Effect of C:N ratio and hydraulic loading rate on wastewater treatment in constructed wetlands

master's thesis

• Title (croatian): Učinak C:N omjera i hidrauličke stope opterećenja na tretman otpadne vode u građenim močvarama
• Author: Kristina Kralj
• Mentor: Lana Filipović (mentor)
• Mentor: Zhongbing Chen https://orcid.org/0000-0001-8801-4842 (komentor)
• Committee member: Lana Filipović (predsjednik povjerenstva)
• Committee member: Zhongbing Chen https://orcid.org/0000-0001-8801-4842 (član povjerenstva)
• Committee member: Igor Bogunović (član povjerenstva)
• Committee member: Ivan Mustać (član povjerenstva)
• Granter: University of Zagreb; Faculty of Agriculture; (Department of Soil Amelioration); Zagreb
• Defense date and country: 2022-09-15, Croatia
• Scientific / art field, discipline and subdiscipline: BIOTECHNICAL SCIENCES; Agronomy

Abstract

The effect of carbon to nitrogen ratio and hydraulic loading rate has an important role in constructed wetlands element removal efficiency. The effect of C:N ratio and hydraulic loading rate on element removal efficiency in constructed wetlands were assessed using 8 constructed wetland reactors watered by synthetic wastewater with 4 different C:N ratios (2, 2.2, 2.9, 3.4) at high and low hydraulic loading rates. Wastewater samples were analyzed after passing through reactors for total carbon, total organic and inorganic carbon, and total nitrogen concentrations using FormacsHT-I TOC/TN analyzer (SKALAR). Concentrations of ammonium was measured using Cary 60 UV-VIS spectrophotometer (Agilent Technologies). Phosphate, nitrate, and sulfate concentrations were measured using 883 Basic IC plus ion chromatograph (Metrohm). The conducted experiment showed that low hydraulic loading rate benefits TC, TOC, IC and PO43- removal. High HLR was beneficial for NO3- and SO42- removal, while NH4+ and TN removal were similar for both HLRs. Increase in C:N ratio increased NO3- removal efficiency, but only at high hydraulic loading rate. Arbuscular mycorrhizal fungi inoculation in reactors possibly had a positive effect on phosphorus removal efficiency.

Abstract (croatian)

Omjer ugljika i dušika i hidraulička stopa opterećenja imaju važnu ulogu u učinkovitosti umjetno građenih močvara u uklanjanju elemenata iz otpadne vode. Učinak variranja navedenih parametara na stopu učinkovitosti umjetno građenih močvara u uklanjanju dušika, ugljika, fosfora i sumpora iz otpadne vode ispitan je na 8 reaktora koji predstavljaju umjetno građene močvare. Reaktori su zalijevani simuliranom (umjetnom) municipalnom otpadnom vodom s 4 različita C:N omjera (2, 2.2, 2.9, 3.4) u visokim i niskim hidrauličkim stopama opterećenja. U uzorcima otpadne vode nakon njenog prolaska kroz reaktor analizirane su koncentracije ukupnog ugljika, ukupnog organskog i anorganskog ugljika te ukupnog dušika FormacsHT-I TOC/TN (Skalar). Koncentracija amonijaka mjerena je Cary 60 UV-VIS spektofotometrom (Agilent Technologies). Koncentracija fosfata, nitrata i sulfata mjerena je 883 Basic IC plus ionskim kromatografom (Metrohm). Provedeni eksperiment je pokazao kako niska hidraulička stopa opterećenja pozitivno utječe na uklanjanje ukupnog ugljika, ukupnog organskog ugljika, anorganskog ugljika te fosfata. Visoka hidraulička stopa opterećenja pozitivno utječe na uklanjanje nitrata i sulfata, dok je uklanjanje amonijaka i ukupnog dušika jednako za nisku i visoku hidrauličku stopu opterećenja. Veći omjer ugljika i dušika imao pozitivno je utjecao na uklanjanje nitrata, ali samo pri visokoj hidrauličkoj stopi opterećenja. Arbuskularne mikorizne gljive kojima su reaktori bili inokulirani imale su mogući pozitivan učinak na uklanjanje fosfora.

• Keywords: wastewater treatment; constructed wetlands; optimization of constructed wetland reactors; nutrient removal efficiency
• Keywords (english): pročišćavanje otpadne vode; građene močvare; optimizacija reaktora građenih močvara; učinkovitost uklanjanja hranjiva
• Language: english
• URN:NBN: urn:nbn:hr:204:217554
• Study programme: Title: Renewable energy sources in agriculture; Study programme type: university; Study level: graduate; Academic / professional title: magistar/magistra obnovljivih izvora energije u poljoprivredi (magistar/magistra obnovljivih izvora energije u poljoprivredi)
• Type of resource: Text
• File origin: Born digital
• Access conditions: Access restricted to authenticated users
• Created on: 2022-10-03 11:18:45