Background

Viticultural waste refers to the solid organic waste produced during the various stages of wine making, throughout the year. Lees, to date, have no alternative applications, thus they result in a cost of storage and disposal for producers. Environmentally, the release of lees on the soil causes karstification, the release in an anaerobic environment results in the production of methane and carbon dioxide, and the release in an aquatic environment results in sterilization of the biota. In addition, the treatment of wine-making lees by DA produces an effluent (digestate) with chemical characteristics that limit its environmental discharge, thus emphasizing the need for further treatment aimed at removing the ammonium. The application of the DA effluent to microalgae cultivation becomes a sustainable pathway to valorization of the viticultural waste, with two main benefits: the phytodepuration of the effluent with the removal of organic and inorganic compounds and the production of biogas and microalgal biomass rich in secondary products with high added value.

Technology Overview

This process solves the well-known limitations of microalgal cultivation on effluents from wastewater anaerobic digestion of wine waste. The process is surprisingly advantageous as an efficient treatment, applicable on-site by wine producers. It consists of biomass cultivation on an undiluted centrifuged anaerobic co-digestated effluent derived from any type of winemaking lees and activated sludge, which is fed semi-continuously without biomass recirculation.

By applying the AD system, the organic substrate is converted into biogas (renewable energy source), while the obtained effluent (digestate) has chemical characteristics, such as high nutrient content, compatible with microalgae growth. The system promotes phytodepuration of the digestate and the production of microalgal biomass that can find applications in biorefinery context and for the production of other products through green chemistry such as animal feed.

Benefits

Efficient on-site vinification lees treatment (no disposal costs).
Valorisation of waste into secondary products with high added value.
Phytodepuration of effluent and removal of organic and inorganic compounds.
Recirculation of the post-treatment effluent to the head of the system (no external discharge).

Applications

Autonomous treatment system even for small-scale wine producers.
Waste valorization in circular economy.
Production of biodiesel and secondary products for animal feed.

Opportunity

The university look forward to collaborative project to scale up the system to industrial level.

Zero Wine Waste with Microalgae Processes

Patents

IP Status

Seeking