Search results for " wastewater"
showing 10 items of 209 documents
Lab-scale investigation of a pressure retarded osmosis module fed by "non-conventional" salinity gradient
2015
Aim of this work has been to investigate the feasibility of PRO technology for power generation from saline streams originated by different water treatments plants, namely brine from a thermal desalination plant and fresh water from a sewage treatment plant.
Physical properties and Extracellular Polymeric Substances pattern of aerobic granular sludge treating hypersaline wastewater.
2017
The modification of the physical properties of aerobic granular sludge treating fish-canning wastewater is discussed in this paper. The structure and composition of the Extracellular Polymeric Substances (EPSs) were analyzed at different salinity levels and related to granules stability. Results outlined that the total EPSs content increased with salinity, despite the EPSs increment was not proportional to the salt concentration. Moreover, the EPSs structure was significantly modified by salinity, leading to a gradual increase of the not-bound EPSs fraction, which was close to the 50% of the total EPSs content at 75 g NaCl L-1. The increasing salt concentration modified also the EPSs compos…
Comparison between kinetics of autochthonous marine bacteria in activated sludge and granular sludge systems at different salinity and SRTs.
2019
Biological nutrient removal performances and kinetics of autochthonous marine biomass in forms of activated sludge and aerobic granular sludge were investigated under different salinity and sludge retention time (SRT). Both the biomasses, cultivated from a fish-canning wastewater, were subjected to stepwise increases in salinity (+2 gNaCl L−1), from 30 gNaCl L−1 up to 50 gNaCl L−1 with the aim to evaluate the maximum potential in withstanding salinity by the autochthonous marine biomass. Microbial marine species belonging to the genus of Cryomorphaceae and of Rhodobacteraceae were found dominant in both the systems at the maximum salinity tested (50 gNaCl L−1). The organic carbon was remove…
Comparison between moving bed-membrane bioreactor (MB-MBR) and membrane bioreactor (MBR) systems: Influence of wastewater salinity variation
2014
Two pilot plant systems were investigated for the treatment of wastewater subject to a gradual increase of salinity. In particular, a membrane bioreactor (MBR) and a moving bed biofilm membrane bioreactor (MB-MBR) were analyzed. Carbon and ammonium removal, kinetic constants and membranes fouling rates have been assessed. Both plants showed very high efficiency in terms of carbon and ammonium removal and the gradual salinity increase led to a good acclimation of the biomass, as confirmed by the respirometric tests. Significant biofilm detachments from carriers were experienced, which contributed to increase the irreversible superficial cake deposition. However, this aspect prevented the por…
Simultaneous nitritation-denitritation for the treatment of high-strength nitrogen in hypersaline wastewater by aerobic granular sludge
2015
Abstract Fish processing industries produce wastewater containing high amounts of salt, organic matter and nitrogen. Biological treatment of such wastewaters could be problematic due to inhibitory effects exerted by high salinity levels. In detail, high salt concentrations lead to the accumulation of nitrite due to the inhibition of nitrite-oxidizing bacteria. The feasibility of performing simultaneous nitritation and denitritation in the treatment of fish canning wastewater by aerobic granular sludge was evaluated, and simultaneous nitritation–denitritation was successfully sustained at salinities up to 50 gNaCl L −1 , with a yield of over 90%. The total nitrogen concentration in the efflu…
Pollutant removal efficiency of a pilot-scale Horizontal Subsurface Flow in Sicily (Italy) planted with Cyperus alternifolius L. and Typha latifolia …
2016
Constructed wetland systems (CWs) are developed biological technologies for the treatment and reuse of wastewater. The aims of this study were to evaluate the treatment performance of a pilot Horizontal Subsurface Flow system (HSSFs), to evaluate the reuse of treated wastewater (TWW) from CWs for the irrigation of giant reed (Arundo donax (L.)) and to assess the effects of TWW on the biomass yield of giant reed grown for pellet production. The research was carried out in Sicily (Italy) in a pilot-scale HSSFs which was fed with urban-treated urban wastewater following secondary treatment from an activated sludge wastewater treatment plant. Giant reed plots were irrigated with TWW from plante…
The use of constructed wetlands for the treatment and reuse of urban wastewater for the irrigation of two warm-season turfgrass species under Mediter…
2017
Constructed wetlands (CWs) represent low-cost technology for the treatment and reuse of wastewater in urban areas. This study aimed to evaluate the pollutant removal efficiency of a CW system and to assess the effects of irrigation using treated urban wastewater on soil and on two warm-season turf species. The research was carried out in Sicily (Italy) on a pilot-scale horizontal subsurface flow system which was fed with treated urban wastewater following secondary treatment from an activated-sludge wastewater treatment plant. The pilot system was located in an open urban park and comprised two separate parallel planted units. Experimental fields of Cynodon dactylon (L.) Pers. and Paspalum …
New tailor-made bio-organoclays for the remediation of olive mill waste water
2013
A systematic study aimed at obtaining new organoclays for the treatment of Olive Mill Waste water (OMW) has been performed. Several organoclays have been prepared by loading different amounts of the biocompatible surfactant Tween20 onto the K10 montmorillonite (MMT). Complementary kinetic and equilibrium studies on the adsorption of the Tween20 onto the MMT have been carried out and the characterization of the new tailor-made bio-materials has been performed by means of the XRD and FT-IR measurements. Finally the prepared bio-organoclays have been successfully applied for the OMW remediation and they proved to be highly effective in decreasing the organic content (OC) to an extent that depe…
Aerobic granular sludge: State of the art, applications, and new perspectives.
2018
The aerobic granular sludge (AGS) process has attracted significant interest over the last decade and is one of the most promising wastewater treatment technologies. AGS offers several advantages over conventional activated sludge (CAS) including excellent settling, and higher volumetric loading capacity. Because of porosity, concentration gradients develop and stratified aerobic, anoxic, and anaerobic layers develop throughout granule depth. This is the reason for simultaneous nutrient removal in a single tank. Aerobic granulation is influenced by many parameters including wastewater characteristics and operating conditions. Among these, the anaerobic upflow feeding strategy and a properly…
The role of extracellular polymeric substances (EPS) on aerobic granules formation: comparison between a case of synthetic wastewater supply and anot…
2015
The paper focused on the evolution of extracellular polymeric substances (EPSs) content during the granulation process in two Granular Sequencing Batch Airlift Reactors (GSBAR) (3,5 L) fed with synthetic and industrial wastewater. Results showed that EPSs, in particular proteins (PN) were mainly produced during the feast phase because of high substrate availability, especially under conditions of metabolic stress. Than EPSs content reduced during the famine period. More in detail, during the granulation process, a greater polysaccharides (PS) consumption occurred in both reactors, while PN content reduced significantly only in R2. As a result PN/PS ratio increased significantly during granu…