EIA Study- Final Report-May 10 - UNDP

More documents

Recommendations

Info

Environmental Impact Assessment Khan Younis Wastewater Treatment Plant May 2010 Process Advantages Disadvantages load. Sludge production more important and more difficult to treat. Modular construction and easy automation. Membrane bioreactors Very high treatment performances, also on fecal coli form. Uncertainty regarding real membrane life length and related replacement cost. No tertiary treatment required. Low sludge production. Compact process, easy to cover. Modular construction and easy automation. High energy demand (40 % higher than activated sludge). Need for regular membrane supply for replacement. Higher investment costs (50% higher activated sludge). High O&M costs The selected wastewater treatment biological process is Activated sludge and is designed for average daily flow of 26,656 m3/day in the first phase and 44,948 m3/day for the second phase, consisting of the following process units: • inlet works and flow metering • screening • grit and grease removal • biological treatment with nitrification denitrification process • final sedimentation • tertiary treatment by sand filtration and UV disinfection • outlet works with treated effluent pumping and flow metering. The sludge treatment includes the following steps: • gravity thickening for concentration of biological excess sludge • natural dewatering in drying beds • stabilization by composting. 4.2.3.1. Pretreatment Inlet works and flow metering: Wastewater is conveyed to KY WWTP by two separate trunk lines: the first one comes from PS 8 and conveys wastewater from Khan Younis City to the treatment plant; the second one comes from the pumping station proposed in Khirbat Khuza’a and conveys effluent from the Eastern Villages to the treatment plant. Design of both of these pumping stations takes into account required head to assure gravity flow through the KY WWTP from inlet structure downstream secondary clarifiers. No additional lifting station is therefore needed at the KY WWTP inlet. SOGREAH/UG CONSULTANTS 40
Environmental Impact Assessment Khan Younis Wastewater Treatment Plant May 2010 Both incoming trunk lines are connected to a wastewater inlet structure, situated in head of the pre-treatment. Screening: The purpose of the screening is to remove large particles that could clog or otherwise disturb the downstream facilities. Coarse screening is not needed at KY WWTP since PS 8 is already equipped with 40 mm coarse screen and the PS to be implemented for transfer of Eastern Areas wastewater should also include coarse screening in order to protect the transfer pumps. Screenings are conveyed by belt conveyer or screw conveyer towards a screenings compactor and then deposited into a 20 m3 skip. When the skip is full, it is loaded on a truck and the screenings deposited on land fill. Grit and grease removal: The grit and grease removal is carried out in a combined longitudinal tank with two parallel lines in the first phase and three parallel lines in the second phase. An aeration device will ensure that grease, oil and scum float at the surface and will facilitate the separation of grit from organic matter and maintain the organic matter in suspension. Each line is provided with a traveling bridge which scrapes the grease at the surface and collects the grit at the bottom of the tank. The grease is evacuated towards a hopper where surplus water is removed and grease is then transported to land fill by vacuum tank. The deposited grit is extracted by pumping or by air-lift towards a grit classifier. It is then conveyed to a 20 m 3 skip for evacuation to land fill. 4.2.3.2. Secondary Treatment (Activated Sludge) Treatment principles: Biological treatment will be carried out on 2 identical parallel lines in Phase 1 and 4 identical parallel lines in Phase 2. Activated sludge is suspension of microorganisms, both active and dead, in a wastewater consisting of entrapped and suspended colloidal and dissolved organic and inorganic materials. The activated sludge process is aerobic, biological process, which uses the metabolic reactions of microorganisms to attain an acceptable effluent quality by removing substances exerting an oxygen demand. In bio-aeration basins performed microbial floc particles are brought into contact with the organic components of the wastewater. Contents of the reactor basin are referred to as mixed liquor suspended solids (MLSS), and consist for the most part of microorganisms and inert and non-biodegradable matter. The overall reactions, occurring in the activated SOGREAH/UG CONSULTANTS 41
Page 1 and 2: UNDP/PAPP PROVISIONS OF CONSULTANCY
Page 3 and 4: Environmental Impact Assessment Kha
Page 41: Environmental Impact Assessment Kha
Page 77 and 78: !(!(!(!( !( Environmental Impact As
Page 93 and 94:
Environmental Impact Assessment Kha
Page 95 and 96:
Page 97 and 98:
Page 99 and 100:
Page 101 and 102:
Page 103 and 104:
Page 105 and 106:
Page 107 and 108:
Page 109 and 110:
Page 111 and 112:
Page 113 and 114:
Page 115 and 116:
Page 117 and 118:
Page 119 and 120:
Page 121 and 122:
Page 123 and 124:
Page 125 and 126:
Page 127 and 128:
Page 129 and 130:
Page 131 and 132:
Page 133 and 134:
Page 135 and 136:
Page 137 and 138:
Page 139 and 140:
Page 141 and 142:
Page 143 and 144:
Page 145 and 146:
Page 147 and 148:
Page 149 and 150:
Page 151 and 152:
Page 153 and 154:
Page 155 and 156:
Page 157 and 158:
Page 159 and 160:
لا)‏ لا)‏ Environmental Imp
Page 161 and 162:
لا)‏ لا)‏ Environmental Imp
Page 163 and 164:
Page 165 and 166:
Page 167 and 168:
Page 169 and 170:
Page 171 and 172:
Page 173 and 174:
Page 175 and 176:
Page 177 and 178:
Page 179 and 180:
Page 181 and 182:
Page 183 and 184:
Page 185 and 186:
Page 187 and 188:
Page 189 and 190:
Page 191 and 192:
Page 193 and 194:
Page 195 and 196:
Page 197 and 198:
Page 199 and 200:
Page 201 and 202:
Page 203 and 204:
Page 205 and 206:
Page 207 and 208:
Page 209 and 210:
Page 211 and 212:
Page 213 and 214:
Page 215 and 216:
Page 217 and 218:
Page 219 and 220:
Page 221 and 222:
Page 223 and 224:
Page 225 and 226:
show all

EIA Study- Final Report-May 10 - UNDP

Create successful ePaper yourself

Delete template?

Save as template?