Search | Engineering

订阅投稿

首页工程期刊工程焦点工程成就工程前沿关于我们 English

资源类型

期刊论文 2

年份

2021 1

2007 1

关键词

检索范围：

排序：展示方式：

Performance of bioferric-submerged membrane bioreactor for dyeing wastewater treatment

ZOU Haiyan, XI Danli

《环境科学与工程前沿（英文）》 2007年第1卷第3期页码 374-380 doi: 10.1007/s11783-007-0064-7

摘要： Adding iron salt or iron hydroxide to sludgemixed liquor in an aeration tank of a conventional activated sludge processes (bioferric process) can simultaneously improve the sludge s filterability and enhance the system s treatment capacity. In view of this, Fe(OH) was added to a submerged membrane bioreactor (SMBR) to enhance the removal efficiency and to mitigate membrane fouling. Bioferric process and SMBR were combined to create a novel process called Bioferric-SMBR. A side-by-side comparison study of Bioferric-SMBR and common SMBR dealing with dyeing wastewater was carried out. Bioferric-SMBR showed potential superiority, which could enhance removal efficiency, reduce membrane fouling and improve sludge characteristic. When volumetric loading rate was 25% higher than that of common SMBR, the removal efficiencies of Bioferric-SMBR on COD, dye, and NH-N were 1.0%, 9.5%, and 5.2% higher than that of common SMBR, respectively. The trans-membrane pressure of Bioferric-SMBR was only 36% of that in common SMBR while its membrane flux was 25% higher than that of common SMBR. The stable running period in Bioferric-SMBR was 2.5 times of that in common SMBR when there was no surplus sludge discharged. The mixed liquor suspended solids concentration of Bioferric-SMBR was higher than that of common SMBR with more diversified kinds of microorganisms such as protozoans and metazoans. The mean particle diameter and specific oxygen uptake rate of Bioferric-SMBR were 3.10 and 1.23 times the common SMBR, respectively.

关键词： hydroxide surplus aeration SMBR Bioferric process

HTML PDF 收藏

INTENSIFICATION OF GRASSLAND-BASED DAIRY PRODUCTION AND ITS IMPACTS ON LAND, NITROGEN AND PHOSPHORUS USE EFFICIENCIES

Jouke OENEMA, Oene OENEMA

《农业科学与工程前沿（英文）》 2021年第8卷第1期页码 130-147 doi: 10.15302/J-FASE-2020376

摘要： Many grassland-based dairy farms are intensifying production, i.e., produce more milk per ha of land in response to the increasing demand for milk (by about 2% per year) in a globalized market. However, intensive dairy farming has been implicated for its resources use, ammonia and greenhouse gas emissions, and eutrophication impacts. This paper addresses the question of how the intensity of dairy production relates to N and P surpluses and use efficiencies on farms subjected to agri-environmental regulations. Detailed monitoring data were analyzed from 2858 grassland-based dairy farms in The Netherlands for the year 2015. The farms produced on average 925 Mg·yr milk. Milk production per ha ranged from<10 to>30 Mg·ha ·yr . Purchased feed and manure export strongly increased with the level of intensification. Surpluses of N and P at farm level remained constant and ammonia emissions per kg milk decreased with the level of intensification. In conclusion, N and P surpluses did not differ much among dairy farms greatly differing in intensity due to legal N and P application limits and obligatory export of manure surpluses to other farms. Further, N and P use efficiencies also did not differ among dairy farms differing in intensity provided the externalization of feed production was accounted for. This paper provides lessons for proper monitoring and control of N and P cycling in dairy farming.

关键词： ammonia externalization feed forage maize front runners manure production milk yield nitrogen surplus