Enhanced sludge stabilization coupled with microbial fuel cells (MFCs)

This study presents research results on electricity production from waste activated sludge using MFCs during stabilization process. Different MFC configurations equipped with various electrodes were used. Voltage measurements were continuously done during 35 days of MFC operation. Experimental results showed that bioelectricity generation was linked to volatile solids (VS) and protein reductions as a fraction of extracellular polymeric substances (EPS). Double chamber MFC reactor equipped with graphite electrodes had better power and current densities as 312.98 mW/m² and 39.07 μA/cm² while single chamber MFC equipped with titanium electrodes revealed better power and current densities as 97.60 mW/m² and 17.63 μA/cm², respectively. Molecular results indicated that power outputs of MFCs effected by diverse microbial communities in anode biofilms. Although organic matter degradation is reported as 35%–55% VS reduction for digesters, this research provided a promising approach for sludge stabilization with enhanced degrading of organic matters up to 75% by using MFCs.     

不锈钢酸洗污泥微波场中升温特性的研究

本文就酸洗污泥微波场中的升温特性进行了系统研究,旨在为探求酸洗污泥微波辐射深度脱水新工艺提供理论依据.结果表明,酸洗污泥干泥在微波场中的升温特性为先缓慢升温至拐点温度后开始快速升温;酸洗污泥湿泥在微波场中的升温特性为先快速升温至110℃左右后开始缓慢升温,直至水分蒸发完才出现拐点温度并开始快速升温.     

Synergistic effect of nanoparticles and Thalassospira sp. isolated from Bahregan area in biodegradation of oil sludge

Oil sludge is obtained from the contaminated site of Bahregan area in the Persian Gulf in Iran. Chemotaxis was used for the isolation of alkane-degrading bacteria from oil sludge and the alk genes were determined with specific primers. bac1 identified in Thalassospira was selected as a powerful strain for biodegradation of oil sludge. Biodegradation of oil sludge by bac1 in the presence of nanoparticles was investigated by GC-MS analysis. Synergistic effect of Fe₂O₃ and Fe₃O₄ nanoparticles on bacteria increases the biodegradation of oil sludge and produces cyclosiloxane compound which is used in the field of medicine; however, the Thalassospira reduced its toxicity in the environment.     

Design of Watertight Barriers for Retention Ponds of Cyanide Using Sludge from Water Purification Station （Ziga）

In a context of sustainable development and use of eco- materials, it was examined the possibility of using sewage sludge from the water treatment plant of Ziga as an inorganic support to achieve sealing barriers that can withstand high stresses to overcome any weaknesses of the geological barrier （called passive barrier）. The station Ziga that potabilises the water from the river Nakamb6 is located 45 km north east of Ouagadougou. Some experiments on the rheology of sludge from Ziga as well as the filtration of the mixture Ziga＇s sludge and clays from Nouna, Zorgho and Ticare, three regions of Burkina Faso, were conducted. These studies demonstrated the complex hydro-mechanical behavior of Ziga＇s slurries： Newtonian fluid thixotropic threshold for solids contents less than 16.5 wt% and non-Newtonian for higher values. Sludge from the water treatment station Ziga have a hydraulic conductivity of 10^-8 m/s. The results are below regulatory requirements. However, the permeability can be reduced to achieve the value of 10^-9 m/s in particular by adding the clay from Zorgho or Nouna to mixtures of Ziga＇s sludge and neutral leachate, typically mineral water. Beside neutral leachate, two types of leachate were used. One type is composed of acid leachate and the other type is basic. It was shown that the limewater solutions cause deterioration of the seal probably due to the presence of hydroxide ions.     

Understanding phosphorus phases in sewage sludge ashes: A wet-process investigation coupled with automated mineralogy analysis

Phosphorus (P) recovery from SSA (sewage sludge ashes) is highly relevant to address future P-shortages. Efficient recycling strategies require an in-depth knowledge of P-phases present. These may be subject to changes during treatment. Treatment was simulated, initial and treated material studied using automated mineralogy. Automated mineralogy, using the MLA system, is an established tool in ore processing evaluation and adapted here to examine P-phases in SSA. Coupling SSA treatment for P-recovery routines with MLA investigations allows for documenting phase compositions during chemical and thermochemical processes. Behaviour of P-phases during treatment and type of SSA govern P-recycling capacity. Findings lend additional insight to the identification of SSA types.Two different P-recovery routines have been investigated. Target phase groups (phosphates) have successfully been digested. Understanding phosphate setup in terms of composition, particle sizes and phase association is vital for an efficient P-extraction from SSA. P-recovery is not straightforward, but rather a series of steps in order to address different P-phase types. SSA is a complex secondary resource, which needs to be understood prior to P-extraction.     

Performance and Modeling of an Up-flow Anaerobic Sludge Blanket(UASB) Reactor for Treating High Salinity Wastewater from Heavy Oil Production

In this study,an up-flow anaerobic sludge blanket(UASB) reactor was applied to treat the high salinity wastewater from heavy oil production process.At a HRT of ≥24 h,the COD removal reached as high as 65.08% at an influent COD ranging from 350mg/L to 640mg/L.An average of 74.33% oil reduction was also achieved in the UASB reactor at an initial oil concentration between 112mg/L and 205mg/L.These results indicated that this heavy oil production related wastewater could be degraded efficiently in the UASB reactor.Granular sludge was formed in this reactor.In addition,two models,built on the back propagation neural network(BPNN) theory and linear regression techniques were developed for the simulation of the UASB system performance in the oily wastewater biodegradation.The average error of COD and oil removal was-0.65% and 0.84%,respectively.The results indicated that the models built on the BPNN theory were wellfitted to the detected data,and were able to simulate and predict the removal of COD and oil by the UASB reactor.     

精制卤水中含盐泥问题初探

针对精制卤水中含有盐泥的问题,从反应时间、絮凝剂添加、转料及过滤等几方面进行深入探讨,分析了盐泥可能存在的原因,并提出了切实可行的改造方案,对生产运行进行了优化,取得了很好的效果.