Synthesis and Modeling of Poly(L-lactic acid) via Polycondensation of L-Lactic Acid.

We present synthetic experiments of lactic acid (LA) polycondensation to produce poly(lactic acid) (PLA) as well as kinetic modeling calculations that capture the polymer molecular weight increase with time, given the initial concentrations. Tin-octoate-catalyzed polycondensation of (D,L)- or L-lactic acid was carried out in pre-dried toluene after azeotropic dehydration for 48-120 h at 130-137 °C. The polymerization was optimized by varying lactic acid and catalyst concentrations as well as the temperature.

Occurrence of pharmaceuticals in the wastewater of a Greek hospital: Combining consumption data collection and LC-QTOF-MS analysis.

In this article we applied drug consumption approach and chemical analysis in parallel to investigate the concentrations of a large number of pharmaceuticals in different streams of a General Hospital. Drugs consumption data was collected during two periods (Period 1, 2) and the predicted environmental concentrations (PECs) were estimated for the wastewater of a building housing specific medical services (Point A) and for the entire hospital (Point B). Hospital wastewater samples (HWW) samples were also collected from these points and periods and the measured environmental concentrations (MEC) were determined using UHPLC-ESI-QTOF-MS/MS.

A web-based GIS platform supporting innovative irrigation management techniques at farm-scale for the Mediterranean island of Crete.

The aim of this paper is the creation of an integrated and free-access web platform for parcel irrigation water management on a large spatial scale (Water District of Crete, in Greece) in order to: a) accurately determine the irrigation needs of the main crops for Crete such as olives, citrus, avocados and vineyards, b) design strategies, for optimal adaptation of the agricultural sector in the context of climate change, and c) incorporate the dynamic integration of the above information through the creation of a digital platform. In the proposed decision-making system, essential factors are taken into account, such as real-time meteorological data, information about the type and spatial distribution of the agricultural parcels in Crete, algorithms for calculation crop evapotranspiration per development stage and age of the crops, satellite remote sensing techniques in combination with field surveys to depict accurate soil texture map for the whole island of Crete as well as sustainable cultivation practices for saving water per crop and parcel geomorphology. Based on the proposed decision-making system, users will have the opportunity in any specific location/farm in Crete to know the irrigation needs of the crops in real-time and obtain information about proper climate-water adaptation practices.

In vitro digestion and microbial fermentation of dried food residues, a potential "new" component for pet food, and different non-digestible carbohydrate sources.

Food residues are often fed to dogs in private households and might also be a potential "new" ingredient for pet food in the future. As food residues might contain not only digestible, but also fermentable substrates, an effect on the intestinal microbiota can be assumed. In the present study, two batches of dried food residues (DFR) collected from hotels in Crete were microbially fermented in an in vitro batch culture system with canine fecal inoculum: non-sterile DFR including meat (DFRm), sterile DFR including meat (DFRms) and sterile DFR without meat (DFRwms).

Impact of the dietary inclusion of dried food residues on the apparent nutrient digestibility and the intestinal microbiota of dogs.

The use of food residues for animal nutrition might imply ecological and economic advantages; however, their effects as a potential ingredient have not yet been evaluated in dogs. In the present study, four diets with 0, 5, 10 and 15% dried food residues (DFR), derived from hotel catering, were fed to 10 healthy adult dogs. At the end of each three-week feeding period, faeces and blood were collected.

The food for feed concept. Performance of broilers fed hotel food residues.

1. In recent times the use of food waste in animal diets has gained considerable attention because of the increasing demand to cover the needs of human population and the high prices of conventional, arable based, animal feeds.2.

Bioactive Compounds in Food Waste: A Review on the Transformation of Food Waste to Animal Feed.

Bioactive compounds are substances which are present in foods in small amounts and have the ability to provide health benefits. Bioactive compounds include but are not limited to long-chain polyunsaturated fatty acids, vitamins, carotenoids, peptides, and polyphenols. The aim of the present study is to review literature for potential bioactive compounds present in food waste material and discuss the transformation of food waste to animal feed under the perspective that usage of food waste, rather than disposal, may tackle food insecurity and provide health benefits.

Innovative methodology for the prioritization of the Program of Measures for integrated water resources management of the Region of Crete, Greece.

An innovative multi-criteria methodology was proposed for the prioritization of the Program of Measures (PoM) in the Water Region of Crete, and applied specifically to the basin of Geropotamos river according to the requirements of the Water Framework Directive. This study relied on the four pillars of sustainability and the EU cross-compliance legislative objective for the minimization of the climate change impact. The multi-criteria evaluation methodology was based on the results of four different types of analyses: a DPSIR analysis, a SWOT analysis, a Cost-Benefit Analysis and a climate change impacts analysis.

Effects of treated wastewater irrigation on the establishment of young grapevines.

Irrigation with treated wastewater could produce excessive accumulations within the plant and soil, negatively affecting the yield and production quality. In addition, the presence of biological and chemical contaminants could harm the agricultural environment, as well as the health of farmers and consumers. During this work, the suitability of secondary and tertiary treated wastewater for use in young grapevines was evaluated by studying the effect of the wastewater irrigation on the soil-plant system, crop yield, fruit quality and the presence of inorganic chemical contamination (salts, elements and heavy metals), organic chemical contamination (polycyclic aromatic hydrocarbons) and microbial contamination (E.

Production of organic fertilizer from olive mill wastewater by combining solar greenhouse drying and composting.

Olive mill wastewater (OMW) is generated during the production of olive oil. Its disposal is still a major environmental problem in Mediterranean countries, despite the fact that a large number of technologies have been proposed up to date. The present work examines for the first time a novel, simple and low-cost technology for OMW treatment combining solar drying and composting.

Effect of Graphene Oxide on the Reaction Kinetics of Methyl Methacrylate In Situ Radical Polymerization via the Bulk or Solution Technique.

The synthesis of nanocomposite materials based on poly(methyl methacrylate) and graphene oxide (GO) is presented using the in situ polymerization technique, starting from methyl methacrylate, graphite oxide, and an initiator, and carried out either with (solution) or without (bulk) in the presence of a suitable solvent. Reaction kinetics was followed gravimetrically and the appropriate characterization of the products took place using several experimental techniques. X-ray diffraction (XRD) data showed that graphite oxide had been transformed to graphene oxide during polymerization, whereas FTIR spectra revealed no significant interactions between the polymer matrix and GO.

Improving biogas production from anaerobic co-digestion of sewage sludge with a thermal dried mixture of food waste, cheese whey and olive mill wastewater.

Anaerobic co-digestion of sewage sludge and other organic wastes at a wastewater treatment plant (WWTP) is a promising method for both energy and material recovery. However, transportation and storage of wastes to WWTP may be the bottleneck for the successful implementation of this technology. In case of wet wastes and wastewater it is possible to reduce their volume and as a result the transportation and storage cost by using a drying process.

Use of halophytes in pilot-scale horizontal flow constructed wetland treating domestic wastewater.

Recent findings encourage the use of halophytes in constructed wetlands for domestic wastewater treatment due to their special physiological characteristics as the ability to accumulate heavy metals and salts in their tissues makes them ideal candidates for constructed wetland vegetation. In this particular study, we investigated the application of halophytic plants in a horizontal flow constructed wetland for domestic wastewater treatment purposes. The pilot plant which was situated in Crete (Greece) was planted with a polyculture of halophytes (Tamarix parviflora, Juncus acutus, Sarcocornia perrenis, and Limoniastrum monopetalum).

Boosting biogas production from sewage sludge by adding small amount of agro-industrial by-products and food waste residues.

In Greece, in many cities, wastewater treatment plants (WWTPs) operate their own anaerobic digestion (AD) facility in order to treat sewage sludge rather than achieve optimum biogas production. Nowadays, there is a growing interest regarding the addition of other co-substrates in these existing facilities in order to increase gas yield from the biomass. This practice may be possible by adding small amount of co-substrates which will not affect significantly in the designed hydraulic retention time.

Halophytes as vertical-flow constructed wetland vegetation for domestic wastewater treatment.

Recent findings show that halophytes have the ability to accumulate salts in their tissues, making them a very interesting group of plants for domestic wastewater treatment in constructed wetlands (CWs). In that case, it might be possible to reduce the salinity of the final effluent, which is a crucial parameter for wastewater reuse in agriculture. During this study three halophytes, Atriplex halimus, Juncus acutus and Sarcocornia perennis, were tested for phyto-desalination of domestic wastewater in a vertical flow constructed wetland (VFCW) and compared with common reeds (Phragmites australis).

Pilot-scale anaerobic co-digestion of sewage sludge with agro-industrial by-products for increased biogas production of existing digesters at wastewater treatment plants.

Due to low degradability of dry solids, most of the digesters at wastewater treatment plants (WWTP) operate at low loading rates resulting in poor biogas yields. In this study, co-digestion of sewage sludge (SS) with olive mill wastewater (OMW), cheese whey (CW) and crude glycerol (CG) was studied in an attempt to improve biogas production of existing digesters at WWTPs. The effect of agro-industrial by-products in biogas production was investigated using a 220L pilot-scale (180L working volume) digester under mesophilic conditions (35°C) with a total feeding volume of 7.

Single house on-site grey water treatment using a submerged membrane bioreactor for toilet flushing.

Wastewater recycling has been and continues to be practiced all over the world for a variety of reasons including: increasing water availability, combating water shortages and drought, and supporting environmental and public health protection. Nowadays, one of the most interesting issues for wastewater recycling is the on-site treatment and reuse of grey water. During this study the efficiency of a compact Submerged Membrane Bioreactor (SMBR) system to treat real grey water in a single house in Crete, Greece, was examined.

Deployment of municipal solid wastes as a substitute growing medium component in marigold and basil seedlings production.

The possible use of municipal solid waste compost (MSWC) in the production of marigold and basil seedlings examined. Six medium prepared from commercial peat (CP) and MSWC (0, 15, 30, 45, 60, and 100% v/v). There was not any plant growth when MSWC used alone (100%).

Use of fertigation and municipal solid waste compost for greenhouse pepper cultivation.

Municipal solid waste compost (MSWC) and/or fertigation used in greenhouse pepper (Capsicum annuum L.) cultivation with five different substrates with soil (S) and/or MSWC mixtures (0-5-10-20-40%) used with or without fertigation. Plants growth increased in 10-20% MSWC and fertigation enhanced mainly the plant height.

Assessing odour nuisance from wastewater treatment and composting facilities in Greece.

The problem of odour nuisances in Greece was explored using: (a) field measurements of a range of malodorous compounds (hydrogen sulfide, ammonia, benzene, toluene, xylenes, formaldehyde, acetaldehyde, acetone, methyl-mercaptan and carbonyl sulfide) from selected wastewater treatment plants and composting facilities; and (b) questionnaires, completed by wastewater treatment plant operators, to investigate potential odour problems, the odour abatement technologies used, and potential interest and motives for adopting such technologies. The sparse information available in the literature is also exploited. Results indicate that on several occasions there was an odour problem, often stemming from the uncontrolled city sprawl, which results in mixed and often conflicting land uses.

Co-digestion of sewage sludge with glycerol to boost biogas production.

The feasibility of adding crude glycerol from the biodiesel industry to the anaerobic digesters treating sewage sludge in wastewater treatment plants was studied in both batch and continuous experiments at 35 degrees C. Glycerol addition can boost biogas yields, if it does not exceed a limiting 1% (v/v) concentration in the feed. Any further increase of glycerol causes a high imbalance in the anaerobic digestion process.

Fate and effect of linuron and metribuzin on the co-composting of green waste and sewage sludge.

The fate and effect of the herbicides linuron and metribuzin on the co-composting of sewage sludge and green waste were addressed in this work. The experiments were conducted in metal cubic containers of 1.0m(3) volume simulating a windrow composting system.

The role of bulking agent in pile methane and carbon dioxide concentration during wastewater sludge windrow composting.

Wastewater sludge and wood chips were used as feedstock for the construction of two piles, Pile I ("PI") and Pile II ("PII"), at a ratio of 1:1 and 1:2 v/v, respectively. Each pile was originally 1.3-m high, 2.

Enhanced methane and hydrogen production from municipal solid waste and agro-industrial by-products co-digested with crude glycerol.

The effects of crude glycerol on the performance of single-stage anaerobic reactors treating different types of organic waste were examined. A reactor treating the organic fraction of municipal solid waste produced 1400 mL CH(4)/d before the addition of glycerol and 2094 mL CH(4)/d after the addition of glycerol. An enhanced methane production rate was also observed when a 1:4 mixture of olive mill wastewater and slaughterhouse wastewater was supplemented with crude glycerol.