复合肥料生产和粪便污染物的处理有机结合在一起的粪便资源化综合利用工程模式，集能源、环保和资源再利用为一体。建设内容主要包括６个方面，分别是粪便和污水的前处理系统、厌氧消化系统、好氧水处理系统、能源利用系统、沼渣生产高效固体有机肥料…     

高温厌氧消化处理养禽场废弃物的新进展

近年来有关家禽场废弃物的处理技术发展迅速。美国目前已经建立了一种高效的喜温厌氧消化处理体系。这种装置能把动物粪便转化成沼气、固体残渣和富有营养的液体，分别用作能源、饲料添加剂和水产养殖的营养液；可以消灭废弃物中的病原菌而保护环境卫生。在这种体系中还发现了一种能降解羽毛的喜温细菌──地衣芽孢杆菌ＰＷＤ─１菌株，它能使羽毛发酵并能把羽毛转化成羽毛溶解产物，这是一种可消化的饲用蛋白资源。现已查明这种能水解羽毛的细菌分泌一种角蛋白酶，把这种酶做为饲料添加剂掺入饲料可以明显地提高鸡对羽毛粉的消化率。     

养猪生产生命周期评估(LCA)专题(综述)(续完)

正2.3粪便处理生命周期评估虽然研究表明饲料始终是家畜生产最大的环境压力,但在养殖地区,粪便处理是更大的问题,因为如果排泄物管理不善,N和P有可能流失进入淡水和地下水,NH3也存在酸化风险。可通过厌氧消化等技术减少直接施肥等传统处理方式带来的风险,同时沼气生产还可获得新效益。有效施肥也可减少化肥用量。LCA分析方法已经大量应用于猪粪分析。法国布列塔尼地区是硝酸盐脆弱区,所以     

几种促进沼气发酵产气的途径

<正>沼气发酵时沼气微生物在厌氧条件下分解有机物质产生甲烷和二氧化碳的过程。整个厌氧消化过程分三个阶段:水解发酵阶段、产氢产乙酸阶段、产甲烷阶段[1]。整个厌氧消化过程中,微生物之间有着密不可分相互依存的内在和外在的关联。不过处在连锁末端的甲烷菌对整个厌氧处理微生物生态系统来说,起着至关重要的作用。产甲烷菌的活性受温度、pH值、有毒物质、以及C、N、P比值、无机元素等的影响[2]。     

养殖业应用沼液四例

沼液是沼气发酵原料经过微生物厌氧消化后所生成的具有水溶性的剩余物,其中含有动物生长发育所必需的多种氨基酸、微量元素、生长素等营养成分,是一种潜在的动物营养资源。目前,沼液做为动物饲料添加剂广泛应用于养殖业中。     

规模化奶牛场的粪污处理模式

规模化奶牛场粪便、污水等废弃物排泄量大,对生态环境的污染日益严重,制约了奶牛养殖业的健康发展,所以选择适合本场条件的粪污处理模式,进行粪污处理势在必行。目前主要的粪污处理模式有＂粪便有机肥＋污水厌氧处理＂模式、＂粪便有机肥＋污水达标排放＂模式、＂粪便自然堆肥＋污水还田/回用＂模式、＂循环利用＂模式、＂粪便沼气利用＋污水农业利用/回用＂模式。     

畜禽规模养殖污染防治技术

正(接上期)6.2奶牛养殖场沼气工程处理与牛粪生产有机肥实例介绍6.2.1奶牛场概况润翔乳业有限公司奶牛养殖基地位于辛集市马庄乡北营村,存栏奶牛840头,日产鲜牛粪21.5吨、污水26.2吨。养殖基地四周是林果地,生活区、生产区、生产辅助区、粪污处理区严格分开。该养殖基地建设粪污沼气处理工程。6.2.2奶牛场粪污处理工艺流程该养殖基地奶牛粪污经调节池调节水质水量后,提升到厌氧消化池;厌氧消     

牛粪厌氧消化效率提升技术研究进展

规模化养牛业在提高生产效率的同时,也导致牛粪在一些地区大量集中产生,这些牛粪如不妥善处理,将会带来严重的环境污染问题。厌氧消化（沼气发酵）技术既能降解有机污染物,又能生产清洁能源和有机肥料,是有效且环保的牛场粪污治理手段。然而,由于牛粪中难降解的木质纤维素含量较高,以及操作问题和工艺不稳定等原因导致牛粪厌氧消化甲烷产量较低。因此,为了使牛粪厌氧消化技术在经济上可持续,还需要进一步的研究。本文详细介绍了工艺参数,如C/N比、温度和固体浓度等对牛粪厌氧消化性能的影响,总结了提高牛粪厌氧消化甲烷产量和工艺稳定性的策略,如预处理、共消化和添加外源添加剂等,以期为提升牛粪厌氧消化技术的研究和技术推广提供参考。     

规模猪场不同粪污处理模式和利用效果对比分析

粪污处理模式的选择是影响猪场可持续性发展的重要因素之一,文章对国内规模化猪场粪尿清理、污水处理、末端还田利用等环节进行了系统阐述,对比分析了不同粪尿清理及污水处理方式下还田利用的效果及投资运行成本。规模化猪场污水处理首选种养结合模式,当污水不具备资源化利用条件时可选择达到农田灌溉标准的经济、高效污水处理模式。对于用于农田灌溉用水的污水处理,从投资和运行成本考虑优先选择水泡粪+污水预处理+UASB+A/O模式,土地资源不足情况下选择干清粪+污水预处理+UASB+A/O处理模式。采用沼液还田时,若配套土地面积充足,可选择水泡粪+污水预处理+黑膜沼气处理模式,配套土地面积不足时选择干清粪+污水预处理+黑膜沼气处理模式。     

The survival of pathogenic bacteria and plant growth promoting bacteria during mesophilic anaerobic digestion in full‐scale biogas plants

The introduction of biogas plants is a promising way to recycle organic wastes with renewable energy production and reducing greenhouse gas. Application of anaerobic digestate as a fertilizer reduces the consumption of chemical fertilizers. In this study, the survival of pathogenic bacteria and plant growth promoting bacteria (PGPB) in two full‐scale biogas plants operated at mesophilic condition were investigated. Feedstock and anaerobic digestate samples were collected from biogas plants and bacteria load in samples were detected using standard dilution plate method. Pathogenic bacteria were reduced to not detected level through mesophilic digestion tank except for Campylobacter. However, it could be reduced by 98.7% through a sterilization tank. Bacillus was detected at 8.00 and 7.81 log₁₀ CFU/g dry matter in anaerobic digestates, and it was also resistant to sterilization tank. Bacillus spp. is considered to be the safe bacteria that hold remarkable abilities for promoting plant growth. The results showed that treatment at biogas plants is effective to reduce pathogenic bacteria in dairy manure, and sterilization could further reduce the sanitary risks of pathogenic bacteria relating to anaerobic digestate application. Anaerobic digestates could also be utilized as bio‐fertilizer as the high load of plant growth promoting bacteria.     

The survival of multidrug‐resistant bacteria in thermophilic and mesophilic anaerobic co‐digestion of dairy manure and waste milk

Anaerobic digestion is considered as a promising method to manage animal waste with antibiotic‐resistant bacteria. Current research was conducted to investigate the survival of multidrug‐resistant bacteria (MDRB) resistant to three groups of antibiotics: (i) cefazolin, neomycin, vancomycin, kanamycin (group 1); (ii) penicillin, oxytetracycline, ampicillin, streptomycin (group 2); and (iii) cefazolin, neomycin, vancomycin, kanamycin, penicillin, oxytetracycline, ampicillin, streptomycin (group 3), in anaerobic digestion of dairy manure and co‐digestion of dairy manure and waste milk at 37°C and 55°C for 22 days, respectively. The population densities of three groups of MDRB on peptone, tryptone, yeast and glucose agar plates incubated at 30°C for 7 days before and after digestion showed 100% destruction in both digestates at thermophilic temperature. Overall reduction of more than 90% of three groups of MDRB was observed in mesophilic digestion with no significant differences (P > 0.05) between manure and milk mixture. Co‐digestion of dairy manure and waste milk always produced significantly (P < 0.05) higher total gas and methane gas than digestion of manure alone at both temperatures. Gas production in each case was significantly (P < 0.05) higher in thermophilic digestion than in mesophilic digestion. The results demonstrate that thermophilic co‐digestion of dairy manure and waste milk offers more benefits in terms of the environment and economy.     

The effect of temperature on survival of pathogenic bacteria in biogas plants

The paper deals with the hygienic advantages of sanitation to treat dairy manure in full‐scale biogas plants. The slurry samples were collected from two thermophilic biogas plants (55°C) and two mesophilic biogas plants (38°C) in Hokkaido Japan. A detectable number of Coli‐aerogenes group and Enterococcus in the slurries after anaerobic digestion (AD) could not be found in either thermophilic biogas plants. However, in both mesophilic biogas plants the viable numbers of Coli‐aerogenes group and Enterococcus were detected in the slurries even after anaerobic digestion. The mean decimation reduction time (T₉₀) values of the Coli‐aerogenes group and Enterococcus in the slurries during mesophilic digestion were 13.3 days and 16.7 days, respectively.     

Survival of Salmonellas and Ascaris Suum Eggs in a Thermophilic Biogas Plant

In a continuous biogas plant, receiving manure from 200 dairy cows and 400 calves and young stock, survival of salmonellas and Ascaris suum eggs was studied. The bacteria and parasite eggs were kept in filter sacs in the manure that had a temperature of 55°C. No viable salmonellas or Ascaris suum eggs could be found after 24h in the digester.Survival of salmonellas and Ascaris suum eggs was also studied in the manure pit where the manure was stored after digestion. The temperature in the manure pit varied between 22–27°C. Salmonellas survived 35 but not 42 days. On day 56, when the experiments had to be stopped, 60% of the Ascaris eggs were viable.     

我国发展生物天然气的潜力与措施

生物天然气是一种绿色清洁的可再生能源,已被列入国家能源发展战略。发展生物天然气不仅可以弥补我国天然气供需短板,降低对外依存度,保障国家能源安全,推进能源结构的转变,也可解决畜禽粪便和秸秆等有机废物带来的环境污染问题。介绍了我国生物天然气发展现状,分析了发展生物天然气的潜力,并提出了加快生物天然气健康发展的相应措施,我国需建立统一的生物天然气标准,引进消化吸收国外成熟先进的技术,自主创新研究形成适合中国大中规模沼气提纯技术和成套化提纯设备,并在政策和补助方面加大扶持力度,尤其是增加运营管理和终端产品（生物天然气、秸秆、有机肥和液肥）的补贴。     

Process performance of biogas digesters incorporating pre-separated manure

The yield from anaerobic digestion of liquid manure is often too low to make biogas production economically viable. This study examined the potential for partly substituting the liquid manure with solids from solid–liquid separation. The proportion of manure solids was gradually increased to 60%, which resulted in a higher gas production per digester volume than could be achieved by liquid manure alone. During the period with 60% substitution, the yield in the high-solids digester was almost twice that in the digester based on liquid manure alone. The yield in the high-solids digester was slightly above 200 L CH₄ kg^− 1 VS for the most part, while the yield in a reference digester containing only liquid pig manure was mostly above 300 L CH₄ kg^− 1 VS. Thus, the high ratio of solid matter reduced gas yield as a proportion of VS under thermophilic conditions, indicating that the high-solids process was inhibited by the high amounts of solid manure. This was most likely caused by NH₃ inhibition, as the NH₄–N level increased to more than 5 g L^− 1. However, post-digestion in a mesophilic digester almost fully compensated for the lower conversion of VS in the high-solids digester.     

Sustainable livestock production: Low emission farm-The innovative combination of nutrient,emission and waste management with special emphasis on Chinese pig production

Global livestock production is going to be more and more sophisticated in order to improve efficiency needed to supply the rising demand for animal protein of a growing, more urban and affluent population.To cope with the rising public importance of sustainability is a big challenge for all animal farmers and more industrialized operations especially. Confined animal farming operations(CAFO) are seen very critical by many consumers with regard to their sustainability performance, however, the need to improve the sustainability performance especially in the ecological and social dimension exists at both ends of the intensity, i.e., also for the small holder and family owned animal farming models. As in livestock operations, feed and manure contribute the majority to the three most critical environmental impact categories global warming potential(GWP), acidification(AP) and eutrophication potential(EP)any effort for improvement should start there. Intelligent combination of nutrient-, emission-and waste management in an integrated low emission farm(LEF) concept not only significantly reduces the environmental footprint in the ecological dimension of sustainability, but by producing renewable energy(heat, electricity, biomethane) with animal manure as major feedstock in an anaerobic digester also the economic dimension can be improved. Model calculations using new software show the ecological improvement potential of low protein diets using more supplemented amino acids for the Chinese pig production. The ecological impact of producing biogas or upgraded biomethane, of further treatment of the digestate and producing defined fertilizers is discussed. Finally, the LEF concept allows the integration of an insect protein plant module which offers additional ecological and economical sustainability improvement potential in the future. Active stakeholder communication about implementation steps of LEF examples improves also the social aspect of sustainability.     

Effect of solid–liquid separation on anaerobic digestion of dairy manure in semi‐continuous stirred tank reactors: Process performance and digestate characteristics

The objective of this study was to investigate the effect of solid–liquid separation on anaerobic digestion of dairy manure in semi‐continuous stirred tank reactors. Reactors fed with liquid fraction of dairy manure (screened liquid manure) were kept in water baths at mesophilic (Run 1) and thermophilic (Run 3) temperatures, respectively, while reactors fed with water diluted manure and kept at mesophilic (Run 2) and thermophilic (Run 4) temperatures as control reactors. The performances of reactors were compared in terms of biogas and methane production, and digestate characteristics. The methane yields obtained from screened manure were higher than those from diluted manure at both mesophilic and thermophilic temperatures, while the highest methane yield was 185 L/kg VS_added under thermophilic temperature. Solid–liquid separation also had improved the effect on digestate fertilizer characteristics. Among four digestates from reactors, the highest contents of nutrients, N (4.12 g/kg) and P (2.36 g/kg) were found in Run 3, while the highest content of K (3.42 g/kg) was found in Run 1. These results showed the benefits of solid–liquid separation of dairy manure on process performance and digestate characteristics.