Veterinary drugs in groundwater in a dairy region of central Argentina and risk assessment for human health

Veterinary drugs used in dairy production are potential contaminants of surface or groundwater sources, being able to affect human and environmental health. It is known that chronic exposure to antibiotics in low concentrations present in water can generate microbial resistance. This study aimed to evaluate the presence of veterinary drugs in 53 groundwater samples used for animal and human consumption, collected in dairy milking parlors, in an important milk-producing area of central Argentina, and to assess the risk to human health when they are used as drinking water. In 75% of the total samples analyzed, at least one veterinary drug was detected. The most frequently found drugs in water samples were the antibiotics tetracycline in 58.5% and oxytetracycline in 56.6%, and an anti-inflammatory, flunixin in 39.6%. In the water samples, the tetracycline and oxytetracycline concentrations were between 0.1 and 5.3 μg/L and flunixin concentrations were between 0.01 and 2.1 μg/L. The frequency of appearance and the concentration levels of the substances found in the water samples were evaluated according to the productivity, size, and production system (confined or pasture) of the dairy farms. Higher concentrations and proportions of water samples containing antibiotics were observed when the number of animals per dairy farm was >182 and when the productivity was high (>25 liters per animal per day). In the case of flunixin, the percentage of detection was similar in all evaluated categories. The risk assessment for children and adults, considering the intake of drinking water containing residues of these drugs, did not indicate a significant health risk. It would be advisable to evaluate other sources of drinking water, both surface and underground, in other regions of the country, to provide data to assess the impact of these substances and the other contaminants on environmental and human health.     

Microwave treatment of dairy manure for resource recovery: Reaction kinetics and energy analysis

A newly designed continuous-flow 915 MHz microwave wastewater treatment system was used to demonstrate the effectiveness of the microwave enhanced advanced oxidation process (MW/H₂O₂-AOP) for treating dairy manure. After the treatment, about 84% of total phosphorus and 45% of total chemical oxygen demand were solubilized with the highest H₂O₂ dosage (0.4% H₂O₂ per %TS). The reaction kinetics of soluble chemical oxygen demand revealed activation energy to be in the range of 5–22 kJ mole^?1. The energy required by the processes was approximately 0.16 kWh per liter of dairy manure heated. A higher H₂O₂ dosage used in the system had a better process performance in terms of solids solubilization, reaction kinetics, and energy consumption. Cost-benefit analysis for a farm-scale MW/H₂O₂-AOP treatment system was also presented. The results obtained from this study would provide the basic knowledge for designing an effective farm-scale dairy manure treatment system.     

不同改良措施对煤矸石污染土壤上大豆生长的影响

采用盆栽试验,通过添加粉煤灰和牛粪对煤矸石污染土壤进行改良,并研究了不同改良措施对大豆生长、光合特性和产量的影响。结果表明,添加粉煤灰0.07 kg.kg-1(T1)、添加牛粪0.07 kg.kg-1(T2)、添加粉煤灰和牛粪各0.07 kg.kg-1(T3)3种土壤改良措施对大豆的株高、叶面积和单株根瘤数均有显著影响,不同生育期株高、叶面积和单株根瘤数均表现为T3>T2>T1>CK。在花期和鼓粒期,3种土壤改良措施下大豆的叶绿素含量和光合速率均显著高于对照,且T3处理显著高于T2和T1。与对照相比,不同土壤改良措施对大豆的单株荚数、百粒重、单株粒重和产量均有显著影响,T3、T2和T1处理的大豆产量较对照分别提高68.47%、40.99%和30.63%。     

天津市规模化奶牛养殖场废水中典型抗生素处理效果及生态风险评估

为了解天津市规模化奶牛养殖场废水处理前后典型抗生素的浓度水平及处理效果,使用固相萃取-超高效液相色谱-串联三重四极杆质谱仪(SPE-UPLC-MS/MS)技术,对天津市12家规模化奶牛养殖场废水中7种典型抗生素进行调查监测.结果表明,12家规模化奶牛养殖场废水处理前后均不同程度地检测出抗生素残留.废水处理前,替米考星(TIL)、盐酸土霉素(OTC)、司帕沙星(SPA)、磺胺噻唑(STZ)、氧氟沙星(OFL)和盐酸沙拉沙星(SAR)检出率均为100%,磺胺嘧啶(SDZ)检出率为83. 33%.其中替米考星和盐酸土霉素为未处理废水中主要的抗生素成分,浓度为25. 21μg·L~(-1)和9. 87μg·L~(-1).处理后废水中磺胺嘧啶和氧氟沙星的检出率下降至25. 00%和41. 66%,主要成分为替米考星和盐酸土霉素,但浓度有着明显地降低,分别为11. 30μg·L~(-1)和3. 71μg·L~(-1).不同的规模化奶牛养殖场对于抗生素的处理效果在24. 95%～81. 05%之间.厌氧-缺氧-好氧(AAO)处理工艺的综合处理效果优于厌氧好氧(AO)处理工艺.氧氟沙星、盐酸沙拉沙星、盐酸土霉素为处理后废水中主要的高风险污染物,各规模化奶牛养殖场都含有一种或多种RQs 1的抗生素,其排放对环境构成一定的生态风险.     

温度分化对APBR反应器性能及产甲烷菌群落的影响

为了研究温度分化对固定床厌氧反应器(anaerobic packed bed reactor,APBR)牛粪发酵处理效果及产甲烷菌群落的影响,反应器发酵温度从室温(22℃±1℃)阶梯式分化到低温(15℃±1℃)、中温(37℃±1℃)和高温(55℃±1℃).温度变化的过程中,温度越高COD(chemical oxygen demand)去除率和日总产气量越高,分化后COD去除率分别为25%、45%、60%,相应的日产气量为2.3、4.0、8.5 L·d-1,但是甲烷含量基本保持不变(~60%);温度突然变化造成挥发性脂肪酸含量骤然增加,并处于波动状态.16S r RNA基因克隆文库法分析表明,室温时包含广古菌门中的常见重要产甲烷菌MBT(甲烷杆菌目)、Mst(甲烷鬃菌科)、Msc(甲烷八叠球菌科)和MMB(甲烷微菌目),以及嗜热菌,也有少部分泉古生菌门,发酵温度分化后,产甲烷菌多样性减少,中温条件下产甲烷菌种类相对较少.定量PCR表明Mst、MMB和Msc总基因浓度都有所减少,并且温度越高减少越多,各菌数量相对比例变化较大,但Mst仍为优势产甲烷菌.     

Assessing Economic Changes Due to an Expanding Dairy Industry in the Texas High Plains

The dairy industry in the Texas High Plains has experienced rapid expansion in the past two decades. This study assesses the impact of the increased presence of dairies on overall water use, crop composition, and the local economy. The increase in water use related to the dairy industry from 2000 to 2015 was primarily due to an increase in demand for drinking by the cows (direct water) as well as an increased demand for silage (indirect water). However, a comparative analysis (dairy presence vs. no dairy presence) from a single year indicates minimal impacts on total water use due to dairies. During the same time period, the number, size, and employment of related local business establishments have increased economic activity in rural areas. Editor's note : This paper is part of the featured series on Optimizing Ogallala Aquifer Water Use to Sustain Food Systems. See the February 2019 issue for the introduction and background to the series.     

乳品废水活性污泥总DNA提取方法的比较

为了从乳品废水活性污泥中快速提取总DNA,本文系统对SDS高盐缓冲液抽提法、冻融+SDS高盐缓冲液抽提法、溶菌酶+SDS抽提法与冻融+溶菌酶+SDS抽提法等4种抽提活性污泥总DNA方法做了比较研究,并对提取的DNA浓度以及通过PCR扩增技术对DNA的质量进行了检测。结果表明:4种方法均可从乳品废水活性污泥中提取出DNA4,种方法提取的DNA总量与纯度存在差异,其中采用冻融+SDS高盐缓冲液抽提活性污泥总DNA效果最好,以该方法提取的总DNA为模板,PCR扩增16 SrDNA,可扩增出分子量为1.5 Kb左右的DNA产物。本文为研究乳品废水活性污泥总DNA的提取提供了一种简便、快速的方法。     

高氟环境对奶牛生产和繁殖性能的影响

通过检测宁夏某地奶牛内外环境中的饮水、饲料和土壤氟、硒、铜及血氟、毛氟、尿氟和全血硒、铜，证实该场奶牛高氟低硒低硐。日粮添加０。２６ｍｇ／ｋｇ硒和３．２ｍｇ／ｋｇ铜。连续饲喂３个月，低硒低铜现象消失，但高氟仍旧存在。高氟使奶牛子宫复旧时间、首次发情时间 科后配妊天数分别延长６．６ｄ、６ｄ和３８．５ｄ，产后孕酮含量始终低于健康奶牛，同时，奶牛胎衣不下发病率和乳房炎发病率分别高于健康奶牛１６．７％和１     

INEQUITIES FOR SMALL FOOD PROCESSING PLANTS RESULTING FROM LIQUID WASTE TREATMENT REGULATIONS1

ABSTRACT: The cost of the liquid wast treatment measures required to meet federal as well as typical state and local regulations was examined for dairy processing plants of various sizes. Federal effluent standards were found to produce higher estimated capital costs per unit of raw material for smaller plants, even with relaxed requirements for smaller plants. State regulations limiting the effluent BOD₅- concentration were also found to result in inequitable costs for smaller processors. These inequities result from economies of scale and not such factors as level of process technology employed or amount of waste produced per unit of raw material. In contrast, applying an example sewer surcharge formula did not produce inequities from economies of scale.     

用UASB-TF工艺处理某乳品厂生产废水

利用UASB TF工艺处理某乳品厂废水 ,出水达到GB8978 1996中的一级排放标准。该工艺处理乳品废水具有投资低、运行成本低、污染物去除率高、操作方便稳定的特点。在进水CODCr浓度 10 0 0mg L时 ,出水浓度可以降到 60～80mg L ,UASB的水力停留时间 12h ,TFCODCr负荷 0 4kg m3·d ,水力停留时间 4h ,出水回用于冷冻机冷却水 ,直接运行成本 0 3 0元 m3。