Two-Stage Dilute Acid Hydrolysis of Dairy Manure for Nutrient Release, Solids Reduction and Reducing Sugar Production

S K Yawson,P.H Liao,K.V Lo

doi:10.4236/nr.2011.24028

S K Yawson, P.H Liao + Show 1 more

Open Access

https://doi.org/10.4236/nr.2011.24028

Copy DOI

Journal: Natural Resources	Publication Date: Jan 1, 2011
Citations: 20	License type: CC BY 4.0

Affiliation: University of British Columbia

Abstract

The microwave enhanced advanced oxidation process (MW/H2O2-AOP) aided with dilute sulfuric acid was applied in a two-stage treatment of dairy manure for nutrient release, solids reduction, and reducing sugar production. A much higher hydrogen peroxide dosage (1.2 g H2O2/g TS) was used in Stage 2 than that in Stage 1 (0.38 g H2O2/g TS). Most of the reducing sugar was produced in Stage 1, and only a small amount produced in Stage 2. The highest reducing sugar yield of 15.5% was obtained at 160℃, 0 mL H2O2/, and 20 min of heating time. With a high hydrogen peroxide dosage and a higher operating temperature of 160℃ in Stage 2, the nutrient release conversion rate was much higher in Stage 2 than Stage 1. All of total phosphorus was converted to orthophosphate, and a very high ammonia concentration was obtained in the treated solution. The results indicated that the MW/H2O2/-AOP operated under the reducing process (without hydrogen peroxide) provided the best yield of reducing sugar; however, when operated under an oxidative process (with hydrogen peroxide), it favoured nutrient release and solids disintegration. The concentration of total chemical oxidation demand (TCOD) in the treated solution decreased with an increase of temperature, hydrogen peroxide dosage and heating time. Soluble chemical oxidation demand (SCOD) concentration decreased with a very high hydrogen peroxide dosage. Volatile fatty acids (VFA) concentration decreased with an increase of hydrogen peroxide dosage. Ammonia and orthophosphate concentrations increased with an increase of temperature and hydrogen peroxide dosage.

Highlights

Dairy manure contains fats, proteins, lignin, carbohydrates and inorganic residue, and is rich in a variety of nutrients including nitrogen, phosphorus, and minerals
With a high hydrogen peroxide dosage and a higher operating temperature of 160 ̊C in Stage 2, the nutrient release conversion rate was much higher in Stage 2 than Stage 1
All of total phosphorus was converted to orthophosphate, and a very high ammonia concentration was obtained in the treated solution

Summary

Introduction

Proteins, lignin, carbohydrates and inorganic residue, and is rich in a variety of nutrients including nitrogen, phosphorus, and minerals. It is a bio-resource, which can be converted into valuable products, instead of a waste material to be disposed. Dilute acid hydrolysis is the most commonly applied process It is used either as a pretreatment of lignocellulose for subsequent enzyme hydrolysis or as the actual hydrolysis to produce fermentable sugar. In a two-stage process, dilute acid is used in general in the first stage to solubilize the hemicelluloses, and to reduce cellulose crystallinity. More sugars can be produced from dairy manure in a two-stage hydrolysis than that from a one-stage hydrolysis procedure [6]

Methods

Results

Conclusion