Battle of QadisiyyahMain article: Battle of Qadisiyyah

The site of the Battle of Qadisiyyah, showing Muslim army (in red) and Sassanid army (in blue)

Umar ordered his army to retreat to the bordering areas of Mesopotamia near the Arabian desert and began raising armies for another campaign into Mesopotamia. The Arab armies were concentrated near Madinah, and owing to the critical situation Umar wished to command the army in person. This idea was opposed by the members of Majlis al Shura at Madinah, who claimed that the two-front war required Umar's presence in Madinah. Umar appointed Saad ibn Abi Waqqas as commander for the campaign in Mesopotamia. Saad left Medina with his army in May 636 and arrived at Qadisiyyah in June.

While Heraclius launched his offensive in May 636, Yazdegerd was unable to muster his armies in time to provide the Byzantines with Persian support. Umar, allegedly aware of this alliance, capitalized on this failure: not wanting to risk a battle with two great powers simultaneously, he quickly moved to reinforce the Muslim army at Yarmouk to engage and defeat the Byzantines. Meanwhile, Umar ordered Saad to enter into peace negotiations with Yazdegerd III and invite him to Islam to prevent Persian forces from taking the field. Heraclius instructed his general Vahan not to engage in battle with the Muslims before receiving explicit orders; however, fearing more Arab reinforcements, Vahan attacked the Muslim army in the Battle of Yarmouk in August 636. Heraclius's Imperial army was routed.[23]

With the Byzantine threat ended, The Sassanid Empire was still a formidable power with vast manpower reserves, and the Arabs soon found themselves confronting a huge Persian army with troops drawn from every corner of the empire and commanded by its foremost generals. Among the troops were fearsome war elephants that the Persian commander brought with him for the sole purpose of vanquishing the Muslims. Within three months, Saad defeated the Persian army in the Battle of al-Qādisiyyah, effectively ending Sassanid rule west of Persia proper.[24] This victory is largely regarded as a decisive turning point in Islam's growth: with the bulk of Persian forces defeated, Saad later conquered Babylon, Koosie, Bahrahsher and Madein. Ctesiphon, the Imperial capital of the Sassanid Empire, fell in March 637 after a siege of three months.

Conquest of Mesopotamia (636–638)

After the conquest of Ctesiphon, several detachments were immediately sent west to capture Qarqeesia and Heet the forts at the border of the Byzantine Empire. Several fortified Persian armies were still active north-east of Ctesiphon at Jalula and north of the Tigris at Tikrit and Mosul.

After withdrawal from Ctesiphon, the Persian armies gathered at Jalaula north-east of Ctesiphon. Jalaula was a place of strategic importance because from here routes led to Mesopotamia, Khurasan and Azerbaijan. The Persian forces at Jalula were commanded by General Mihran. His deputy was General Farrukhzad, a brother of General Rustam, who had commanded the Persian forces at the Battle of al-Qadisiyyah. As instructed by the Caliph Umar, Saad reported everything to Umar. The Caliph decided to deal with Jalula first. His plan was first to clear the way to the north before taking any decisive action against Tikrit and Mosul. Umar appointed Hashim ibn Utbah to the expedition of Jalula and Abdullah ibn Muta'am to conquer Tikrit and Mosul. In April 637, Hashim led 12,000 troops from Ctesiphon to win a victory over the Persians at the Battle of Jalula. He then laid siege to Jalula for seven months. After seizing a victory at Jalula, Abdullah ibn Muta'am marched against Tikrit and captured the city after fierce resistance and with the help of Christians.[citation needed] He next sent an army to Mosul which surrendered on the terms of the Jizya. With victory at Jalula and occupation of the Tikrit-Mosul region, Muslim rule in Mesopotamia was established.

After the conquest of Jalula, a Muslim force under Qa'qa marched in pursuit of the Persians. The Persian army that escaped from Jalaula took its position at Khaniqeen fifteen miles from Jalula on the road to Iran, under the command of General Mihran. Qa'qa defeated the Persian forces in the Battle of Khaniqeen and captured the city of Khaniqeen. The Persians withdrew to Hulwan. Qa'qa moved to Hulwan and laid siege to the city which was captured in January 638.[25] Qa'qa sought permission for operating deeper into Persian land, i.e. mainland Iran, but caliph Umar didn't approve the proposal and wrote a historic letter to Saad saying:

“ "I wish that between the Suwad and the Persian hills there were walls which would prevent them from getting to us, and prevent us from getting to them.[26] The fertile Suwad is sufficient for us; and I prefer the safety of the Muslims to the spoils of war."

Waste sorting is the process by which waste is separated into different elements.[1] Waste sorting can occur manually at the household and collected through curbside collection schemes, or automatically separated in materials recovery facilities or mechanical biological treatment systems. Hand sorting was the first method used in the history of waste sorting.[2]

Waste can also be sorted in a civic amenity site.

Waste segregation means dividing waste into dry and wet. Dry waste includes wood and related products, metals and glass. Wet waste, typically refers to organic waste usually generated by eating establishments and are heavy in weight due to dampness. Waste can also be segregated on basis of biodegradable or non-biodegradable waste.

Landfills are an increasingly pressing problem.[citation needed] Less and less land is available to deposit refuse, but the volume of waste is growing all time. As a result, segregating waste is not just of environmental importance, but of economic concern, too.

Contents

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1 Methods 2 By country 3 See also 4 References 5 External links

Methods[edit]

Waste is collected at its source in each area and separated. The way that waste is sorted must reflect local disposal systems. The following categories are common:

Paper Cardboard (including packaging for return to suppliers) Glass (clear, tinted – no light bulbs or window panes, which belong with residual waste) Plastics Scrap metal Compost Special/hazardous waste Residual waste

Organic waste can also be segregated for disposal:

Leftover food which has had any contact with meat can be collected separately to prevent the spread of bacteria.

o Meat and bone can be retrieved by bodies responsible for animal wasteo If other leftovers are sent, for example, to local farmers, they can be sterilised before

being fed to the animals Peel and scrapings from fruit and vegetables can be composted along with other degradable

matter. Other waste can be included for composting, too, such as cut flowers, corks, coffee grindings, rotting fruit, tea bags, egg- and nutshells, paper towels etc.

Chip pan oil (fryer oil), used fats, vegetable oil and the content of fat filters can be collected by companies able to re-use them. Local authority waste departments can provide relevant addresses. This can be achieved by providing recycling bins.

By country[edit]

In Germany, regulations exist that provide mandatory quotas for the waste sorting of packaging waste and recyclable materials such as glass bottles.[3]