Four additives namely iron slag (IS), works debris (WD), fly ash (FA), and lime kiln dust (LKD) are added to biosolids and their effects are investigated on the selected properties of biosolids. The biosolids used are final products of the wastewater treatment process at a Wastewater Treatment Plant (WWTP), Auckland, New Zealand. The additives are mixed manually with biosolids at different percentages. Most of the mixtures, finally called amendments has selected amount of lime in them. The amendments are placed separately into respirometer reactors (air tight bottles) for two weeks, measuring gas continuously to find out the total gas production and to analyse methane (CH 4 ) and carbondioxide (CO 2 ) production to completely understand the biochemical activity. Water content (WC %), volatile solids (VS %), and pH are determined before putting the amendments into the reactors and after two weeks as well. Gases that are being produced from the respirometer reactors are analysed after 5, 10 and 15 days for CH 4 and CO 2 percentages. After comparing results of all the amendments and comparing results of solids parameters to that of gas analysis, it is concluded that FA 50% with lime 20% inhibited most of the biochemical activities and maintained pH of biosolids at elevated level of 12 or above and thus could be applied to biosolids for stabilization before landfilling. FA 50% with lime 20%, like all the other additives, is added to wet biosolids on the basis of dry weight. Solid content of biosolids is around 25% so the addition of even 70% additive to wet biosolids on the basis of dry weight is very less in amount.

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In Pakistan, construction and demolition waste(CDW) is generated in voluminous amount each year. CDW iswidely ill-handled and ultimately fed to landfills causing harm tothe already alarming environmental conditions. In order tosearch for the solution of this drastic matter, a study was done,which is explained in this paper. This paper presents the studydone at a demolition site near Karachi, in Sindh while thedemolition works were being carried out. At the site there wereold barracks which were being demolished. Before the demolitionworks were commenced, the site was surveyed and structuralcomponents of the barracks were counted and their dimensionswere measured. When the demolition was over, the demolishedwaste was calculated which comprised of concrete and masonryrubble, steel round bars, steel doors, steel windows, steel ceiling,steel girders, steel main gate, and plastic water tank. This studyinterpreted that construction and demolition (C&D) works wereprogressing considering the works’ deadline and the clients’requirements but the ecosystem’s ecology and the environmentalhealth were not taken into account. Recommendations are madeto handle CDW properly throughout its lifecycle. Theserecommendations aim to provide technological and logicalsolutions to grip CDW. The recommendations include wastereduction and reusing waste, life cycle assessment and costing,environmental and economic impact, material flow analysis, andadvanced computerized-tools.

In Pakistan, construction and demolition waste(CDW) is generated in voluminous amount each year. CDW iswidely ill-handled and ultimately fed to landfills causing harm tothe already alarming environmental conditions. In order tosearch for the solution of this drastic matter, a study was done,which is explained in this paper. This paper presents the studydone at a demolition site near Karachi, in Sindh while thedemolition works were being carried out. At the site there wereold barracks which were being demolished. Before the demolitionworks were commenced, the site was surveyed and structuralcomponents of the barracks were counted and their dimensionswere measured. When the demolition was over, the demolishedwaste was calculated which comprised of concrete and masonryrubble, steel round bars, steel doors, steel windows, steel ceiling,steel girders, steel main gate, and plastic water tank. This studyinterpreted that construction and demolition (C&D) works wereprogressing considering the works’ deadline and the clients’requirements but the ecosystem’s ecology and the environmentalhealth were not taken into account. Recommendations are madeto handle CDW properly throughout its lifecycle. Theserecommendations aim to provide technological and logicalsolutions to grip CDW. The recommendations include wastereduction and reusing waste, life cycle assessment and costing,environmental and economic impact, material flow analysis, andadvanced computerized-tools.