Traditional Wisdom and Monte Carlo Tree Search Face-to-Face in the Card Game Scopone

We present the design of a competitive artificial intelligence for Scopone, a popular Italian card game. We compare rule-based players using the most established strategies (one for beginners and two for advanced players) against players using Monte Carlo Tree Search (MCTS) and Information Set Monte Carlo Tree Search (ISMCTS) with different reward functions and simulation strategies. MCTS requires complete information about the game state and thus implements a cheating player while ISMCTS can deal with incomplete information and thus implements a fair player. Our results show that, as expected, the cheating MCTS outperforms all the other strategies; ISMCTS is stronger than all the rule-based players implementing well-known and most advanced strategies and it also turns out to be a challenging opponent for human players.Comment: Preprint. Accepted for publication in the IEEE Transaction on Game

Competitive reaction modelling in aqueous systems. The case of contemporary reduction of dichromates and nitrates by nZVI

In various Countries, Cr(VI) still represents one of the groundwater pollutant of major concern, mainly due to its high toxicity, furthermore enhanced by the synergic effect in presence of other contaminants. As widely reported in the recent literature, nanoscale zero valent iron particles (nZVI-p) have been proved to be particularly effective in the removal of a wide range of contaminants from polluted waters. In this work, experimental tests of hexavalent chromium reduction in polluted groundwater in the presence of nitrate by nZVI-p are presented and discussed. The effect of different nitrate amounts on Cr(VI) reduction mechanism was investigated and the obtained results were successfully interpreted by the proposed kinetic model. nZVI-p produced by the classical borohydride reduction method were added in to synthetic solutions with the initial concentration of Cr(VI) set at 93, 62 and 31 mg L-1 and different nitrate contents in the range 10-100 mg L-1. According to the experimental results, nitrate showed an adverse effect on Cr(VI) reduction, depending on the nZVI/Cr(VI) and Cr(VI)/NO3 - ratio. The proposed kinetic model soundly grasps the competitive nature of the Cr(VI) reduction process when other chemical species are present in the treated solution

Chemical reduction of hexavalent chromium (VI) in soil slurry by nano zero valent iron

The increasing industrial development of recent decades has lead to the production of increasing quantities of waste containing heavy metals, elements often harmful to the environment, which in the past were not properly disposed of, thus inducing soil and groundwater pollution. In particular, chromium (Cr) and its derivatives are largely used in industries such as textiles, electronics, metallurgy, tanneries. Consequently, large quantities of this element were released into the environment due to leakage or incorrect disposal. Chromium is a transition element present in nature in three stable forms: metallic Cr, trivalent Cr(III) and hexavalent Cr(VI). Metallic Chromium is rarely found in nature, mainly as natural chrome metallic inclusions in diamonds, fragments of as meteorites and metal alloys in fluvial deposits. The trivalent form is characterized by a relatively low toxicity, while the hexavalent chromium present in different compounds of industrial origin, is considered highly toxic towards the respiratory system and carcinogenic. In the present work, lab experiments of Cr(VI) contaminated soil clean-up by chemical reduction with nanoparticles of zero valent iron (nZVI) are presented and discussed. The aim of the work was to optimize the main operative parameters of the reduction process (pH, nZVI concentration, liquid/solid ratio). Cr(VI) reduction using nZVI was found to obey a pseudo-first-order kinetic: the kinetic constant depended upon the nZVI: Cr(VI) ratio. The use of nZVI in combination with sodium dithionite was also studied, by performing tests in batch conditions at pH = 1.3, in order to assess the optimal ratio between nZVI and Cr(VI), and between dithionite and Cr(VI). The results obtained showed an increase of Cr(VI) reduction rate with respect to the tests carried only with nZVI: for long treatment times, up to 24 hours, an almost total removal of Cr(VI) was achieved when a large excess of reagents was used

Production of nano zero valent iron particles by means of a spinning disk reactor

Nitrates are considered hazard compounds for human health due to their tendency to be reduced to nitrites, in particular in reducing environment. Nano zero valent iron (nZVI) represents an efficient and low-cost adsorbent/reductive agent for nitrate removal from groundwater. In this work, nZVI particles were produced by means of two different equipment types based on the same chemical synthesis method: a batch stirred tank reactor (BSTR) and a spinning disk reactor (SDR). This latter apparatus is capable to strongly promote micromixing at a steady-state, continuous condition, and such as qualifies to subsist in the framework of process intensification. Particle size distribution (PSD) of the obtained nZVI particles were measured by a DLS technique. The removal efficiency of the produced nVI particles were checked by using two NO3-solutions (1.6 and 6.4 mM) and by monitoring nitrate concentration reduction rates at selected time intervals. Results showed that the nZVI particles produced by SDR have a narrow PSD with a mean diameter of 65nm; on the contrary, particles produced by BSTR shows bimodal PSD with modal sizes of 105 nm and 400 nm, respectively. Experimental tests of nitrates reduction in water have been performed, using both the particles produced by the above mentioned techniques. Results of batch tests showed that the highest removal efficiency of nitrates was observed by using the nZVI particles produced by means of SDR, as a consequence of the higher average specific surface. Since nitrate removal process involves both reduction and adsorption processes, the removal mechanism has been investigated, and the pseudo-first-order reduction kinetic model was successfully tested and reported in both cases

Shortcut biological nitrogen removal (SBNR) in microbial fuel cells (MFCs)

Microbial Fuel Cells (MFCs) represent nowadays a promising technology for the treatment of industrial wastewater. In this work the Shortcut Nitritation/Denitritation process in H-type MFC was investigated. The cell was fed by sodium acetate and fumaric acid, as organic carbon source, and ammonium sulphate, sodium nitrite and sodium nitrate as nitrogen source. Anaerobic digestion supernatant (digestate) was used as bacterial source. Batch tests were performed at a TOC/N ratio of 0.35, and Total Organic Carbon (TOC), pH and Open Circuit Voltage (OCV) were daily monitored. High organic carbon removal (up to 85%) in short time (within 6 days) were achieved. The nitritation proved to be independent of organic carbon amount and composition: an ammonium content reduction of about 45% was observed. Regarding the denitritation step, an almost quantitative removal of nitrite and nitrate was observed when fumaric acid was used as a carbon source

Photolysis of in-situ electrogenerated hydrogen peroxide for the degradation of emerging pollutants

This study investigates the degradation of paracetamol, an emerging contaminant widely used as pain and fever reliever, by means of hydrogen peroxide either alone or in combination with UV-C photolysis. In particular, we provide a comparison between the performance of both commercial and electrogenerated H2O2 whose production has been achieved by galvanostatic electrolysis in undivided reactor with a gas diffusion cathode. The performance of the treatments has been assessed in terms of both pollutant decay and mineralization. The influence of the H2O2 to paracetamol molar ratio is discussed. The results show that the electrogenerated hydrogen peroxide, when activated by UV-C irradiation, results in faster degradation and mineralization of paracetamol. However, under the conditions adopted, complete depletion of the total organic carbon (TOC) has never been attained

Study on fouling behaviour of ultrafiltration and nanofiltration during purification of different organic matter polluted wastewaters

The boundary flux concept is a profitable tool to analyse fouling issues in membrane processes. The boundary flux value separates an operating region characterized by reversible fouling formation from irreversible one. Boundary flux values are not constant, but function of time, as calculated by the sub-boundary fouling rate value. The knowledge of both parameters may fully describe the membrane performances in sub-boundary operating regimes. Many times, for wastewater purification purposes, ultrafiltration and nanofiltration membranes are employed to treat different wastewater streams. This appears to be feasible from both technical and economical point of view many times. Whereas initial productivity and selectivity to reach the desired purification targets are generally guaranteed, key to reach process feasibility is that the membrane must resist to fouling issues, with a limited reduction of the performances as a function of time. In other words, longevity of the membranes must be that high to minimise their substitution and, consequently, operating (consumable) costs for the replacement. In this work, after a brief introduction to the boundary flux concept, for many different wastewater, the boundary flux and sub-boundary fouling rate values of different microfiltration and ultrafiltration membranes will be discussed and compared. By this approach, it will be possible to separate those systems where the use membranes for their treatment results successfully from those that represent a challenge (from a technical and/or economic point of view). This will depend sensibly of the feedstock characteristics and, in detail, on the particle size of the suspended matter and guidelines for process designers will be discussed. In most cases, it will be shown that membranes appear to perform very well, making this technology very interesting for many case studies

Shortcut Biological Nitrogen Removal (SBNR) in an MFC anode chamber under microaerobic conditions. The effect of C/N ratio and kinetic study

In this work, the feasibility of the Shortcut Biological Nitrogen Removal (SBNR) in the anodic chamber of a Microbial Fuel Cell (MFC) was investigated. Thirty day experiments were carried out using synthetic wastewaters with a Total Organic Carbon vs. nitrogen ratio (TOC/N) ranging from 0.1 to 1. Ammonium, nitrite, nitrate, pH, and TOC were daily monitored. Results showed that microaerobic conditions in the anodic chamber favored the development of nitritation reaction, due to oxygen transfer from the cathodic chamber through the membrane. Nitritation was found to depend on TOC/N ratio: at TOC/N equal to 0.1 an ammonium removal efficiency of up to 76% was observed. Once the oxygen supply to the cathodic chamber was stopped, denitritation occurred, favored by an increase of the TOC/N ratio: a nitrite removal of 80.3% was achieved at TOC/N equal to 0.75. The presence of nitrogen species strongly affected the potential of the electrochemical system: in the nitritation step, the Open Circuit Voltage (OCV) decreased from 180 mV to 21 mV with the decrease of the TOC/N ratio in the investigated range. Lower OCV values were observed in the denitritation steps since the organic carbon acted as the energy source for the conversion of nitrite to nitrogen gas. A kinetic analysis was also performed. Monod and Blackman models described the ammonium and the organic carbon removal processes well during the nitritation step, respectively, while Blackman-Blackman fitted experimental results of the denitritation step better

Magnetic core nanoparticles coated by titania and alumina for water and wastewater remediation from metal contaminants

Nanomaterials have been widely used for remediation of contaminated streams. However, using nanomaterials within water and wastewater might be dangerous since fate and health impact of nanoparticles is still unknown. Therefore, it is mandatory to avoid contamination by removing all the nanoparticles from the treated stream. This can be performed by immobilizing the nanoparticles on supports, although this approach leads to lower efficiency values. Another possibility is to use suspended nanoparticles: in this case, efficiency of the treatment process is enhanced. If nanomaterials have a magnetic core-shell, then suspended nanoparticles can be removed in a safe and easy was by using magnetic traps. In the present study, new nanomaterials based on magnetic core-shell structure were developed: the magnetic core guarantees a complete removal from the treated water and wastewater streams, whereas the shell (coating) is functionalized to eliminate specific classes of pollutants. A first experimental step allowed to produce the magnetic nanoparticles and perform a coating with SiO2 in order to electrically isolate the core from the ambient and to avoid degradation. This procedure is well established and the production of SiO2 coated magnetic nanoparticles are nowadays a validated procedure by using a spinning disk reactor.In a successive step, the silica shell magnetic cores were coated by titania and/or activated alumina particles with the aim of removing metals by adsorption. In the present study, the arsenic adsorption capacity of silica shell magnetic cores nanoparticles coated by titania and/or activated was investigated through kinetic experiments. All the tested adsorbents performed very well showing very rapid rates of the adsorption process. Among them, the best performing media were found to be those with titania coating. The best fitting kinetic model was found to be the pseudo-second order one for all of the adsorbents

From soil remediation to biofuel. Process simulation of bioethanol production from Arundo donax

A range of energy crops can be grown on marginal land (i.e. land that is not suitable for food crop production or contaminated site) to provide feedstocks for bioenergy, non-food products and biofuels. The food versus fuel debate had a significant negative impact in Europe on first generation biofuels production from food crops (i.e. wheat, rapeseed, etc). A new approach involving the use of marginal land for the production of lignocellulosic species for the production of bioethanol is now pursued in Italy and in many other countries, where the demand for high quality water resources, arable land, food and fossil fuels is rapidly growing. With an emerging “feed versus fuel debate” there is a pressing need to find options for the use of marginal lands and wastewaters or saline ground waters to produce second generation biofuel or bio paper crops. Arundo donax was selected as a potential crop for use in these areas, since it produces more cellulosic biomass and sequesters more contaminants, using less land and pesticides than any other alternative crops reported in the literature. The objective of this paper is to evaluate economically a simplified process for the production of second generation bioethanol from A. donax. Process calculations and economic analyses are performed using the software SuperPro Designer®