Heavy metals removal from water by wood sawdust, pulp and lignin

Apstrakt je obrađen tehnologijama za optičko prepoznavanje teksta (OCR). Istraživana je mogućnost primene piljevine različitih vrsta drveta, tehničke celuloze i Kraft lignina kao adsorbenata različitih teških metala iz vode. Za adsorpciju teških metala koji su u vodi prisutni u vidu katjona, kao najbolji adsorbenti su se pokazale piljevine drveta hrasta i bagrema i Kraft lignin. Za adsorpciju hromatnih anjona najbolje su se pokazali Kraft lignin i piljevina drveta jele. Kapacitet adsorpcije piljevine drveta se može poboljšati prethodnim tretiranjem piljevine rastvorom natrijum hidroksida. Efikasnost adsorpcije teških metala iz vode je bolja: kada se primenjuju sitnije čestice piljevine, kada se radi sa većom količinom piljevine i/ili dvostepeno, na povišenoj temperaturi. Utvrđen je optimalni pH za adsorpciju pojedinih teških metala, optimalno vreme kontakta adsorbenta i vode, uticaj prisustva različitih teških i lakih metala i anjona na efikasnost adsorpcije teških metala. Adsorbovani teški metali se mogu desorbovati sa piljevine drveta rastvorima različitih mineralnih kiselina. Piljevina drveta se može primeniti u više ciklusa adsorpcije-desorpcije, uz nešto smanjeni kapacitet adsorpcije. Ispitivani adsorbenti se mogu primeniti i u dinamičkim uslovima adsorpcije u koloni.Abstract was processed by technology for Optical character recognition (OCR). The possibility of adsorption of different heavy metals from water by sawdust of different species of wood, pulp, and Kraft lignin has been investigated. Oak and black locust sawdust, and Kraft lignin were shown to be the most efficient adsorbents for heavy metals in cationic form. Kraft lignin and fir sawdust were shown to be the most efficient adsorbents for chromium anions. Previous treatment of wood sawdust by sodium hydroxide solution can increase its adsorption capacity. Better adsorption efficiency was accomplished: when smaller parts of sawdust were used, when a large amount of sawdust was used and/or two stage process was applicated, and adsorption process was done on higher temperature. There were established: optimum initial pH value for different heavy metals, optimum adsorbent - water contact time, and degree of influence of other different heavy and lite metals, and anions on adsorption efficiency. Adsorbed heavy metals can be desorbed from vvood sawdust with solutions of different mineral acids. Sawdust can be applied in several cycles of adsorption - desorption, with some decrease of adsorption capacity. Investigated adsorbents can be also used in dynamic conditions of adsorption in column

Improvement of wastewater treatment by use of natural coagulants

An activated sludge and other organic sludges from wastewater treatment processes are usually anaerobically digested prior to application on land. The purpose of digestion is to convert bulky, odorous sludges to relatively inert material that can be rapidly dewatering. The important benefit of this process is a biogas production, too. It is proper to enlarge primary sludge production in a primary settler by adding some coagulation aids, with aim to increase a biogas production, as much as possible. The most common coagulant is alum, but presence of large quantities of aluminum salts in sludge has a harmful impact on digestion and digested sludge application. Some natural coagulants, that have a numerous advantages, can be used instead of alum. Natural coagulants could be extracted from a different plant material, and considering the fact that they are of organic nature, the biogas yield can be enhanced by their presence. A plant material that remains after extraction can be used as a feed. The aim of this paper is a consideration of potential environmental benefits of substitution of alum by natural coagulant extracted from common bean seeds in sewage wastewater treatment process

Heavy metals removal from water by wood sawdust, pulp and lignin

Apstrakt je obrađen tehnologijama za optičko prepoznavanje teksta (OCR). Istraživana je mogućnost primene piljevine različitih vrsta drveta, tehničke celuloze i Kraft lignina kao adsorbenata različitih teških metala iz vode. Za adsorpciju teških metala koji su u vodi prisutni u vidu katjona, kao najbolji adsorbenti su se pokazale piljevine drveta hrasta i bagrema i Kraft lignin. Za adsorpciju hromatnih anjona najbolje su se pokazali Kraft lignin i piljevina drveta jele. Kapacitet adsorpcije piljevine drveta se može poboljšati prethodnim tretiranjem piljevine rastvorom natrijum hidroksida. Efikasnost adsorpcije teških metala iz vode je bolja: kada se primenjuju sitnije čestice piljevine, kada se radi sa većom količinom piljevine i/ili dvostepeno, na povišenoj temperaturi. Utvrđen je optimalni pH za adsorpciju pojedinih teških metala, optimalno vreme kontakta adsorbenta i vode, uticaj prisustva različitih teških i lakih metala i anjona na efikasnost adsorpcije teških metala. Adsorbovani teški metali se mogu desorbovati sa piljevine drveta rastvorima različitih mineralnih kiselina. Piljevina drveta se može primeniti u više ciklusa adsorpcije-desorpcije, uz nešto smanjeni kapacitet adsorpcije. Ispitivani adsorbenti se mogu primeniti i u dinamičkim uslovima adsorpcije u koloni.Abstract was processed by technology for Optical character recognition (OCR). The possibility of adsorption of different heavy metals from water by sawdust of different species of wood, pulp, and Kraft lignin has been investigated. Oak and black locust sawdust, and Kraft lignin were shown to be the most efficient adsorbents for heavy metals in cationic form. Kraft lignin and fir sawdust were shown to be the most efficient adsorbents for chromium anions. Previous treatment of wood sawdust by sodium hydroxide solution can increase its adsorption capacity. Better adsorption efficiency was accomplished: when smaller parts of sawdust were used, when a large amount of sawdust was used and/or two stage process was applicated, and adsorption process was done on higher temperature. There were established: optimum initial pH value for different heavy metals, optimum adsorbent - water contact time, and degree of influence of other different heavy and lite metals, and anions on adsorption efficiency. Adsorbed heavy metals can be desorbed from vvood sawdust with solutions of different mineral acids. Sawdust can be applied in several cycles of adsorption - desorption, with some decrease of adsorption capacity. Investigated adsorbents can be also used in dynamic conditions of adsorption in column

Biosorption of copper(II) and chromium(VI) by modified tea fungus

The tea fungus was found to have good adsorption capacities for heavy metal ions. In this work it was treated with HCl or NaOH at 20°C or 100°C, with the aim to improve its adsorption ability. The sorption of Cu(II) and Cr(VI) ions from aqueous solutions by raw and treated tea fungus was investigated in the batch mode. The largest quantity of adsorbed Cu(II), of about 55 mg/g, was achieved by tea fungus modified with NaOH at 100°C. For Cr(VI), the largest quantity of adsorbed anions, of about 58 mg/g, was achieved by the adsorbent modified with NaOH at 20°C. It was shown that acid modification of tea fungus biomass was not effective. [Projekat Ministarstva nauke Republike Srbije, br. III 43005 i br. TR 31002

Characterization and utilization of the permeate and retentate obtained after “dead-end” ultrafiltration

In the recent years, with the increase in bioethanol production, the increasing amounts of distillery wastewater are generated. Such wastewater (stillage) is one of the most polluted waste product of the food and beverage industries. The present study evaluates the treatment of distillery wastewater by ultrafiltration (UF), in order to reduce its pollution and evaluate the composition of the permeate and retentate. Polyethersulfone ultrafiltration membrane with molecular weight cut-off (MWCO) 30000 Da, was used for the experiments. The UF was carried out in dead-end mode. The results of the analyses of the permeate and retentate obtained after ultrafiltration were considered as well as different ways for their further utilization. The pollutant level in the permeate was decreased significantly in comparison to the raw stillage, and suspended solids were completely removed from the stillage. [Projekat Ministarstva nauke Republike Srbije, br. TR 31002

Ispitivanje koagulacione aktivnosti prirodnih koagulanata ekstrahovanih iz različitih sorti pasulja

Coagulation and flocculation by adding chemicals are the methods that are usually used for removal of water turbidity. This study is concerned with the coagulation activity of extracts of various strains of bean. The aim was to ascertain if bean varieties influence coagulation activity. Active components were extracted from 1 g of ground sample with 100 ml distilled water. Contents of dry matter and nitrogen were specified in the solid samples, and the content of soluble nitrogen was determined in the extracts. These data were used to calculate the efficiency of extraction of nitrogen-containing compounds. The coagulation activity was assessed by jar test using synthetic turbid water, of the initial pH 9 and turbidity 35 NTU. The jar test was carried out by adding different amounts of extracts to model water, and stirring the content. After sedimentation for 1 h, residual turbidity was determined by turbidimeter and coagulation activity was calculated. The increment of organic matter concentration after the coagulation was also determined. These experiments confirmed that extracts of all investigated strains of bean could be used successfully as natural coagulants.Koagulacija i flokulacija predstavljaju najčešće primenjivane metode za bistrenje vode, i uglavnom se izvode dodatkom hemijskih koagulanata. U ovom radu je ispitivana koagulaciona aktivnost ekstrakata dobijenih iz semena različitih sorti pasulja, a s ciljem da se utvrdi mogućnost njihove primene kao prirodnih koagulanata za uklanjanje mutnoće vode, i da se utvrdi uticaj sorte pasulja na koagulacionu aktivnost. Ekstrakcija aktivnih komponenti je izvedena sa 100 ml destilovane vode iz 1 g samlevenog uzorka. U čvrstim uzorcima je određen sadržaj suve materije i azota, a u ekstraktima sadržaj rastvorljivog azota, na osnovu čega je određena efikasnost ekstrakcije jedinjenja sa azotom. Za određivanje koagulacione aktivnosti ekstrakata izveden je džar-test, dodavanjem različitih doza ekstrakata model vodi, čiji je pH 9 i početna mutnoća 35 NTU. Nakon mešanja u određenom vremenskom intervalu, čaše su ostavljene da se njihov sadržaj istaloži, a zatim je u bistrom delu određivana mutnoća, i preko nje koagulaciona aktivnost. Takođe je utvrđen doprinos svakog od ekstrakata porastu sadržaja organskih materija u vodi nakon njenog bistrenja u odnosu na slepu probu, a preko permanganatnog broja. Ovim eksperimentima potvrđeno je da se ekstrakti svih ispitivanih sorti pasulja mogu uspešno primeniti kao prirodni koagulanti

Microfiltration of distillery stillage: Influence of membrane pore size

Stillage is one of the most polluted waste products of the food industry. Beside large volume, the stillage contains high amount of suspended solids, high values of chemical oxygen demand and biological oxygen demand, so it should not be discharged in the nature before previous purification. In this work, three ceramic membranes for microfiltration with different pore sizes were tested for stillage purification in order to find the most suitable membrane for the filtration process. Ceramic membranes with a nominal pore size of 200 nm, 450 nm and 800 nm were used for filtration. The influence of pore size on permeate flux and removal efficiency was investigated. A membrane with the pore size of 200 nm showed the best filtration performance so it was chosen for the microfiltration process

Characterization of natural zeolite (clinoptilolite) as one of the high cation exchange capacity geopolymer material

The aim of this research is to subject one of the specific and locally used natural zeolite (clinoptilolite) from Vranjska Banja, Serbia with high cation exchange capacity. Mineralogical - X-Ray Diffraction Analysis (XRD), Scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDS) and determination of cation exchange capacity (CEC) were investigated. Results showed homogenous structure with dominant clinoptilolite - heulandite type zeolites as most abundant minerals. The important aspect of this research is possibility of wider usage of natural zeolite-clinoptilolite due to cost-efficiency aspects of this natural material that can be exploited in large amount from several Serbian deposits e.g. “Zlatokop” (Vranjska Banja) and “Igroš Vidojević” (Brus), Serbia. The present of higher, but also extremely concentration of heavy metals in Pannonian, Internal Dinarides and wider European region lead us to boost novel high performance but economically viable techniques. The starting points are geochemical characterization of novel geo- materials before further water-treatment implementation

Optimization of microfiltration for distillery wastewater purification

In our previous work we examined the possibility of application of microfiltration for distillery stillage purification in the systems without [1] and with the presence of static mixer [2]. Feed flow rate (Q = 40; 100 and 160 l/h ), transmembrane pressure (TMP = 0.3; 0.6 and 0.9 bar) and feed pH (3; 6 and 9) were considered for design of experiments. Influence of choosen factors on permeate flux and specific energy consumption was investigated using Response Surface Methodology. The results showed that Response Surface Methodology is an appropriate model for mathematical presentation of the process. To optimize a process that has two or more responses, several methods can be applied, but the most commonly used method is the concept of the desired function (desirability function) [3]. In this work optimization of the experimental conditions was conducted using the modified Harrington method of the desired function. To optimize the microfiltration process of distillery wastewater, the following responses were selected: mean flux permeate in the static mixer system (JSM) and the relative change in specific energy consumption (ER). The goal of optimization was to select the feed flow rate and transmembrane pressure values for which the observed responses will be maximum, ie their desired functions will have a higher value. Obtained results (Figure 1) showed that the microfiltration was best performed at maximum flow and transmembrane pressure values, at all pH values, with the fact that the value of total desired function decreases with the increase of pH. If all factors, including pH value, are used for optimization, the optimum values of the parameters for optimization showed that the microfiltration was best performed at the values of feed flow of 160 l/h and TMP of 0.9 bar, at pH value of 5.81. Under these conditions, the total desired function had a maximum value of 0.944, the mean permeate flux for the system with static mixer was 58.3 l/m 3 h, while the relative change in the specific energy consumption was 123%