MANAGEMENT PRACTICES OFWASTEWATER SLUDGE

Large amounts of wastewater sludge, a secondary pollutant of wastewater treatment plants, commonly containing over 90% water and pathogens, organic pollutants and heavy metals, are produced daily worldwide.  Main treatment routes of wastewater sludge are: landfill, anaerobic digestion, land application and incineration. Anaerobic sludge digestion is a technology employed worldwide to reduce solids, stabilize organic matter, and destroy pathogens and to produce biogas as a source of energy.Compositing is applied for sludge treatment and conversion of complex biowaste into a stabilized product that can be used as organic fertilizer in agriculture. In this paper we present the main practices employed in the management of wastewater sludge, in order to reduce its volume, to capitalize it and to protect the environment

APPLICATIONS OF ROTATING BIOLOGICAL CONTACTORSIN WASTEWATER TREATMENT

Rotating biological contactors are generally used as secondary treatment of domestic, hospital and industrial wastewater, operating asan aerobic and anaerobic fixed film biological treatment. Rotating biological contactors areeffective in the removal of biodegradable matter,pathogenic bacteria,nitrogen, recalcitrant compounds, heavy metals,emerging contaminants, and dyes from wastewater. In this paper, we present the design and operating principles of rotating biological contactors, and we review some of the most important results related to the applications of rotating biological contactors for the treatment of wastewater originating from different activities

NANOMATERIALS FORHEAVY METALS REMOVAL FROM WASTEWATER

Human, agricultural, industrial, and mining activities generate large quantities of wastewater contaminated with toxic and non-biodegradable heavy metals such as As, Cr, Cd, Co, Cu, Hg, Ni, Pb and Zn.To avoid the harmful effects of heavy metals on terrestrial and aquatic ecosystems and on human health, it is essential to develop and implement innovative technologies for the removal of these toxic and hazardous pollutants from wastewater.In wastewater treatment, and particularly in nanotechnology applications, many efficient, ecological and cost-effective nanomaterials have been developed, having unique functions of heavy metals removal from industrial effluents, surface waters, groundwater and drinking water.Due to their antimicrobial properties, nanoparticles are also used for wastewater disinfection and microbial control

ELECTROCOAGULATION IN WASTEWATER TREATMENT

Within the past decades,water scarcity is one of the greatest challenges faced by humans, sothe treatment and reuse of wastewater generated daily from household, sanitary and industrial activities iswidely practiced and encouraged.Electrocoagulation has emerged as an effectivetechnology for the treatment ofdifferent categories of wastewater. The electrode materials should non-toxic to human health and environment and these usually involve aluminium or iron, but new materials are also used.The efficiency of electrocoagulation depends on current density, gap between anodes and cathodes, electrodes arrangement, composition and shape, initial pollutant concentration, composition and pH of the solution, electrolysis time.This paper aims to reviewthe mechanisms involved in wastewater electrocoagulationand the results of electrocoagulation applied in the treatment of wastewater from different sources

THE EFFECTS OF WASTEWATER IRRIGATION ON AGRICULTURAL SOILS

In arid and semi-arid areas, wastewater is often recovered for crop irrigation, contributing to the sustainable agriculture. Although positive effects have been observed on crop yields (50-80% growth) due to wastewater nutrients, the reuse of untreated wastewater harms both the environment and human health. Soil is mostly affected by excess salts, sodium, nutrients and heavy metals in wastewater. High salinity affects the upper layer of soil (0–30 cm); sodium and chlorine reduce crop yields by 40%; high content of organic matter in wastewater decreases soil pH, and heavy metals and pathogens enter the food chain. Irrigation technology is also important: sodium and salinity are higher in sprinkler than in furrow or subsurface irrigation; subsurface drip irrigation is more effective in reducing soil pathogens than surface drip irrigation. This paper examines the effects of wastewater irrigation on soil salinity, sodium, heavy metals and pathogen contamination

STRUCTURAL STATIC ANALYSIS OF THE CURVED STILT BY FEM USING THE ELCUT PROGRAM

The paper presents a study of the distribution of stresses and strains in the curved stilt of the plough-body, using the ELCUT analysis program by the finite element method. In its public version, the program allows the static structural analysis in three stages of precision. However, there are some limitations on the number of nodes for the discretized structure, depending on its complexity (250 to 500 nodes)

ANALYSIS OF THE STATE OF STRESSES AND STRAINS IN THE CURVED STILT, USING TRIANGULAR FINITE ELEMENTS (CST)

The paper presents a study on the analysis of the distribution of stresses and strains in the curved stilt of the plough-body, using the Finite Element Method. Modeling was performed with the help of triangular finite elements "CST" (Constant Strain Triangle), using a special program for this type of applications “CSTPL.EXE”, developed at University Politehnica of Bucharest, Department of Materials Strength

Contemporary management of mixed hiatal hernias

Spitalul Clinic Republican, Catedra Chirurgie FEC MF, Chişinău, Al XI-lea Congres al Asociației Chirurgilor „Nicolae Anestiadi” din Republica Moldova și cea de-a XXXIII-a Reuniune a Chirurgilor din Moldova „Iacomi-Răzeșu” 27-30 septembrie 2011Introducere. Hernie hiatală (HH) este o problemă actuală cu incidența globală 15%, din care 60% sunt asimptomatici. În patologiile cronice gastrointestinale HH se plasează pe locul trei după ulcerul peptic gastroduodenal şi litiază biliară. Conform clasificării Allison şi Sweet din 1952 după mecanismul de producere sunt trei tipuri de hernii: HH prin alunecare (axială) – 90%HH prin rostogolire (paraesofagiană) – 5-7%HH mixtă – 3%. Manifestarea tipică a unei HH mixte este refluxul gastroesofagian. Scopul lucrării. Elucidarea managementului contemporan corect al HH mixte şi superiorității tratamentului chirurgical comparativ cu cel conservativ. Material şi metode: În clinica chirurgie FEC MF timp de 10 ani (2000-2011) au fost operați 32 de pacienți cu HH mixtă: 30 pe calea laparoscopică şi 2 prin laparotomie. Dintre care 25 de cazuri – hernii cardiofundale, 7 cazuri – subtotale. La 20 de pacienți s-a practicat fundoplicatura anterioară pr.Dor (180°), la 5 pacienți – Nissen –Rossetti şi la 7 pacienți pr. Toupet. 5 cazuri au fost rezolvate utilizînd şi plasa sintetică. Concluzii. Fiecare din metodă de tratament chirurgical a fost practicată de noi electiv în dependență de avantajul sau dezavantajul său pentru fiecare caz aparte. Rezultatele la distanța au fost apreciate după „scara Visick”: Rezultat excelent – 5 cazuri (15,6%), Rezultat bun – 25 cazuri (78%), Rezultat nesatisfăcător – 2 cazuri (6,25%). Cercetarea efectuată de noi ne-a permis să concludem că fiecare metodă are dreptul la existență în raport cu situația concretă.Introduction. Hiatal hernia (HH) is a current problem with the overall incidence 15%, 60% are asymptomatic. HH three ranks after gastro-duodenal peptic ulcer and gallstones in chronic gastrointestinal pathologies. According to the classification Allison Sweet (1952) based on the mechanism there are three types of hernias: Sliding HH (axial) - 90%Roll HH- 5-7%Mixed HH - 3%. The typical event of mixed HH is a gastro-esophageal reflux. Purpose. Elucidation of the contemporary management of mixed HH and the superiority of surgery treatment versus conservative. Material and methods: In the department of surgery CEM were operated 32 patients with mixed HH for 10 years (2000-2011): 30 by laparoscopy and 2 by laparotomy. 25 cases of which – cardio-fundal hernias, 7 cases – subtotal hernias. In 20 patients underwent previous fundoplication pr.Dor (180 °), 5 patients - Nissen-Rossetti and 7 patients pr. Toupet.5 cases were resolved and using synthetic mesh. Conclusions. Each method of surgical treatment has been practiced in the new elected its advantage or disadvantage depending on each case.The results distance were evaluated by the “Visick scale”: Excellent result - 5 cases (15,6%), Good result – 25 cases (78%), Unsatisfactory result - two cases (6,25%). Research carried out by us has allowed to conclude that each method has the right to exist in relation to the situation

USE OF MODERN TECHNIQUE IN PREPARING THE TECHNICAL DOCUMENTATION FOR THE REGISTRATION IN THE LAND BOOK OF A PROPERTY

The paper presents the way of drawing up the cadastral documentation for the first registration in the Land Book of a property. The total station and GNSS receivers were used as topographic devices for measurements, which offered a high accuracy of the measured data and a shortening of the time spent in the field. The data processing and the elaboration of the documentation was done through specialized programs (Toposys, Autocad). As the surveying method was used the method of closed planimetric traverse supported on known coordinate points (previously determined with GNSS technology), combined with the method of polar coordinates

Surgical reinterventions in gastro-esophageal junction pathology

Catedra chirurgie FECMF, USMF “Nicolae Testemițanu”, Secția chirurgie generală, Spitalul Clinic Republican, Chişinău, Republica Moldova, Al XII-lea Congres al Asociației Chirurgilor „Nicolae Anestiadi” din Republica Moldova cu participare internațională 23-25 septembrie 2015Introducere: Tratamentul chirurgical al patologiei joncțiunii esogastrice (JEG) pînă la sfîrșitul anilor ҆90 a fost axat doar pe rezolvarea complicațiilor acestor patologii. Problema a devenit atractivă la implementarea chirurgiei laparoscopice. Scopul lucrării: Evidențierea ratei intervențiilor chirurgicale cît și a patologiilor în cadrul cărora a fost necesitatea de reintervenții chirurgicale. Material și metode: În Clinica noastră timp de 15 ani (2000-2014) au fost tratați 621 pacienți cu patologia JEG. Din aceștia, 76 (12,2%) pacienți au suportat reintervenții chirurgicale. Intervenții repetate prin abord laparoscopic au avut loc în 25 cazuri pentru hernii hiatale (HH) și boală de reflux gastroesofagean (BRGE). HH recidivante au necesitat implantarea plasei sintetice în 75% cazuri. Rezultate: Structura patologiilor JEG reoperate după frecvență, se prezintă astfel: herniile hiatale – 32 cazuri; BRGE – 18 cazuri; esofagul Barrett – 12 cazuri; acalazia – 5 cazuri; stenoza JEG – 5 cazuri; cancer JEG – 2 cazuri; ulcer polar superior – 2 cazuri. Concluzii: Rata reintervențiilor noastre chirurgicale la JEG este comparabilă cu datele din literatura mondială. Reintervențiile au fost adresate predominant BRGE și herniilor hiatale (65,8%). Cauza principală a reintervențiilor chirurgicale este examinarea incompletă a pacienților și experiența insuficientă a chirurgului.Introduction: Surgical treatment of gastro-esophageal junction (GEJ) pathology to the late ҆90 was focused only on treatment of complications of these diseases. The problem has become attractive after implementation of laparoscopic surgery. The aim: Highlighting both the rate of surgical operations and pathologies which needed re-interventions. Material and methods: During a 15 years period (2000-2014) in our department were treated 621 patients with GEJ pathology. Surgical re-interventions were done in 76 (12.2%) cases. Repeated interventions by laparoscopic way occurred in 25 cases for hiatal hernia (HH) and gastroesophageal reflux disease (GERD). Recurrent HH required synthetic mesh implant in 75% of cases. Results: Structure of re-operated GEJ pathology depending on frequency, are as follows: hiatal hernia – 32 cases; GERD – 18 cases; Barrett ҆s esophagus – 12 cases; achalasia – 5 cases; GEJ stenosis – 5 cases; GEJ cancer – 2 cases; superior polar ulcer – 2 cases. Conclusion: Our rate of surgical re-interventions on GEJ is comparable to the world literature. Re-interventions were addressed predominantly to GERD and hiatal hernias (65.8%). The main reason for surgical re-intervention is incomplete examination of patients and insufficient experience of the surgeon