Synthesis of Microalgal Photogranules for Hydroponics Effluent Treatment

IF 4.3 Q1 ENVIRONMENTAL SCIENCES

ACS ES&T water Pub Date : 2025-07-30 DOI:10.1021/acsestwater.5c00417

Harshit Tiwari, and , Sanjeev Kumar Prajapati*,

{"title":"Synthesis of Microalgal Photogranules for Hydroponics Effluent Treatment","authors":"Harshit Tiwari,  and , Sanjeev Kumar Prajapati*, ","doi":"10.1021/acsestwater.5c00417","DOIUrl":null,"url":null,"abstract":"Amidst the global challenge of nutrient-rich hydroponics effluent (HE) discharge, microalgal technology offers a sustainable solution for wastewater treatment and resource recovery. However, microalgae harvesting remains a major economic constraint. To address this, novel microalgal photogranules (MPGs) were developed by using Scenedesmus obliquus for HE treatment and recycling. Over 60 days of photoillumination, MPGs self-aggregated into dense granules with superior settleability (SVI30 = 20 mL g–1). Field emission scanning electron microscopy (FE-SEM) revealed compact structures with surface-attached microalgae and internal micropores that facilitate substrate and gas transport. HE-grown MPGs showed enhanced biomass productivity (0.18 ± 0.09 g L–1 day–1) compared to those from sewage sludge (0.13 ± 0.06 g L–1 day–1) and achieved a high CO2 biofixation rate (25.53 ± 2.12 g L–1 day–1). MPGs enabled complete removal of biological oxygen demand (BOD) and chemical oxygen demand (COD), ≈99% of PO43– and NH3-N and 90.2% of NO3–-N. Metagenomic analysis (16S rRNA) indicated a cyanobacterial shift under HE conditions, enhancing pollutant removal. Outdoor validation confirmed effective pollutant removal with only a 1-day delay compared to indoor trials. Succinctly, MPGs offer a sustainable and ecoefficient solution for wastewater recycling, supporting environmental resilience and circular bioeconomy transitions.","PeriodicalId":93847,"journal":{"name":"ACS ES&T water","volume":"5 8","pages":"4715–4728"},"PeriodicalIF":4.3000,"publicationDate":"2025-07-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"ACS ES&T water","FirstCategoryId":"1085","ListUrlMain":"https://pubs.acs.org/doi/10.1021/acsestwater.5c00417","RegionNum":0,"RegionCategory":null,"ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q1","JCRName":"ENVIRONMENTAL SCIENCES","Score":null,"Total":0}

引用次数: 0

Abstract

Amidst the global challenge of nutrient-rich hydroponics effluent (HE) discharge, microalgal technology offers a sustainable solution for wastewater treatment and resource recovery. However, microalgae harvesting remains a major economic constraint. To address this, novel microalgal photogranules (MPGs) were developed by using Scenedesmus obliquus for HE treatment and recycling. Over 60 days of photoillumination, MPGs self-aggregated into dense granules with superior settleability (SVI₃0 = 20 mL g^–1). Field emission scanning electron microscopy (FE-SEM) revealed compact structures with surface-attached microalgae and internal micropores that facilitate substrate and gas transport. HE-grown MPGs showed enhanced biomass productivity (0.18 ± 0.09 g L^–1 day^–1) compared to those from sewage sludge (0.13 ± 0.06 g L^–1 day^–1) and achieved a high CO₂ biofixation rate (25.53 ± 2.12 g L^–1 day^–1). MPGs enabled complete removal of biological oxygen demand (BOD) and chemical oxygen demand (COD), ≈99% of PO₄^3– and NH₃-N and 90.2% of NO₃^–-N. Metagenomic analysis (16S rRNA) indicated a cyanobacterial shift under HE conditions, enhancing pollutant removal. Outdoor validation confirmed effective pollutant removal with only a 1-day delay compared to indoor trials. Succinctly, MPGs offer a sustainable and ecoefficient solution for wastewater recycling, supporting environmental resilience and circular bioeconomy transitions.

Abstract Image

查看原文本刊更多论文

水培废水处理微藻光颗粒的合成

在富营养化水培废水（HE）排放的全球挑战中，微藻技术为废水处理和资源回收提供了可持续的解决方案。然而，微藻的收获仍然是一个主要的经济限制。为了解决这一问题，利用斜状微藻（Scenedesmus obliquus）开发了一种新型微藻光颗粒（MPGs），用于HE处理和回收。经过60天的光照，MPGs自聚集成致密的颗粒，具有优异的沉降性（SVI30 = 20 mL g-1）。场发射扫描电镜（FE-SEM）显示，表面附着微藻和内部微孔的致密结构有利于基质和气体的输送。he培养的MPGs生物量生产力（0.18±0.09 g L-1 day-1）高于污泥培养的（0.13±0.06 g L-1 day-1）， CO2固定率（25.53±2.12 g L-1 day-1）较高。MPGs能够完全去除生物需氧量（BOD）和化学需氧量（COD），约99%的PO43 -和NH3-N以及90.2%的NO3——N。宏基因组分析（16S rRNA）表明，在HE条件下蓝藻发生了转变，增强了污染物的去除。与室内试验相比，室外验证证实了有效的污染物去除，仅延迟1天。简而言之，mpg为废水回收提供了可持续和生态高效的解决方案，支持环境弹性和循环生物经济转型。

本文章由计算机程序翻译，如有差异，请以英文原文为准。

求助全文

约1分钟内获得全文求助全文

来源期刊

ACS ES&T water

CiteScore

5.40

自引率

0.00%

发文量