Session 13 - Wastewater treatment

An innovative way to treat municipal wastewater and produce energy at the same time is anaerobic treatment. Anaerobic processes are traditionally used for high-strength wastewater or municipal sludge treatment and only recently have been applied for the treatment of low strength municipal wastewater. To investigate the performance of anaerobic wastewater treatment through the incorporation of membrane technology, a 40 L laboratory scale Anaerobic Membrane Bioreactor (AnMBR) with a flat sheet submerged membrane along with a 40 L reservoir for trapping and measuring the biogas produced have been installed and set in operation. The operation of the AnMBR unit with real wastewater is an important step for data generation, since most of the studies related to AnMBR have been performed with synthetic wastewater offering no insight to problems that a real-world unit might face. This paper presents the start-up of the unit and operating results from the first phase of laboratory scale experiments, conducted at temperatures between 14-18oC. More experiments will be held in the near future at different temperatures and also different operating conditions in order to examine the efficiency of the reactor under realistic conditions, by identifying the possibility of integrating the technology into WWTPs.

Session: 13, Room: A, at Thu, 09/05/2019 - 15:45 to 16:00
Oral presentation in Wastewater treatment

Water is very precious and inevitable for every living objects including human beings. Huge quantity of waste water is generated by us every day and there are various methods to regenerate safe and pure drinking water from these waste waters. Researchers all over the world are continuously trying to develop low cost filtration system using various adsorbents. Agricultural waste products are being used as adsorbents and gaining momentum because of various attractive factors such as easy availability, low cost, non-toxic nature etc. In the present investigation, date pit (date stone) powder is used an adsorbent to remove Pb (II). The analysis revealed that date pit powder can be successfully used in a column filtration set-up to remove Pb (II) ions from the waste water streams with high efficiency.

Session: 13, Room: A, at Thu, 09/05/2019 - 16:00 to 16:15
Oral presentation in Wastewater treatment

Natural treatment systems are gaining preference as a wastewater treatment option since it is a form of ecosystem-based adaptation to climate change. The study investigated the performance of a laboratory scale horizontal, subsurface flow constructed wetland (SSFCW) planted with cogon grass (Imperata cylindrica) in reducing the pollutant concentration of slaughterhouse wastewater in Zamboanga City, Philippines. Results showed that the mean efficiency of BOD5 removal at seven (7) and 14 days detention time were 94.49 percent and 89.31 percent, respectively; while the average TSS removal efficiency were 97.8 percent and 99.9 percent, respectively. Statistical analysis of the BOD5 removal efficiencies revealed significant difference; which means that higher BOD5 removal is achieved at seven (7) days detention time. Analysis of the TSS removal efficiencies likewise revealed a significant difference, proving that longer detention time results in higher suspended solids removal. Therefore horizontal, SSFCW planted with cogon grass can be used to treat slaughterhouse wastewater at seven (7) days detention time. A pilot study is recommended to validate laboratory-scale finding. Future reseach should also investigate the performance of horizontal, SSFCW using other wastewater sources, different parameters, other endemic hydrophytic grasses, and to consider meteorological and climatological factors.

Session: 13, Room: A, at Thu, 09/05/2019 - 15:30 to 15:45
Oral presentation in Wastewater treatment

A fully biobased layer-by-layer deposition method, containing kraft lignin and chitosan as the polyelectrolytes, was employed to improve the anti-fouling properties of polyethersulfone membrane. Results revealed that the water in air contact angle decreased from 70° ± 2° for the pristine membrane to 34° ± 1° for the modified double-bilayer membrane, indicating enhanced hydrophilicity. The synthesized film was ultrathin and caused a slight decrease in permeation flux of the modified membrane compared to the pristine membrane. Additionally, the deposited film showed excellent stability after 6 hours running water test using a dead-end filtration cell.

Session: 13, Room: A, at Thu, 09/05/2019 - 15:00 to 15:15
Oral presentation in Wastewater treatment

In this study, the applicability of a hybrid chemical/membrane process for the treatment of the boiler blow-down (BBD) water from steam assisted gravity drainage (SAGD) operation was explored. For the chemical pre-treatment prior to the membrane filtration, another waste stream of SAGD, i.e., ion exchanger regeneration wastewater (IERW), was used as a coagulant to reduce the concentration of organic matter and silica. The proposed method involved the direct use of the NF process for the purification of BBD water, followed by an integrated IERW conditioning and nanofiltration (NF) to purify the concentrated retentate. This process could operate with a zero-liquid discharge (ZLD) configuration and it was found to be an efficient method in terms of water recovery and water product quality.

Session: 13, Room: A, at Thu, 09/05/2019 - 15:15 to 15:30
Oral presentation in Wastewater treatment

In this study, fly ash zeolites (FAZ) were synthesized by a double stage fusion-hydrothermal treatment. Magnetite nanoparticles were added to FAZ between the two synthesis stages. The obtained nanocomposites (MNP-FAZ) and their parent FAZ were studied with respect to their surface characteristics and were tested for decontamination of polluted waters. The experimentally obtained equilibrium adsorption isotherms were described applying different computational models.

Session: 13, Room: A, at Thu, 09/05/2019 - 16:30 to 16:33
Flash presentation in Wastewater treatment

This study investigated the applicability of Direct Contact Membrane Distillation (DCMD) process for the treatment of a petrochemical industry effluent, intending to recover water from the concentrate produced by reverse osmosis (RO). In DCMD, the experiments were accomplished with a feed and permeate-inlet temperature of 60 °C and 20 °C, respectively. Four commercial microporous hydrophobic flat-sheet membranes made of polytetrafluoroethylene (PTFE), with or without a support layer, laminated or not with butylated hydroxyanisole (BHA), having different thickness, pore size, effective porosity and contact angle, were evaluated. All evaluated membranes presented a very satisfactory water recovery ratio (~90%), getting high rejection factors (above 99.5%) for all analysed parameters and producing a high-quality water having a very low electrical conductivity (around 2 μS cm-¹). The membrane with BHA in its composition presented the lowest permeate flux decay that occurred gradually along the experimental runs, representing a productivity loss of only 14% for a water recovery ratio near 90%. These results indicate that this membrane has a low propensity to fouling and scaling when treating a wastewater with characteristics like the ones evaluated in this work.

Session: 13, Room: A, at Thu, 09/05/2019 - 16:24 to 16:27
Flash presentation in Wastewater treatment

The determination of Heavy Metals such as Copper, Iron, Manganese and Zinc in Aluminum alloys is usually achieved following ASTM E3061-17 Method. Alternatively, for time and cost saving, the laboratory’s ΕΝ ISO 11885:2009 method for wastewater analysis was appropriately modified producing satisfactory results. Parameters such as matrix effect, wavelength, plasma conditions, calibration standards and dilution conditions of the alloy were examined for the accurate measurement of these elements in Aluminum alloys (e.g. CRMs, according to their Certified Values).

Session: 13, Room: A, at Thu, 09/05/2019 - 16:27 to 16:30
Flash presentation in Wastewater treatment

Batch experiments were conducted in order to investigate the use of microalgae Chlorella sorokiniana for the treatment of different types of municipal wastewater (raw sewage, anaerobically treated wastewater, aerobically treated wastewater) and investigate the role of light and addition of ammonium on its growth. All experiments were conducted in triplicates and lasted for 7 days. Several parameters were monitored during the experiments in order to check the experimental conditions (pH, temperature, DO), the growth of biomass and the removal of major pollutants (COD, NH4-N, PO4-P, NO3-N) from wastewater. According to the results, the target microalgae can be sufficiently developed in raw and anaerobically treated sewage, while it can remove an important part of the major pollutants found in raw sewage, reaching up to 94%, for COD, 99% for PO4-P and 94% for NO3-N. The addition of NH4-N in aerobically treated does not enhance growth of biomass, while the application of mixotrophic conditions (16h light/8h dark) enhanced microalgae growth and major pollutants’ removal.

Session: 13, Room: A, at Thu, 09/05/2019 - 16:21 to 16:24
Flash presentation in Wastewater treatment

Brewery wastewater is generated from the beer brewing process in large amounts (4-8 m3 per m3 of beer produced). Brewery wastewater consists of high organic matter content, significant nitrogen and phosphorus concentrations and easily biodegraded compounds. Even though most biological treatment technologies applied to brewery wastewaters include the use of bacteria, cyanobacteria (photosynthetic microorganisms) constitute attractive means for sustainable and low cost wastewater treatment producing high biomass concentration. In this study, the capacity of a filamentous cyanobacterium Leptolyngbya sp. for the pollutants removal from brewery wastewater was investigated coupled with objective to determine its proteins, carbohydrates and lipids content after wastewater treatment. The experiments were conducted in batch mode under non-sterile conditions in lab-scale photobioreactors. The removal rates of nitrate, ammonium, orthophosphates, total phosphorus and chemical oxygen demand (COD) were almost 49.2%, 100%, 57.1%, 57.9% and 24.3%, respectively, within the first 7 days of cultivation. The maximum biomass concentration was 350 mg/L, while the biomass produced was consisted of approximately 53.5% carbohydrates, 20.2% proteins and 10% lipids. Therefore, the treatment of brewery wastewater using cyanobacteria species could be effective, while the cyanobacterial biomass could be used in numerous fields for diverse applications.

Session: 13, Room: A, at Thu, 09/05/2019 - 16:15 to 16:18
Flash presentation in Wastewater treatment

Greece, although not over-industrialized, faces issues connected to pollution of its water resources, as conventional wastewater treatment methods often proved ineffective at removing some pollutants such as suspended solids and pigments. Therefore, the need of developing efficient, modern anti-pollution techniques for the preservation of a viable environment is urgent as ever. Electrocoagulation (EC) is one of these widely studied, promising methods. EC consists of generating coagulant species by electrolytic dissolution of sacrificial anode materials triggered by electric current applied through the electrodes, leading to the removal of different pollutants.In the present study EC was studied for the treatment of various agro-industrial wastewaters (table olive, cheese whey and printing ink),examining its efficiency under a wide range of operating parameters (current density, initial pollutant concentration, pH, electrode material).According the results EC proved efficient in most of the experimental sets performed, achieving significant removal efficiencies of color and organic matter. Also,acost analysis of the process that was conducted to evaluate the economic feasibility of the process showed that EC can be a viable and realistic choice for agro-industrial wastewater treatment.

Session: 13, Room: A, at Thu, 09/05/2019 - 16:18 to 16:21
Flash presentation in Wastewater treatment