生物沥浸法去除不同初始pH值猪粪中的重金属

试验研究了不同初始pH值下猪粪中Cu、Zn和Cd的生物沥浸效果,结果表明猪粪生物沥浸对初始pH值的要求并不严格,具有较广的适用范围。猪粪粪液即使在初始pH值为8的弱碱性条件下,其pH值也可随沥浸时间快速降低,生物沥浸12天降到1.37,Cu、Zn和Cd沥出率可达到90.76%、97.97%和80.45%。初始pH值对重金属的沥浸速率有一定影响,降低初始pH值可以缩短生物沥浸周期,重金属的沥浸周期受不同初始pH值的影响程度从大到小依次为:CuZnCd。初始pH值为5的猪粪粪液可以在9天内完成生物沥浸,Cu、Zn和Cd沥出率可达到93.83%、99.24%和70.98%     

Effect of phosphogypsum and dicyandiamide as additives on NH3, N2O and CH4 emissions during composting

A laboratory scale experiment of composting in a forced aeration system using pig manure with cornstalks was carried out to investigate the effects of both phosphogypsum and dicyandiamide (DCD, C2H4N4) as additives on gaseous emissions and compost quality. Besides a control, there were three amended treatments with different amounts of additives. The results indicated that the phosphogypsum addition at the rate of 10% of mixture dry weight decreased NH₃ and CH₄ emissions significantly during composting. The addition of DCD at the rate of 0.2% of mixture dry weight together with 10% of phosphogypsum further reduced the N₂O emission by affecting the nitrification process. Reducing the phosphogypsum addition to 5% in the presence of 0.2% DCD moderately increased the NH₃ emissions but not N₂O emission. The additives increased the ammonium content and electrical conductivity significantly in the final compost. No adverse effect on organic matter degradation or the germination index of the compost was found in the amended treatments. It was recommended that phosphogypsum and DCD could be used in composting for the purpose of reducing NH₃, CH₄ and N₂O emissions. Optimal conditions and dose of DCD additive during composting should be determined with different materials and composting systems in further study.     

Microbial population dynamics and changes in main nutrients during the acidification process of pig manures

This study evaluated the impact of pig manure acidification on anaerobic treatment and composition of the fecal microbial community.According to the different chemical oxygen demand (COD) in the anaerobic treatment processes,pig manure was diluted 4 times (×4),16 times (×16),or 64 times (×64) and subjected to acidification.During the acidification process,pH,soluble chemical oxygen demand (SCOD),volatile fatty acids (VFAs),nitrogen (N),phosphorus (P) and potassium (K) were determined along with microbial po...     

藏猪扰动作用下的高寒草甸土壤退化特征及微生物群落结构变化

微生物作为土壤生态系统的重要组成部分,对环境干扰异常敏感,可以反映土壤的健康状况.人类活动导致高寒泥炭土壤面临退化风险,生产力下降、碳汇功能丧失,进而影响土壤微生物的群落结构及多样性.藏猪放牧是我国高海拔藏区一种特有的放牧方式,是导致高寒草甸土壤退化的重要干扰因素之一.应用16S rRNA高通量测序技术对比分析了藏猪放牧干扰和对照（无藏猪放牧）条件下的滇西北高寒草甸泥炭土壤微生物群落结构变化及其对干扰的响应特征.结果表明,藏猪放牧导致土壤微生物α多样性显著降低,且群落结构发生明显变化.高寒草甸泥炭土壤的主要优势菌为变形菌门（Proteobacteria）、酸杆菌门（Acidobacteria）和绿弯菌门（Chloroflexi）.与门水平相比,干扰前后土壤微生物在属水平上的差异更明显,其中鞘氨醇单胞菌属（Sphingomonas）和薄层菌属（Hymenobacter）的相对丰度在干扰后的土壤中显著增加,而硝化螺菌属（Nitrospira）和红游动菌属（Rhodoplanes）则显著降低.Venn图分析进一步发现,干扰与对照土壤样品中分别有71和136个核心OTU.干扰条件下的土壤特有微生物主要包括伯克霍德氏菌（Burkholderiales）、假单胞菌（Pseudomonadales）、鞘脂单胞菌（Sphingomonadales）等,这些微生物主要聚集在目水平,可以作为干扰条件下的指示微生物.CCA排序表明,硝化螺菌属和红游动菌属的微生物对含水率、速效磷、有机质等土壤环境变量的响应较为敏感.该研究结果为揭示高寒草甸泥炭土壤退化与微生物群落结构及多样性之间的关系提供了理论借鉴.     

堆肥处理过程中猪粪有机物的动态变化特征

为了解猪粪堆肥过程中各种有机物的变化特征,并为判断猪粪堆肥腐熟度提供参考指标,进行42d的高温好氧堆肥.结果表明,堆体中的有机质含量呈下降趋势;水溶性有机碳(DOC)含量在第10d达到最大值,之后呈下降趋势;易分解有机质含量呈下降趋势,但在高温开始阶段呈上升趋势;腐殖质含量呈上升趋势.说明堆肥过程中有机物不断向腐殖化方向转化.在研究H/F变化时发现,它与判断堆肥腐熟度常用的化学指标(有机质、DOC)呈一定的相关性,而且与易分解有机质和腐殖质也有较好的相关性.     

Level and characteristics of polychlorinated dibenzo-p-dioxins and dibenzofurans in feed and feed additives

Feed security is a prerequisite for safe animal food products. In this study, 13 groups of feed and feed ingredients, totaling 2067 samples, were collected in the period of 2011 to 2014 from China. The highest mean level of polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) was found in fish meals and shell powders, with a concentration of 60.35 ng/kg, followed by mineral origin materials. In terms of the toxicity equivalent concentration, the fish oil group showed the highest PCDD/F levels because of their bio-accumulation through the aquatic food chain, with an average concentration of 1.26 ng WHO-TEQ/kg, while the lowest level was observed in compound feed for chickens and pigs, with an average value of 0.16 ng WHO-TEQ/kg. OCDD and OCDF were the predominant congeners in all groups except fish oils, in which the primary congeners were 2,3,4,7,8-PeCDF and 2,3,7,8-TCDF. For zinc chloride samples, different from other zinc-based compound samples, the main congeners were 1,2,3,4,6,7,8-HpCDF (17%), 1,2,3,4,7,8,9-HpCDF (15%), 1,2,3,4,7,8-HxCDF (12%) and OCDF (30%). Considering toxicity equivalency factors, the dominant congeners were 2,3,4,7,8-PeCDF, 1, 2,3,4,7,8-HxCDF, 2,3,7,8-TCDF and 1,2,3,7,8-PeCDD, and the contribution to the total TEQ was 29%, 16%, 14% and 12%, respectively. Overall, 2.1% (43 out of 2067) of all the analyzed samples exceeded the different individual ''European Union maximum limited levels for PCDD/Fs. This study is beneficial for the determination of the status of contamination levels of feed and feed ingredients.     

污泥与猪粪作为培养基微生物去除垃圾焚烧飞灰中的重金属

以污泥或猪粪代替常规的无机盐(SM)作为A.ferrooxidans和A.thiooxidans复合菌株的培养基,利用微生物淋滤法去除垃圾焚烧飞灰中的重金属.结果表明,重金属去除率大小顺序为:污泥+菌液>SM+菌液>猪粪+菌液.污泥+菌液的处理中,经过15d的微生物淋滤,Cd、Zn、Cu去除率最高分别达到88.1%、78.7%、69.6%,而猪粪+菌液的处理,3种金属的去除率分别为82.4%、73.5%、60.0%.试验也表明,相同浓度的猪粪DOM对硫杆菌复合菌株的抑制作用远大于污泥DOM.当污泥DOM和猪粪DOM中水溶性有机碳浓度分别高于400mg/L和150mg/L时,就表现出对硫杆菌的不可修复的抑制作用.猪粪DOM中小分子量组分较多是造成这一现象的主要原因.     

兽药金霉素在畜禽粪便上的吸附特征研究

通过振荡平衡吸附试验,研究了兽药金霉素在鸡粪和猪粪上的吸持特征并对其吸附机制和影响因素进行探讨.结果表明,金霉素能被畜禽粪便强烈吸附,吸附过程属于快速吸附,吸附等温线呈非线性,能用Freundlich模型很好地描述;雨水很难解吸被粪便吸附的金霉素,存在解吸迟滞现象,用甲醇、3 mol/L NaCl和3 mol/L MgCl2 3种溶液仅分别解吸出了18.3%～20.4%、18.7%～19.4%和55.7%～57.6%被粪便吸附的金霉素.金霉素在畜禽粪便上的吸附受pH和离子强度影响,随pH值和离子强度增大吸附量减少,二价钙离子体系比一价钠离子体系对吸附的影响大.表明有机质吸附和阳离子交换可能是金霉素在畜禽粪便上主要的吸附机制.     

生物沥浸法去除畜禽粪便中重金属的影响因素研究

研究了粪液固体浓度和硫细菌混合菌液接种量对猪粪中重金属生物沥浸的影响。结果表明,猪粪固体浓度越低,重金属沥浸周期越短,沥浸效果越好。从沥浸效果和经济效益2方面综合考虑,固体质量浓度采用70~100 g.L-1较为合适。接种量也是影响生物沥浸的重要因素,试验结果表明,接种量越大,生物沥浸速度越快,但接种量小的粪样只需适当延长沥浸时间即可达到较高的重金属去除效果,2%接种量的猪粪沥浸14 d时,Cu、Zn和Cd沥出率可分别达到76.9%、75.2%和47.8%。从经济角度考虑,接种量采用2%即可满足生物沥浸的需要。     

黄土及其他添加物对猪粪贮存过程氨气和温室气体排放的影响

畜禽粪肥在贮存阶段养分损失严重,是CO_2、CH_4、NH_3和N_2O等大气污染物的重要排放来源.本文采用室内培养方法,研究了添加黄土、秸秆、生物炭和膨润土对猪粪贮存过程中氨气及温室气体排放的影响.结果表明,添加10%用量的生物炭和膨润土处理的CO_2累积排放量与不添加任何添加物的猪粪对照相比分别降低了15.4%和20.9%,N_2O累积排放量分别降低了19.8%和37.6%.添加膨润土处理的NH_3损失量显著增加,但添加生物炭和膨润土处理的综合温室效应与猪粪对照相比均显著降低.添加10%秸秆处理的CH_4和NH_3累积排放量分别较猪粪对照降低了56.8%和95.8%,但其综合温室效应与对照相比差异不显著.模拟黄土垫圈过程添加黄土处理的氨气及温室气体累积排放量均显著降低,综合温室效应显著低于其他处理(p0.05).可见,黄土垫圈是保蓄粪肥碳、氮养分的有效措施,猪粪贮存阶段添加少量生物炭、膨润土对于减少粪肥综合温室效应具有积极作用.