A particular attention is given to the passage of the wastewatersludge by the sticky form, where the performances of the con
ductive dryer are altered. As reported by Kudra  , during
stickiness period, the material deposits on the dryer wall causing the alteration of the hydrodynamics of the dryer and in extreme cases it leads to chocking the dryer leading to a notable decrease of the dryer performances. The author reports that non sticky materi als can present better heat transfer coefﬁcient of about 60% than a sticky material during rotary drying. The author successes to trans form by mean of a control box the registered torque into a current/ voltage signal. The sticky point and the sticky phase are easily deﬁned when the voltage signal changes from its constant values. 2.3. Solar drying of wastewatersludge
Bioconversion of WastewaterSludge and Glycerol to Biodiesel
Prof. R.D. TYAGI & R.Y. SURAMPALLI GROUP
Institut National de la Recherche Scientifique, Centre Eau – Terre – Environnement, 490 rue de la Couronne, Québec, Québec, G1K 9A9. (Email: email@example.com )
Animal Fatty WastewaterSludge (AFWS), like animal fats, rep resent an important source of glyceride and free fatty acid material for potential conversion into biodiesel ( Chakraborty et al., 2014; Da Cunha et al., 2009; Jeong et al., 2009 ). Any bio fuel made from AFWS would be classified as a non consumable, 2nd generation raw material and is considered to ‘count double’ on carbon emis sions savings according to the Renewable Energy Directive (RED 2009/28/CE) of the EU, thus sources such as used cooking oil, are already being exploited for their economic and environmental ben efits ( Jørgensen et al., 2012; López et al., 2010; Tu and McDonnell, 2016 ). AFWSs can vary greatly in their nature depending on their origin and the manner in which they are collected. In general, the washings of the slaughterhouse are drained through a scraper that removes any large pieces of insoluble material (bones, feath ers, skin, etc.) and collected in a floatation tank. Here the animal fats float to the top of the tank, (hence they are often referred to as floatation greases), and are separated by skimming off the fat into a secondary container, normally exterior to the slaughter house and open to air. Due to their collection and treatment AFWSs are generally regarded to be completely hydrolyzed to the free fatty acids (FFAs), however, as our analysis shows they can contain up to 20% of un hydrolyzed compounds, namely the tri , di and mono glycerides. The amount of un hydrolyzed material generally depends on the amount of time the lipids are left to stagnate (open to air) before being collected. Currently there are no commercial uses for AFWSs and thus slaughterhouses are obliged by law to pay for its destruction. For the purposes of this work, we will report on two very different, but very representative types of AFWS and our efforts to convert the lipid material contained within them into liquid biofuels.
Québec, Canada; 2 US Environmental
Protection Agency, Kansas City, USA
The identification and quantification of bisphenol A (BPA) in wastewater (WW) and wastewatersludge (WWS) is of major interest to assess the endocrine activity of treated effluent discharged into the environment. BPA is manufactured in high quantities fro its use in adhesives, powder paints, thermal paper and paper coatings among others. Due to the daily use of these products, high concentration of BPA was observed in WW and WWS. BPA was measured in samples from Urban Community of Quebec wastewater treatment plant located in Quebec (Canada) using LC-MS/MS method. The results showed that BPA was present in significant quantities (0.07 µg L –1 to 1.68 µg L –1 in wastewater and 0.104 µg g –1 to 0.312 µg g –1 in wastewatersludge) in the wastewater treat- ment plant (WWTP). The treatment plant is efficient (76 %) in removal of pollutant from process stream, however, environmentally sig- nificant concentrations of 0.41 µg L –1 were still present in the treated effluent. Rheological study established the partitioning of BPA with- in the treatment plant. This serves as the base to judge the portion of the process stream requiring more treatment for degradation of BPA and also in selection of different treat- ment methods. Higher BPA concentration was observed in primary and secondary sludge solids (0.36 and 0.24 µg g –1 , respectively) as compared to their liquid counterpart (0.27 and 0.15 µg L –1 , respectively) separated by centrifu- gation. Thus, BPA was present in significant concentrations in the WWTP and mostly parti- tioned in the solid fraction of sludge (Partition coefficient (Kd) for primary, secondary and mixed sludge was 0.013, 0.015 and 0.012, respectively).
Wastewatersludge is naturally produced in large quantity. It was reported that wastewatersludge contained 5 to 20% lipid w/w dry sludge which was comparable to plant seeds (Choi et al., 2014; Kumar et al., 2016; Olkiewicz et al., 2014; Wang et al., 2016). When sludge is used as lipid source, it was expected that the cost of biodiesel production would be highly reduced as sludge was cost free material. In addition, wastewatersludge has been found as a suitable medium to cultivate microorganism due to the fact that the sludge was rich in carbon, nitrogen, and phosphorus (Angerbauer et al., 2008; Ren et al., 2015; Zhang et al., 2014a). Many
Keywords: crude glycerol; hydrogen; mixed-culture; secondary wastewatersludge; 1,3-propanediol
Biodiesel and biohydrogen are considered as renewable, efficient and carbon dioxide (CO 2 )-free
fuel of choice for the future [ 1 , 2 ]. Biodiesel production across the world is increasing rapidly and estimated to reach 20 billion liters in 2020 due to strong government policies and incentives across the world [ 3 , 4 ]. About 100 kg of crude glycerol (CG) is generated as waste by-product with every ton of biodiesel produced [ 5 ]. Sustainable production and commercialization of biodiesel depends on the demand and increased utilization of CG [ 3 ]. With presence of various impurities across CG, refining for glycerin is no longer cost-effective with decreasing market value for glycerin [ 4 , 6 ]. Value added utilization (valorization) of waste CG into biofuels or biochemical for additional market
Keywords: Sludge, Convective drying, temperature effect, Page model, 4 th degree
The increase of food and energy demand is one of the consequences of, in one hand, growing of the world population and, on the other hand, working on having more facilities and life amelioration and accommodation. Unfortunately, it has not only good effects; it leads to the increase of food and energy prices but also to the augmentation of domestic, commercial and industrial wastes. We give a particular attention to the sludges generated from wastewater treatment, whose management has become a real challenge.
landfill  plans the progressive reduction of sludge disposal in dump sites, which is currently the second issue for sludge after landspreading [4-5]. This explains that sludge management will become a real challenge of the years to come.
Two major issues will remain for sludge disposal: incineration and landspreading. In both cases, drying is and will remain a critical and necessary pretreatment after mechanical dewatering by centrifugation or filtration. It can indeed reduce the water content below 5% dry solids (DS). This obviously reduces the mass and volume of waste and, consequently, the cost for storage, handling and transport. The removal of water to such a low level increases drastically the lower calorific value, transforming the sludge into an acceptable combustible. Furthermore, the dried sludge is a pathogen free, stabilized material because of the high temperature treatment. Despite the industrial and economic importance of such process, rather few works have been carried out in order to get a better understanding of the key – rate controlling – mechanisms. The main practical consequence is that the drying behaviour of a sludge is still difficult to predict. Research in this field is however progressively growing, as indicated by recent publications [6-10].
Sample 57.63 ±2.91 97.56 Secondary sludge 0.638 ±6.7 90.42
Effluent 7.28 ±1.71 95.81 Mixed sludge 0.469 ±5.4 87.32
A simple, rapid and sensitive method was developed for the quantiﬁcation of CTC in wastewater samples. The applicability of this method in environmental samples was conﬁrmed by analyzing CTC in WW and WWS and its recovery values. Since there is no chromatographic step involved in the analysis process, the analysis time was reduced from minutes to seconds compared to traditional LC-MS/MS system.
3 Université de Lyon, Ecole des mines de Saint-Etienne, I. Fayol, UMR 5600 EVS, France
PRADEL, M., AISSANI, L., VILLOT, J., BAUDEZ, J.C. , LAFOREST, V., 2015. From waste to product: a paradigm shift in LCA applied to wastewater sewage sludge. SETAC Europe 25th Annual Meeting, Barcelona, Spain, 3-7 May 2015.
Product 1 Product 2
Fig. 3. Effect of broth EPS produced by isolated strains from Beer WWTP sludge on flocculation activity. (a) EPS concentration vs FA; (b) EPS volume vs FA
Fig. 4. Effect of broth EPS produced by isolated strains from leachate on flocculation activity. (a), (b) and (c) EPS concentration vs FA; (d), (e) and (f) EPS volume vs FA
Abstract: The primary goal of wastewater treatment plants (WWTPs) is to remove pollutants from wastewaters so as to reach a set of effluent standards under a set of environmental, cost, and regulatory constraints. To design a WWTP according to these criteria, design engineers usually make the initial sizing of the plant using design guidelines or a set of modeling tools under steady state conditions. In these approaches the effect of different sources of uncertainties are taken into account in an implicit manner through the application of safety factors and/or selection of conservative values for design inputs. In this study, the application of a set of statistical and process-based dynamic modeling tools is proposed to explicitly characterize the uncertainty/variability in the input time series and model parameters and propagate these into the uncertainty in the model outputs (i.e. effluent wastewater composition and costs). The probability of non-compliance (PONC) can be calculated for the applicable effluent standards. The proposed probabilistic methodology provides the design engineers with a concerted framework to utilize and incorporate into the design of WWTPs the available and future information on the characteristics of the sewershed and the climate conditions, as well as the latest advances in dynamic modeling. Moreover, the calculated PONC can be used as an objective criterion
The water reuse is not a standard practice. Based on the aim to resocializing local wastewaters, this study shows that it is now a completely different Reuse from the one discussed in 1989. Questioning actors and interests allows us to extract ourselves from a purely technical conception of this practice and to avoid adopting a definition of a "plastic word" (Cirelli, 2006) that would only make sense in a specific situation. This study invites us to continue the reflection about the socio-technical broader in order to understand the plurality of translations of wastewater reuse practice (TWW reuse, RDW, NEWater, water reuse...).
wastewaters using the same catalytic system (Fontanier et al. 2005 ; Baig and Petitpain 2003 ). The heteroge neous catal ys t involved in this process is made with supported-type metal oxides. Experiments were carried out on treated wastewater issued from biological treat ment to determine the performances, and the global kinetics of this process. As adsorption is an essential step for catalytic ozonation, a focus was made on its kinetics, and the experimental results were confronted to the most common models described in literature.
mixing, sludge disposal, need of a settling or filtration unit). On the other side, sorption systems are more reliable than granular filters because they do not clog and treatment performances are easily determined by adsorption isotherms.
In the literature, treatment performances are presented with both concepts: adsorption isotherms or filter performance (removal efficiency). However, these two approaches are often used without distinction even if they are fundamentally different. Authors of recent literature reviews outline the difficulty to correlate treatment performances between different studies when both methodologies are employed (Chazarenc et al., 2008; Vohla et al., 2001). Adsorption isotherms have been used to predict the treatment performance of filters, but this prediction method was shown to lead to incorrect results (Chazarenc et al., 2008; Drizo et al., 2002). In this study, the filter approach is used, as we were interested in extensive treatment systems. Preliminary adsorption jar-tests are used for comparative purposes.
2.1. Reactor setup and instrumentation
Two upflow anaerobic sludge bed (UASB) reactors with a liquid volume of 0.5 L (0.15 L headspace) each and one UASB reactor with a liquid volume of 3.5 L (1.1 L headspace) were used in the study. The reactors were made of glass (internal diameter of 48 and 100 mm for 0.5 and 3.5 L reactor, respectively) and had external recirculation loops. Water jackets and water heating systems were used to maintain the reactor liquid temperature at 35 °C. The reac- tor pH was controlled using a pH-controller (Cole-Parmer Instru- ment, Vernon Hills, IL, USA) equipped with a probe, which was inserted in the external recirculation line. The pH was maintained at 6.8–7.0 by the controlled addition of NaOH. The reactors were operated at a hydraulic retention times (HRT) between 6 h and 12 h. An upflow velocity of 2 m h 1 was maintained in all reactors.
Although a complex and undefined inoculum leads to more representative results in biodegradability studies, its use has several drawbacks. Ideally, activated sludges from different WWTPs would be similar enough to lead to comparable and reliable results, depending only on the molecular structure of the test compound. Nevertheless, geographical and temporal differences in the structure and function of activated sludge communities are broadly reported [ 8 , 9 ]. Because any microbial population can to adapt to any assimilable carbon source, variations in the inoculum affect mainly the reproducibility of tests on not readily biodegradable compounds. When the biodegrad- ability of these substances is tested, the results depend both on their chemical structure and the composition of the inocula (i.e., the specific fraction of the viable biomass able to grow on the chemical).