**5.2. Pyrolysis**

Waste composition can determine the effectiveness of pyrolysis. It has several advantages comparing the incineration process. Lower temperature is preferable, and the plant for pyrolysis more flexible enough; product derived from pyrolysis can be converted through alternating the temperature and heating performance [43]. The pollutant emissions are lower in this disposal process as there is absence of oxygen and with low processing temperature, although emissions of other compounds simultaneously could increase with lower oxygen ratio [44]. Biochar production can be done by fruits and vegetable peels and other residues from, for example, spinach, bananas, peas, and tomatoes [45]. There are two types of pyrolysis, i.e., slow and fast. For biochar and gas production, slow pyrolysis is preferable, and bio-oil can be produced better in fast pyrolysis (**Figure 5**).

**Figure 5.**

*Bar diagram of pyrolysis produced product. (a) Fast pyrolysis and (b) slow pyrolysis [46–47].*

#### **6. Prospects of horticultural waste management**

It is obvious that waste disposal is not an easy task as it requires bigger margin of resources and right methods to minimize its after-effects. All the techniques or methods of repealing wastes are not efficient enough always. Food recovery hierarchy published by US EPA showed that there are different methods or approaches are proficient at different level. Landfilling and incineration (combustion of the waste materials) are the last resort of wastes disposal, because sometimes it is harmful for our environment. Soil pollution and abundance of toxic gases are visible by this kind of disposal system. Then the composting creates a nutrient-rich soil amendment. It requires specialized area away from the home, and it requires more time for disposal. Industrial uses of wastes are just above from the composting in that pyramid as it provides waste oils for rendering and duel conversion and food scraps for digestion to recover energy. Lots of commercial industries are developing today with the new hope with horticultural by-product establishing. Although some wastes also are considered developing the industries but commercial exposure may be spread rapidly. Main effective approach will be the source reduction and sometimes we waste food more than we consume so that extra food can be donated to food banks, shelters can reduce the possibility food wasting. Public awareness is the big thing for food waste management in horticultural sectors also (**Figure 6**).
