DOC and Ammonium Removal Processes in Slow Sand FIlters - Influence of Grain Size and Flow Rate

Slow sand filters (SSFs) are essential for ensuring microbial quality and biological stability of drinking water in the Netherlands. However, gaps exist in understanding of removal processes of dissolved organic carbon (DOC) and ammonium and the effects of grain size, loading rate, and backwashing on removal in SSFs.<br/>Four lab-scale SSF...

Pilot Study on Low Temperature Stability of Aerobic Granular Sludge

摘要： 好氧颗粒污泥技术具有占地面积小、能耗低、剩余污泥量少、抗冲击性强等优点，是<br/>一种可持续的污水处理技术。以北京某污水处理厂实际生活污水作为基质，在中试规模（有效容积<br/>为2.5 m3）反应器中进行好氧颗粒污泥培养，研究了颗粒污泥在低温条件下的稳定性。中试自夏季<br/>开始运行到次年春季结束，共计运行260 d。结果表明，采用我国实际低碳源市政污水可以培养出好<br/>氧颗粒污泥，污泥颗粒化程度可达94%，SVI5/SVI30为1.1 ~ 1.3。冬季低温会造成颗粒污泥的枝状结<br/>构增多、丝状菌生长，进而引起颗粒化比例略有下降，为80%~91%，污泥平均粒径降低，SVI5/SVI30升<br/>高至1.5 ~ 1.8。在冬季低温条件下，通过优化调控进水流量...

Effect of an increased particulate cod load on the aerobic granular sludge process: A full scale study

High concentrations of particulate COD (pCOD) in the influent of aerobic granular sludge (AGS) systems are often associated to small granule diameter and a large fraction of flocculent sludge. At high particulate concentrations even granule stability and process performance might be compromised. However, pilot-or full-scale studies focusing...

Effect of Light Intensity on Nutrient Removal and Pigment Production by Purple Non-Sulfur Bacteria

Purple non-sulfur bacteria (PNSB) consist of wide genera of phototrophic bacteria found in various aquatic system. A high versatility in their mode of growth ranging from photoheterotrophic to dark fermentation gives them various potential applications. Their nature of being phototrophs require them to obtain light as energy source for growth...

Effects of electron acceptors on sulphate reduction activity in activated sludge processes

The concentration of sulphate present in wastewater can vary from 10 to 500 mg SO₄ ²⁻/L. During anaerobic conditions, sulphate is reduced to sulphide by sulphate-reducing bacteria (SRB). Sulphide generation is undesired in wastewater treatment plants (WWTPs). Previous research indicated that SRB are inhibited by the...

Biological Nutrient Removal in Compact Biofilm Systems

The removal of nutrients such as nitrogen and phosphorus from both domestic and industrial wastewaters is imperative since they potentially harm the environment. One of the main consequences of excessive availability of nitrogen and phosphorus in aquatic ecosystems (freshwater, marine and estuarine) is the overgrowth of algae and other aquatic...

Microbial population analysis of nutrient removal-related organisms in membrane bioreactors

Membrane bioreactors (MBR) are an important and increasingly implemented wastewater treatment technology, which are operated at low food to microorganism ratios (F/M) and retain slow-growing organisms. Enhanced biological phosphorus removal (EBPR)-related organisms grow slower than ordinary heterotrophs, but have never been studied in detail in...

Aerobic granular sludge: Scaling up a new technology

Most conventional wastewater treatment plants need a large surface area for the treatment of their sewage. This is due to the open structure of the biomass used to convert the polluting components in wastewater. Because of the flocculated growth, sludge concentrations in reaction tanks are low and settling times need to be long in order to keep...

Bulking sludge control. Kinetics, substrate storage, and process design aspects

The activated sludge process is the preferred technology for biological wastewater treatment. Despite decades of progress and operation serious operating problems still occur with this process. One major problem is the regular occurrence of excessive growth of filamentous bacteria, phenomena known as filamentous bulking sludge. Poor solid-liquid...

Water-landbouw-milieu: Vergelijking modelresultaten ANIMO en NITSOL/PHOSOL voor PAWN-distrikt 29