Which of the following involves by-product recovery a) open dumping b) incineration c) Compostinga.Only bb.all a, b, cc.only cd.both b and c

The process that involves by-product recovery is incineration. So, the answer is a) Only b.

Here's why:

a) Open dumping is a method of waste disposal where waste is dumped in open areas. This method does not involve any recovery of by-products.

b) Incineration is a waste treatment process that involves the combustion of organic substances contained in waste materials. This process can generate heat, which can be used to generate power, and ash, which can sometimes be used in construction. Therefore, it involves by-product recovery.

c) Composting is a process that involves the decomposition of organic waste materials by microorganisms. The by-product of this process is compost, which can be used as a soil conditioner. However, compost is not typically considered a "recovered" by-product in the same way that heat and ash are in incineration.

So, the answer is a) Only b.