A combined system for asbestos-cement waste degradation by dark fermentation and resulting supernatant valorization in anaerobic digestion.

The use of biological processes for the treatment of asbestos cement waste (ACW) has gained interest in recent years. Nevertheless, this methodology is not yet consolidated because of the incomplete ACW conversion during the biological treatment and the consequent need for further treatments that generally require a high amount of energy and chemicals. In this study, the efficiency of both mesophilic and thermophilic dark fermentation (DF) fed with glucose in fed-batch conditions was assessed for ACW biological treatment. Both thermophilic and mesophilic DF of glucose resulted in a partial conversion of glucose into organic acids that successfully degraded all the asbestos fibers contained in an ACW sample. A hydrogen-rich biogas was produced as well: at the end of the mesophilic DF treatment 0.14 LH2 gglucose-1 were obtained. In addition, the anaerobic digestion (AD) of the DF supernatants led to the production of 0.38 LCH4 gCOD-1.

Current emerging SARS-CoV-2 pandemic: Potential direct/indirect negative impacts of virus persistence and related therapeutic drugs on the aquatic compartments.

The purpose of the present work is to provide a complete overview of possible direct/indirect implications on the quality of aquatic compartments due to the recent SARS-CoV-2 outbreak. With this aim, the environmental impacts are mainly related to i) the virus persistence in sewage and wastewaters, and ii) possible fate in aquatic compartments of drugs tested and administered to SARS-CoV-2 infected patients. Because SARS-CoV-2 spread is very recent, and there is a lack of specific studies on this strain, the virus persistence in wastewaters, the parameters influencing the persistence, as well as the detection methodologies are referenced to the general coronaviruses group. However, the present detailed report of up-to-date knowledge on this topic can provide a useful source for further studies focusing on more deepened investigations of SARS-CoV-2 behaviour in the environment. Such a perspective is significant not only for the control of virus diffusion but also represents a crucial point for the identification of produced alteration to the environmental quality.

Simultaneous removal of Cr(III) from high contaminated soil and recovery of lactic acid from the spent solution.

It is proposed a closed-loop treatment cycle for Cr(III) removal from contaminated soils (2080 mg/kg). The treatment includes the use of lactic acid as washing agent, and the recovery of both Cr(II) and lactic acid from the spent solution. Results indicate that Cr(III) removal efficiency can be very high, passing 70% in all tested operative conditions. The metal forms strong complexes with lactic acid, and therefore cannot be eliminated through direct precipitation simply increasing the pH value. Therefore, lactic acid is preliminarily extracted from the solution using n-butanol at very acidic pH. The obtained extraction degree is generally high, varying between 0.5 and 1 according to the amount of used n-butanol solution. After lactic acid extraction, almost 100% of chromium can be recovered through precipitation in alkaline conditions. Lactic acid, in turns, can be purified and reused for a new washing treatment, separating it from n-butanol solution through water extraction. The extraction efficiency is once more satisfying (around 0.5), and not dependent on the operative pH.

Early diagnosis of anastomotic leakage after colorectal surgery by the Dutch leakage score, serum procalcitonin and serum C-reactive protein: study protocol of a prospective multicentre observational study by the Italian ColoRectal Anastomotic Leakage (iC.

BACKGROUND: Anastomotic leakage (AL) is a dreaded major complication after colorectal surgery. There is no uniform definition of anastomotic dehiscence and leak. Over the years many risk factors have been identified (distance of anastomosis from anal verge, gender, BMI, ASA score) but none of these allows an early diagnosis of AL. The DUtch LeaKage (DULK) score, C reactive protein (CRP) and procalcitonin (PCT) have been identified as early predictors for anastomotic leakage starting from postoperative day (POD) 2-3. The study was designed to prospectively evaluate AL rates after colorectal resections, in order to give a definite answer to the need for clear risk factors, and testing the diagnostic yeld of DULK score and of laboratory markers. Methods and analysis. A prospective enrollment for all patients undergoing elective colorectal surgery with anastomosis carried out from September 2017 to September 2018 in 19 Italian surgical centers. OUTCOME MEASURES: preoperative risk factors of anastomotic leakage; operative parameters; leukocyte count, serum CRP, serum PCT and DULK score assessment on POD 2 and 3. Primary endpoint is AL; secondary endpoints are minor and major complications according to Clavien-Dindo classification; morbidity and mortality rates; readmission and reoperation rates, length of postoperative hospital stay (Retrospectively registered at ClinicalTrials.gov Identifier: NCT03560180, on June 18, 2018). Ethics. The ethics committee of the "Comitato Etico Regionale delle Marche - C.E.R.M." reviewed and approved this study protocol on September 7, 2017 (protocol no. 2017-0244-AS). All the participating centers submitted the protocol and obtained authorization from the local Institutional Review Board.

Enhanced recovery pathways in colorectal surgery: a consensus paper by the Associazione Chirurghi Ospedalieri Italiani (ACOI) and the PeriOperative Italian Society (POIS).

Enhanced Recovery After Surgery (ERAS) pathway is a multi-disciplinary, patient-centered protocol relying on the implementation of the best evidence-based perioperative practice. In the field of colorectal surgery, the application of ERAS programs is associated with up to 50% reduction of morbidity rates and up to 2.5 days reduction of postoperative hospital stay. However, widespread adoption of ERAS pathways is still yet to come, mainly because of the lack of proper information and communication. Purpose of this paper is to support the diffusion of ERAS pathways through a critical review of the existing evidence by members of the two national societies dealing with ERAS pathways in Italy, the PeriOperative Italian Society (POIS) and the Associazione Italiana Chirurghi Ospedalieri (ACOI), showing the results of a consensus development conference held at Matera, Italy, during the national ACOI Congress on June 10, 2019.

Effect of light intensity and nutrients supply on microalgae cultivated in urban wastewater: Biomass production, lipids accumulation and settleability characteristics.

Microalgae cultivation systems fed with wastewater as source of nutrients represents the principal sustainable condition to produce microalgal biomass to be converted conveniently to biofuels. In order to optimize microalgae growth and their lipid content, the effect of light intensity and nutrients load in real wastewater was investigated through batch microalgal cultivation tests. A microalgal polyculture was used as inoculum and grown for 10 days in batch at different conditions of light intensity (i.e. 20, 50 and 100 µmol s-1m-2) and nutrients concentration in wastewater. Experimental results showed that biomass productivity decreased for rich nutrients conditions and increased for high light intensities. The highest lipid mass content (29%) was found for high light intensity condition (100 µmol s-1m-2). Furthermore, microalgae settleability tests, conducted at the end of the cultivation time, resulted in the highest biomass recovery efficiency (72%) for low light intensity and nutrients supply conditions.

Combined yeast and microalgal cultivation in a pilot-scale raceway pond for urban wastewater treatment and potential biodiesel production.

A mixed culture of oleaginous yeast Lipomyces starkeyi and wastewater native microalgae (mostly Scenedesmus sp. and Chlorella sp.) was performed to enhance lipid and biomass production from urban wastewaters. A 400 L raceway pond, operating outdoors, was designed and used for biomass cultivation. Microalgae and yeast were inoculated into the cultivation pond with a 2:1 inoculum ratio. Their concentrations were monitored for 14 continuous days of batch cultivation. Microalgal growth presented a 3-day initial lag-phase, while yeast growth occurred in the first few days. Yeast activity during the microalgal lag-phase enhanced microalgal biomass productivity, corresponding to 31.4 mgTSS m-2 d-1. Yeast growth was limited by low concentrations in wastewater of easily assimilated organic substrates. Organic carbon was absorbed in the first 3 days with a 3.7 mgC L-1 d-1 removal rate. Complete nutrient removal occurred during microalgal linear growth with 2.9 mgN L-1 d-1 and 0.96 mgP L-1 d-1 removal rates. Microalgal photosynthetic activity induced high pH and dissolved oxygen values resulted in natural bactericidal and antifungal activity. A 15% lipid/dry weight was measured at the end of the cultivation time. Fatty acid methyl ester (FAME) analysis indicated that the lipids were mainly composed of arachidic acid.

Continuum and discrete approach in modeling biofilm development and structure: a review.

The scientific community has recognized that almost 99% of the microbial life on earth is represented by biofilms. Considering the impacts of their sessile lifestyle on both natural and human activities, extensive experimental activity has been carried out to understand how biofilms grow and interact with the environment. Many mathematical models have also been developed to simulate and elucidate the main processes characterizing the biofilm growth. Two main mathematical approaches for biomass representation can be distinguished: continuum and discrete. This review is aimed at exploring the main characteristics of each approach. Continuum models can simulate the biofilm processes in a quantitative and deterministic way. However, they require a multidimensional formulation to take into account the biofilm spatial heterogeneity, which makes the models quite complicated, requiring significant computational effort. Discrete models are more recent and can represent the typical multidimensional structural heterogeneity of biofilm reflecting the experimental expectations, but they generate computational results including elements of randomness and introduce stochastic effects into the solutions.

Treatments of asbestos containing wastes.

Since the second half of the twentieth century, many studies have indicated inhalation of asbestos fibers as the main cause of deadly diseases including fibrosis and cancer. Consequently, since the beginning of the 80s, many countries started banning production and use of asbestos containing products (ACP), although still present in private and public buildings. Due to some extraordinary catastrophic events and/or the aging of these products, people's health and environmental risk associated with the inhalation of asbestos fibers keeps being high even in those countries where it was banned. For these reasons, many communities are developing plans for an environmental and sanitary safe asbestos removal and management. Asbestos containing wastes (ACW) are usually disposed in controlled landfills, but this practice does not definitively eliminate the problems related with asbestos fiber release and conflicts with the ideas of sustainable land use, recycling, and closing material cycles. Consequently, many scientific papers and patents proposed physical, chemical, and biological treatments aimed to the detoxification of ACW (or the reduction of their health effects) and looking for the adoption of technologies, which allow the reuse of the end-products. By including recent relevant bibliography, this report summarizes the status of the most important and innovative treatments of ACW, providing main operating parameters, advantages, and disadvantages.

Laparoscopic Deloyers procedure for tension-free anastomosis after extended left colectomy: technique and results.

BACKGROUND: The Deloyers procedure, which includes inversion of the right colon around the axis of the ileocolic vessels, can be used to achieve a well vascularized, tension-free colorectal anastomosis after extended left colectomy. The aim of this study is to report our technique and outcome in a series of ten consecutive patients who underwent right colonic transposition by laparoscopic approach. METHODS: Charts were retrospectively reviewed to analyze postoperative outcome and bowel function. A video was recorded to demonstrate the procedure. RESULTS: Conversion was required in one (10%) patient due to extensive adhesions. No intraoperative complications were recorded. Anastomotic leakage occurred in one (10%) case and was managed with peritoneal lavage and ileostomy. Six months after surgery, all patients reported a median number of 2.5 (range 2-3) bowel movements per day with solid stool consistency. Neither anastomotic stricture nor bowel ischemia was found at 1-year endoscopic follow-up. CONCLUSION: Our experience shows that laparoscopic right colonic transposition is a safe and feasible procedure and provides good functional outcomes.

Biodegradation, ecotoxicity and UV254/H2O2 treatment of imidazole, 1-methyl-imidazole and N,N'-alkyl-imidazolium chlorides in water.

Imidazole-based compounds are used as reagents for the manufacturing of other compounds including imidazolium-based ionic liquids, which have been recently proposed as a green alternative to conventional solvents. Since some imidazole-based compounds have been demonstrated to be harmful to aquatic organisms, the removal of imidazole, 1-methylimidazole, 1-ethyl-3-methyl-imidazolium chloride and 1-butyl-3-methyl-imidazolium chloride from aqueous solutions was attempted by biological oxidation, direct UV254 photolysis, and UV254/H2O2 process at pH 5.5 and 8.5. Results showed that UV254/H2O2 treatment is an effective tool for the removal of the selected compounds at both pHs. In fact, the kinetic constants of the reaction between the photogenerated HO radicals and the four target compounds, estimated by means of both numerical and competition kinetic method, range between 2.32·109 M-1 s-1 and 5.52 ·109 M-1 s-1. Moreover, an ecotoxicity assessment of the contaminated water before and after initial treatment without further processing was assessed by using two living aquatic organisms: Raphidocelis subcapitata and Daphnia magna. The results of this assessment not only corresponded closely to previous findings (in terms of EC50 values) reported in the literature, but also indicated that, in some cases, UV254/H2O2 oxidation by-products could be even more toxic than parent compounds.

Effect of the concentration of essential oil on orange peel waste biomethanization: Preliminary batch results.

The cultivation of orange (Citrus×sinensis) and its transformation is a major industry in many countries in the world, it leads to the production of about 25-30Mt of orange peel waste (OPW) per year. Until now many options have been proposed for the management of OPW but although they are technically feasible, in many cases their economic/environmental sustainability is questionable. This paper analyse at lab scale the possibility of using OPW as a substrate for anaerobic digestion. Specific objectives are testing the possible codigestion with municipal biowaste, verifying the effect on methane production of increasingly high concentration of orange essential oil (EO, that is well known to have antioxidant properties that can slower or either inhibit biomass activity) and obtaining information on the behaviour of d-limonene, the main EO component, during anaerobic digestion. The results indicate that OPW can produce up to about 370LnCH4/kgVS in mesophilic conditions and up to about 300LnCH4/kgVS in thermophilic conditions. The presence of increasingly high concentrations of EO temporary inhibits methanogenesis, but according to the results of batch tests, methane production restarts while d-limonene is partially degraded through a pathway that requires its conversion into p-cymene as the main intermediate.

Single-layer versus double-layer closure of the enterotomy in laparoscopic right hemicolectomy with intracorporeal anastomosis: a single-center study.

BACKGROUND: The aim of our study was to evaluate the short-term outcomes of totally laparoscopic right colectomy, in particular to compare the incidence of leakage of the ileocolic anastomosis after either single-layer (SL) or double-layer (DL) enterotomy closure. METHODS: From March 2010 to July 2014, 162 patients underwent laparoscopic right colectomy with intracorporeal ileocolic anastomosis. The enterotomy was closed with either SL (77 patients) or DL technique (85 patients). Short-term outcomes in both groups were retrospectively analyzed. RESULTS: Median time to perform the ileocolic anastomosis was similar in the two groups (17 min in SL versus 20 min in DL, p = 0.109). DL closure was associated with a significantly lower incidence of anastomotic leakage (1.2 % in DL vs 7.8 % in SL, p = 0.044). Shorter hospital stay was also observed in the DL group. CONCLUSIONS: Adoption of DL closure of the enterotomy resulted in significantly improved outcome. We strongly recommend a double-layer closure technique when performing an intracorporeal enterocolic anastomosis.

Effect of arsenic on nitrification of simulated mining water.

Mining and mineral processing of gold-bearing ores often release arsenic to the environment. Ammonium is released when N-based explosives or cyanide are used. Nitrification of simulated As-rich mining waters was investigated in batch bioassays using nitrifying cultures enriched in a fluidized-bed reactor (FBR). Nitrification was maintained at 100mg AsTOT/L. In batch assays, ammonium was totally oxidized by the FBR enrichment in 48 h. As(III) oxidation to As(V) occurred during the first 3h attenuating arsenic toxicity to nitrification. At 150 and 200mg AsTOT/L, nitrification was inhibited by 25%. Candidatus Nitrospira defluvii and other nitrifying species mainly colonized the FBR. In conclusion, the FBR enriched cultures of municipal activated sludge origins tolerated high As concentrations making nitrification a potent process for mining water treatment.

Biological inverse fluidized-bed reactors for the treatment of low pH- and sulphate-containing wastewaters under different COD/SO4(2-) conditions.

The feasibility of removing sulphate using low-density polypropylene pellets as carrier material in two lactate-fed sulphidogenic inverse fluidized-bed reactors was investigated. Two different COD/sulphate ratios and two different feed-sulphate concentrations were used for the operation of the reactors. During the 242 days of operation, the robustness of the system was studied by suddenly decreasing the feed pH to 3.00. A 10% fluidization degree was used since the carrier material adopted showed not to be adequate to attain a satisfactory immobilization of the biomass with higher fluidization degrees. This resulted in a failure of the process when the feed pH was intentionally decreased to 3.00 in reactor 2, operated with a COD/sulphate ratio of 4.00. On the contrary, when a slightly acidic feed solution was fed to reactor 2, a 97% sulphate reduction efficiency was obtained. In reactor 1, operated with a COD/sulphate ratio of 0.67 throughout the experiment, COD removal and sulphate reduction efficiencies reached the highest values of 75% and 35%, respectively. Higher efficiencies were not achieved also due to the accumulation of acetate and the most likely presence of microbial competition between sulphate reducers and other microorganisms.

Standardization of laparoscopic left hemicolectomy: a single-center experience of 484 cases.

AIM: Laparoscopic surgery has become recognized as an established technique for colon diseases and many different surgical techniques have been described. The aim of our study is to show the results of a single institution where a standardized operative and perioperative procedure for laparoscopic left hemicolectomy (LLH) has been used. METHODS: Between January 2005 and April 2011, 484 patients underwent LLH for colon diseases. Data collected included age, indication for surgery, ASA class, body mass index, operating time, intra and post-operative complications, conversion rate, length of hospital stay, tumor stage, number of lymph nodes harvested, mortality, and a 30-day readmission rate. RESULTS: We found 299 cancer, 29 large dysplastic polyps and 156 complicated diverticular diseases. Average operation time was 120 minutes. The average hospital stay was 5.7 days. In the cancer group, the average number of lymph nodes harvested was 12.7. The intraoperative and early postoperative complications were 3.3% and 10.7 % respectively. The conversion rate was 3.7%. The 30-day readmission rate was 3%. The 30-day mortality rate was 0.4%. CONCLUSION. The standardization of the LLH technique might reduce the technical difficulties and complications. Its potential benefits include the standardization of surgical instrument sets, the definition of benchmarks for conversion before making any inappropriate investment in time and equipment, low rates of complications and readmission rate.

Standardization of laparoscopic left hemicolectomy: a single-center experience of 484 cases.

Aim: Laparoscopic surgery has become recognized as an established technique for colon diseases and many different surgical techniques have been described. The aim of our study is to show the results of a single institution where a standardized operative and perioperative procedure for laparoscopic left hemicolectomy (LLH) has been used. Methods: Between January 2005 and April 2011, 484 patients underwent LLH for colon diseases. Data collected included age, indication for surgery, ASA class, body mass index, operating time, intra and post-operative complications, conversion rate, length of hospital stay, tumor stage, number of lymph nodes harvested, mortality, and a 30-day readmission rate. Results: We found 299 cancer, 29 large dysplastic polyps and 156 complicated diverticular diseases. Average operation time was 120 minutes. The average hospital stay was 5.7 days. In the cancer group, the average number of lymph nodes harvested was 12.7. The intraoperative and early postoperative complications were 3.3% and 10.7 % respectively. The conversion rate was 3.7%. The 30-day readmission rate was 3%. The 30-day mortality rate was 0.4%. Conclusion: The standardization of the LLH technique might reduce the technical difficulties and complications. Its potential benefits include the standardization of surgical instrument sets, the definition of benchmarks for conversion before making any inappropriate investment in time and equipment, low rates of complications and readmission rate.

Model calibration and validation for OFMSW and sewage sludge co-digestion reactors.

A mathematical model has recently been proposed by the authors to simulate the biochemical processes that prevail in a co-digestion reactor fed with sewage sludge and the organic fraction of municipal solid waste. This model is based on the Anaerobic Digestion Model no. 1 of the International Water Association, which has been extended to include the co-digestion processes, using surface-based kinetics to model the organic waste disintegration and conversion to carbohydrates, proteins and lipids. When organic waste solids are present in the reactor influent, the disintegration process is the rate-limiting step of the overall co-digestion process. The main advantage of the proposed modeling approach is that the kinetic constant of such a process does not depend on the waste particle size distribution (PSD) and rather depends only on the nature and composition of the waste particles. The model calibration aimed to assess the kinetic constant of the disintegration process can therefore be conducted using organic waste samples of any PSD, and the resulting value will be suitable for all the organic wastes of the same nature as the investigated samples, independently of their PSD. This assumption was proven in this study by biomethane potential experiments that were conducted on organic waste samples with different particle sizes. The results of these experiments were used to calibrate and validate the mathematical model, resulting in a good agreement between the simulated and observed data for any investigated particle size of the solid waste. This study confirms the strength of the proposed model and calibration procedure, which can thus be used to assess the treatment efficiency and predict the methane production of full-scale digesters.

Mathematical model for sizing combined nitrification and pre-denitrification activated sludge systems.

Two mathematical steady-state models for sizing single activated sludge systems aimed at nitrogen and organics removal from wastewater are proposed. The attention is focused on the combined nitrification system and the pre-denitrification system, considering three (soluble and particulate biodegradable organic matter and ammonia nitrogen) and four (the above cited and nitrate nitrogen) substrates, respectively. Growth and decay of two groups of bacteria (heterotrophic and autotrophic) are taken into account. If the influent flow composition and the kinetic parameters are known and the effluent nitrogen concentration is fixed, both models give explicit expressions of the volumes of the biological reactors. Moreover, the pre-denitrification model makes it possible to define a priori the applicability of the system for a particular wastewater. Model applications show that the nitrification reactor volume increases in the case of a higher influent organic load or to achieve a higher nitrogen ammonia removal efficiency. A smaller denitrification volume is required to face a higher influent organic load. A sensitivity analysis on the kinetic parameters shows an important influence of the maximum ammonia nitrogen removal rate and the ratio between the decay rates of heterotrophic and autotrophic biomass on the nitrification reactor volume.