Study on Piggery Anaerobic Fermentation Slurry Treated by Anoxic/Oxic Process

[Objective] The aim of this study was to provide a fast, stable and efficient piggery wastewater processing technology. [Method] The start-up process was studied through the experiment of piggery anaerobic fermentation slurry treated by Anoxic/Oxic （A/O） reactor. The process was divided into two stages： at the first stage, dominant micro flora were cultivated in Anoxic and Oxic reaction tanks respectively; at the second stage. Anoxic and Oxic reaction tanks were initiated jointly to gradually enhance water load and continued to cultivate and domesticate microorganisms, and finally the start-up process was completed. [ Result] The results showed that return mixture ratio and return sludge ratio was 2 and 1 respectively when the temperature reached 32 ±2 ℃. However. when aeration rate of Oxic reaction amounted to 0.5 m^3/h, the re- moval rate of COD and NH4^＋ -H were 89.87% and 89.31% respectively through practical operation within 50 days, which indicated that the start- up process through A/O reactor was successful. Conclusion This study can provide a scientific basis and reference for innocuous technique of piggery anaerobic fermentation slurry treatment.

Plant Selection of Constructed Wetlands for Treatment of Piggery Wastewater

Piggery wastewater contains high concentrations of organic matter and ammonia nitrogen,and it is difficult to treat it and make the discharged wastewater to meet the standard. Since the treatment of piggery wastewater treated under anaerobic conditions by traditional aerobic methods requires large investment,high running expense and strict management,breeding enterprises could hardly accept the technique. According to the characteristics of piggery wastewater,Pennisetum sp. + Rumex acetosa Linn and Populus + Nerium oleander can be planted in constructed wetlands to treat piggery wastewater,which can improve the treatment effect of piggery wastewater by constructed wetlands,solve the difficulty of wastewater treatment in winter,and bring obvious economic benefit.

Plant Responses to Carbon Dioxide Releasedfrom Piggery

In the present study, lean-to greenhouses were built by sharing a wall of piggeries. The vents in the wall allowed the air exchange between the piggeries and the greenhouses, so that carbon dioxide(CO_2) could be released from the piggeries to the greenhouses, and oxygen(O_2) could be released from the greenhouses to the piggeries. In the greenhouses, tomato, Chinese cabbage and muskmelon were planted and their quality indices were determined to evaluate their response to elevated CO_2. The results showed that the CO_2 concentration in greenhouse was increased, and under such conditions the yield and quality of all tomato, Chinese cabbage and muskmelon were improved.

Monitoring of Sewage Discharging in Piggery

The rapid development of large-scale livestock and poultry breeding industry causes a large number of slurry and waste, which bdngs great pressure on the surrounding environment and has become an important factor for environmental pollution. To further ascertain the pollution emissions of livestock and poultry breeding industry, protect people＇s health and successfully complete the first national census of pollution sources, a large-scale piggery and a breeding field were selected for monitoring. The results revealed that monitoring indicators in pollution sources of livestock and poultry breeding industry showed significantly positive correlation with breeding size and nutritional level, but negative correlation with animal breeding age. Monitoring indicators in summer and autumn were higher than those in spring and winter, and monitoring indicators of sewage in the piggery reduced significantly through sedimentation process.

Evaluation of Methane Yield on Mesophilic-Dry Anaerobic Digestion of Piggery Manure Mixed with Chaff for Agricultural Area

A mesophilic-dry anaerobic digestion process is valid in treating high-concentration substrates containing low moisture content. It has merits of lower wastewater discharge and lower heat capacity required in maintaining reactor temperature as compared with a thermophilic-wet anaerobic digestion process. In fact, chaff can be easily obtained in farming areas and used as a mixture substrate as one of bulking agents for controlling moisture and supplying carbon. For this reason, this study applies the chaff to improve livestock manure, which contains high moisture content and is discharged from domestic pig farms. This study aims at verifying its feasibility for improving methane production efficiency on a basis of BMP (Biochemical Methane Potential) assay obtained through a series of experiments. Finding results were methane gas production and gas production per volatile solid (VS) added, and methane gas production among biogas production were increased as the chaff added in the piggery manure was increased. According to experimental results for improving the methane production efficiency, mixture of the chaff and the piggery manure played an important role in controlling the moisture content and improving the methane gas production rate, and also verified its feasibility in the mesophilic-dry anaerobic digestion process indicating relatively less difficulty for operation and management.

Effects of Different Ventilation Modes and Outlet Height on Nursery Piggery Environment

In order to study the effects of ventilation modes and outlet height on the airflow field of a nursery piggery,computational fluid dynamics (CFD) technology was used to simulate the wind speed and temperature of an experimental pig house in the cold northern region.This study was conducted with simulation and a comparative analysis of transverse ventilation,longitudinal ventilation and roof air intake modes.Furthermore,the effects of the air outlet height of 0.7,0.6 and 0.5 m with the roof air inlet mode on the environment in the pig house were studied.Field experiments verified the model of roof air intake model.The results showed inadequate ventilation in both the vertical and horizontal ventilation.However,the airfield gradients were less variable and more balanced when using the rooftop air intake mode.The variation of outlet height significantly affected nursery pig houses’ airflow velocity and temperature.Roof air inlet mode with an outlet height of 0.7 m was better than the other two.The normalized mean square error (NMSE) of air velocity and temperature was less than 0.01,and the simulation analysis could genuinely reflect the distribution of the airflow field in the nursery.

秸秆过滤养猪废水UASB厌氧发酵及微生物群落分析

养猪废水成分复杂,所含悬浮性固体对其生物发酵过程影响显著;利用经过粉碎压实后的玉米秸秆对养猪废水进行负压抽滤,吸附截留废水中的悬浮性固体。再利用上流式厌氧污泥床(UASB,up-flow anaerobic sludge bed/blanket)反应器对过滤后的养猪废水进厌氧发酵,探究发酵过程中随着有机负荷的增加,化学需氧量(COD,chemical oxygen demand)去除率、pH值、产气量的变化规律,并采用高通量测序技术分析最优负荷时厌氧消化污泥中的细菌与古菌群落组成。过滤试验表明,在过滤压差为40 kPa、滤层厚度为15 cm、滤料压实度为1.6倍密度时有较好的过滤效果,此时总固体(TS,total solid)、挥发性固体(VS,volatile solid)、COD的去除率分别为33.08%、28.05%、23.01%。厌氧发酵试验结果表明,在温度为(35±1)℃时反应器稳定运行的最高负荷为11.00 kg/(m^(3)·d);反应器处理效果最优的负荷为10 kg/(m^(3)·d),此时进水COD浓度为5000 mg/L、COD去除率为76.46%、容积产气率为1.51 m^(3)/(m^(3)·d)。高通量测序结果表明,厌氧发酵过程由多种微生物菌群协同作用,主要的细菌群类是Firmicutes、Bacteroidota,主要古菌群类为Halobacterota,且高效产甲烷菌分布丰富。试验结果可为利用作物秸秆过滤养猪废水进行以废治废的技术应用提供依据。

基于规模化保育猪舍的全新风通风负荷计算模型及测试分析

猪舍的全新风通风不仅能提升猪舍环境质量,还能降低规模化养殖中的交叉感染问题。以保育猪为研究对象,建立了全新风通风负荷计算模型,应用该模型与传统逐时逐项冷负荷方法计算的负荷结果差异小于5%,可应用于工程简化计算。在该模型基础上,提出耦合不同室外气象参数下的猪舍环控参数动态调控方法。通过试验验证,该调控策略下舍内温度测试值与理论值平均相对误差为3.4%,且能够满足夏季猪舍温度、风速控制值及均匀性要求。在冬季运行工况下应用该调控方法,每栏仅需150 m^(3)/h风量即可满足舍内空气质量要求;理论送风参数下,测得舍内空气平均温度约26℃,日平均温差5℃,CO_(2)、NH_(3)、PM_(2.5)等污染物浓度均远低于国家标准指标。该负荷计算模型及动态调控方法可为规模化保育猪舍的热环境与卫生环境研究提供参考。

碳源小球藻强化人工湿地处理养猪沼液的效能与机制

针对传统人工湿地处理畜禽养殖沼液反硝化不足、脱氮效果不佳的难题,该研究将小球藻(Chlorella sorokiniana)作为人工湿地外加碳源,构建小球藻强化人工湿地脱氮系统,通过添加不同浓度的小球藻(0、0.25、0.5、1.0 g/L)来研究系统对养猪沼液水质的去除效果及溶解性有机物(DOMs)的变化规律,并从微生物角度解释强化脱氮机制。结果表明:(1)与未添加小球藻的人工湿地相比,总氮的去除率明显增高,最高可达70.24%,硝氮去除率最高达93.45%;(2)基于三维荧光平行因子分析,DOMs中3组分分别为富里酸/类腐殖酸物质、高分子芳香族物质和类腐殖酸物质;小球藻的添加增强了养猪沼液中DOMs的去除,同时降低了类腐殖酸的含量;(3)小球藻的添加明显增加了人工湿地中微生物的Alpha多样性。其中,门水平上,与反硝化作用相关的优势菌门(变形菌门)相对丰度明显增加;属水平上,亚硝化单胞菌属(Nitrosomonas)和湖沉积杆菌属(Limnobacter)在系统氨氧化和脱氮过程中发挥重要作用。该研究为小球藻作为外加碳源增强人工湿地脱氮除磷提供了理论支持。

猪舍环境精准控制模型及其优化算法

高密度和密闭饲养是现代规模化生猪养殖业的主要特征之一,通过精准环境控制维持猪舍稳定、舒适和符合生猪生物学特性的小气候环境,是生猪养殖获得更高生产性能和饲料转化效率、更好猪群健康、更优畜产品质量和更高生产效益的重要基础。规模猪场猪舍环境影响因素多而复杂,基于数学模型驱动和控制设备运转是实现精准智能环境控制的主要方式。本文围绕影响猪生长、健康的主要环境因素,综述了猪舍环境的控制策略、模型及其优化算法,以期为猪舍环境精准控制技术与智能环控装备研发提供理论依据。

添加原水改善SBR工艺处理猪场废水厌氧消化液性能

采用序批式反应器(SBR)工艺直接处理猪场废水厌氧消化液,处理系统的效率较低,COD去除率仅有10%左右,NH4+-N去除率70%左右;处理出水水质较差,出水COD高于1 000mg/L,出水NH4+-N在200mg/L左右;处理系统的工作不稳定,效能逐渐恶化.在猪场废水厌氧消化液中添加部分未经厌氧消化的猪场废水(原水),处理系统的处理效率明显提高,COD去除率高于80%,出水COD降到250～350mg/L;NH4+-N去除率高于99%,出水NH4+-N小于10mg/L;处理系统的稳定性也得到增强.添加原水后,猪场废水厌氧消化液的BOD5/COD比值从0.19上升到0.54,BOD5/TN比值从0.28上升到2.04,增加了微生物生长和反硝化所需的碳源,强化了反硝化作用,不仅提高了总氮去除效率,而且通过回补碱度,维持了处理系统的pH值稳定.

原水添加比例对猪场废水厌氧消化液后处理的影响

采用序批式反应器(SBR)处理猪场废水厌氧消化液,研究添加原水(配水)比例对处理性能的影响.连续动态试验表明,配水30%的处理,出水NH3-N浓度低,一般在10mg/L以下;配水10%、20%处理的出水NH3-N浓度逐渐升高,至试验结束时,出水NH3-N分别达300mg/L和80mg/L左右.主要是因为配水30%的反应系统,pH能稳定在7.7左右,而配水10%、20%的反应系统,pH逐渐下降直至降到5.5以下.1个运行周期的监测表明,配水10%、20%、30%的处理,NO2--N峰值、NH3-N低值分别出现在曝气第4h、第3h、第2h.配水比例越大,NH3-N氧化速度越快,原因是配水比例越高,反硝化程度越高,系统pH也越高.批式反硝化试验表明,BOD5/TN越高,反硝化速率越快.动态和批式试验都说明,消化液好氧后处理系统正常运行的配水比必须达到30%以上.

复合微生物吸附除臭剂的制备及其除臭应用

为保护畜禽养殖场周围的空气质量,控制臭气是养殖业必须要解决的基本问题。从养猪场土壤中分离出具有除臭效能的微生物菌株3株:巨大芽孢杆菌CCW-Y1菌株、灰色链霉菌CCW-Y2菌株、热带假丝酵母CCW-Y3菌株。以米糠和陶瓷粒为吸附剂载体,与3株微生物菌株的混合培养液混合,制成复合微生物吸附除臭剂,载体上的生物量以4.50～6.05g/kg为好。复合微生物吸附除臭剂载体上微生物干细胞5.36g/kg对猪粪、鸡粪和牛粪中NH3、臭气的去除率可达80%以上,H2S的去除率达65%以上。将此除臭剂放置在底部透气的扁平铁丝盘中,悬挂于猪舍和猪粪堆肥场上方进行除臭试验,结果表明猪舍内NH3、H2S和恶臭浓度分别降低了78.4%、66.7%和83.3%。猪粪堆肥场内NH3、H2S和恶臭浓度分别降低了84.4%、62.1%和88.5%。该除臭剂的有效除臭时间比普通吸附除臭剂长,对生猪的生长没有产生负面影响。

利用秸秆堆肥过程处理猪场废水的研究

进行了以玉米秆、稻草、麦秆为载体吸收猪场废水的堆肥发酵试验,以探讨利用堆肥过程处理猪场废水的可行性。结果表明:秸秆与猪场废水联合堆肥发酵可以有效地处理利用猪场废水,秸秆吸收利用粪水的吸水比为1∶5.94～1∶6.65。秸秆吸收猪粪水堆肥的温度以及50℃、55℃以上持续时间比吸收猪粪水厌氧消化液的高。玉米秆、稻草堆肥温度以及50℃、55℃以上的持续时间高于麦秆的堆肥。以玉米秆、稻草为载体的堆肥,经历了一个pH下降的酸化过程,然后再上升至8以上;以麦秆为载体的堆肥几乎一直处于酸化过程中。堆肥过程中氮、磷、钾是一个累加的过程。以稻草为载体的堆肥,其钾的含量明显高于其余两种。秸秆吸收猪粪水的堆肥,氮、磷、钾含量高于吸收猪粪水厌氧消化液的堆肥。以猪粪水厌氧消化液或麦秆为原料的堆肥不利于腐殖酸,特别是胡敏酸的形成,而玉米秆+猪粪水、稻草+猪粪水的堆肥有利于胡敏酸的形成。结果证明采用堆肥过程处理利用猪场废水是可行的。

猪场污水漂浮栽培植物修复系统的组成及净化效果研究

介绍了2种用于猪场污水氧化塘中进行污水净化处理的漂浮栽培植物修复系统的技术原理、特点、系统组成、种植管理技术,研究了在这个系统中种植美人蕉Cannageneralis、风车草Cyperusalternifolius、香根草Vetiveriazizanioides、蕹菜Ipomoeaaquatica、细叶萼距花Cuphenhyssopifolia、彩叶草Coleusscutellarioides、金叶木Sanchezianobilis和紫杯苋Cyathulaprostrata等几种植物的生长状况以及这些植物对污水中氮、磷的净化效果.结果表明,这2种漂浮植物修复系统具有设施简单、管理方便的特点.这些植物中的美人蕉、香根草、蕹菜、细叶萼距花等在该系统中生长良好并具有很好的水质净化效果和广泛的应用前景.

固液分离-UASB-SBR工艺处理养猪场废水的试验研究

针对养猪场废水有机物浓度高,NH3-N浓度高、恶臭严重的特点,提出了固液分离-UASB-SBR的养猪场废水处理工艺.试验结果证明,经上述工艺处理,养猪场废水中的NH3-N,CODcr,BOD5等指标均能达到排放标准.

厌氧水解-SBR工艺处理高浓度有机废水运行工序的优化

将ASBR反应器和SBR反应器结合组成厌氧水解 SBR工艺用于养猪场废水的处理 ,ASBR反应器作为厌氧水解反应器 ,主要完成对有机物的水解 ,达到初步降解有机物的目的 ,在反应器每次进水量和排水量不大于其有效容积 70 %的前提下 ,研究了ASBR反应器厌氧搅拌段的时间对污水可生化性和对后续SBR脱氮处理效果的影响 .结果表明 ,厌氧搅拌 36h的污水既保持了较高的可生化性 ,出水BOD/COD保持在 0 .4左右 ,又能在后续SBR处理中取得较好的脱氮效果 ,经SBR反应器处理后出水NH+ 4 N <1 0mg/L .通过实验分析进一步确定了好氧SBR反应器运行的最佳工序 ,厌氧水解 SBR运行工序优化后 ,BOD5的总去除率达到 98%以上 ,NH+ 4 N去除率达到 99%以上 ,但出水CODCr达不到排放标准 ,经混凝沉淀处理后方能达标排放 .

基于组态软件和模糊控制的分娩母猪舍环境监控系统

为解决北方寒冷地区分娩母猪对猪舍环境的要求,该文研究了一种舍内环境监测和控制系统。该系统综合考虑舍内温度、湿度、氨气浓度及其相互影响,利用组态软件、模糊控制技术和解耦控制技术,通过机械通风系统和热水采暖系统实现了舍内环境的智能控制。试验结果表明该系统可行且实用,在保证舍内所需温度基本恒定的条件下(舍内温度控制的最大相对误差为5.5%),也能使舍内相对湿度和氨气浓度保持在适宜范围内。

基于ARIMA和BP神经网络的猪舍氨气浓度预测

为了从源头减少生猪养殖过程中的氨气排放,降低猪舍氨气浓度,提出了基于ARIMA-BP神经网络的猪舍氨气浓度组合预测方法,分别从最优权重和残差优化角度对基于ARIMA-BP神经网络的组合预测方法进行了对比研究.将该预测方法应用于江苏省宜兴市某养猪场的氨气浓度预测中,预测结果表明:基于ARIMA-BP神经网络残差优化组合预测方法的预测精度最高,与BP神经网络、ARIMA预测方法和基于ARIMA-BP神经网络最优权重组合预测方法对比分析,评价指标MAE、MAPE和RMSE分别为0.0319、0.1580%和0.0365.本文提出的氨气预测方法可以为猪舍环境精准化调控管理提供科学依据以减小猪舍氨气排放对生态环境的污染.

人工湿地组合生态工艺对规模化猪场养殖废水的净化效果研究

研究了表面流、水平潜流和垂直潜流人工湿地以及地下渗滤系统组合生态工艺对模拟和实际猪场养殖废水的净化效果。结果表明,在进水ρ(COD)=709.2 mg.L-1,ρ(TN)=597.1 mg.L-1,ρ(NH4+-N)=560.4 mg.L-1和ρ(TP)=42.5 mg.L-1的质量浓度条件下组合生态系统对于COD、TN、NH4+-N和TP的去除率分别可以达到87%、95%、97%和95%,其中COD的去除主要在第一级表面流人工湿地,NH4+-N和TN去除主要是在水平潜流和垂直潜流人工湿地,水平潜流和垂直潜流人工湿地对溶解性磷酸盐去除效果明显,地下渗滤起到进一步稳定出水水质的作用。水平潜流和垂直潜流人工湿地的运行结果对比表明,后者对污染物的去除率均高于前者。