Dairy Plant Management and Pollution Control

Module 8. Effluent treatment

Lesson 14
SOLID WASTE MANAGEMENT

14.1 Introduction

The different types of solid waste include agricultural waste, paper waste, plastic waste, food waste, cloth waste, glass waste, building material waste etc.

14.2 Solid Waste

Solid organic waste in dairy processing facilities mainly originates from production processes and includes nonconforming products and product losses (e.g. milk spillages liquid whey and buttermilk), grid and filter residues, sludge from centrifugal separators and wastewater treatment, and packaging waste (e.g. discarded cuts, spent ripening bags, wax residues from cheese production) arising from incoming raw materials and production line damage.

Solid waste is generally

* off-spec product – for example, milk powders and heavy consistency product

* defective product packaging – for example, paperboard cartons, plastic containers

* recovered wastewater treatment sludges

* solid and semi-solid intermediate or finished product spills

14.3 Sources of Solid Waste in Dairy Processing Plants

The types of solid waste typically produced by dairy processors include packaging waste such as cardboard, paper, cartons and plastic; organic wastes such as sludge and reject product; and office waste. They can be generated during processing, or when raw materials and products are being transported, stored and handled.

Category	Type of waste	Disposal stream
Non-organic	Cardboard boxes, paper, slip sheets	Recyclable
	Plastic wrap	Recyclable
	HDPE bottles and caps	Recyclable
	Foil seals	Non recyclable
	Liquid paperboard	Recyclable
	Labels	Non recyclable
	Plastic and metal drums and containers	Recyclable
	Polystyrene	Recyclable
	Office waste (e.g. toner cartridges, paper)	Recyclable
	Canteen waste (e.g. aluminum cans, polystyrene cups)	Recyclable
	Miscellaneous (e.g. waste oil, oily rags,damaged pallets)	Recyclable
Organic	Reject product including in-process	Animal feed
	Returned final product	Animal feed
	Raw material (e.g. liquid flavours)	Re work
	Obsolete or out-of-date raw materials	Animal feed
	Lab samples and samples for online testing	Animal feed
	Separator de-sludge	Animal feed
	Bag house fines, dryer sweepings	Animal feed
	Effluent sludge	Animal feed / compost
	Membrane retentate sludge	Animal feed / compost
	Cheese fines	Animal feed
	Fat recovered from effluent	Animal feed

The cost of generating and disposing of solid waste can include

• treatment costs

• collection and transport costs

• disposal costs

• loss of product, including processing and raw material costs.

14.4 Solid Waste Management

Reducing the loss of materials and improving the rate of reuse, recovery and recycling of valuable resources is a very important aspect of eco-efficiency. The many economic, environmental and social incentives for reducing and utilising solid waste more efficiently include

* reduced treatment, collection and disposal costs

* reduced production costs as a result of recovering and reusing product

* increased revenue from recovering product

* increased revenue from new co-products

* improved risk management

* improved environmental responsibility

* improved resource utilisation.

14.4.1 Biomanagement of sludge

Biotechnology Resource Centre which is located at Pune, Maharastra has developed the technologies for management of sludge produced by different effluent treatment plants as well as city garbage and sewage. Wastes from aquaculture and animal husbandry are becoming increasingly severe for industries and municipalities due to waste disposal legislation. The Biomanagement of solid wastes include vermiculture technology, mushroom culture, growing algae on liquid effluents and aquaculture.