UNITED NATIONS, Dec. 21 (Xinhua) -- The
投稿日時: 2019-1-12 14:33
SAN FRANCISCO Aaron Rodgers Packers Jersey , Aug. 5 (Xinhua) -- Two environmental engineers at Stanford University have developed a computational planning tool to help urban utilities combine two water supply strategies - collecting stormwater runoff and recycling treated wastewater - into an integrated system that replenishes aquifers.
While collecting stormwater runoff and recycling treated wastewater are usually separate processes that can create costly and underused infrastructure, underground aquifers that have been over-tapped for years are in need to be replenished and the U.S. federal government projects that 40 states across the country expect water shortages by 2024.
Inspired by water reuse leaders like Orange County in Southern California, Jonathan Bradshaw, a graduate student in civil and environmental engineering at Stanford, and Richard Luthy, a professor of civil and environmental engineering at the university in Northern California, have worked out the hybrid approach and the planning tool, known as AquaCharge.
Utilities to collect stormwater are designed to channel rainfall during the wet season into ""spreading basins,"" which are essentially leaky ponds that are porous enough for water to percolate back down to an aquifer. Although the approach is effective, engineers typically design the basins to be big enough to capture large volumes of water, and they remain largely idle through the dry months.
By some estimates, according to Stanford University in a news release this week announcing the development of AquaCharge, Los Angeles County's spreading basins on average percolate only 12 percent of their theoretical annual capacity.
Wastewater recycling poses different challenges. Some utilities treat wastewater to the point that it can be used safely for agricultural irrigation or certain industrial purposes, such as circulating through the cooling towers of a power plant. Such uses reduce the burden on aquifers or other water sources. However, regulations require that this recycled water be conveyed in a pipeline separate from drinking water pipes.
Although many utilities have a large potential to produce recycled water, the high cost of such separate piping systems means that only a small fraction of this potential gets developed. So, most treated wastewater flows back into the sea, or into rivers and streams.
Being a leader in groundwater replenishment, Orange County purifies its wastewater so that it is clean enough to drink, then pumps the recycled water into spreading basins to recharge the underground aquifer. It is analogous to stormwater capture, except that the water source is purified wastewater.
California currently recycles about 15 percent of its available treated wastewater effluent. State water planners would like to double or triple that amount by 2030.
To assist local authorities in looking at their circumstances and in comparing the tradeoffs between different designs and finding the most cost-effective system in their region, the Stanford researchers created AquaCharge to combine what has been separate systems into a single approach to recharge groundwater, by making complex calculations that reveal costs and benefits of reuse strategies.
AquaCharge recently won three contest awards from the American Society of Civil Engineers.
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" " Photo taken on Dec. 21, 2017 shows the voting result of a United Nations General Assembly resolution on the status of Jerusalem during a rare emergency special session at the UN headquarters in New York. The General Assembly on Thursday adopted a resolution on the status of Jerusalem that will make U.S. President Donald Trump's decision to recognize Jerusalem as the Israeli capital have no legal effect. (XinhuaWang Ying)
UNITED NATIONS, Dec. 21 (Xinhua) -- The General Assembly on Thursday adopted a resolution on the status of Jerusalem that will make U.S. President Donald Trump's decision to recognize Jerusalem as the Israeli capital have no legal effect.
In a rare emergency special session, the draft resolution tabled by Turkey and Yemen was adopted 128-9 with 35 abstentions.
The nine countries that voted against the text were Guatemala, Honduras, Marshall Islands, Micronesia, Nauru, Palau, Togo, as well as the United States and Israel.
The resolution ""affirms that any decisions and actions which purport to have altered the character, status or demographic composition of the Holy City of Jerusalem have no legal effect, are null and void and must be rescinded in compliance with relevant resolutions of the Security Council, and in this regard calls upon all states to refrain from the establishment of diplomatic missions in the Holy City of Jerusalem.""
It further demands that all UN member states comply with Security Council resolutions regarding Jerusalem, and not recognize any actions or measures contrary to those resolutions.
Such a vote at the General Assembly is non-binding but a resounding ""yes"" reflects the collective will of the international community and carries much political weight.
Before the vote, U.S. ambassador to the United Nations Nikki Haley repeated the threat to cut aid for the countries that would have voted in favor of the draft as well as U.S. contributions to the United Nations.
She said her country will move its Embassy in Israel from Tel Aviv to Jerusalem. ""No vote in theHome > Family > Family. Cheap Jerseys Free Shipping Cheap Jerseys China Wholesale Cheap NHL Jerseys Cheap NFL Jerseys From China Cheap Soccer Jerseys China Cheap NCAA Hockey Jerseys Cheap Wholesale Soccer Jerseys Cheap New MLB Jerseys Cheap NFL Football Jerseys Cheap Nike NBA Jerseys