scholarly journals Influência da pré-cloração na clarificação de águas para abastecimento utilizando coagulante à base de tanino

2021 ◽  
Vol 26 (6) ◽  
pp. 1025-1032
Author(s):  
Jéssica Rodrigues Silveira ◽  
Valéria Menezes de Souza ◽  
Renata Medici Frayne Cuba ◽  
Francisco Javier Cuba Teran
Keyword(s):  
Jar Test

RESUMO Diferentes técnicas de tratamento de água destinada ao abastecimento público, como a pré-cloração e o uso de coagulantes orgânicos, têm sido relatadas como alternativas econômica, técnica e ambientalmente viáveis. Entretanto, o resultado da interação entre esses processos deve ser estudado para sua aplicação com segurança. Dessa forma, este estudo objetivou avaliar a influência da pré-cloração na clarificação de água para abastecimento público, utilizando coagulante à base de tanino. Os ensaios foram conduzidos em jar test com o uso de Tanfloc SG como coagulante, variando as dosagens de 2,5 a 45,0 mg L−1, e de oxidante hipoclorito de sódio (NaClO) nas concentrações de cloro residual livre (HClO(NaClO)) de 0,8 e 5,0 mg L−1, no tratamento da água do ribeirão João Leite. As dosagens ótimas de coagulante foram determinadas para as seguintes condições de tratamento: adição somente de tanino; tanino e NaClO aplicados simultaneamente; e tanino adicionado após 30 min da pré-cloração. Nessas condições, o pH de coagulação foi analisado de 6,0 a 8,5. Foram avaliados parâmetros como turbidez, cor aparente, pH e HClO(NaClO). A melhor condição de tratamento com pré-cloração foi a adição simultânea de NaClO e coagulante tanino nas dosagens de 0,8 mg L−1 (HClO(NaClO)) e 10,0 mg L−1, respectivamente, com remoção de turbidez de 71,6% e cor aparente de 62,7%. Os resultados demonstraram que a pré-cloração afetou negativamente o processo de tratamento, e para maior concentração de HClO(NaClO) maior foi a dosagem de tanino requerida, sem apresentar aumento significativo nas eficiências de remoção de turbidez e cor aparente.

PENURUNAN KEKERUHAN AIR BAKU PDAM GUNUNG POTENG SINGKAWANG DENGAN MENGGUNAKAN KOAGULAN TAWAS DAN PAC

2016 ◽  
Vol 4 (1) ◽  
Author(s):  
BEWA MULYATAMA ◽  
Laili Fitria ◽  
Ulli Kadaria
Keyword(s):  
Jar Test

ABSTRAKPengolahan air baku di PDAM Gunung Poteng Singkawang menggunakan proses pengolahan konvensional lengkap. Koagulan yang digunakan adalah tawas. Hasil pengolahan air baku masih belum konsisten. Pengolahan air baku pada tahun 2015 menghasilkan kekeruhan antara 0,2 NTU sampai 9,2 NTU. Upaya perbaikan untuk masalah di PDAM Gunung Poteng Singkawang adalah dengan mencampurkan koagulan tawas dan PAC yang diharapkan dapat mengurangi kekeruhan dari hasil pengolahan air baku. Tujuan dilakukannya penelitian ini adalah sebagai berikut: Menganalisis efektifitas penurunan kadar kekeruhan dengan pencampuran koagulan tawas dan PAC untuk memperbaiki tingkat kekeruhan air baku di PDAM Gunung Poteng Singkawang sesuai baku mutu dan menganalisis perbandingan dosis pencampuran koagulan tawas dan PAC yang optimum terhadap tingkat kekeruhan di PDAM Gunung Poteng Singkawang. Pengujian yaitu dengan mengadakan eksperimen pengolahan air baku menggunakan koagulan Tawas dan PAC yang dilakukan dengan menggunakan metode Jar Test. Percobaan dilanjutkan dengan pemeriksaan kualitas air yang meliputi kekeruhan dan pH yang akan dilakukan sebelum dan setelah jar test. Variasi larutan Tawas dan PAC dengan perbandingan 1:0, 1:1, 1:2, 2:1, 1:3, 3:1 dan 0:1. Hasil dari penelitian didapat bahwa dosis 1:0 dan 0:1 menghasilkan kekeruhan yang buruk daripada perbandingan dosis lainya. Pengkondisian kekeruhan dari data sekunder kualitas air baku PDAM Gunung Poteng Singkawang tahun 2015 didapat kekeruhan 116 NTU untuk kekeruhan tertinggi dan 9,6 NTU untuk kekeruhan terendah. Pengujian penegasan dilakukan dengan kondisi kekeruhan sebenarnya di lapangan didapat kekeruhan 22,42 NTU. Perbandingan yang efektif untuk kondisi kekeruhan 116 NTU adalah 1:2 dengan efektivitas penurunan kekeruhan mencapai 98,9 % dan kondisi kekeruhan 9,6 NTU adalah 1:3 dengan efektivitas penurunan kekeruhan 93,5 %. Hasil uji penegasan menghasilkan perbandingan efektif dengan kondisi kekeruhan 22,42 NTU (kekeruhan air baku bulan September tahun 2016) adalah 1:2  dengan efektivitas penurunan kekeruhan 96,3 %. Penggunaan perbandingan dosis pencampuran koagulan dapat menunjukkan bahwa pada kondisi kekeruhan kurang dari 10 NTU sampai 20 NTU dapat menggunakan perbandingan dosis 1:3. Kekeruhan pada nilai 21 NTU sampai 116 NTU dapat menggunakan dosis pencampuran 1:2.Kata Kunci : Kekeruhan, air baku, koagulan, tawas, PAC

Effect of Starch on the Flocculation and Settling Behaviour of Titanium Dioxide Suspensions

1974 ◽  
Vol 9 (1) ◽  
pp. 154-171
Author(s):  
S.N. Ray ◽  
C. Hsi ◽  
B.C. -Y. Lu
Keyword(s):  
Titanium Dioxide ◽  
Suspended Solids ◽  
Settling Velocity ◽  
Pollution Abatement ◽  
Paper Mills ◽  
Paper Making ◽  
Jar Test ◽  
Settling Behaviour ◽  
Dimensionless Function ◽  
Flocculation Rate

Abstract This study concerns the problem of removal of suspended solids from the effluent streams of paper mills by chemical treatment. As titanium dioxide is one of the ingredients used in paper mills and present in the effluent streams, its flocculation and settling behaviour were investigated. Jar test experiments were conducted using alum and organic polyelectrolyte as the flocculants. As starch is also used in the paper making process, its influence on the flocculation and settling behaviour of titanium dioxide was conducted with the concentration of starch varying between 0–3% of the dry solids. The experimental results on flocculation are expressed in terms of dimensionless function Gθϕ and flocculation rate constants. The fraction of solids settled is presented in terms of the settling velocity. Concentration of starch was found to have a significant influence. The amount of alum required could be reduced by 75% by using starch 0.6% of the amount of titanium dioxide in the suspension and at the same time improving the settling velocity two folds. A possible application of this finding in pollution abatement is discussed.

Premiere etape dans l'elaboratton d'un modele mathemahque general permettant de remplacer le “jar‐test’

1993 ◽  
Vol 14 (4) ◽  
pp. 341-350 ◽  
Author(s):  
M. Franceschi ◽  
E. Puech‐Costtes ◽  
M.T. Maurette ◽  
A. Girou
Keyword(s):  
Jar Test

Properties of flocs produced by water treatment coagulants

2001 ◽  
Vol 44 (10) ◽  
pp. 231-236 ◽  
Author(s):  
J. Gregory ◽  
V. Dupont
Keyword(s):  
Test Procedure ◽  
Dynamic Monitoring ◽  
Optical Technique ◽  
Water And Wastewater Treatment ◽  
Aluminium Sulfate ◽  
Jar Test ◽  
Water And Wastewater ◽  
Clay Suspensions ◽  
Polyaluminium Chloride ◽  
Floc Breakage

Hydrolyzing coagulants are extensively used in water and wastewater treatment, often under conditions where hydroxide precipitation is important, giving “sweep flocculation”. Pre-hydrolyzed coagulants, such as polyaluminium chloride (PACl) are also widely used and have several advantages over traditional additives, such as aluminium sulfate. Their action is usually discussed in terms of cationic species and charge neutralization. However, precipitation may also be important and this aspect has not been considered in detail. The present work has compared the action of alum and three commercial PACl products on model clay suspensions. The conventional jar test procedure has been used, along with measurements of settled floc volume and dynamic monitoring of floc formation and break-up by an optical technique. The latter method gives very useful information on the nature of the flocs produced and their response to different shear conditions. It is clear from the results that the PACl products form larger and stronger flocs than alum. With all coagulants floc breakage appears to be essentially irreversible. Sediment volumes are slightly lower for flocs produced by PACl than by alum, but the value is proportional to the dosage in all cases.

New retting method of cassava roots improve sensory attributes of Bobolo and Chikwangue in Central Africa: an approach through just about right (JAR) test

2021 ◽  
pp. 475
Author(s):  
Nardis NKOUDOU ZE ◽  
Marie-Joseph MEDZEME ENGAMA ◽  
Jean Justin ESSIA NGANG
Keyword(s):  
Sensory Analysis ◽  
Central Africa ◽  
Pasting Properties ◽  
Sensory Attributes ◽  
Sensory Characteristics ◽  
Sensory Profile ◽  
Jar Test ◽  
Two Samples ◽  
By Products ◽  
Penalty Analysis

Aim: the aim of this study was to determine sensory profile, through the use of just-about-right (JAR) scales and penalty analysis, of Bobolo and Chikwangue from the cassava roots fermented with previously cassava-fermented chips powder (PCFCP). Furthermore, retting time, cyanide content and pasting properties of retted roots were evaluated. Methods: for that, two samples of Bobolo and Chikwangue obtained from two cassava retting methods were studied: a control made from the retting without PCFCP and a product made from retting with PCFCP. Results: retting time was carried out in 48 hours less with PCFCP and 60% of cyanide reduction more than control. No major modifications occurs in pasting properties of paste fermented with PCFCP. The sensory analysis indicated high levels of acceptability for products made from retting with PCFCP. The penalty analysis showed that attributes “too sour” and “too much fermented odor” affected the acceptability of the Bobolo from retting without PCFCP significantly. Conclusion: fermentation of cassava through the use of PCFCP is suitable to improvement of sensory characteristics of fermented cassava by-products.

Treatment of Textile Wastewater using Biodegradable Flocculants of Chitosan and Extracted Pandan Leaves

2013 ◽  
Vol 64 (1) ◽  
Author(s):  
Norzita Ngadi ◽  
Nor Aida Yusoff
Keyword(s):  
Solvent Extraction ◽  
Extraction Method ◽  
Textile Wastewater ◽  
Settling Time ◽  
Turbidity Removal ◽  
Test Experiment ◽  
Jar Test ◽  
Solvent Extraction Method ◽  
Flocculation Process

The study investigated the performance of chitosan and extracted pandan leaves towards treatment of textile wastewater by using flocculation process. Pandan leaves were extracted by using solvent extraction method. Flocculation process was conducted using a Jar test experiment. The effect of dosage, pH, and settling time on reduction of COD, turbidity and color of textile wastewater was studied. The results obtained found that chitosan was very effective for reduction of COD, turbidity, color and indicator for color. The best condition for COD and turbidity removal was achieved at 0.2 g dosage, pH 4 and 60 minutes of settling time. Under this condition, about 58 and 99% of COD and turbidity was removed, respectively. However, the results obtained using extracted pandan was opposite compared to the chitosan. Extracted pandan was not able to remove both COD and turbidity of the waste. 

Effects of pre-treatment with magnetic ion exchange resins on coagulation/flocculation process

2008 ◽  
Vol 57 (1) ◽  
pp. 57-64 ◽  
Author(s):  
B. Sani ◽  
E. Basile ◽  
C. Lubello ◽  
L. Rossi
Keyword(s):  
Ion Exchange ◽  
Treatment Plant ◽  
Drinking Water Treatment ◽  
Water Treatment Plant ◽  
Ion Exchange Resin ◽  
Test Procedures ◽  
Aggregation State ◽  
Jar Test ◽  
Pre Treatment ◽  
Magnetic Ion

A new Magnetic Ion EXchange resin for DOC (Dissolved Organic Carbon) removal (MIEX®DOC Resin) has been evaluated as water pre-treatment at the Drinking Water Treatment Plant (DWTP) of Florence in order to reduce the oxidant demand and disinfection by-products (DBPs) formation potential. This pre-treatment leads to several effects on downstream treatment processes. In this experimental study the effects of MIEX® pre-treatment on clariflocculation process were evaluated with respect to coagulant demand reduction and characteristics of flocs formed. The analysis was conducted using traditional jar test procedures and a Photometric Dispersion Analyser (PDA2000) which provided continuous information about the aggregation state of particles during the jar tests. For a fixed turbidity goal in clarified water, ion exchange pre-treatment led to coagulant dosage reduction up to 60% and PDA results shown that flocs formed in pre-treated water were bigger and more resistant to shearing effects than those formed by conventional clariflocculation.

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