给水中的氨氮问题

文中介绍了水中氨氮是水质黑臭的导因，富营养化的重要因素，在水处理上造成除锰困难，消毒水时产生氯化氰副产物，影响水中有机物的生物氧化效率，并对曝气法，折点加氯法，沸石过滤法和生物氧化法4种除氨方法做了比较和讨论。     

好氧生物膜法处理工业微污染水的研究

针对化工微污染废水中的有机污染物,采用好氧生物膜法进行处理,研究好氧生物膜法对处理微污染工业废水的去除效果。     

蒸汽再压缩技术处理高浓度氨氮废水的工程实例

本工程针对电子行业高浓度氨氮废水处理和综合利用,通过对高浓度氨氮废水进行预处理除杂后,采用蒸汽再压缩技术(MVR)对高浓度的氨氮废水进蒸发浓缩,浓缩液经过结晶生产出氯化铵产品,冷凝水经离子交换法处理后达标排放。     

Effects of supplementing condensed tannin extract on intake, digestion, ruminal fermentation, and milk production of lactating dairy cows

A lactation experiment was conducted to determine the influence of quebracho condensed tannin extract (CTE) on ruminal fermentation and lactational performance of dairy cows. The cows were fed a high forage (HF) or a low forage (LF) diet with a forage-to-concentrate ratio of 59:41 or 41:59 on a dry matter (DM) basis, respectively. Eight multiparous lactating Holstein cows (62 ± 8.8 d in milk) were used. The design of the experiment was a double 4 × 4 Latin square with a 2 × 2 factorial arrangement of treatments, and each period lasted 21 d (14 d of treatment adaptation and 7 d of data collection and sampling). Four dietary treatments were tested: HF without CTE, HF with CTE (HF+CTE), LF without CTE, and LF with CTE (LF+CTE). Commercial quebracho CTE was added to the HF+CTE and the LF+CTE at a rate of 3% of dietary DM. Intake of DM averaged 26.7 kg/d across treatments, and supplementing CTE decreased intakes of DM and nutrients regardless of forage level. Digestibilities of DM and nutrients were not affected by CTE supplementation. Milk yield averaged 35.3 kg/d across treatments, and yields of milk and milk component were not influenced by CTE supplementation. Negative effects of CTE supplementation on feed intake resulted in increased feed efficiency (milk yield/DM intake). Although concentration of milk urea N (MUN) decreased by supplementing CTE in the diets, efficiency of N use for milk N was not affected by CTE supplementation. Feeding the LF diet decreased ruminal pH (mean of 6.47 and 6.33 in HF and LF, respectively). However, supplementation of CTE in the diets did not influence ruminal pH. Supplementing CTE decreased total volatile fatty acid concentration regardless of level of forage. With CTE supplementation, molar proportions of acetate, propionate, and butyrate increased in the HF diet, but not in the LF diet, resulting in interactions between forage level and CTE supplementation. Concentration of ammonia-N tended to decrease with supplementation of CTE. The most remarkable finding in this study was that cows fed CTE-supplemented diets had decreased ruminal ammonia-N and MUN concentrations, indicating that less ruminal N was lost as ammonia because of decreased degradation of crude protein by rumen microorganisms in response to CTE supplementation. Therefore, supplementation of CTE in lactation dairy diets may change the route of N excretion, having less excretion into urine but more into feces, as it had no effect on N utilization efficiency for milk production.     

MBR处理垃圾渗滤液的短程硝化研究

研究了膜生物反应器处理垃圾渗滤液的现象及机理,研究表明,反应器内存在较好的短程硝化效果。考察了DO、Ph、C/N等对有机物和氨的去除效果以及对同步硝化反硝化的影响。试验结果表明,在pH值为7.0～8.5,温度为25℃,DO为0.75 mg/L的条件下,短程效果最好,亚硝态氮的积累稳定在90%左右,氨氮去除率可达95%以上,但总氮去除率仅有50%,其原因是碳源不足。     

去除废水中氨氮方法的比较

介绍了废水中氨氮的去除方法,包括折点氯化法、选择性离子交换法、空气吹脱法与汽提法、生物法、化学沉淀法等,并简要分析了各方法的优劣。     

Relationships between dry matter content,ensiling, ammonia-nitrogen,and ruminal in vitro starch digestibility in high-moisture corn samples

The objectives of the study were (1) to determine relationships between high-moisture corn (HMC) dry matter (DM), ammonia-N [% of crude protein (CP)], and soluble CP concentrations, and pH, with 7-h ruminal in vitro starch digestibility (ivStarchD), and (2) to evaluate the effect of ensiling on pH, ammonia-N, soluble CP, and ivStarchD measurements in HMC. A data set comprising 6,131 HMC samples (55 to 80% DM) obtained from a commercial feed analysis laboratory was used for this study. Month of sample submittal was assumed to be associated with length of the ensiling period. Data for month of sample submittal were analyzed using Proc Mixed in SAS (SAS Institute Inc., Cary, NC) with month as a fixed effect. Regressions to determine linear and quadratic relationships between ivStarchD and ammonia-N, soluble CP, pH, and DM content were performed using Proc Mixed. The ivStarchD increased by 9 percentage units from October to August of the following year. Similar results were observed for ammonia-N and soluble CP with increases from 1.8 to 4.6% of CP and 31.3 to 46.4% of CP, respectively, from October to August of the following year. Ammonia-N was positively related to ivStarchD (R² = 0.61). The DM content of HMC at silo removal was negatively related (R² = 0.47) to ivStarchD with a decrease of 1.6 percentage units in ivStarchD per 1-percentage-unit increase in DM content. The pH of HMC was negatively related to ammonia-N (R² = 0.53), soluble CP (R² = 0.57), and ivStarchD (R² = 0.51). Combined, ammonia-N, DM, soluble CP, and pH provided a good prediction of ivStarchD (adjusted R² = 0.70). Increasing pH, ammonia-N, soluble CP, and ivStarchD values indicate that HMC may need up to 10 mo of ensiling to reach maximum starch digestibility. Ammonia-N, DM content, soluble CP concentration, and pH are good indicators of ruminal in vitro starch digestibility for high-moisture corn.     

MAP-UBF工艺用于高氨氮垃圾渗滤液预处理的试验研究

针对老龄垃圾渗滤液水质季节变化大、氨氮含量高的特点,设计MAP-UBF工艺处理全年各个时期的垃圾渗滤液。探讨了MAP法的最佳运行条件和氨氮浓度对厌氧处理去除率的影响,在氨氮小于2500mg/L时,不会对去除率产生明显影响,此时非离子氨浓度为282mg/L。试验表明,系统最佳条件下,COD去除率可达72%,氨氮去除率可达82%。UBF运行稳定,具有较强的酸碱缓冲能力。     

凹凸棒石吸附地下水中氨氮的实验研究

采用甘肃和安徽明美矿物公司的凹凸棒石进行模拟地下水氨氮去除实验研究。结果表明,在氨氮浓度为10mg/L的条件下,凹凸棒石吸附氨氮的平衡时间为3h,凹凸棒石用量3.00g,最佳pH值约6～7,20℃有利于凹凸棒石对氨氮的吸附,正交实验表明,影响吸附因素大小的顺序为:pH值氨氮初始浓度凹凸棒石用量温度。对吸附等温线进行线性拟合,符合Langmuir等温式,饱和吸附量分别为4.06mg/g和4.54mg/g。为凹凸棒石作为一种处理地下水材料提供了数据和理论依据。